Transaxle clutch Job summary
(This is an article found on the Internet a couple of years back - I have lost the name of the original author. I have made corrections to this file partly based on my own experiences)
Removing the clutch and transmission.

I did the job in my driveway with jacks and jack stands. If you have a lift, the procedure will be slightly different.

  • Jack up rear of car on DeDion tube. Place jack stands under tube right near the wheels. This will allow the DeDion triangle to pivot, allowing removal of the clutch and transmission.
  • Remove rear and center muffler sections.
  • Remove the clutch slave. Be careful not to let the piston fall out of the cylinder. Have a clamp ready to hold it in.
  • Remove the wires for the reverse switch and the speedometer.
  • Unbolt the rear donut. You may be able to leave the 3 bolts that attach it to the drive shaft (just remove those that attach it to the clutch spider. Mine was rusted on to the clutch spider, so I ended up removing all six bolts.
  • Unbolt the bolts connecting the shift connecting rod, let loose.
  • Unbolt the six bolts from the rear cross member.
  • Jack up on the rear of the DeDion, the transmission should lower. The donut should separate from the clutch. If it's not freeing up, remove all bolts from the donut.
  • Put another jack under the trans to support it. Locate it behind the flange (you'll be removing this).
  • Unbolt the trans mounts from the trans (leave attached to the cross member).
  • Unbolt the cross member from the DeDion. Remove the cross member.
  • Jack up rear jack, lower front jack so that the clutch housing will fit through the opening. Don't overdo it - could create too much stress on the Watts linkage.
  • Remove the shift rod connection piece from the splined shaft.
  • Unbolt the 4 bolts holding the clutch housing to the trans case.
  • Pull out the clutch. You may have to adjust the jacks.
  • Put a oil pan under the trans.
  • Unbolt all the bolts connecting the trans to the differential. Oil will pour out.
  • Remove the front case, leaving the gears and flange there. Pick up the reverse gear idler that will fall out.
  • Remove the gears and flange section...carefully. It's heavy.
  • Let the DeDion return to it's original position, to relieve stress on the Watts linkage.
Clutch Replacement
  • The whole clutch is replaced as a unit.
  • Unbolt the spider (3-pronged thing). This can be a pain. First, you need the right sized socket around 32mm, forget exactly). Then you need to hold the spider while you loosen. I stuck two of the bolts in and held in place with a bar.
  • Pull the spider with a 3-prong gear puller.
  • The clutch will pull out of the case.
  • Check the 2 bearings in the case for "roughness". Not a bad idea to replace anyway (about $16 each). I replaced the rear one that felt marginal.
  • To remove the rear bearing, you have to remove 2 outside-thread locknuts, which is a pain. I didn't have a tool to do this, so I used a air-chisel with a stubby end on it to loosen it. Then the bearing needs to be pressed or hammered out (I hammered since I had a new one).
  • The front bearing has a lock-clip holding it in, but it falls out from back end, along with a spacer.
  • Replace the rear bearing by using the old one as a protector and hammering carefully around the edges a little one each side at a time. Replace the locknuts.
  • Check the boot and bushing around the shifter shaft. Mine was ok.
  • Put in the new clutch, greasing the shaft well, including the splines.
  • Reassemble the spider along with the dust shield. Tighten the nut.
  • Grease the clutch fork pivot. Grease the throw out sleeve-thing.
Synchro Replacement

This is the fun part. A large work surface is needed - one large enough to lay out the parts in sequential order. I ordered 4 synchro rings and 2 synchro sleeves ahead of time with the assumption that this was the minimum that I would replace.

Some definitions for this discussion, (using terms in the manual):

pinion shaft  the shaft with the pinion linking to the differential

main shaft the input shaft from the clutch

I've heard the term "lay shaft", but I'm not sure which one that is.

  • Study the transmission gears. Understand how it works. Know which is 1st, 2nd gear, etc.
  • Remove the locking balls for the shift forks. There are 3 square nuts on the flange. Remove these. Watch for falling marbles. There will be one ball in each hole.
  • Disconnect the shift forks. Pull out the rods starting with 5th gear then 3/4 then 1/2. Retrieve the interlock pins from the holes in the flange between the shafts.
  • Engage two gears at once to lock the shafts.
  • Clear the pinched metal from the main and pinion shaft nuts. I used a punch.
  • Remove the main shaft nut. This requires a large box-end wrench which I was lucky enough to have (30mm, I think).
  • The next step can be enough to discourage you. Remove the pinion shaft nut. This requires a 1 7/16 deep socket...a rare find. I ended up borrowing the special Alfa tool from Peter Krause (local mechanic). I've heard that farm supply places might have them. It's also on there tight.
  • Remove the gears on the nut side of the pinion and main shafts. Keep in order on the bench.
  • Remove the pinion shaft from the flange. Continue removing the gears from the shaft. Careful not to drop the needle bearings. Also careful to note the placement of the two spacers.
  • Check bearings for obvious wear. I didn't replace any of mine, but it might be a good idea if you have the time and money.
  • Locate the 1st gear synchro. Remove the circlip retaining the synchro ring. Remove the ring. Note the position of the "quadrants". The one for 1st gear is different than the rest. It's asymmetrical, and it needs to get back together the same way it comes out. Clean the parts. Reassemble with new synchro ring.
  • Replace 1st gear assembly on the pinion shaft, cleaning parts and coating surfaces with engine assembly lube. Use new synchro sleeve.
  • Do the same with 2nd, 3rd, 4th gear synchros. These have symmetrical quadrant pieces. Careful about putting the spacers on the pinion shaft when reassembling (one between 2nd and 3rd and one between 4th and the flange race).
  • Refit the pinion shaft into the flange.
  • Do the 5th gear synchro if you have a new one. I did not. I just reversed the synchro sleeve when reassembling, since the reverse gear side is not used.
  • Refit the 5th gear and reverse gears to the pinion shaft. Also refit the gears to the main shaft. You kind of have to do these together to make them mesh.
  • Put the nuts on, but not real tight. Check that the gears are aligned and meshing properly. Check that the synchros slide properly (will require some force). Tighten nuts.
  • Reassemble shifter forks in reverse order. Careful with the interlock pins and the detent balls. Clean and lube parts.
At this time it's probably a good idea to replace the seals around the main shaft and the shift rod where they enter the transmission case. See the Don't Save the Seals article for information.

Refitting Clutch and Transmission

This is a little harder than removal, because you have to get everything to lined up right.

  • Clean up all the casing surfaces. I used brake cleaner and a rag for most of it. A plastic scraper may help with the tough spots. The aluminum is easy to damage, so be careful if you use metal scrapers.
  • Put the gearbox in neutral.
  • Give the gears a final look over for dirt. Clean with brake cleaner, shoot with compressed air.
  • Put a thin bead of casing sealer on the casing still in the car. I used a loc-tite product ( 518, I think. it's red).
  • Lower the DeDion back down using the rear jack.
  • Before refitting the transmission, I ensured that the cross member bolts would screw in with minimal torque (ie. by hand). I had to loosen a couple with a tap. This helps a lot later when you're trying to line up the cross member.
  • Fit the gear shafts back into the rear gearbox section. It'll take some wiggling, turning of the input shaft to get it to slide into place. You shouldn't have to force'll just slide. It's not easy with all that weight though...two people might help. You may want to somehow clamp the flange temporarily while you get the front case into place. The flange kept sliding back for me.
  • Put a bead of casing sealer on the front case half.
  • Have the reverse idler gear ready under the car. Slide the front case over the shafts, but don't fit all the way on.
  • Be sure that the fork for 5th, reverse is fitted into the synchro sleeve. Position the idler gear so that it fits into position on the fork extension. Hold there as you slide on the case. Hold the idler so that it slides onto its shaft extending from the front case. Double check this after sliding the cases to within 3/4" from each other. Use a flashlight to peek in. You don't want to have to take it all apart to fix this.
  • Slide the case together, bolt. Don't forget the clutch slave mount.
  • Finally, slide on the clutch. Fix with 4 bolts.
  • Attach the shift shaft piece on the spline with the single bolt.
  • Attach the cross member to the DeDion. Be sure to include the washer.
  • Adjust jacks so that the trans mounts are aligned with the holes in the trans. Bolt cross member to trans.
  • At this point I switched the position of the jack stands to underneath the rear jack points. This frees the DeDion to ease alignment of the cross member with the six holes in the chassis. However you perform this move, don't put too much force on the transmission mounts. ie. support the DeDion by the cross member, not the transmission if applying car weight to this support.
  • Try out the cross member bolts in the bolts in the chassis. Clean them off if necessary so that they go in with just your fingers (you'll see why below).
  • Raise the cross member with the front jack (lowering rear jack if necessary). As you do this, line up the drive shaft with the spider yolk on the clutch. I had the donut already attached to the drive shaft with 3 bolts (not tight). Be sure the bearing isn't cocked when you do this.
  • Align the six holes in the cross member with the six in the chassis. Put spacers in position. Put in bolts using fingers only. These are easy to strip! You may have to fiddle quite a bit to get them aligned properly. Once you get all the bolts started, tighten them down.
  • Put bolts in the donut. Careful of clearance problems between the nuts and the drive shaft tunnel (chassis). I faced the nut heads away from the donut. Washers should go by the nuts. Also, my bolts were two different lengths. This is probably a mistake, but I was sure to use 3 equal length bolts all on the same side (front/back) for balance reasons.
  • Attach the shift linkage.
  • Replace the clutch slave. Grease the ends of the rod. You'll have to reach in with your fingers and line up the flat portion of the throw out slider-thing. This may take a while to get it lined up so that the fork fits in right.
  • Hook up the reverse light wires and the speedometer sensor wires.
  • Fill the trans with gear oil. I used Castrol 80w90 initially. After a couple hundred miles, I'll change to Redline 80w90. The castrol will collect the dirt residue and also wear in the synchros a bit.
  • Refit the exhaust. You'll probably want to clean the rust off first and lube the sliding fittings with lithium grease. You might need new clamps if they were on for a while.
Test Drive

This is where you get your reward (hopefully).

  • First try the shift action. Try to get it into all gears. It may be tough with no oil. Mine went in with a little pressure and rocking.
  • Be sure that the clutch is fairly firm. You may need to bleed if the piston came out of the slave. Be sure that there are no squeaks when depressing the clutch. If so, you didn't grease the throw-out sleeve. Get some spray grease and go to it.
  • Start her up. Feel for drives haft vibrations. Listen for drive shaft clearance problems. Listen for gearbox clatter .
  • Try engaging 1st. Inch forward with clutch.
  • Try reverse.
  • Go out for a drive and enjoy!

Expect the synchros to be a bit "stiff" for a while, especially 2nd. They'll get easier after a few hundred miles.

Don't Save the Seals (GTV6 transaxle story)

Well, the transaxle is out of my GTV6 again. This time the whole thing. Since rebuilding the gearbox and replacing the clutch a couple months ago, I was noticing a smell of transmission fluid (Redline stinks!). I traced the leak to two places:

  • one of the front gearbox/clutch housing seals which I didn't replace when I had it apart.
  • one of the differential stub-axle seals.
I decided to fix both because:
  • I don't want to be running low on fluid and
  • I don't like the smell and
  • It's not fun when transmission fluid gets on your rear rotors during track events
Since I needed to disconnect the stub axles to get to the rear seals and since I needed to disconnect the drive shaft to get to the front seals, I decided to just take the whole thing out. And I'm glad I did. It's so much easier working on the bench rather than underneath the car. I would recommend it even if you're just doing the gearbox. The outer set of stub axle nuts are usually not too bad (it's the inner ones that can be a bear). The only extra things you need to disconnect are:
  • stub axle nuts (6 each side)
  • single brake flex tube
  • handbrake cable
  • single rear mount bolt
Stub Axle Seals

With the unit on the bench, I removed the rotor bolts. I had previously replaced these with the hex/Allen type bolts, so removal was not so bad. Loosening the caliper bolts allows removal of the rotors. Four more Allen bolts hold on the inner stub axles. They come out as a unit. They are composed of a flange (attached to end of axle), then in order over the axle: shield, oil seal, casing, bearing and lock ring. As you can see, the unit has to be disassembled to get to the oil seal.

R&R of these units is tricky. A bench press is required and special Alfa tools make the job a lot easier. First, the lock ring has to be pressed off. Alfa provides some special plates for this, but a regular press clamp will work. Then the casing/bearing has to be pressed off. For this I used the special Alfa plates (different than the one for the lock ring). Now the oil seal and the bearing can be removed from the casing. I replaced both. The bearing/casing/seal piece then needs to be pressed on with a 3rd special Alfa tool, but probably a pipe of the proper diameter would work. Finally, the lock ring needs to be heated to 190C (I used a fry daddy with motor oil) and then pressed on with the same pipe/Alfa tool. This whole procedure took me about an hour (with special Alfa tools available) to do both sides.

Transaxle Front Seals

There are two seals in the clutch/gearbox casing. One is for the main shaft and one is for the gear selector shaft. To get to these, you first have to remove the clutch front case. There's the four bolts holding the case. The arm on the gearshift selector shaft is probably already off.

Now, you'll be able to see the two seals, but to remove them you need to separate the case and get the shafts out of the way. Drain the fluid. Undo all the bolts. Separate only the front case from the center flange. Now the seals can be removed with a seal puller. The main shaft bearing can also be removed by first removing one of the circlips. I replaced this too.

I also replaced the pinion shaft support bushing which was badly marked. This required a special Alfa-tool extractor.

Just to be sure I covered all bases, I removed the spring-loaded thing on the side of the case. Some casing sealer between the case and the plate will keep the oil in.


So the moral of this story is that you should replace all seals when you have the opportunity. Shortcuts will just cost you time later...

The whole thing went back together ok. No more leaks. Just a couple residual problems: an exhaust clunking noise and a drive shaft vibration. The story is never-ending.
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