gearbox rebuild?

[nick sparrow]

Hi all, are there any parts out there such as seals, gasket sets, bearings?.to rebuild a type 4, 4 speed gearbox, or are there parts that can be used from other Vw's
I would like to undertake a rebuild as I have a few spare gearboxes now, and would really like a nice one to use in the car. The current box has seen much better days.

nick sparrow

[ray greenwood]

In a word...No. But, There is a lot that can be done..especially if you have a few gearboxes at your disposal. I have rebuilt numerous type 4 gearboxes. They are the best geared trannies VW ever built in my opinion. Heres the basics. There are 3 basic types. The very early with the 19mm slave cylinder...which should be avoided because they were slightly different...and by now...quite old ...and very few in #. 4 speeds were rare on this continent. Do not get rid of anything! At one point there was a differnt synchro set up on 2nd to 3rd. Thats okay...just be aware. There were two flaws in this transaxle design. All of the trannys suffer from it...and you better fix them...or they will destroy themselves. They only show up in very high miles...but they are there. But first...Parts. There are differntial bearings available..easily. Side and pinion shaft bearings are no problem. Contact me and I will tell you how to make the two tools you will absolutely need to service the differential. Do not start without them. 15 minutes of welding and 5 bucks worth of scrap metal will make the tools so don't be scared. Since the type 3 and 4 auto use the same design of differential as the type 4 , 4-speed, ring and pinion...which is very different from the type 1-3 differntials, the only adjusting specs that are even close, that are available, are in the bentley type 3 manual. The specs for adjusting the type 3 auto differntial will get you almost dead on...but calculating the bearing pre-loads without a rotational dynomometer are complex...but I have done them..and can tell you how to set it up for less than 20 bucks worth of tools. Contact me and I will tell you what NOT to disassemble before you measure it. Not trying to scare you. This is the simplest transmission to rebuild...period. It just has some very different rules. Anyway...you will need to replace the counter gear shaft. It is the key to the destruction of these transaxles. They are a straight 18mm shaft with a step cut in the end..down to 15mm. Have it tooled up...about 60 bucks ...made from chromaly. Hardening will not be necessary. Since the needle bearing surfaces in the counter gear will ALWAYS be destroyed...I can tell you the part #'s for commonly available, shielded needle bearings that fix that problem. The flaw in the countershaft was not enough oil holes. I will tell you how and where to drill one more easily. Synchros rarely wear out in these. Simply swap brass synchro rings from another tranny until the gap measurements are within specs...but do not swap hubs. The other flaw is the spider pinions in the differential. They have very high gear ratios...very few teeth...but very long teeth. As the shims internally start to wear out, the teeth start to contact the side shafts too deeply, destroying the side gear teeth. If this has not yet started to happen...simply replacing the shims will work well. The pinions fit nothing else. The needle bearings on the main shaft flat out never wear out, except on 4th gear. I have part #'s for those...they are available through bearing jobbers. The mainshaft seal...is cheap...but only availble by size from bearing dealers. Side differntial seals are common from parts shops. Gaskets, I cut by hand. The cool thing about this transaxle..is that if the gear section is bad...but the differential is good...you can swap one with another. They are sperate units. The mainshaft/gearbox assembly has only 3 shims in it...and only two sizes/sets were available. It will be one set or another. So one gearset...gears 1-4...are set up to the case section they came with. Do not mix one gearset into another case...unless the two counter gear shims and the 2nd to 3rd spacer goes with it...but thats all. There are no special jigs needed for this transaxle. Sorry this is so long. Contact me for help and I will be happy to help you get this off the ground. It will run like new. Ray