Gearbox Oil Leak

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Ogri

Well-known member
Joined
Feb 10, 2007
Messages
324
I'm losing the will to live with this truck...

I bought a reconditioned gearbox about 2 months ago and had it fitted along with clutch, rear crank seal and spigot bearing by a local mechanic who I've know for years and trust.

All was great until I went on a longish run of about 100 miles and got back to find an oil leak. The oil was clean gearbox oil. The oil was spread all over mainly the offside (drivers side), of the gearbox, torsion bar, prop shaft and rear diff housing.

My mechanic removed the box again and split the transfer box and gearbox to reseal the transfer box thinking that he must have failed to get a good seal the first time around.

Again there were no problems running around for the next couple of weeks until yesterday we came down to Devon for the week and the bottom of the truck is once again coated with gear oil.

Again, the leak seems to be right hand side but worse than the last time. The only thing my mechanic noticed different about the two boxes was that my old box had two breathers and the new one only one.

I't worth saying that there is oil forward of the transfer box/gearbox joint but there's no obvious place at which it begins.

It's a really frustrating problem because it seems that to replicate it you have to drive the thing for miles at fairly high speed.

Could be box be pressurising on a long run? Any thoughts you guys have will be gratefully accepted.

Cheers,

Ian.
 
I'm losing the will to live with this truck...

I bought a reconditioned gearbox about 2 months ago and had it fitted along with clutch, rear crank seal and spigot bearing by a local mechanic who I've know for years and trust.

All was great until I went on a longish run of about 100 miles and got back to find an oil leak. The oil was clean gearbox oil. The oil was spread all over mainly the offside (drivers side), of the gearbox, torsion bar, prop shaft and rear diff housing.

My mechanic removed the box again and split the transfer box and gearbox to reseal the transfer box thinking that he must have failed to get a good seal the first time around.

Again there were no problems running around for the next couple of weeks until yesterday we came down to Devon for the week and the bottom of the truck is once again coated with gear oil.

Again, the leak seems to be right hand side but worse than the last time. The only thing my mechanic noticed different about the two boxes was that my old box had two breathers and the new one only one.

I't worth saying that there is oil forward of the transfer box/gearbox joint but there's no obvious place at which it begins.

It's a really frustrating problem because it seems that to replicate it you have to drive the thing for miles at fairly high speed.

Could be box be pressurising on a long run? Any thoughts you guys have will be gratefully accepted.

Cheers,

Ian.

If it is a pressure thing then surely it will stop once it hits the right level? Only a thought though :nenau
 
The gearbox and transfer box are two completely separate items bolted together, they must both have a breather, my guess is this is your problem, Rick
 
The gearbox and transfer box are two completely separate items bolted together, they must both have a breather, my guess is this is your problem, Rick

I changed the gearbox but retained my old transfer box and that's why he initially thought he might not have got a good seal between the two and removed to re-seal. I'll have to quiz him when/if I get home in it about the breathers but I think he meant my old gearbox had two plus one on the transfer box and the new gearbox only one plus one on the transfer box. :nenau

On the plus side, there's so much oil on the chassis now that I won't have to worry about the rot for a while :doh

Ian
 
wait to hear then mate, as a side note I have seen one box that leaked from the gearlever area but did not investigate it, Rick
 
as a side note I have seen one box that leaked from the gearlever area but did not investigate it, Rick

Thanks Rick, this was something that has crossed my mind (because I can't think of many other places for the oil to come from!), so it's something that I'll bee trying to check.

I'll let you know how I get on.

Ian
 
Yours is the same model year as mine, is there anything i can easily check for you? I could snap a few pics if weather allows tomorrow? :nenau
 
Thanks Alex but I think all the bits that I need to look at are well hidden away and a fair few bits need to come off to get to look at them.

Until I get back home all I can really do is go buy me a 1/2" drive breaker bar, some oil, some tubing and a big syringe so I can easily keep it topped up until the box can removed again.

I really like this truck but it sure knows how to wind me up.
 
Well I finally got to the bottom of the oil leak - turns out that the new gearbox had an extra small threaded hole for a sensor/bracket or something else that my original box didn't have so there was nothing to screw into it when all the parts were transferred over.

My mechanic either didn't see it at all or must have assumed it was a blind hole?

Anyway another trip to the mechanic and a small plug later and all is fixed and my mechanic held his hands up to it so no charge :thumb2

I love a happy ending.

Ian.
 
awesome result, top marks to your mechanic too:thumbs

Well I finally got to the bottom of the oil leak - turns out that the new gearbox had an extra small threaded hole for a sensor/bracket or something else that my original box didn't have so there was nothing to screw into it when all the parts were transferred over.

My mechanic either didn't see it at all or must have assumed it was a blind hole?

Anyway another trip to the mechanic and a small plug later and all is fixed and my mechanic held his hands up to it so no charge :thumb2

I love a happy ending.

Ian.
 
...Anyway another trip to the mechanic and a small plug later and all is fixed and my mechanic held his hands up to it so no charge :thumb2
I love a happy ending.
Ian.

Oils well that ends well..:lol
:doh
Sounds like he is a good mechanic, and very fair.
Who would have expected that :nenau

If he is an expert in removing gearboxes, plenty of experience now lol... how is he with replacing clutches ?
I would be nice to have a contact in our area for future reference.
Whereabouts is he?

best regards,

Richard
 
He put the clutch in mine at the same time and works from a large garage beside his house in a small village called Hanbury, near Burton upon Trent.

He's always been fair with me. I should declare that our daughters go to Scouts together but I think he's a genuinely fair man.

The only thing I would say is that he is always very busy and it's not always easy to pin him down to a date/time for either dropping the car off or him finishing the work! For that reason, for some jobs I often use T Turner Autos in Lichfield who I have also found to be very fair.
 
Fair play. I know a garage or two that would have quoted you for a new gearbox instead :augie

nice bloke, you should stick him in the sticky section here for trusted mechanics :thumb2
 
Fair play. I know a garage or two that would have quoted you for a new gearbox instead :augie

nice bloke, you should stick him in the sticky section here for trusted mechanics :thumb2

It was a recon box :lol
 

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