Thread: Gearbox issues!

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.

Originally Posted by 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

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

Originally Posted by 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.

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.

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.

Originally Posted by Deaf Ender

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

Originally Posted by Bearman

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.

Originally Posted by 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.

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.