Gearbox issues!

[Deaf Ender]

G'day All,

I'm looking for advice on Gearbox's. My 4 Speed Parentie is difficult to get out 2nd, into 3rd and after a professional inspection inside the box, I've been told she needs an overhaul .. cost approximately $3-3500 (excluding removal and installation). I've sourced a used Parentie 5 speed, for $2,500 (with a 1 or 3 month warranty), but am unsure of;
a) Whether i'd be better off overhauling my 4 speed?
b) Whether the engine will labour with a 5 speed box?
c) Whether it will bolt straight in with minimal hassle?
d) Whether the tail shaft length needs adjusting?
e) Any other unknown issues?

I'd appreciate any input from some knowledgable members out there please.

What do you think?
Deaf Ender.

[landy]

Hi,
I'm no expert by a long shot however I have spoken at length to the RAEME boys at work about our Landrovers,
I have been told that the first trails vehicles where fitted with 5speed transmissions and performed well only being discounted because defence wanted to limit top speed to 80kmh. Apparently due to the safety concerns with towing the 1/4 ton trailer. And,
The box is capable of being converted to a 5 speed as defence simply optioned the Range Rover box minus 5th as this was the only box available that could handle the 3.9 litres torque at the time. Therefore one would assume that the tail shaft should be ok.
Have you checked prices on the Ashcroft Transmissions website? I'm sure you could get one delivered much cheaper.

[Homestar]

The LT95 4 speed you have is about the strongest box LR ever used, and is much stronger than the 5 speed. The torque pulses from the 4BD1 engine give boxes a hard time. Shop around for a decent second hand box. The Perentie boxes have the roller taper bearing conversion in the transfer case, and is worth keeping - they are an expensive bit of kit.

Parts for a rebuild are around $1000 so the price you've been quoted seems ok I suppose. Are you handy with the spanners? You could at least remove the box yourself and save some dollars. Probably not a beginners box to try and rebuild yourself.

We need Bearman to chime in now, not much he doesn't know about these units. :)

[Deaf Ender]

The LT95 4 speed you have is about the strongest box LR ever used, and is much stronger than the 5 speed. The torque pulses from the 4BD1 engine give boxes a hard time. Shop around for a decent second hand box. The Perentie boxes have the roller taper bearing conversion in the transfer case, and is worth keeping - they are an expensive bit of kit.

Parts for a rebuild are around $1000 so the price you've been quoted seems ok I suppose. Are you handy with the spanners? You could at least remove the box yourself and save some dollars. Probably not a beginners box to try and rebuild yourself.

We need Bearman to chime in now, not much he doesn't know about these units. :)

Thanks bacicat, I take it you think I should get her overhauled. The quoted rebuild price included the transfer case. At least then I'll know exactly what I've got.

Appreciated, Deaf Ender.

[Deaf Ender]

Hi,
I'm no expert by a long shot however I have spoken at length to the RAEME boys at work about our Landrovers,
I have been told that the first trails vehicles where fitted with 5speed transmissions and performed well only being discounted because defence wanted to limit top speed to 80kmh. Apparently due to the safety concerns with towing the 1/4 ton trailer. And,
The box is capable of being converted to a 5 speed as defence simply optioned the Range Rover box minus 5th as this was the only box available that could handle the 3.9 litres torque at the time. Therefore one would assume that the tail shaft should be ok.
Have you checked prices on the Ashcroft Transmissions website? I'm sure you could get one delivered much cheaper.

Hi Landy, I'll check Ashcroft thanks mate. Thanks for the good oil.
Deaf Ender.

[Blknight.aus]

The perentie Never had a 5 speed

if you have a 5 speed "perentie" box what you have is an r380 from one of the td5 110's that were bought into guiseas a perentie late in the piece.

no, its not going to bolt straight onto or into your 4bd1 perentie.

parts for a mainbox overhaul are between $500 and $2500 depending on what can be salvaged

parts for the Tcase side go about the same

$3-4k is an average ball park.

a quality workshop working effeciently and quickly generally wont let you get away with paying less than $1.5K for a rebuild alone as there are some things that while you technically can reuse experience and best practice says you dont.

[Deaf Ender]

Thanks blknight, I'll determine whether it's an R380. Is it possible to use the R380 on the 4bd1 at all, perhaps with minor modification?

Deaf Ender

[Blknight.aus]

Depends on your definition of minor modification

you might need to have an adaptor plate /flywheel housing made up and you might need to change the friction plate

an lt85 with an lt230 should be just about a drop in fit but you'd have to get the diesel version. IT wont last as long as the lt95 though

[Deaf Ender]

Depends on your definition of minor modification

you might need to have an adaptor plate /flywheel housing and you might need to change the friction plate made up. I think the input shaft lengths are different.

an lt85 with an lt230 should be just about a drop in fit but you'd have to get the diesel version. IT wont last as long as the lt95 though

Sounds like I should stick with the Lt95 then.
Much appreciated,
Deaf Ender.

[Dervish]

Thanks blknight, I'll determine whether it's an R380. Is it possible to use the R380 on the 4bd1 at all, perhaps with minor modification?

Deaf Ender

There are a number of 4BD1(T)s out there with R380s behind them, of which I've driven a couple and own one. If you decide to go that route, you'll need a friction plate to suit the fine spline R380 input shaft and a bellhousing modified to accept the gearbox (and the R380 itself, LT230, gearbox and transfer case mounts to suit and a Defender front propshaft). Parts for the conversion are available through KLR Automotive.

Modified LT95 Bellhousing/R380/LT230 on the left - LT95 on the right, because everyone likes pictures.
http://i940.photobucket.com/albums/ad246/OreganoM1/IMG_9139_zpsujd2yth5.jpg

[JDNSW]

My first check would be what oil is in it. Difficulty coming out of gear on mine in cold weather was fixed by using synthetic oil. Note that normal gear oils must not be used in this box, as cold starts will destroy the oil pump.

John

[Deaf Ender]

I think I'll try to steer clear of modifying things and sounds like the original 4 spd is stronger in any case, so I'll try for an overhaul or a good used 4 spd.

Great picture!
Deaf Ender.

[Deaf Ender]

My first check would be what oil is in it. Difficulty coming out of gear on mine in cold weather was fixed by using synthetic oil. Note that normal gear oils must not be used in this box, as cold starts will destroy the oil pump.

John

Have been using Penrite HPR Diesel 20w-60 or HPR30 20w-60 mineral oil.
Thanks,
Deaf Ender.

[Bearman]

G'day Deaf Ender, As others have hinted, I would stick with the LT95 box and get it recoed. $3500 is an average price to do one - that's replacing ALL bearings, seals, synchros and gears 1,2 and 3 and probably hi range gear in the t/case plus a freshen up of the centre diff assembly and a new oil pump assembly. Make sure they use quality bearings like RHP for mainshaft and Timken on everything else. Also genuine LR synchro rings and a genuine gasket kit are recommended. If extras like main or layshafts, 4wd vacuum actuator etc are required the price will increase.

[Deaf Ender]

G'day Deaf Ender, As others have hinted, I would stick with the LT95 box and get it recoed. $3500 is an average price to do one - that's replacing ALL bearings, seals, synchros and gears 1,2 and 3 and probably hi range gear in the t/case plus a freshen up of the centre diff assembly and a new oil pump assembly. Make sure they use quality bearings like RHP for mainshaft and Timken on everything else. Also genuine LR synchro rings and a genuine gasket kit are recommended. If extras like main or layshafts, 4wd vacuum actuator etc are required the price will increase.

Glad to hear from you Bearman, your name keeps coming up as the one to ask.

I'm trying to find a good, low km, 2nd hand box, but failing that, I'll go for an overhaul. Have been scared off a bit by suggested prices of $3000 up to $5000, depending on how badly she's worn. I had a mechanic look into it from the top and he said the Main shaft had play in it, due to the thrust bearing. Sometimes when I start her on a cold morning I hear a Thrust bearing noise. It can be quite difficult getting out of 2nd, there's no crunching, but i need to accelerate suddenly, then back off and immediately change up to 3rd. Often I'll have to have a few goes at changing up to 3rd. Do you have any suggestions of where I should send it for reco? Someone suggested a Melbourne company called "Three Sixty". How about yourself, do you entertain doing reco's? Appreciate the detail you've provided.

Many thanks,
Deaf Ender.

[Chris078]

I'm not an expert by any means, have just read around these forums a fair bit so take what I am about to say with an appropriate amount of salt.

It's supposed to have 15w-40 in it. Not sure if putting 15w60 will do it any good.(or any harm for that matter)

Try draining the oil, putting in some fresh 15w40 and adding a some Nulon G70 to it (50ml per litre of oil). There are a few reports of this making quite a difference.

[Bearman]

Glad to hear from you Bearman, your name keeps coming up as the one to ask.

I'm trying to find a good, low km, 2nd hand box, but failing that, I'll go for an overhaul. Have been scared off a bit by suggested prices of $3000 up to $5000, depending on how badly she's worn. I had a mechanic look into it from the top and he said the Main shaft had play in it, due to the thrust bearing. Sometimes when I start her on a cold morning I hear a Thrust bearing noise. It can be quite difficult getting out of 2nd, there's no crunching, but i need to accelerate suddenly, then back off and immediately change up to 3rd. Often I'll have to have a few goes at changing up to 3rd. Do you have any suggestions of where I should send it for reco? Someone suggested a Melbourne company called "Three Sixty". How about yourself, do you entertain doing reco's? Appreciate the detail you've provided.

Many thanks,
Deaf Ender.

G'day Deaf Ender,
Just be wary of getting a s/h box and putting it in as it may be worse than yours and it's a pain if you have to pull it out and then reco it or your original box, which is probably the best way to go. And you would have to make sure it has the tapered roller intermediate shaft assembly in it - in other words it would have to come from another ex army Perentie with the same transfer ratio. Range rover boxes are different. A rattling noise without the clutch pushed in is normal for these boxes behind the Isuzu donk. Have you checked that the clutch is disengaging properly first. The symptoms you describe could indicate a dragging clutch. What about 1st and 4th gear, are they hard to engage/disengage. Try gear changing with the engine stopped and then with it running and see if there is any difference. If the clutch is not disengaging properly it will be hard to get into/out of gear when running and relatively easy when stopped. With regards to oil, use the same as the engine (15W/40 diesel engine oil). Apart from the disengaging problems, are there any other noises in the box/transfer? I do a few of these boxes and could do it for you if you want to send it to me but I am pretty flat out at the moment and it would probably be 3-4 weeks before I could do it. Try what I have suggested and get back to me....Brian

[Deaf Ender]

G'day Deaf Ender,
Just be wary of getting a s/h box and putting it in as it may be worse than yours and it's a pain if you have to pull it out and then reco it or your original box, which is probably the best way to go. And you would have to make sure it has the tapered roller intermediate shaft assembly in it - in other words it would have to come from another ex army Perentie with the same transfer ratio. Range rover boxes are different. A rattling noise without the clutch pushed in is normal for these boxes behind the Isuzu donk. Have you checked that the clutch is disengaging properly first. The symptoms you describe could indicate a dragging clutch. What about 1st and 4th gear, are they hard to engage/disengage. Try gear changing with the engine stopped and then with it running and see if there is any difference. If the clutch is not disengaging properly it will be hard to get into/out of gear when running and relatively easy when stopped. With regards to oil, use the same as the engine (15W/40 diesel engine oil). Apart from the disengaging problems, are there any other noises in the box/transfer? I do a few of these boxes and could do it for you if you want to send it to me but I am pretty flat out at the moment and it would probably be 3-4 weeks before I could do it. Try what I have suggested and get back to me....Brian

G'day Bearman,
From what you are saying, the "dragging clutch" scenario is a definite possibility and I'll pay attention to the ease/difficulty of changing gears with engine running vs stopped. 3rd to 4th and 4th to 3rd are always easy. When changing from 3rd to 2nd with engine running, I have to give it a distinct pull through the syncro, to get into 2nd. 2nd to 1st is a bit hit and miss, sometimes it goes straight into 1st and sometimes I need to have a second go at it, with engine running and doubling the clutch helps here. I'll have another look at 2nd to 1st with engine stopped, not sure. There are no other obvious noises coming from the gearbox or transfer case, which makes me think its basically still a good box. The vehicle has done 177,000 kms. The gearbox doesn't rattle at all, but the clutch does rattle when in neutral with clutch out (i think). Oil info noted thanks.

Many thanks again,
Deaf Ender.

[Deaf Ender]

I'm not an expert by any means, have just read around these forums a fair bit so take what I am about to say with an appropriate amount of salt.

It's supposed to have 15w-40 in it. Not sure if putting 15w60 will do it any good.(or any harm for that matter)

Try draining the oil, putting in some fresh 15w40 and adding a some Nulon G70 to it (50ml per litre of oil). There are a few reports of this making quite a difference.

G'day Chris078,
I'm a bit wary of adding products, but have already squirted a tube of Molly into the gearbox, which helped. Haven't tried Nulon G70. Not sure if these products would damaged to box in any way?

Thanks mate,
Deaf Ender.

[Chris078]

G'day Chris078,
I'm a bit wary of adding products, but have already squirted a tube of Molly into the gearbox, which helped. Haven't tried Nulon G70. Not sure if these products would damaged to box in any way?

Thanks mate,
Deaf Ender.

A couple of people on here have mentioned using it with success. I've contacted their tech support and they reckon it's compatible.

I have reasonably similar symptoms to you to, though not quite as bad.
Always takes a second go to get into first from idling in neutral, will mostly go into 1st from 2nd if going slowing.
Occasional grinding/grabbing feel through the brake pedal if I'm sitting in neutral with my foot off the clutch pedal (like when waiting for lights). also get a nice metallic 'Clack" when it goes into second.

I've had a tube of g70 waiting to go in for a while, but seeing as I only changed the oil 300km ago and I don't drive it much at the moment, I'm waiting for a bit before I do a change.

[Deaf Ender]

A couple of people on here have mentioned using it with success. I've contacted their tech support and they reckon it's compatible.

I have reasonably similar symptoms to you to, though not quite as bad.
Always takes a second go to get into first from idling in neutral, will mostly go into 1st from 2nd if going slowing.
Occasional grinding/grabbing feel through the brake pedal if I'm sitting in neutral with my foot off the clutch pedal (like when waiting for lights). also get a nice metallic 'Clack" when it goes into second.

I've had a tube of g70 waiting to go in for a while, but seeing as I only changed the oil 300km ago and I don't drive it much at the moment, I'm waiting for a bit before I do a change.

Hi Chris078,

I've changed the oil to 15w40 mineral oil and added a tube of Nulon G70 and yes, there is a significant improvement. I am now able to make the change from 2nd to 3rd on the first attempt, 95% of the time and she feels much slicker. I'm now encouraged to keep this gearbox as is, rather than overhauling it just yet, as there is no adverse noise from it. I did however find a couple of small metal chips in the oil, one looked like the corner of a gear tooth about an 1/8th inch square and the other looked like a flake about a 1/4 of an inch long and very thin, similar to a sheath from a grain of oats. I asked a gearbox overhauler in Ballarat about adding Nulon G70 and he reckons its safe to use, but advised against synthetic oil as it "gunks up" some of the more porus components.

Deaf Ender.

[Chris078]

Hi Chris078,

I've changed the oil to 15w40 mineral oil and added a tube of Nulon G70 and yes, there is a significant improvement. I am now able to make the change from 2nd to 3rd on the first attempt, 95% of the time and she feels much slicker. I'm now encouraged to keep this gearbox as is, rather than overhauling it just yet, as there is no adverse noise from it. I did however find a couple of small metal chips in the oil, one looked like the corner of a gear tooth about an 1/8th inch square and the other looked like a flake about a 1/4 of an inch long and very thin, similar to a sheath from a grain of oats. I asked a gearbox overhauler in Ballarat about adding Nulon G70 and he reckons its safe to use, but advised against synthetic oil as it "gunks up" some of the more porus components.

Deaf Ender.


Glad you had a good result! :) From what I have read, the gearbox action may continue to improve over time as the additive works it's way into the roller bearings and other parts.

This gearbox is notorious for keeping on going way past when other gearboxes would simply give up.
Drive as smoothly as possible, change the oil regularly, adding the G70 and you'll probably get a surprising number of km out of it before you have to rebuild it.

Enjoy your smooth(er) shift action! :burnrubber:

[slickrok]

G'day Deaf Ender,
Just be wary of getting a s/h box and putting it in as it may be worse than yours and it's a pain if you have to pull it out and then reco it or your original box, which is probably the best way to go. And you would have to make sure it has the tapered roller intermediate shaft assembly in it - in other words it would have to come from another ex army Perentie with the same transfer ratio. Range rover boxes are different. A rattling noise without the clutch pushed in is normal for these boxes behind the Isuzu donk. Have you checked that the clutch is disengaging properly first. The symptoms you describe could indicate a dragging clutch. What about 1st and 4th gear, are they hard to engage/disengage. Try gear changing with the engine stopped and then with it running and see if there is any difference. If the clutch is not disengaging properly it will be hard to get into/out of gear when running and relatively easy when stopped. With regards to oil, use the same as the engine (15W/40 diesel engine oil). Apart from the disengaging problems, are there any other noises in the box/transfer? I do a few of these boxes and could do it for you if you want to send it to me but I am pretty flat out at the moment and it would probably be 3-4 weeks before I could do it. Try what I have suggested and get back to me....Brian



Hi Brian,


You've just described the exact symptoms my Perentie has started to show over the past few days. I couldn't get it out of 1st this morning with the engine running. Turned it off and I could easily go through the gears. My clutch peddle started to get really soft a bout 3 days ago and I have to have my foot hard to the floor to change gear. Some have suggested a new slave cylinder. Would this seem right to most people?
Many thanks
Shaun

[Bearman]

Hi Brian,


You've just described the exact symptoms my Perentie has started to show over the past few days. I couldn't get it out of 1st this morning with the engine running. Turned it off and I could easily go through the gears. My clutch peddle started to get really soft a bout 3 days ago and I have to have my foot hard to the floor to change gear. Some have suggested a new slave cylinder. Would this seem right to most people?
Many thanks
Shaun

Hi Shaun, Yes but replace both the master and slave cylinders at the same time. it will save you some grief not far down the track if you only do one of them.