Gearbox leaking into Tranny box

I has one for sale and can post

I can lend you something that'll do the job Al but would be more scaffoldy and chains more than crane. If you pick the right weekend and the sun comes out I'll give you a hand!

Thanks dr evil but all my cash is gone
Glyn that would be awesome, it would probably be some time in May/June? ill give you a shout nearer the time, cheers
More beers eh!

I have finally got myself sorted to put my replacement g.box and OD into my S3. Picking up my crane on monday then the missus is going away with the baby:baby: for a few days so have taken a couple of days off work to complete the job.

I have a new clutch kit ready to go, 2 new UJs and a box of various stainless bolts.

As this is a one time shot at doing it all in those 2 days and my first ever g.box change, is there anything else I might need in terms of random tools, parts etc...? What might break if persuaded too hard?:Cry:

Cheers muchly for any advice. I'm taking some photos as I go so if its of any interest to people on here, I'll post them up in order to show the process.

PS. I have waterproofs on standby

I'd get some new bellhousing bolts and make sure you have a long enough socket to reach the top bolt or allen bolt depending if they were replaced before!

And an old input shaft to use for clutch alignment makes life **** easy

Couple things you want to do in my opinion.

1. The leaking from the gbox to transfer can be dramatically lessened by venting both units properly. Drilling removable covers and tapping for hose barbs, then running vent tubes up the firewall to J-bends will keep the units from pressurizing - and keep the oil where it belongs.

2. Get 4 long bolts the proper thread for the flywheel bellhousing studs, cut off the ends and point them. Insert these in place of 4 of the studs while you have the tranny out - it makes it a doddle to get the damn thing back in properly when you can line up square and then engage the clutch splines and the pilot bushing.

3. Buy or borrow a pilot shaft for the clutch plate to flywheel alignment. Plastic ones can be had for a few quid at the local auto parts shop, or if you are lathe-enabled make one - it's a 10-minute job. A bit of time spent getting that properly aliigned will pay off big.

need to do this job myself - just got a shipment of parts in from the UK for a tranny rebuild - the layshaft on ym IIA is trying to jump out of the box on overrun and I decided to just build up a replacement and save trying to strip/fix/reinstall.

ajr

Cheers both, will prep myself accordingly

I just pulled the rear prop shaft but forgot to mark where it lined up on diff and handbrake!
am i screwed here or does it not make any diff? (sorry )
hope i havent buggered up this already!

it doesnt need marking at all its only if you seperate prop at its slide that you ensure its aligned properly when put back

Phew thanks James

[FONT=&quot]Had a day off today and with my family being away for a couple of days it was a good chance to try and nail this gearbox swap. Here are a few photos and by the way, it has been both enjoyable and soul destroying so far.......
Its my first go so if anyone spots any massive errors, abuse welcomed. Its not really a 'how to' but maybe a 'not not to':-

Removed floors, luckily someone in the past had done this recently so all bolts were reasonably decent.




Pull of the seats to access the seat box bolts. The little ones to the bulkhead are fiddly, mmmm.

You can leave the handbrake in at this point as it lifts over the handle.

These bulkhead bolts are fiddly too, you can leave the seatbelt anchor on and get access to the bolts from the rear near the rear tire.

Have someone to look after your children while you do this.

Unbolt this thing.....

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[FONT=&quot][FONT=&quot]As your under the car, whip off the prop nuts at the front and rear trans brake. I pulled the whole rear prop off to replace a UJ (another painful experience... )

Get your wife to help you remove the seatbox whilst the baby is in bed. Explain that it wont be there for long.

Using new found access, unbolting the trans brake to prop nuts can be a bit easier. I think it was 9/16 all around.

Undo the speedo cable and put it somewhere where it will be in your way for the next few hours until you get pi$$ed off and bungee it out of the way.

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[FONT=&quot]This is the handbrake mecahnism. Do yourself a favour and unbolt this bit from the chassis as well as undoing the clevis pin and split pin. It unscrews and is a bit awkward. As with everything, flood it in WD40. I did this to all nuts/bolts/stuff 2 days before I did anything and right before I started. It works wonders. Leave the handbrake lever in place if you like.

Gbox mounts. Unbolt these. and leave the gbox rest on the mounts.

Unbolt this earth strap on the bellhousing and stow out of the way.

Here is a closeup of the handbrake clevis pin bit.


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To avoid removing the exhaust and handbrake lever I undid these bolts holding the mounts to the gbox. Undo them so the mounts will flap about when you lift the box. That way you can just whip them off once you have slid the box back off the clutch.



Jack up the engine and box now and chock a thick bit of wood in. I didn't put a very thick piece in and ended up spending 4 hours wondering why the new gbox wouldnt fit! Basically, it was fouling on the crossmember under the bellhousing. Do yourself a huge favour and get it as high as you can to avoid grounding it all out.



Bungee the front prop out of the way.



I removed the clutch slave then and bungeed her out of the way. Got the crane in then and roped up the gbox.



Boring this isn't it? The bits I skipped were the tranny tunnel being removed and next time I would remove the steering wheel and passenger door maybe (if it would be 100% guaranteed to go back on properly). I'll post more tomorrow.

A normal seat box will not I believe lift off without removing handbrake yours has had a piece cut out. Has it been plated for the cutout?

Blackburn said:

A normal seat box will not I believe lift off without removing handbrake yours has had a piece cut out. Has it been plated for the cutout?

Click to expand...

Interesting, yes mine had a bit cut out of it. It has a rubber boot on a bit of plastic (or maybe metal?) that then screws over the top of that to brace it effectively. Wasn't aware that was non-standard.

I've made some pretty stupid mistakes on this gearbox swap so I'll try and document those here.

I pulled the old box out, this was a one man job and I found that bit quite easy with the crane.


This was the replacement box. I swopped the trans brake, gear lever and clutch fork over. I installed a new clutch kit with new plates and bearing, just to be sure.


There was a lot of oil on the box, it was hard to tell but some was gear oil and some was engine oil. The inside of the bell housing had what smelt like engine oil (carbon/burnt oil smell not cat pee) so I may have a leaking rear crank oil seal possibly? I hope not as I have a 3MB 2.25 and it looks like a nasty job to swop them out.


I think my sump gasket has gone too


Here is the new box in. Like I said it took a while thanks to us not jacking the engine up high enough before removing the old box.



Its hard to see from here but the box has ended up a few cm off straight. I only noticed when I put the tranny tunnel back. I was in a real panic at this point as I thought I had really f**ked this job up. What I can gather from those on the forum who know far more than I ever will, is that I have probably put the gearbox mounts on the wrong sides. These bits on the gearbox I didn't touch, but the rubber mounts and brackets I did move.



I didn't realise they were L and R sided

So I need to try and switch them over this weekend.

To compound this the gearbox wouldnt go into 3rd or 4th for love nor money. Again thanks to knowledgeable types (James Martin) I think it was just due to the box being laid up for a while as now its had the engine running for a little while and I have driven round the block a few times, it goes in fine.
The downchange from 3rd to 2nd is crunchy as well which is gutting. Its an all synchro box but I wonder if that means the synchro is knackered on 2nd? So its not been a bed of roses.......:crutch:
I'll go hide under a stone now.

Surely the gearbox mounting brackets can only go on one way or the holes for the rubbers would be totally in wrong place?

It wasnt obvious to me as i was in a rush, always a recipe for error. it fits as is but one side is pushed over a few cm so it was quite easy to get the bolts in still. Im going to remove them later so this will reveal all.

Blackburn said:

Surely the gearbox mounting brackets can only go on one way or the holes for the rubbers would be totally in wrong place?

Click to expand...

the rubbers are the same on either side its just how the crush under pressure and over the years

Just out of interest for any body doing a rebuild to cure oil migration, the mainshaft bearing housing is very often free to turn in the gearbox case and oil can migrate through there.
I used too loctite the housing in the case.

Thanks owl, im going to rebuild the old box i hope at some point, although it may just be seals and a clean!
I switched the gearbox mounts and replaced the rubbers, it now sits straight again, phew.

You can see how out it was here.



Mounts to show difference (ok ok it is quite obvious now!)



The box drives better now its had a chance to oil up plus its easier to shift when its straight : )