Exploding Gearbox

[biz]

Has anyone else experienced exploding gearboxes.
First gear decided to launch itself through the gearbox casing, is this a common problem and is there anything that can be done to prevent this happening in the new box?
Cheers
Biz
PS - The car had done 100k

[black_vr6]

yes mate.that happened to me too.My car was a 1990 16valver and when i was passing a guy on the motorway i heard a clunk and a lot of smoke and oil mist appeared in the rear view mirror.in my case it was the something in the diff housing,the mechanic discovered that rivets on a gearwheel had got shorn off and basically put holes into the clutch housing area and gearbox making a hell of a mess.when i tried to get another gearbox i was told that this was a weak point in 16valvers and i couldn,t find one anywhere as all second hand ones had already been snatched up by other unfortunate owners.i had considered putting an 8valve gearbox into my car but was advised not to as it wouldn,t stick the pressure of the i6 valve grunt.I opted to get the gearbox i had fixed and reconditioned and it worked a treat after that and did wasn,t overly expensive either.

[biz]

Glad I'm not the only one!!
May look at getting box reconditioned if it's not too much, never know what you are getting with a second hand box or engine.
Cheers
Biz

[ajh]

Hi,

I've got a gearbox for sale out of a 1986 D reg 8v... It's done 123k miles, and is in good condition.

You can have it for ?60 if you like? And, I can get it delivered to you if need be (for extra of course)?

ajh

[modulater]

My Gearbox on my '91 16V suffered from the dreaded rivets breaking on the diff, Mine made itself known by dropping oil everywhere then after about a year of this and topping it up it finally gave up and the bellhousing gave way, The rivets breaking off on the 020 boxes is a well known problem and VW sell a bolt kit to fix it.

[richandhazel]

Just been reading back through some posts about sheared diff rivets. Father in laws has just chucked a couple of rivets through the side of his gearbox..........he didn't realise what had happened and carried on driving it with no oil.............

modulator, you mention a 'bolt kit' to fix it. Obviously its too late for this box but I have another 2 in bits at the moment and think, having seen this one, it would be prudent to mod these 2 boxes. Any idea on the part number etc.?
Steve (mk1) I think you've mentioned it too..........can you shed any light? Anyone else?
TIA.

[Dragon6]

Same prob happened on my 16v,the problem started out by car not going into reverse,removed and stripped the box,was lucky as one of the rivet heads had sheared but luckily missed everything and lodged itself onto the magnet in the box,cant remember the part no though sorry RichandHazel but the kit cost me ?37.40+VAT.. from VAG the rivets are easy enough to remove just grind off the head and punch out with a 10mm punch,the reason box wouldnt go into reverse was another prob though,just replaced all bearings gaskets etc,2 litres on synthetic oil and she`s as good as new..You could replace the rivets with high tensile bolts but you only have about 3-4mm of clearance on one side of the diff/casing...so you would need to get the bolt heads machined down to clear..

[richandhazel]

Cheers oakie..........I'll have a look in my ETKA later and see if that mentions anything. Sound like it would be well worth doing whilst I have the box apart.
Did the pre 020 (Mk1) boxes suffer the same problem?

[Dragon6]

I couldn`t honestly say but if the diff is riveted to the crown wheel then I suppose it could cause a problem,but as far as I know  16v boxes are prone to major failure in this department..there was also an issue with this box where the pin can fly out of the diff
(the pin that holds the bevel gears in place) The fact that a lot of the power in the 16v is higher up in the rev range and they tend to get worked hard by moving up and down the box a lot is prob what helps them on their way but to last 12years it hasnt done bad.Was pleased I got mine sorted with peace of mind,as originally I thought it was shot and didnt strip till I got a second hand one from volks-apart for ?280 that was nothing more than scrap I didnt even take it off the pallet that was severley shafted in the above department......

[Lee]

Would a mk3 16v box fit because it has the stronger rivets fitted from the factory. The reason for this is because vw know the mk2 16v had weak diff rivets. I have read this in a book somewhere, i cant remember what book though.