GTV6 Trans/Clutch Job summary

I recently replaced the clutch and synchros on my gtv6. Some people expressed interest in the procedure and outcome, so here's a rundown, with some tips.

Note: I am not a professional mechanic. I don't guarantee that any of this is the correct way to perform the job, but it's worked for me. Twice. Use what you want and ignore the rest.

Note 2: The Milano/75 is essentially the same.

Removing the clutch and transmission

• Jack up rear of car on dedion tube. Place jackstands (heavy duty) under tube right near the wheels. This will allow the dedion triangle to pivot, allowing removal of the clutch and trans.
• Remove rear and center muffler sections. This could be a pain. I soaked the center/front junction with liquid wrench for a while. Then I place a block of wood above the cat so that the front piece was fairly fixed. This allowed me to work the center section loose by moving it up/down/sideways while pulling.
• 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 speedo.
• Unbolt the rear donut. You may be able to leave the 3 bolts that attach it to the driveshaft (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 2 bolts connecting the shift connecting rod, let loose. Note: mine's an '84, so it has the simple linkage. There's more bolts if you're post-'84.
• Unbolt the six bolts from the rear crossmember.
• Jack up on the rear of the dedion, the trans should lower. The donut should separate from the clutch. If it's not freeing up, remove all bolts from the donut (if you haven't already).
• 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 xmember).
• Unbolt the xmember from the dedion. Remove the xmember.
• 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 throwout sleeve-thing.

Synchro Replacement

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

• 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). [ Someone has since told me that it's not necessary to remove the main shaft gears. ]
• 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 asymetrical, 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 syncho 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 kinda 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.

Refitting Clutch and Transmission

• 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 lookover 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 crossmember 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 crossmember.
• 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 anything...it'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 crossmember 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 crossmember to trans.
• At this point I switched the position of the jackstands to underneath the rear jack points. This frees the dedion to ease alignment of the crossmember 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 crossmember, not the transmission if applying car weight to this support.
• Try out the crossmember 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 crossmember with the front jack (lowering rear jack if necessary). As you do this, line up the driveshaft with the spider yolk on the clutch. I had the donut already attached to the driveshaft with 3 bolts (not tight). Be sure the bearing isn't cocked when you do this.
• Align the six holes in the crossmember 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 driveshaft 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 throwout 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 speedo 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

• 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 squeeks when depressing the clutch. If so, you didn't grease the throw-out sleeve. Get some spray grease and go to it.
• Start er up. Feel for driveshaft vibrations. Listen for driveshaft clearance problems. Listen for gearbox clatter :-(.
• Try engaging 1st. Inch forward with clutch.
• Try reverse.
• Go out for a drive and enjoy!

Addendum

I have just finished the long process of replacing worn synchros in my GTV6's transmission as well as miscellaneous seals and bearings. The process was a long one because of my lack of experience in the matter but it actually is fairly straightforward. I would like to add a few points to Colin Verrilli's excellent instructions for performing this task. His instructions were posted on the digest a while back and can also be found on the GTV6 web page.

First and foremost, there are NO errors whatsoever in his instructions. There is one point that may or may not be needed, depending on whether you want to replace items on the input shaft of the transmission or not.

• if you are just replacing the synchros, you do not need to undo the 30mm nut on the input shaft;
• at the rebuild stage, Colin recommends to put the transmission in neutral. That is the way to do it initially (to install the intermediate flange back on. At this point, make sure that the three selector shaft are level with one another (indicating that all is well and all shafts have slipped in there mounting holes). If the shafts are not level, make them even. Now, engage 3rd gear. This will prevent ANY of the shafts from moving when you put the final casing on. Leaving the transmission in neutral, I had the idle pulley push the 5th/reverse shaft in when putting the casing in, then having to re-open the transmission... Once the casing is one, put the transmission back in neutral and verify that the input shaft can spin freely.
• to re-attach the deDion to the transmission, leave the triangle down very low. It will be easier to re-install the big bolt in the middle of the triangle, and it will also be easier to re-attach the transmission to the mounts (slowly raise the deDion until the holes match. At this stage, raise the deDion completely. If you are lucky, the holes will align with the mounting points on the body. If not, take the car off its ramps/jacks and move the car back and forth. This way, any stress that was put on the suspension will be relieved and the triangle will align itself with the mounting holes (I could screw in all six mounting screws by hand until it was time to tighten them...)

As Colin said, the transmission is STIFF after this, but it feels MUCH better, and there are no more vibrations or rattles... YEAH!!!

I hope this helps you out...

Article originally came from here.

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