Different opinions on T4 syncro gearbox - what's the truth?

[Racemag]

I've been told two different things about the T4 syncro gearboxes.
The first thing is that they are totally different to the standard T2 FWD box.
The second thing is that they are the same as the FWD box but with a bolt on transfer case, so you can bolt this transfer case onto the FWD box to make a syncro box.
I've searched the WWW to little avail to find out if the latter is true. My interest is that I want to find out the options for a gearbox replacement if the worst should happen.

[jets]

What is a T2 FWD box?

[Racemag]

Sorry T4 FWD box, which I believe was 02B and the Syncro was a 02D

[supclean]

Hello mate They are almost the same The O2D has a slightly modified case to accept the transfer case and also to flow oil to and from the transfer The diff also has a modification to send drive to the transfer Aside from that and slightly different gear ratios for the syncro they are essentially the same gearbox
Not sure what you are trying to do but fitting an O2D to a FWD only car you will need to upgrade the sump
The transfer also has a rear support bracket which attaches to the block Worth checking to see if it has the mounting holes

[Racemag]

I have a T4 dual cab syncro and would like to put a bit more power through the gearbox. I've been told (by Dande Volks) that they are a bit fragile in a bearing, particularly when people try to use 5th gear to slug their way up a hill. So I'm just concerned about how to replace the box if it goes bad. There are plenty of FWD T4's in a local pick a part wrecker, but not many Syncro's.

[Seano]

If you kill the box internals then you'll be fine in terms of parts. However, if you wreck the case in the process then you'll be in trouble.

Bear in mind that you're also expecting the VC and rear diff to cope with the extra torque.

Mind you I reckon if you are staying within a 10 to 15% increase then you'll probably be fine...margins for error being what they are.

[Racemag]

I hope so, but I'd be looking for a 20% increase in torque to make the effort worthwhile. Most fo the time it is not required, but on some occasions another 50nm would be handy on a hill just to be able to accelerate past a truck etc.

[Seano]

The thing to bear in mind is that your petrol engine never produced the torque that the diesels did - mine knocked out 250 torques when it was new. Even the 5 cylinder petrol engines only managed 200 torques tops and the four cylinder engines 160 torques. I reckon you'll be fine.

[Racemag]

Thanks.

[MadMentalist]

I had an interesting chat with a mechanic the last time I was back in the UK, he had done his apprenticeship with VW and spent a good 20 years working on them, so I'd say fairly reliable information... He told me that the T4 Syncro boxes are good for about 200bhp and only really get reliability issues over that. Taking into account the most powerful engine made for the T4 was the 149bhp TDi engine with 295Nm of torquey goodness and was also available in Syncro version on the Multivan, your looking pretty safe.
I've done a little research into this as I own 2 syncro's, a 2.5 petrol here and a 2.4d in the UK. My final conclusion was although the diesel really needs more power(a massive 77bhp), the 2.5 petrol is pretty good and until the engine dies (I'm sure it never will!) there is little point in upgrading.
As far as the boxes and differences go, supclean is 100% right

[jets]

I've searched the WWW to little avail to find out if the latter is true.

While searching did you come across this thread?
syncro gear box and 2wd box the same - VW T4 Forum - VW T5 Forum

Not sure if you are aware that a stronger gearbox [02G] was introduced at the time of the 2.5TDI around 1996 in Europe & 2000 in OZ.
Some in the UK say it's an Iveco box. This is the box that's fitted to my Syncro & looks different to the VW box, even the drain & filler plugs are different to the VW produced bevel box. So when a mechanic says they are good for 200hp, the question needs to be asked, which gearbox?

[MadMentalist]

A fair point Jets, at the time I was discussing my 1997 UK one with the mechanic, can't say I have compared that with the one out here (another '97 van) but I'd say they were both 02D boxes, there would be little point putting the 02G onto the AAB or AET engine!
I suppose there is the possibility the mechanic was thinking of the 02G box when advising up to 200bhp?!?

I'm pretty damn sure I wont be able to get 200bhp out of my AET anyhows so, Life is good in the slow lane