[Vwpickups] gearbox woes

Fri Jul 2 21:03:14 CDT 2010

I agree with Eric, swapping in a known good gearbox will be easiest by far.

Swapping the trans out is not difficult, someone with reasonable mechanical skill could do it in a weekend.

You might not need a new clutch, if yours isn't worn or oil soaked its probably OK.  But its quite inexpensive to replace now that you will have it apart, almost a given that you replace at least the disc.  If you can see that the clutch disc was recently replaced, and didn't get oiled, its probably OK. If other things like seals and springs don't fail, a reasonably driven clutch should last 300,000 miles.  Replacing the clutch would be your decision. 

Once you get the trans on the floor, you can decide whether its cheaper/better to have yours fixed or get a replacement.  VW transmissions can be finnicky to disassemble, replace parts, and re-assemble correctly.  Lots of people claim to be able to do it, but many of those just don't get it right.  If its not perfect, it will still work, but the shifting won't be right.  Nobody does VW transmissions better than the factory, and those that do them equally well are rare.  To pay someone to re-gasket and re-work your transmission will probably be more expensive than a used replacement.

If you do get a replacement transmission, be sure to put in a new clutch pushrod bushing and seal.  They take 2 minutes to put in when the transmission is on the floor, and a day to make right when your clutch gets fouled with tranny lube.  

The axle flange seals are probably something you could leave alone if not leaking, they aren't too hard to do later.  If axle flange seals on a used transmission are leaking, that could indicate that the transmission was run low on oil, and it could indicate that the differential-final-drive bearings might be getting to the service limit in terms of allowable movement.

When hunting for replacement, find out what trans code you have, and determine if you want the same code/ratios or something different.  First step is to find out your existing transmission code.  Then if you think you could benefit from a ratio change, higher-numbered gearing gives you more brisk acceleration, lower numbered gearing gives you lower revs at highway speed and more relaxed cruising, and probably a bit better fuel economy.  Roger Browns 4-crawler site has some good VW tranny info.

Remember to fill the tranny to the level plug, and then add 700ml of oil thru the speedo drive hole.  VW found that 020 transmissions are less prone to 5th gear failure with the oil level slightly higher.  Sometime during the A2 years VW changed the casting, moving the oil plug up about 1/2 inch.  Transmissions built after that are filled only to the plug.  I can find the Bentley page covering that oil level update if you want it.

Good luck, let us know what you decide, and of course, ask more questions if you need.

Mathew Banack
81 LX diesel
98 Beetle tdi
03 Jetta tdi

----------------------------------------
> Date: Thu, 1 Jul 2010 14:02:06 +0100
> From: scott.miller at durham.ac.uk
> To: vwpickups at neubayern.net
> Subject: [Vwpickups] gearbox woes
>
> My pickup has dumped a load of oil out the gearbox. I have degreased and
> pressure washed the whole engine bay, and I can see that the gasket
> between the bell-housing and the rest of the gearbox seems to have
> failed. (It is the big gasket that goes around the differential, and the
> bigger of the two papery gaskets. I'm struggling to find its Proper
> Name, as I'm sure it will have one). The leak has gone from a minor seep
> to a major leak very quickly. I can see the oil coming out and dripping
> down. I have thoroughly inspected the outer casing and I cannot see any
> damage, so I don't think it is a case of the self-machining differential
> problem from VW's cheapskate rivets.
>
> I haven't got the time or the facilities to drop the gearbox and replace
> the gasket. I've also not done it before so I'd be at the bottom of the
> learning curve, so I will have to take it to a repair centre. I am
> getting some quotes from clutch fitting centres, as I will get a new
> clutch at the same time.
>
> OK, I know this is a FAQ, but silly me, I have never retained the
> information...
>
> What are all the 'extras' that should be done at the same time.
> Obviously I will need a new clutch and gearbox gasket/seals. Apart from
> seals on the gearbox itself, what others are essential to replace, and
> what other bits and pieces that should be done while everything is
> apart? I'd like to be able to ensure that the mechanics replace all the
> bits necessary so it doesn't have to come apart again in the near
> future.
>
> Regards,
> Scott
>
>
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