Gearbox Mainshaft Wear

[101RRS]

Hi All,

I have read most of the threads listed over the past year or so concerning spline wear on the gearbox output mainshaft. In particular I have followed the thread at
http://www.aulro.com/modules.php?name=Foru...iewtopic&t=1281 (http://www.aulro.com/modules.php?name=Forums&file=viewtopic&t=1281)

Great stuff.

I think i am happy with the whole issue but have a couple of additional questions. I have a 94 Disco V8 manual (early R380) - first batch of the updates - I have had the car from new and it is just coming up to 100,000 km. The car has done little offroad work and little around town work - mainly high speed expressway work. However due to clutch and engine cutting out problems early in its life the drive train has had a bit of a hammering in its life.

The drive train is starting to get a bit slack which I am assuming is the early stages of the above problem - just noticeable but not a major problem yet. Clearly I can simply get the Transfer Case Input gear drilled as described and that will stabilise the drivetrain slack but I would prefer to remove as much of it as possible without playing around with the gearbox - will do that when the clutch is due.

Questions

1. When the wear takes place, is there equal wear on the mainshaft splines and the splines on the input gear - if not which wears the most or what wear ratios can I expect eg 30% mainshaft/50% input gear.

2. If I put in a new transfer case input gear onto the worn mainshft splines the drive train slack will be reduced but not removed - does anyone have any ideas how I could reduce the slack further eg different transfer case oil, products that are supposed to help slightly worn splines etc

3. If I do nothing, at what sort of KM does the problem become - exactly that - a problem?

I am inclined to put a new new transfer case input gear but if I cannot expect an improvement in the drive train slack then I am inclined to get the gear drilled or not worry about it and do the mainshaft and input gear when the clutch needs to be renewed - but given the type of driving I do this is not likely to happen in the near future.

Answers to the questions and other thoughts would be appreciated.


Thanks

Gazz


94 Disco
98 Freelander TD - currently only Front WD

[Michael2]

Hi Gazz,
when I bought my 1988 Range Rover with 220,000km on it, I had a post purchase vehicle inspection done by a thorough and reputable Land Rover mechanic. He advised that I don't do any long & remote trips before attending to the shaft wear.

185,000 km later I cooked the gearbox, but the shaft was still going, (albiet 85% worn :!: :!: 8O :!: ). I drove gently, that is to say, no harsh gear changes and 5th gear only for prolonged speed over 90kph.

I've now bought a new shaft and gear and the car feels sooooo tight style_emoticons/<#EMO_DIR#>/biggrin.gif :!:

It's a total gearbox disassembly to do the shaft, I can't comment on doing the gear only, but McNamara's (Difflock) told me that doing the gear only prolongs the life of the transmission, even at high km's.

[shaunp]

The transfer cases are different between 88 and 94, the 94 car will be a 230t, t means taper bearings this is the problem they pump oil away from the spline. At 100k it may still be ok and you will get away with drilling the gear or replacing it. The wear on the shaft and gear are normally similar. At 100k your car will also want an A frame ball joint, this will be some of the slack. I find that the splines are about 1/2 worn at 180-200k. Having said that mine was done at 60k by LR for free.

[camel_landy]

The other place you could do with checking for wear are the splines on the rear hubs....

Mark.

[sclarke]

OK my experiance.

My Defender 1994 LT77 box and 200k on the clock.

Gear was worn about 50% shaft about 30%

OK here is what i did.
i asked lots of people the best thing and they all said, Rebuild....

So one guy who always serviced it said, just replace the gear with a new one cross drilled and then wait until it is rooted before you rebuild

So rebuild is about $3k, versus gear with shimming $300-$400

I know which way i would go....

[101RRS]

Thanks to all you guys for the replies - sort of reinforces my own thoughts

I think I will buy a new cross drilled transfer case gear and have that put in - with only a relatively small amount of wear on the shaft that should take most of the lack out. When I do the clutch next I will pull the gearbox down and replace the mainshaft then and anything else like synchros, bearings etc that needs doing - it will be realtively cheap doing the heavy work myself and sub-contracting the techo bits - I remember seeing some threads on the a-frame ball joint so will take the easy way out and get an exchange unit - relatively cheap.

Thanks for the pointers.

Gazz

[camel_landy]

...Don't forget to use a decent oil in there too.

Mark.

[shaunp]

Penrite 10 tenths synth 75/90 race oil.

[101RRS]

I was quoted the price of the gear at $280 - just need to confirm the number of teeth on the gear (95MY but actually built Jan 94) - guess I will have to check when I pull the old one out - seems like a pretty cheap fix if the problem is identified early - also if identified early, then no other parts should be needed other than the oil you mentioned Mark. I will need to investigate this a little more - winter morning temperatures -4 to -6 sometimes - summer afternoons up around 35 or higher.

[camel_landy]

Originally posted by garrycol
I was quoted the price of the gear at $280 - just need to confirm the number of teeth on the gear (95MY but actually built Jan 94) - guess I will have to check when I pull the old one out - seems like a pretty cheap fix if the problem is identified early - also if identified early, then no other parts should be needed other than the oil you mentioned Mark. I will need to investigate this a little more - winter morning temperatures -4 to -6 sometimes - summer afternoons up around 35 or higher.

We've done some temp tests in the UK and found that operating temperatures tend not to be much of a problem but we have still had failures & excessive wear... (The fitting of an over-temperature sender to the R380 is quite simple and the wiring for the dash warning light is already there on the Defender!)

The key to solving most gearbox problems is the oil. LandRover have used ATF for years, this is completely wrong and is too thin to lubricate properly. Recently, LandRover have changed to MTF which is soooo much better.

HTH

Mark.

[101RRS]

Thanks Mark

I must admit the my gearbox still has ATF in it and that will be changed to something more suitable real soon - the transfer case where the wear takes place has never had ATF in it and has always had some suitable gear oil in it.

Gazzz

[shaunp]

Garry use Penrite 75 , valvoline Dura gear 75/85 or similar in the 5 speed and Penrite 10/teeths synth in the trans fer box comes in 2.5L bottle and the box take 2.3 so you have some.

[101RRS]

Thanks Shaunp will give them a try - as I said I still have the ATF in the gearbox and the transfer case, swivel pin housings and diffs have Castrol VMX 80 in them.

Gazz

[shaunp]

I reckon VMX 80 is a bit lite for diffs and swivels. I run Penrite 90/140 in the swivels and if you don't drive in water I'd put Castrol SAF-XA synth in the diffs, it's not cheap so you don't want to be changing it too often beause you got water in the diffs. SAF -XA was originally designed in conjuction with jaguar for use in their Lemans winning race cars and later used in the XJ220 supercar. It is factory fill for all HSV holdens and XR6 tubro and XR8 falcons. Castrol quote a life span or 300k km in Rockwell/Eaton diffs in road trains etc. It is rated at 90/140 but is quite thin. So if you put it in a Disco that doesn't go near creeks put it in and forget it just make sure it does leak out, but you should not need to change it.
VMX 80 is only rated at GL4 extreame pressure, diffs really want GL5 and VMX 80 will not be as shear stable at high temp either.

[101RRS]

Thanks - I have been putting the specs contained in the workshop manual - since I have been using this discussion forum (4 weeks only) it hs become clear that some of the L/R specs are a bit dodgy - I should have realised 10 years ago after my Disco gearbox was rebuilt under warranty - I came back to the car after the stealer had supposedly finished the job and the was about 2 litres of ATF on the floor of the workshop - after abusing them for the leak - the gearbox had to be pulled down again to fix the leak - I accused them of putting the wrong oil in - at the time I really didn't believe them that a manual gearbox had ATF in it - but then they were the supposed experts - I went home and checked the books and sure enough it was ATF.

I have put a V8 Commodore Getrag 5 speed behind a Jag V12 I Have - it has ATF in it also - think I might change it to MTF as well.

My Freelander also has a GL4 spec for the transfer case - a GL5 spec might be better?

Thanks

gazz

[shaunp]

Maybe ok in the free loader as it is kind of a transaxle. which normally run on GL4

[shaunp]

Penrite web site says 10 tenths syngear75/90 for your freeloader as well.
I've done some 5 speed Supra boxes in XJSs and xj6s (and don't tell anyone but my E type has one to) a manual makes XJs a really sweet thing. My E type was the first of Jeff Delows Jag bellhouseing to go in a car. One of my old mates Ron helped Jeff with the design by suppling a jag all syncro bell housing for him to play with, Ron actually had a factory 4 speed XJS. Jef also makes a Tremec housing for Jags as well. Ron has sold over 1500 conversion kits around the world for jags, he makes flywheels, pedal , cross members etc. We put a Tremec in Dave's ser3 E type but then it's got a blowen 383cui injected Chev in it that gies 700hp+ at the wheels. If you know anyone who needs un breakable Jag diff stub axles come see me. Standard stubs are cast and hardened to 8 rockwell, we can supply ones CNC machined from hard billet and hardened to 35 rockwell, only ones in the world, short of the ones in the Walkinshaw XJS race cars as far as I know. You will tear the center out of the wheel before you break one.

[101RRS]

Shaunp - well don't tell anyone but the V12 I talked about is also a series 3 e-type roadster - maybe we should start a Jag thread or better still a Jag forum but the moderators might get a bit upset. As the Getrag has an integrated bell housing I had a 10mm adapter plate made - the car has the box installed etc and has been driven about 50km (for testing purposes only off course) but the car is still being rebuilt - I would spend more time on it if I didn't have to fix Freaklanders and Discos.

20 years ago (I had the e-type then) I seriously considered putting a V12 in the front of my then 1950 Series 1 Landrover - I was putting a holden 161 in the L/R and I noticed the Jag engine was about the same length as the 161 - just twice the capacity - it would fit too - thankfully common sense prevailed - mainly brought on by the front drum brakes and the landys wild braking or lack of and the need to counteract the swerving under brakes that brought the project to an end before it started - even considered the jag rear end in the Landy- oh to be young again and dream up these foolish ideas.

A V12 series 1 landy with auto box, awd and 4wheel disc brakes - now there is an interesting thought!!

[camel_landy]

Originally posted by garrycol

20 years ago (I had the e-type then) I seriously considered putting a V12 in the front of my then 1950 Series 1 Landrover - I was putting a holden 161 in the L/R and I noticed the Jag engine was about the same length as the 161 - just twice the capacity - it would fit too - thankfully common sense prevailed - mainly brought on by the front drum brakes and the landys wild braking or lack of and the need to counteract the swerving under brakes that brought the project to an end before it started - even considered the jag rear end in the Landy- oh to be young again and dream up these foolish ideas.


Jeezzzz.... I thought it was bad enough taking one out with the 2.5 6cyl lump. :!: That was a nightmare to drive... Even emergency stops have to be planned in advance!!!!

Mark

[Jojo]

Hi all!
Back to the start, I had the trouble described and in my case the drive shaft splines were worn off completely. One clonk too much and the whole thing came to a halt and wouldn't do anything anymore.
If I were you I would change all components as you have to take out the gear boxes anyway.
To refill with a decent transmission oil goes without saying.