are the gearboxes different?

[zonger]

hi guys,
 i was wondering if there is a difference in gearboxes between the standard 1.8, the 8v and the 16v?

cheers

[Agreeable Slick]

different ratios, different splines onto the clutch. In that respect yes. Mounting no.

The ratios on a 8v are shorter through the first 4 gears mainly then the 5th is longer to allow it to cruise at motorway speeds.

The spline to the clutch on an 8v is also 21splines, where as a 16v is 24 splines. 

[zonger]

cheers m8, thats cleared up alot.
i was doing routine enginebay cleaning when i noticed an oil leak from the gearbox, after taking the drive shafts off i realised that the diff was actually F*&^ed.
oh well ill have to search for an 8v gearbox....

thanx guys

[Agreeable Slick]

thats what happened to my old valver box, was working on it trying to change the belts on it. Never did get them done as i got the wrong belt. However the diff on mine was shafted, this was after i took the drive shafts off and replaced the seals. I have now changed the box over to an 8v one and bought a 8v clutch to go with it. Took us all afternoon to change it all over and the linkages back on again, but was a worthwhile mod imo. All i used on the change over of the clutch was the friction plate as the mounting for the pressure plate and the flywheel are still the same. If possible you could also do what i did and sourced a lightened and balanced flywheel. Fitted that it has improved the power delivery 10 fold.

It's very straight forward but just time consuming. ESPECIALLY IF YOU HAVE POWER STEERING 

[rubjonny]

It also depends on the gearbox codes, the later 8v GTI box is actually identical to the 16v box in gears 1-4 with a longer 5th for better motorway cruising.  Fitting an 8v box on a 16v is a popular mod to reduce the ammount of bleeding from the ears when driving long distances down the motorway

As a side note, the early MK3 GTI rod change box is identical to a MK2 16v box

[monzablue16v]

So on an 8v box on a 16v it would be 16v clutch pressure plate and 8v clutch disc? with 16v flywheel? is that right? better cruising on motorways but not so long through the first 4?

[rubjonny]

yep, but you can use either an 8v or 16v fly, they are the same

[monzablue16v]

Thanks RJ ,
Oh and when you buy a clutch kit do you get the pressure plate in the kit? mine needs renewing.

[rubjonny]

As a bare minimum you'll get a friction disc & pressure plate. Some kits also include 6 new pressure plate bolts (you should always renew these), special clutch spline grease, release plate etc.