I'm counting on you guys with manuals for some information here.

As some of you may recall, I have been stockpiling the parts to do a C6 auto to 3 speed manual conversion.

Solo, I'm halfway there after eight hours. I have the automatic out and everything cleaned up and ready to accept the manual stuff. I have five main questions that I must have answered before I can continue:

1. Do I have to use brand new flywheel to crank bolts? If so, do I have to order these or does NAPA carry them? I'd like to get this thing put back together in the next few days if I can.

2. Do I have to have special bolts for the pressure plate to the flywheel? I have regular Dorman grade 8 bolts, washers, and lockwashers from Lowe's, but I read that I may need to have shoulder bolts for my flywheel. The pressure plate I have has one normal size hole and one enlarged hole on each third, and the flywheel has piloted bolt holes. Do I just use one of the shoulder bolts on each third in the enlarged holes and one regular grade 8 bolt in the others? Does NAPA carry these shoulder bolts or will I have to order them?

3. What, if anything, do I need to use threadlocker on?

4. Upon removing the C6, I found that there was a layer of silicone on both sides of the center plate that goes between the block and the trans. Should I do that again when I put the manual in? And do I need to do it on both sides of the plate?

5. Is there anything special I need to know about installing the pilot bearing in the crankshaft? Do I just put it in as-is and tap it home with a drift or the correct size socket, do I have to grease anything, etc.

Thanks in advance! I can almost feel the clutch pedal under my foot as we speak!

 

1. New flywheel bolts?
I'll admit, I've reused them in the past with good luck, but if you plan on racing or any heavy duty use, it would be cheap insurance to replace them while you're at that point. Just go with a decent quality brand like ARP. Some auto parts stores carry cheap offshore stuff and you may be better off with the used Ford stuff in that case.

2. Honestly don't know.

3. I use thread locker on the flywheel bolts and pressure plate bolts.

4. I really don't see any reason to use sealer on the spacer plate. All surfaces (spacer plate, block and bellhousing) should be free of grit and debris. It actually may be harmful and cause binding, premature wear of the pilot bushing or trans bearings if the motor and trans are out of alignment.

5. Drive the bearing in so the force is applied to the outer ring of the bearing, not the center.

 

If you only have the flexplate bolts you will need new flywheel bolts, but if you have the original flywheel bolts they should work just fine.
If the bolts are the same size as the hole in the flywheel I would not worry about shouldered bolts, but if the holes are larger they may need the special bolts to center the clutch onto the flywheel
The rest I agree with the above post..

 

Thanks for the input.

I have the original 33K mile 1969 flywheel bolts that go with this exact flywheel. They aren't rusty or damaged at all. I don't plan on doing anything heavy duty with this truck...at least nothing outside a normal bed load. So original flywheel bolts are OK, right?

The idea of using silicone on the spacer plate is to keep any leaking oil, water, etc. from entering the bellhousing and contaminating the clutch. I have no idea why they would do that on an automatic, but would it be worth the money and the effort to do this, or does it even make a difference? I know I am replacing the foam material on the inspection cover to keep it watertight, but I'm not going to go through all the aggravation of putting together large pieces with RTV unless it's actually going to do something worthwhile.

All of the pressure plate mounting holes on the flywheel are piloted. Only one of the two bolt holes on the pressure plate itself is the same size as the threads in the flywheel. The others are enlarged and look as if they take shoulder bolts. My question is, as long as there are three out of six holes in the pressure plate that are the same size as the bolt that goes through them, is it really necessary to use shoulder bolts on the rest of the holes just because they are enlarged?

 

The bolts will be fine.. I wouldn't put silicone between the trans and motor, if something leaks that bad I would just fix the leak.. You should be okay with 3 regular bolts and 3 shouldered bolts as long as they alternate the balance would not be affected, probably would not be enough to worry about anyway, but 3 will center it I am sure if alternated with regular bolts

 

I've only used new flywheel bolts once (ARP) - on a 600HP 351W.

I've used regular bolts before on a PP - The car they were used on is still doing fine 5 years later.

I use blue thread locker on anything I don't want backing out, but I may have a chance of removing again later down the road.

I wouldn't reapply the silicone. Is your rear main seal leaking? If so, now is the perfect time to change it. If not, don't mess with it.

Nothing special about the pilot bearing, just gently tap it in.



That's all what I have done before, and have not had problems. YMMV.

 

Some guy's use a little adhesive on the plate to hold it on the engine , so when they install the automatic transmission , if it gets bumped it will not pop off of the pins and drop down in the way. Maybe they got a little carried away and sealed the whole thing on . I don't see any other reason to do it other than keeping things clean inside , but then you need all of the other openings sealed to do any good . I reuse bolts if they haven't been rounded off,be sure to get them tight.

 

I appreciate all of the help!

 

Put your pilot bearing or bushing on ice. Freeze it and it will slightly shrink and installing it will be a very easy to tap in.

 

OK, finally got up under Ed to get some work done once it cooled down outside...

And I noticed that the flywheel (once I got the holes lined up) had an ever so slight wobble on the crank without the bolts in it. Does this mean that the whole flywheel is warped, or is it common to have a little "play" in it before you install the bolts?

It tightens down fine with no binding, but I did not want to do anything permanent until I got some more reassurance from you guys. It has only 33K original miles on it and the surface has little if any wear. I don't know how it could be warped after barely any use.

If I can avoid having it machined, I will... I have enough tied up in this conversion as it is...and I have to get the truck put back together ASAP.

Hopefully this will be the last thing I have to ask about this job. I'm just ready to have it done and get it back on the road.

 

The flywheel should fit flush and should be perfectly flat. If it is wobbling or not sitting flush something isn't kosher.

It's also a good idea to have the flywheel surfaced whenever doing clutch servicing. Although sometimes it can actually be cheaper to buy a new one than to mess with an old one.

Josh

 

Flywheel and clutch are in...but the only torque numbers I could find for the pressure plate come from my 1964-1971 Chilton manual.

1964-1966 Thunderbird with 390 - 20-23 ft. lbs.

1967-1971 Thunderbird with 390 - 12-20 ft. lbs.

Being that they are grade 8, 5/16 X 18 X 1 1/4 bolts, that number sounded right to me, so that's what I did... Put LocTite blue threadlocker on them and torqued them to 23 ft. lbs.

Should that be OK, or do I need to go higher? I'd be concerned about over stressing such small bolts.

 

Looks like you're right in the ballpark according to this chart.

Steel Bolt Torque Specifications Table - Engineer's Handbook

If your bolts are fine thread and lubricated with Loctite, it may vary a bit from the chart, but I think you're still O.K..

 

Hey, just curious, did you change the transmission crossmember or are you re-using the C6 x-member?

And what did you have planned for the driveshaft?

Josh

 

Thanks, jade79. I'll consider the clutch done, then.

Bullitt, I am re-using my C6 crossmember. I got the crossmember from the donor truck in case I needed it, but my original turned out to be in almost perfect shape. I may have to turn it around and/or use the next hole forward in the frame to bolt it back in with the manual, but it will work. I'm re-using the rear mount assembly from the C6, too. It is in great shape...better than the donor mount.

The '69 longbed I got the trans from sacrificed its intermediate driveshaft and carrier bearing, too. The C6 intermediate shaft (not including the trans yoke) is 24" from end to end while the donor shaft is 34" from end to end. The bellhousing, gearbox, and tailshaft of the manual are all together right at 10" shorter than the C6. Everything should bolt right up.

Should.

The support brace between the torsion bar mounts will probably be the biggest bear to get back in. Had to unbolt it and drop it down to get the C6 out. When I did, I noticed that the mounts popped in closer to each other a little bit. Warmin' up the hammer as we speak.