question Jeep Gearbox, some help and advice please

[w896andy]

A friend of mine has just bought a Jeep, without boring you all with the details, this supposedly professionally rebuilt Jeep, isn't !! The net result is apart from various other things which we can help him sort the gearbox jumps out of second on over-run badly, I know its not unusual but this one is extreme and it leaks a lot of oil, again I know they are not perfect but this leaves an oil patch the size of a top hat over night, its also nowhere near as smooth changing as mine.

 

Getting the box out is not a problem but can anybody please suggest somewhere to either get this box re-built or a replacement box supplied. My friend is new to MV's so it would be good if I could try and help him out with a sensible solution. We are based in Somerset.

 

Thanks

 

Andy

[Willyslancs]

when it stops leaking its out of oil:nut:mine use to leave a patch the size of a small cravat, (prefer your tophat measurement tho )hope it gets sorted..........:thumbsup:

[Rick W]

The gearbox is extremely simple to rebuild, there is an idiot guide on the g503 forum, complete with photos and step by step guide, I've got to do mine over the next few weeks.

[arcot1751]

I believe either Jeffrey Engineering or Rex Ward (both have websites) will be able to help you, both highly respected in the military vehicle scene. Good luck. :-)

[Pete Ashby]

I believe either Jeffrey Engineering or Rex Ward (both have websites) will be able to help you, both highly respected in the military vehicle scene. Good luck. :-)

 

Agreed, either will do you a very good job.

As Rick points out the box is very simple and all parts are available to completely rebuild both the gearbox and transfer box. If you are loosing that much oil it's a fair bet that you will need to at least change the seals in the transfer box as well. Jumping out of second is as you note a common problem when the box gets worn it can be caused by any one or a combination of issues with the syncro hub, lay shaft thrust washers, input and output main bearings or excessive ware in the gear sets themselves, or of course the fact that it was never rebuilt properly the last time it was done.

The series of articles on the gearbox are well written on the G503, it's pegged to the top of the GPW/MB technical forum so you will be able to find it easily. If you do decide to do it your self use the truck manual and measure all shafts and thrust washers against the factory specs and replace if out of tolerance. It really is a waste of time and money putting worn kit back into a engine or drive train when you've got it stripped as the cost of new parts are both reasonable and available for MB's and GPW's.

 

Also don't forget there is a large pool of knowledge and experience on the Forum here at HMV so use the search engine and never be afraid to ask.

 

Good luck

 

Regards

 

Pete

Edited September 3, 2013 by Pete Ashby

[sharky]

we're based in frome somerset and would be able to do the work on your friends gearbox.

iain

whitestar historic militaria

[Wolfy]

The best tutorial for rebuilding the gearbox is on youtube, the guy does each section in short easy to follow stages.

 

Now....having said that I made two common mistakes -

 

1) On the end of the shift rail there should be a thimble cup that stops the oil leaking into the bellhousing and its often overlooked. I bought mine 2 years before and forgot to fit it. Dallas do a mod that keeps it held in place.

 

2) To stop oil leaking into the handbrake you can I'm told use a sealant behind the rear gear of the gearbox, I didnt do this either.

 

So my box will be dropped in the coimng months to do theres, frustrating but a necessity.

[w896andy]

Guys

 

Thanks for your advice so far, I'm feeding back to my friend as we go.

 

Andy

[Nickmow]

Bit late on the reply but I rebuilt mine, followed similar advice as given above, plenty articles and pictures. My first big mechanical project. It's not that hard and quite satisfying to have done.