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Dropping the gearbox/rear diff
Posted: 16 Jan 2012, 18:20
by pirata
Hi all,
I need to drop the gearbox/rear diff of my Syncro...only problem is I've never done such a thing before. My mate is very good with cars and is coming over to give me a hand, but as Syncros are quite unique and we are first timers on this sort of job any help will be much appreciated. I need to buy some tools for the job, so any advice on this will be welcome also - what tools will I need and so on.
Do I need axle stands or car ramps will do? How high should we lift the van, as much as possible or a minimum hight will do? Long reach hydraulic jacks are very expensive, will we be ok using a high lift farm jack? Do I still need a hydraulic jack to lower the box - I'm presuming it's heavy? What seals/gaskets will I need to replace and where can I get them from?
I have both the Bentley and Haynes manuals, but I can't seem to find any step by step on how to tackle this job....does anyone know if there's a thread on this forum I can use as a sort of step by step guide? I've searched, but haven't found anything...or if anyone is willing to write up a mini wiki on how to approach this task, that'd be brilliant too!
I talked to Aidan and he's pretty busy until March, but offered his help for diagnosing what might be wrong with the box - top bloke - but I need to take it down first of course..
I appreciate this might be a big task for first timers, but cannot really afford to have the van towed and pay a garage to do the job.
All help appreciated!
Rob
Re: Dropping the gearbox/rear diff
Posted: 16 Jan 2012, 19:55
by Aidan
6 tonne axle stands, 2 tonne jack, high lift, read the wiki, it's all in the Bentley just substitute for the ramp and vw gearbox clamp
Re: Dropping the gearbox/rear diff
Posted: 16 Jan 2012, 21:13
by PetenAli
Check out this thread from Rollercoaster
https://club8090.co.uk/forum/viewtopic.p ... 7&start=15" onclick="window.open(this.href);return false;
Its about getting a box back in but it has some useful info - particularly his "trolley dolly"

Re: Dropping the gearbox/rear diff
Posted: 16 Jan 2012, 21:52
by Hacksawbob
https://club8090.co.uk/wiki/Ge ... oval_clamp
I use a farm jack with a land rover adapter it just about works, but I have had it scratch the side of the van if there is some m9ovement sideways on the way down. Jack the van in two stages halfway on each side, then repea to get it to full height. The higher the better so long as your gearbox removal jack is high enough. Also support the bell housing end of the engine with a chunky bit of wood across the engine bay and a ratchet strap. Yo can do it alone but a second pair of hands is recomended esp when refitting.
Re: Dropping the gearbox/rear diff
Posted: 17 Jan 2012, 16:42
by pirata
Wow guys, thanks so much for the info...I did look in the wiki and the forum search, but I must have got lost cause I didn't find any of the links you guys posted...getting lost on the web, not bad for a professional web designer, uh? There's a Spanish saying that goes "en casa del herrero, cuchillo de palo"...which loosely translates as "ironworker using a wooden knife"...
My friend arrives tomorrow night and with this info plus the Bentley I'm sure we'll have a good start. I got a portable car park today so that we can have a nice working area protected from the elements - rain this week for London I believe...
That trolley/dolly looks the business btw
I'm sure we'll hit dead ends, so I'll be back for more of your expertise...thanks a lot!

Re: Dropping the gearbox/rear diff
Posted: 18 Jan 2012, 15:17
by Woody49
I have just finished this task on a non synchro but I guess you only have a few more bolts to undo.
As this was my first time I read up all the advice and made up an Aidan board to hold the box - it is pretty heavy so don't try anything clever. My Aidan board fell to bits cause I used rubbish threaded rod from B&Q.
My trolley jack didn't give much lift ( a 90 quid halfords job) but I managed to get the axle stands in place and had sufficient room to crawl about.
Mine is a petrol engine and I got stuck trying to separate the box from the engine. There was a bolt holding a support plate in the middle of the rear exhaust cross over pipe it bolts to the engine at the join and was almost impossible to see with all the muck about but it did a great job of holding the two together.
The half shafts came of pretty easily though remember to rotate the wheel to present the bolt in as open a position as you can then reapply the handbrake ( I didn't twig this till late on). Clean off the bolts as much as you can and make sure you know what to use to remove them - two types 12 point or Allen key types.
All the other nuts and bolts came off pretty much as per Haynes.
I also knackered a couple of the bolts that hold the gearbox support bracket to the tub (there is a separate thread on this) I haven't fixed this yet.
Good luck
Re: Dropping the gearbox/rear diff
Posted: 18 Jan 2012, 16:17
by dash
It's not all that complicated, as long as there's two of you, as pretty much all of the steps are infinitely easier if there's someone under the van and someone 'up top'. Take getting the driveshafts off for example, how long would it take to crawl out from underneath, walk to the cab, let the brake off, rotate the wheel, reapply the brake, crawl back underneath, take a couple of bolts out, repeat.
We had the van as high as it would go on my (cheap Halfords) axle stands. Trolley jack under the gearbox (so you can roll it forwards/back), bottle jack under the engine.
Did have an amusing moment trying to refit the box where it wouldn't push fully home onto the engine. Couldn't figure out why until I noticed that it was actually being stopped by the trolley jack hitting the blocks of wood the bottle jack was stood on

.
Re: Dropping the gearbox/rear diff
Posted: 20 Jan 2012, 14:14
by pirata
Thank you all for your input, much, much appreciated...I'll upload some pics later today or tomorrow so that you can have a look at how we're doing...
One question for you all, what size are the 12 point screws that bolt on the half shafts? I need to order the bit, but not sure I'm measuring it right...is it 10mm?
Re: Dropping the gearbox/rear diff
Posted: 20 Jan 2012, 15:15
by PetenAli
pirata wrote:Thank you all for your input, much, much appreciated...I'll upload some pics later today or tomorrow so that you can have a look at how we're doing...
One question for you all, what size are the 12 point screws that bolt on the half shafts? I need to order the bit, but not sure I'm measuring it right...is it 10mm?
Check this out:
http://www.brickwerks.co.uk/shop?page=s ... ory_id=174" onclick="window.open(this.href);return false;
Should sort you out and not break the bank. All good stuff if it comes from BW

Yours is 14"? If not the next page has bolts for 16" I think.
Don't forget to torque them up correctly. Worse thing is if they come loose and shear - usually as you are just accelerating off a roundabout!!

Re: Dropping the gearbox/rear diff
Posted: 21 Jan 2012, 20:40
by pirata
PetenAli wrote:pirata wrote:Thank you all for your input, much, much appreciated...I'll upload some pics later today or tomorrow so that you can have a look at how we're doing...
One question for you all, what size are the 12 point screws that bolt on the half shafts? I need to order the bit, but not sure I'm measuring it right...is it 10mm?
Check this out:
http://www.brickwerks.co.uk/shop?page=s ... ory_id=174" onclick="window.open(this.href);return false;
Should sort you out and not break the bank. All good stuff if it comes from BW

Yours is 14"? If not the next page has bolts for 16" I think.
Don't forget to torque them up correctly. Worse thing is if they come loose and shear - usually as you are just accelerating off a roundabout!!

Ace! Thanks a lot...mine's a 16''...we're still waiting for a couple of bits and bobs to get started...hopefully everything will be delivered on Monday or Tuesday the latest and we can get on with it as soon as...
Re: Dropping the gearbox/rear diff
Posted: 25 Jan 2012, 23:46
by pirata
We've managed to drop the gearbox today...a bit of a struggle with one of the cv joints, it was a little stuck, and the jack which didn't reach high enough for a comfortable manoeuvre.
Anyways, I'll be changing the slave clutch cylinder because it's quite rusty and I've had bubbles in the system a couple of times too often lately, I'd also like to renew all cv joint bolts and some of the other bolts - like the stud bolts that fix the gearbox to the engine on the lower side of it, where can I get them?
Also, we believe the problem with the box has to do with the 1st/2nd gear synchronizer, can anybody tell me where can I get this? I'll be taking the gearbox to Western Transmission in Plumstead, SE London. I'd like to make sure I know where to get the spares as I think this will be a first syncro box for them. Also, would somebody tell me what elements are worth replacing when opening the box and where to get them? I'll need new oil, but I think there's something in the wiki regarding gearbox oil.
Just in case you're wondering, here's a description of what it feels like to drive the van with the gearbox in its current state:
Reverse and crawling gears work fine. All remaining gears engage fine with the engine idling. First and second gears make the van vibrate quite a lot and you have to slip the clutch to avoid stalling the engine, but once you're on your way (say in first) the engine tends to stall nonetheless...leading us to believe it's the synchronizer for 1st/2nd gears. When the van was running fine, second gear was sometimes difficult to engage, however. Is it worth renewing 3rd/4th synchronizer too? Are both synchronizers interchangeable?
Many thanks all for your help so far, hopefully we'll get this van on the move shortly.
Cheers!
E D I T: I forgot to mention, is it worth fitting the SA oiling plates at this time?
Re: Dropping the gearbox/rear diff
Posted: 26 Jan 2012, 06:44
by Aidan
I can obviously supply anything that is required but I can't advise you what is wrong with your box over the web as I'm not psychic, be prepared for a big bill is all I can advise

Re: Dropping the gearbox/rear diff
Posted: 26 Jan 2012, 07:13
by pirata
Aidan wrote:I can obviously supply anything that is required but I can't advise you what is wrong with your box over the web as I'm not psychic, be prepared for a big bill is all I can advise

Thanks Aidan, I'm going to take the box down to them this morning so it can be opened and diagnosed...I'd rather you did the job, but cannot wait until march...how much are we talking per synchronizer if that was the case? I'll send you a pm with my shopping list as soon as I can...
Re: Dropping the gearbox/rear diff
Posted: 26 Jan 2012, 13:20
by Hacksawbob
I have had an experience of having a syncro box re-conned by someone who thought he knew what he was doing, a year and constant oil leaks later it was back out and off to Aidan to get it done proper. Can you really not wait a month? Or fit a known good 2wd box in the meantime (I think a 5sp will go in)
Re: Dropping the gearbox/rear diff
Posted: 30 Jan 2012, 09:34
by pirata
Hacksawbob wrote:Can you really not wait a month?
I'd need to get personal to answer that question, but trust me, if I could...I would...
I'm going to take the opportunity to have the SA oiling plates installed, does anybody know of a machine shop in SE London that can be trusted for the job?