My gearbox has broken.. :(

raygreenwood · Post by **raygreenwood** » Thu Apr 10, 2003 9:57 pm

Sadly, no. There is not a single part in the type 2 that is even similar. Well...except the differential side adjuster rings, but thats all. The differential in the type 4 is very different. Picture this: In the type 1 and 2, the pinion shaft and gear is all one piece. In the type 4, it is splined onto the pinion shaft. The pinion shaft in the type 4 is about 3 feet long. In the type 1 and 2, the pinion gear is located on the side of the differential cavity farthest from the clutch. On the type 4, it is just behind the clutch. It is 180 degrees opposite. The pinion shaft has a separate carrier that crosses over the differential. It causes the diff to have to have a very narrow body and small diameter ring gear. The bolt pattern for the gear is different than the type 1 and 2 ...so even if there were room for the diff...it would not fit. The spyders are totally different as well. But...get an a type 3 or 4 auto. Pull the differential. The gear ratio is nearly the same. The make is the same...the 180 design is the same and the pinion will press onto the shaft. You will need to have a steel bearing spacer milled for each end of the differental housing to be able to install the bearings. You will have to use the late model diff from an auto to be able to install the side stub axles. Use the one that has the through bolts through the stub. The autos also have superior spyder gears. They have the bolt through keeper so even if they wear out of adjustment...they will not crap the spyders out. You will need to grind a notch in the pinion carrier from the type 4 to clear the slightly fatter diff body. Carefully measure the adjustment of the auto diff from its carrier, then adjust per the type 3 bently manual. Its not really a lot of work...but its not for the non-persistant, the impatient or the faint of heart. Ray

Specky VW freak · Post by **Specky VW freak** » Sat Apr 12, 2003 2:40 pm

Sounds like you've had the exact same thing that happen to me two years ago after I bought a 412 variant - drove 75 miles, went to pull away and no gears at all. Clutch was working fine. Guess who wasn't impressed!

Under the rear seat is an access panel where you can get to the top of the gearbox to another cover panel to remove a circlip to withdraw the main gear shaft towards the front of the car before dropping the engine. If this isn't done it can damage the casing where the clip mounts. If this happens the shaft becomes free - the result no gears, nothing. We bodged a repair, but sourced another box to be safe.

raygreenwood · Post by **raygreenwood** » Sat Apr 12, 2003 2:56 pm

I had the shaft slip syndrome happen to me last spring. At worst, it can damage the splines on either end of the shaft, but cannot damage any of the internal parts. It has contact only at the clutch splines and in the splines at the rear bearing in the tranny. It is caused either by a bent e-clip underneath, or a nut that was tightend improperly. Overtightening can casue this too.
The spyder gear failure is its own syndrome. It is caused by a combination of things. The spyders in the type 4 manual trans are unique. They have very long pointy teeth and only have 9 teeth on each spyder gear. This gives them a very high ratio. That puts a lot of pressure on the faces. They must remain properly adjusted. The years and miles wear the flat shims under the differential output shafts. Those are the shafts that attach to your stubs and driveshafts. Also the ring spacers that drop onto the splined stubs before the flanges and C-clip go on...wear with age.The result is inward motion of the side stub shafts. They end up contacting the teeth too deeply...and alternately too shallowly. This causes heavy wear on these high ratio parts. The teeth chip and crack...then they are gone. This usually happens when going around a sharp corner at high speeds.
The trick is to get a decent transmission, and simply open the differntial and replace the side stub shims, the spider shims and the ring shims behind the drive flanges. It will not allow the spalling of the gears to start. Any tranny above about 80k miles is suspect for this. While you are at it...replace the counter shaft, and all the diff and pinion bearings. Readjust everything ...and you should be good for another 100k or so. Ray

Chris Percival · Post by **Chris Percival** » Mon Apr 14, 2003 1:54 am

Ha, you're going to love this!! I found out what was wrong with my box, it wasn't the diff after all. This picture might give you some clues.

Why is that hole there!? Neil and Ray, it sounds like you have both had this same problem. When I took the box out, I thought it a bit odd that the shaft comes through the end cover plate! After comparing my old and new (to me) gearbox, I descovered that the circlip was missing, holding the shaft in. The end cover plate was the only thing holding it it, and then it wore though allowing the splines to disengage. i don't know what happened to the clip, maybe it broke, maybe it was never replaced last time the engine was out? Who knows?

With my new gearbox I will be very careful to put the clip back properly. How tight should I do the clip retaining nut up after puting on the circlip?

Just goes to show how the smallest part, can have a vital role! It has caused me much agro and wasted much time...

Here is my engine out (resting on my axeminster carpet!)

Here is the car:

raygreenwood · Post by **raygreenwood** » Mon Apr 14, 2003 5:57 am

HA!...You are so lucky. That is the exact thing that happened to me in the spring!. The shaft backed out. It drilled a hole in the cap with the threaded end. Find the right size E-clip and locktite the locking screw back on after checking the splines for burrs...and you are back in business. Nice looking type 4. Ray

raygreenwood · Post by **raygreenwood** » Mon Apr 14, 2003 6:10 am

Oh....sorry...forgot...The book mentions 14ft lbs of torque. Its worth it to mention that the nut is special. It has a flat bottom. and a slice cut in the side of it. The purpose of that slice is to allow the nut to distort and lock on the threas. All the nut does is spread the e-ring outward...like a piston ring....to make contact in the "groove" at the outer edge. Make sure that the outer groove around the E-clip is not damaged. If the nut is gone, you can use either anormal nut with a thin Jamb nut and a flat waher underneath it, or a self locking nut with a poly center. Use an old clutch disc and a pair of locking pliers to hold the shaft still from the other end. Ray

Chris Percival · Post by **Chris Percival** » Mon Apr 14, 2003 6:11 am

Obviously another weak point then.. Do you know what happend to your clip?

Chris Percival · Post by **Chris Percival** » Mon Apr 14, 2003 6:12 am

Thanks, I need to get myself a torque wrench!

Guest · Post by **Guest** » Mon Apr 14, 2003 9:43 am

My e clipwas still floating around in the back. I had to replace it. You will notice a sloped or angled section of the shaft right at the bottom of the thread section. That spreads the e-ing outward to make contact. If someone replaced the e-ring with one that had shorter teeth on the inside, it may very well have not spread out enough to make contact at the outside. Be careful with your selection of the e-clip. You can also use a thinspring washer. Grind/file the outside of thewasher to fit just slightly smallet...about .015" smaller...than the "cup" area in the bearing end of te hub. Grind/file the inside of the washer to be about the same amount smaller than the the sloped/ramped area right below the thread at the end of the shaft. Right under the sloped area...you will notice a fine bead ground into the shaft where the clip snaps in. Then cut out a pie shaped section of the washer so it can spread when forced down over the cone at the end of the thread, by the nut....effectively spreading the outside edges of the washer into the outer groove. Just make sure the washer is not too thick. It has to be grasped by the overhang of the outer groove in the hub.
When I next have mine out, I am also going to cut two fine shallow slots in the sides of the hub...and drill a small hole in the nut for a fine piece of stainless safety wire to get rid of the risk factor.
One thing you will notice with these 4 speeds, is that they were designed with longevity in mind. I was told by an old factory/dealer mechanic than more than a handful of parts were designed to be replaced easily..and usually were at the first sign of trouble. Things like the simple counter shaft which can be easily withdrawn with only taking the tail cone off. The counter gear bearings and slider forks can be accessed once the tail cone is off...by simply removing the plate and the two slider crossover bolts. The detents are all accessable from the outside while taking no parts off the transmission. The reverse gear depth of engagement can be adjusted from the outsdie without taking anything loose as well. This guy alsotold me that it was common practice to replace the E-clip and nut...anytime the box came out...as the dealer always loosened it and removed the shaft. I was also told that....a lot of these replacing of wearable parts...never happened. Thats why so few parts were ever in th dealers hands. Usually, the trannys ran to 80-90K and the owner either had wrecked the car by the, sold it, or blew the engine and they just disapeared from the road before very many had enough miles to warrant the dealer tearing into them. Add to that the relative rarity of them on this continent and you see why we have no parts anywhere for them. This man said he has never in his life seen a spare pair of synchros laying on the dealer shelf for a type 4 box. This is all part of the reason that I have found it good sense to dissasemble any box I find over 70K...clean..put new countershaft and differential shims and bearings in. Ray

Chris Percival · Post by **Chris Percival** » Mon Apr 28, 2003 3:03 am

I have fitted my replacement box now, and tested it at the weekend. So far so good. Its good to have her back on the road. The box seems better than my last one. I was very careful to make sure the clip was fitted corretly and securely. I will check it periodicly now!