LT95 Transfer Thrust Muncher

[captainslow]

I'm looking for some help diagnosing the cause of some rather drastic thrust washer munching in my recently rebuilt LT95. This resulted in loss of Hi Range (a long way from home - but that's another story...)

Here is what happened at the Low Range end of the Transfer Intemediate Shaft

https://www.aulro.com/afvb/images/imported/2016/04/543.jpg

https://www.aulro.com/afvb/images/imported/2016/04/544.jpg

You can see that the outer most Thrust Washer is toast. And the next Thrust Washer in line is on the way out.
The outer Thrust Washer has ground itself into both the Low Range Gear and the Outer Pinned Washer. It has also deformed badly - so much so that the Inner Washer won't fit inside it and has pushed itself into the roller bearing.

So, my observations:-
1. Oil is Castrol GTX Diesel 15W-40
2. Oil was black and sludgy as you'd expect with the damage (but no glitter - because no brass)
3. Oil channels in the Intermediate Shaft were all clear
4. Only the Thrust Washers each side of the Low Range Gear were damaged. Thrust Washers either side of the High Range gear had no wear.
5. Running behind a N/A ISUZU
6. About 800km of use since the rebuild with no unusual noise (but who can tell with a 4BD1).
7. At the rebuild the Hi Range Gears were changed to the .996 ratios using a set supplied by Craddocks.

So what have I done wrong to cause this sort of damage?

It seems that all of the axial thrust is coming from the Input Gear. Is there a right and wrong way around to assemble this gear onto the Intermediate Shaft? I can't see any method of orientation - but the force does seem to come from this gear towards the Low Range end.

Just to clarify my terminology regarding part numbers:-
Thrust Washer = FRC3500
Low Range Gear = 591891
Outer Pinned Washer = FRC6284..8 (selectable thickness)
Intermediate Shaft = FRC3507
Inner Washer = 591900

If the normal brass Thrust Washers had been used I think I would have know within about 10km but the steel washers have held up well in trying circumstances and done a bit of damage as well. I imagine the steel will be very good in the long term if I can get this problem sorted.

Any help most appreciated.

Pete

[Bearman]

Hi Pete, That's very unusual and bad luck after a rebuild. I don't know what has caused this if it was set up with the correct clearances, mind you I haven't seen one with steel thrust washer only brass. It doesn't matter which way the input gear is turned - it performs the same in either position. The outer pegged thrust washer shows signs of excessive heat which should not happen. It sort of looks like the steel thrust washer might have stuck to low gear and started heating the pegged one up and wearing into it and then wore into low gear as well. Did the steel thrust washer have oil channels moulded into both surfaces like the brass ones do?
Let me know what thickness the outer pegged one is and I will have a look through my spares. Fair chance I will have one as well as a good low range gear. They are yours for the cost of postage.

[captainslow]

Thanks for the help Brian.

So you've ruled out the only thing I could think of. It sure must have generated some serious heat so there must have been significant force involved.

I haven't tried this before but I think I'll try some gear marking method (prussian blue?) to see if there is some mismatch happening in the gears. I'm not comfortable putting this back together until I can find some explanation.

Thanks for the offer of the Low Range Gear and washer. I'm pretty sure I have usable spares from a third box that I bought but I appreciate the offer if they don't look right.

Yes, interesting the steel Thrust Washers, I'll do some research on that...

I'll throw up the results of the gear contact tests once they're done.

Cheers
Pete

[Bearman]

You know what the ultimate answer is - a TRB intermediate shaft.

[captainslow]

Ha! You've got me at a weak moment.

From what I've heard TRB runs cooler, runs longer and doesn't require any maintenance - where's the challenge in that??

If I can get my hands on one I'd put it in like a shot.

But, I'm still worried about this muncher. I'm guessing that whatever is wrong with this transfer would have given TRBs a bit of a fright too...

[Busted Syncro]

G'day Pete,

Looks like a major loss of lubrication on those steel thrusts with Metal to Metal contact producing all that heat.
My experience with Bronze thrusts is you cannot use a GL5 (EP) type oil. You must use a GL4 manual gear oil for Bronze thrusts.
Hence GTX is OK for bronze thrusts as specified in your Transfer G/B.
However for steel thrust maybe you need a GL5 (EP) type oil.
What are the recommendations for your Transfer G/B using steel thrusts regarding Oil type GL4 or GL5?
Chris

[captainslow]

Looks like a major loss of lubrication on those steel thrusts with Metal to Metal contact producing all that heat.

Chris, that's an interesting point. Having a look around the net, for the Thrust Washers part number FRC3500, it seems that Britpart supply steel and AllMakes supply bronze (and I'm guessing genuine are still bronze). Mine were the Britpart make supplied by Craddocks in the UK.

I'm no expert on oils but I take your point that engine oil may not be good enough for steel thrusts. So, maybe a better oil may make all the difference. I'd be loath to use a GL5 oil just in case it migrated into the main gearbox and harmed the synchros, but maybe a gear oil like Castrol VMX-80 may do the trick.

But having said that, surely I'm not the only LT95 user in the world who has used engine oil with Britpart thrusts? I'll ping an email to Britpart and see if they have any comment.

Anyway, that's something to try. I'll do the gear contact tests to make sure the input or High Range gear aren't mismatched. If they look ok I'll try gear oil and monitor very carefully for a while.

Thanks for chipping in, looking for any ideas at the moment.

Pete

[Busted Syncro]

G'day Pete,
All your info noted. OK on Emailing Cradocks as you have excellent pictures of the damaged components to send to them.
My thinking is why not go back to bronze thrusts and GTX oil the way it was designed to be used. The bronze thrusts are kinder to the gears and are meant to wear and be replaced. Steel is going to wear the expensive gears as well.
Also if you need to shim up the bronze thrusts to get the correct end float you can make up steel shims to fit behind the steel backing on the bronze thrusts.
If you go for a GL5 for the transfer it mean you have two types of oil you have to use.
I had the same problem with my series 2a when I fitted a rocky mountain O/D. Had to use a GL4 oil in the transfer box so went for the suggested synthetic Castrol Syntrans 75w/85 GL4 and also use it in the main G/B without any problems. I buy in bulk so only one drum pump required.

Don't you just love Landrovers!!!!!!
Chris

[captainslow]

Don't you just love Landrovers!!!!!!


Hehe, yes it will take more than this to dampen the love affair.

I've sent off some info to Britpart (rather than Craddocks) and I'll see if anything comes back. But it does make sense that the oil may be the culprit. The Low Range gear is spinning pretty fast when the High Range gear is selected and it was only the thrust washers each side of the Low Range gear that failed.

Yes, it would be a good experiment to go back to the bronze thrusts. However, I do like the idea of steel thrusts if a higher spec oil will solve the munching - sort of like a poor mans TRB setup ;)

I'll post any responses from Britpart

Pete

[PhilipA]

This is most probably teaching grandma to suck eggs, but have you checked that the bore of the intermediate shaft is clear of debris?

I recall many years ago stuffing an air line into the intermediate shaft and a great plug of bronze being ejected.

As you probably know the lubrication for the bearings and thrust washers is via oil running into a pocket at the end of the shaft and centrifugal ( on second thought just drip) force ensuring the oil was ejected from the many holes in the shaft. I think logically the holes should point down.
Regards Philip A

[captainslow]

but have you checked that the bore of the intermediate shaft is clear of debris?

Philip, yes I'd checked that and all the radial and axial holes were clear. However it does raise another issue. I've got two intermediate shafts to choose from (see below). They're both not perfect but the hardening is still intact. At the Low Range gear end of the shaft (where I have the problem) one of the shafts has a ring milled around the entire circumference however the other only has a slot. So there has obviously been a bit of evolution of the shafts. Anyone know which is the latest and best to use?

https://www.aulro.com/afvb/images/imported/2017/03/755.jpg

[Bearman]

I haven't seen one like that before. It look like someone has milled it themselves probably to increase the oil flow around the rear thrust on low gear. Assemble the gears etc on the shaft and have a look where the groove is in relation to the rear thrusts. Might be worth giving it a go if you intend staying with the steel thrusts.

[captainslow]

I haven't seen one like that before.

Yes, that shaft is a bit weird. It looks like it was manufactured that way - it seems to have a hardened surface. But when positioned in the box the slot lines up nicely with the Internal Spacer washer - which can easily fall into the slot. So not sure how this ever worked. It's possible that the Internal Spacer washer wore itself into the shaft - but it's an amazingly neat job if it did and can't have ended well - another mystery...

BTW, this shaft was not used in the current failure. For reference, here's what it looks like in-situ...

https://www.aulro.com/afvb/images/imported/2016/04/473.jpg

[Bearman]

Yes, that shaft is a bit weird. It looks like it was manufactured that way - it seems to have a hardened surface. But when positioned in the box the slot lines up nicely with the Internal Spacer washer - which can easily fall into the slot. So not sure how this ever worked. It's possible that the Internal Spacer washer wore itself into the shaft - but it's an amazingly neat job if it did and can't have ended well - another mystery...

BTW, this shaft was not used in the current failure. For reference, here's what it looks like in-situ...

https://www.aulro.com/afvb/images/imported/2016/04/473.jpg

When you think about it, the internal spacer can't fall into the slot because it is captured by the outer thrust washer that it fits into, so what it's doing is allowing a bigger space for oil to accumulate. Not a bad idea really.

[captainslow]

Well, had a short note back from Britpart...

"Thank you for your email, we have checked our stock to a genuine LR one and both are steel"

I'm a bit surprised, every thrust washer I've seen is bronze. Can anyone confirm (or otherwise) if their statement is correct?

Cheers
Peter

[Bearman]

Likewise, I have mainly seen bronze, but on a couple of occasions have seen bronze ones with white metal covering like big end shells. I have never seen full steel ones like you have.

[captainslow]

An update on the LT95 thrust washers:-

Britpart have confirmed that their thrust washers are actually zinc plated bronze. This is good and what I would have expected.

I was pretty certain that the thrust washers I was supplied came in Britpart packaging, but I could be mistaken so I will chase up the suppliers (Craddocks in the UK) to see if I can confirm who is supplying their fully steel thrust washers.

In the mean time I've done some superficial gear contact tests (see below). The drive gear and high range gear seem to be meshing right in the middle where you would expect. So I think this rules out any misalignment issues.

I'll be rebuilding the transfer case with bronze thrust washers (and a new low range gear) and I'll keep a close eye on it for a while until I can get some confidence back...

https://www.aulro.com/afvb/images/imported/2016/04/199.jpg

https://www.aulro.com/afvb/images/imported/2016/04/200.jpg

Cheers
Pete

[Busted Syncro]

G'day Pete,

Glad you have made progress.

The gear marking compound show nice contact between the gears so another possible cause eliminated. Maybe for "piece of mind" what about checking the low range gear set as well when you get new thrusts?.
Interesting that aftermarket has a cheaper thrust made from steel that clearly hasn't been tested in real life!!! and will fail with the wrong oil. (Recon your not the only one that's had this problem.)

For a number of years now I always measure and inspect critical parts for correct size and tolerance for my Series 2a. When there is a difference between after market and the original part I buy a genuine part to compare and measure. When genuine and original are the same I buy genuine if it available.!!!!

Excellent thread and pic's for future reference!!!.

Chris

[captainslow]

Well, thanks to Brian I now have a replacement low range gear, pear washers and BRONZE thrust washers installed into the transfer case and should hopefully have Sandy back on the road by the weekend. With the box still in the car it's a tricky job on your back with bits falling in your face, but certainly doable.

https://www.aulro.com/afvb/images/imported/2016/04/59.jpg

Still no luck getting any response from the supplier about the source of the steel thrust washers - in fact I've had no response at all to several emails which is a bit disappointing so I'll follow up with a phone call.

Chris, I took your advice and finished off the gear contact checks by testing the Low Range gear and it looks pretty good. Certainly worth checking. Here's the results for completeness...

https://www.aulro.com/afvb/images/imported/2016/04/60.jpg

https://www.aulro.com/afvb/images/imported/2016/04/61.jpg

Cheers
Pete

[Busted Syncro]

G'day Pete,

Good feeling to have it all back together!!!!. Fortunately you have a low parts count on this failure. It could have been much worse!!!!
(Also very interesting the part supplier has gone quite.)
OK on the contact tests on Low range. Last thing to eliminate. I always remember my TAFE teacher saying "If you haven't measured it, IT"S WRONG until you do"
Now it's back to L/R original spec. you only have to monitor the thrust wear over time.
Probably the bottom lines is how hard you drive it. If it becomes an issue again maybe as already suggested a TRB shaft setup.
Chris

[350RRC]

Excuse my dumbness, but how come the contact point on those gears isn't in the longitudinal centre?

Just trying to learn something here!

cheers, DL

[captainslow]

Excuse my dumbness, but how come the contact point on those gears isn't in the longitudinal centre?


DL, yes I was just making sure that there was no significant bias pushing the gears sideways. But I'm no expert at all. The results that I got seem to indicate that contact was made in the "meat" of the gear - it may not be exactly on center but seemed to be reasonable to me. What I was trying to eliminate was the possibility that the box may have been warped in some way so that the shafts weren't aligned properly. This is a highly unlikely problem but I'm trying to eliminate everything. I'd be very happy if someone could confirm that this is a valid test.

And,yes, the TRB setup would solve my problems in the long term. Stay tuned...

Cheers
Pete

[captainslow]

Well, it's been many months since I last posted on this issue and its time to give a report on the outcome.

Firstly, there is no doubt that the steel thrust washers were a faulty part and were the cause of the failure. I've put 5K on the box using second hand bronze thrust washers and they haven't worn at all (they can be inspected through the oil filler hole on the top of the transfer box - that's convenient!).

However, the support from the supplier has been absolutely disgusting. I won't slander them but this is a short history of the facts:-

May - denied that they could possibly have supplied faulty part
June - returned one of the parts to them (at my expense) for their inspection
July - confirmed receipt of part
Sept - confirmation that the parts had been received as part of a "job lot" and had been removed from stock
Oct - refund denied because parts were "out of warranty"
Nov - no response to my emails

The "out of warranty" was an absolute insult after the time it took to get an admission. I've been very polite at all stages of the negotiation but it's been a constant battle to get any response from them, I've been bounced from person to person, ignored, basically been called a liar then given no apology (or support) when they've been found to be at fault.

I've given up...

Pete

[Toxic_Avenger]

Terrible service. I'd go so far as to call it douchebaggery.

What did you want from the vendor? Refund? Replacement? Damages?

By the lead times above, I'm guessing it's an offshore vendor?

[captainslow]

Well, fortunately the damage was isolated to the transfer section of the LT95. There was so much steel dust floating around that it has prematurely worn all the brand new bearings I had installed. Thanks to Bearman it's running on a set of second hand hi range gears, bearings and washers but the whole transfer section needs a rebuild. This isn't an overly expensive rebuild (if you discount the damaged gear). I made up an order to the supplier (for around $200) and asked if they'd offer me a special deal (wasn't even asking for freebies). They said no, so I then asked if they would at least replace the faulty thrust washers - that's when they told me that the warranty had lapsed.

Fortunately our West Australian RAC recovered the vehicle 500km(!) without charge - now that is amazing service, even if I am a long term member on the highest membership (ahhhh, I own a Land Rover...). So I've got out of jail fairly lightly, but, wow, that is downright awful service - yes they're UK, I guess they feel they can get away with it with an Oz customer.

If anyone else has ordered these washers off Cr**docks, just check them with a magnet before you put them in. There was quite a lag between me raising the issue and them removing them off the shelf.

Pete

[captainslow]

The saga continues but there has been some progress.

After getting the proprietor of Craddocks involved I was sent a kit of parts to rebuild the transfer case free-of-charge (bearings, seals, gaskets and thrust washers). This support was most appreciated after the 6 month run-around.

The irony is that the thrust washers supplied in this kit were supplied by Britpart and made of steel (yes, steel, not bronze). Both Britpart and Craddocks had denied ever stocking steel thrust washers so this was a bit of a surprise to me and them (I couln't be sure the first supply of thrust washers were from Britpart because I'd thrown away the packaging - but I had my suspicions).

Craddocks contacted Britpart on my behalf and Britpart have now confirmed that they do make the thrust washers out of steel and have not had any problems with supplying them as such.

Ok, that's their prerogative but I would advise any prospective purchaser to do their homework before installing them.

As documented in this thread, steel washers ground away the pear washer and low range gear in a very short period of time.

Contributing factors may be:-

It was a long drive (500km) at highway speeds (well, 90k/hr).
The Hi range transfer gears are the .996 ratio.
Its behind an ISUZU 4BD1.

But I don't believe any of this should have caused a premature failure - I've run bronze thrust washers under the same conditions with no problems at all.

From my research I have found that thrust washers in this application should be made from bronze or hardened/ground and lapped steel. The thrust washers supplied by Britpart don't look like hardened steel and do not have machined surfaces.

So, I think they're made from the wrong material, but Britpart say there are no problems.

I can see why the Perenties went with tapered bearings.

Pete

[Davo]

Thanks for the story, as it certainly says a lot. Just so you know, somewhere here, just once, someone (who seemed to have a lot of experience) said that the .996 ratio tends to damage the thrust washers more than any other ratio, because of the tooth angle. I'm sorry I can't point you towards the actual thread, but it was just one of those things you read and file away in your head in case you ever need it. At any rate, it may be worth researching.

[Busted Syncro]

G'day Pete,

Thanks for the update. All good info.

( My latest challenge with the Series2a is modern brake fluid. Gone back to straight DOT3 for brake and clutch as the modern additives have effected the rubbers and hoses.)

Chris

[captainslow]

someone (who seemed to have a lot of experience) said that the .996 ratio tends to damage the thrust washers more than any other ratio, because of the tooth angle.

Thanks Davo - it may be a contributing factor and that was why I noted the configuration I was running. The bronze washers are holding up well but I'll be keeping an eye on them (fortunately you can peek into the top of the transfer box from the oil filler plug and get an idea of wear). Even if the .996 ratio is the worst case I wouldn't be trusting the steel thrust washers in any install.

Cheers, Pete

PS I think I found the thread you were referring to. Interesting...
LT 95 (https://www.aulro.com/afvb/the-isuzu-landy-enthusiasts-section/154273-lt-95-a-post1725380.html#post1725380)

[Dervish]

It's the fundamental flaw in the LT95 transfer case; the intermediate gear not driving the centre diff is being driven by the centre diff. That is, at 100 km/h the hi range gear is spinning at ~2000rpm, while the poor low range gear is spinning it's brain's out at 6500-7000rpm. That means more heat and wear.

That's the reason the LT230 is so far superior, with it's one piece intermediate cluster.

I recall the famous Bill once postulating on the forum about replacing the thrust washers with torringtons (the discussion was focussed on the LT230R, but same idea); it would be an interesting experiment.

[fitzy]

It's the fundamental flaw in the LT95 transfer case; the intermediate gear not driving the centre diff is being driven by the centre diff. That is, at 100 km/h the hi range gear is spinning at ~2000rpm, while the poor low range gear is spinning it's brain's out at 6500-7000rpm. That means more heat and wear.

That's the reason the LT230 is so far superior, with it's one piece intermediate cluster.

I recall the famous Bill once postulating on the forum about replacing the thrust washers with torringtons (the discussion was focussed on the LT230R, but same idea); it would be an interesting experiment.

Please excuse my ignorance.
What are torringtons?

[Dervish]

Please excuse my ignorance.
What are torringtons?

My fault for using what is probably an incorrect term but one I'm used to, the correct name is needle thrust bearing.

120046

[captainslow]

It's the fundamental flaw in the LT95 transfer case; the intermediate gear not driving the centre diff is being driven by the centre diff. That is, at 100 km/h the hi range gear is spinning at ~2000rpm, while the poor low range gear is spinning it's brain's out at 6500-7000rpm. That means more heat and wear.


Thanks, yes, that makes sense. If there is more sideways thrust from the .996 gear set and the low range gear is running faster than normal it results in the perfect storm. All the thrust is directed towards the low gear end. I may have to change to the 1.113 gear set as a compromise.

Needle thrust washers would be a great idea. Not sure if anyone has tried this in anger. It would probably only be required for the two thrusts surrounding the low range gear.

[Davo]

Thanks Davo - it may be a contributing factor and that was why I noted the configuration I was running. The bronze washers are holding up well but I'll be keeping an eye on them (fortunately you can peek into the top of the transfer box from the oil filler plug and get an idea of wear). Even if the .996 ratio is the worst case I wouldn't be trusting the steel thrust washers in any install.

Cheers, Pete

PS I think I found the thread you were referring to. Interesting...
LT 95 (https://www.aulro.com/afvb/the-isuzu-landy-enthusiasts-section/154273-lt-95-a-post1725380.html#post1725380)

I do believe that is the thread! Well done. There is a lot of heat in that area at high speed, and once upon a time I saw an eBay UK auction for an LT95 transfer case sump with an oil pump in it. Apparently it was Genuine, but so rare it didn't even have a part number, which sounds about right for the Land Rover factory from the old days. The pump was driven by one of the transfer gears, so the oil could go through a cooler. I kept photos, (which won't upload right now), and I always thought it would be great to make one. But still, you obviously found the culprit with those crappy parts.

[Davo]

Here we go.

[d2dave]

Philip, yes I'd checked that and all the radial and axial holes were clear. However it does raise another issue. I've got two intermediate shafts to choose from (see below). They're both not perfect but the hardening is still intact. At the Low Range gear end of the shaft (where I have the problem) one of the shafts has a ring milled around the entire circumference however the other only has a slot. So there has obviously been a bit of evolution of the shafts. Anyone know which is the latest and best to use?

https://www.aulro.com/afvb/images/imported/2017/03/755.jpg

In a previous life I used to work in/own a gearbox repair shop. Both these shafts from your pics look to be in excellent condition.
We would put them in a lathe and run linishing tape over them and they would look like new.

As for your problem. I would be very hesitant using steel thrust washers and I believe this has probably caused your failure.

A previous post also noted the use of Torrington bearings. This was what we always knew them as.

Captianslow, what is the yellow stuff that you used for checking gear mesh? I used to have stuff called yellow orca, but I cant seem to find it any more.
I recently rebuilt my sons diff in his county and had to use bearing blue. This is much harder to use due to its dark color not showing up well on the teeth.

[captainslow]

In a previous life I used to work in/own a gearbox repair shop. Both these shafts from your pics look to be in excellent condition.
We would put them in a lathe and run linishing tape over them and they would look like new.

As for your problem. I would be very hesitant using steel thrust washers and I believe this has probably caused your failure.

A previous post also noted the use of Torrington bearings. This was what we always knew them as.

Captianslow, what is the yellow stuff that you used for checking gear mesh? I used to have stuff called yellow orca, but I cant seem to find it any more.
I recently rebuilt my sons diff in his county and had to use bearing blue. This is much harder to use due to its dark color not showing up well on the teeth.
Thanks Dave,
I wasn't aware of linishing tape so I'll do that next time I have the shaft out - which may be pretty soon. I'm sure the steel washers are a contributing factor but I'm going to change the hi ratio gear back to the 1.116 even though it makes long drives a bit more painful. I will do a bit of research on the torrington thrust bearings just in case there is something that would be a drop-in replacement for the thrust washers - you never know your luck...

The contact paint I used to check the gears was artists oil paint - cadmium yellow to be precise, available from any art supplier. I had got that tip off another forum and it worked a treat. A bit of degreaser on the gears then painted the contact surfaces with a small paintbrush.

Cheers, Pete.

[captainslow]

Ok, here's one for the gearbox gurus. There is a torrington thrust needle roller that could replace the LT95 transfer case thrust washers.

Here is an example:-
Koyo FNT-5070 Thrust Needle Roller and Cage Assembly, Open, Steel Cage, Metric, 50mm ID, 70mm OD, 3mm Width, 5900rpm Maximum Rotational Speed, 40200lbf Static Load Capacity, 8520lbf Dynamic Load Capacity: Thrust Roller Bearings: Amazon.com: Industrial & Scientific (https://www.amazon.com/Koyo-FNT-5070-Assembly-Rotational-40200lbf/dp/B007EE5WHG)

This is exactly the same size as the thrust washers - 50mm bore, 70mm outside diameter, 3 mm thick.

Am I simplifying it too much to think that this thrust needle roller is a drop-in replacement? It seems too good to be true...
The thrust needle roller would "roll" on the surfaces of the pear washer and gear so there may be a wear issue.
Any advice appreciated.

BTW, there was a previous AULRO post on this issue but it wasn't first hand. For reference the post was: LT95 intermediate shaft bearing upgrade (https://www.aulro.com/afvb/technical-chatter/121045-lt95-intermediate-shaft-bearing-upgrade-2.html)

[isuzutoo-eh]

SNIP
This is exactly the same size as the thrust washers - 50mm bore, 70mm outside diameter, 3 mm thick.

Am I simplifying it too much to think that this thrust needle roller is a drop-in replacement? It seems too good to be true...
The thrust needle roller would "roll" on the surfaces of the pear washer and gear so there may be a wear issue.
Any advice appreciated.


I'm also very keen to know if this could be a solution, I have a well worn transfer case in my County and another two of these boxes in vehicles that could be upgraded if it is a simple solution...

[captainslow]

I'm not convinced that this is going to be a solution.

As Dervish pointed out, the low range gear can be spinning very fast at highway speeds. By my calculations with the .996 hi range ratio and a 4BD1 cruising along at 2500RPM then the low range gear will be spinning at roughly 3 times this rate - 7500RPM which is way outside the maximum rpm rating for a Torrington Thrust Needle bearing of this size - nominally 6000rpm. Also, I suspect to get close to that maximum rating an oil better than "engine oil" may be required. Add to this the uncertainty of using the low range gear and a pear washer as the races for the Torrington.

Unless I can be convinced otherwise I'm going to have to abandon this plan (it did seem too good to be true).

So, just when I thought I could shrug off the captain slow tag, looks like I'm stuck with it. I'll go back to the 1.116 hi range ratio [bigsad]

[Bearman]

The answer is to just go with a tapered roller intermediate shaft Pete. You can have either 0.996 or 1.123 ratio. No more worries!!!!!

[Davo]

Where do you get these TRB conversions these days? A couple of searches didn't turn up anything.

[Bearman]

Where do you get these TRB conversions these days? A couple of searches didn't turn up anything.

They were only in the military gearboxes Davo. Some of these boxes have been auctioned at the AFM auctions with the Perenties. PM sent.

[d2dave]

I have memories from back in my RR Clasic days of Ritters doing a tappered bearing conversion for these.