Clutch fork travel

[DanEC]

Originally Posted by ERA Chas

Got the Thinking Cap on eh Dan?-Great thought.

Well, with me it's sometimes hit or miss. But if anyone else after reading through this entire thread has another conclusion as to what the problem is, I wish they would chime in. Lippy did a complete engine/clutch/trans installation in one push and thought he was in the home stretch and then "Bang - busted". Having to pull and install a 100+ lb tansmission across the floor twice is just no fun. I hate this has happened knowing how meticulous he has been in his build so far.

Lippy - another thought based on Jerry's post above, a lot of clutch disks have survived a lot of abuse during transmission installations and functioned fine. But, it would be a good idea to take a close look at those disks when the transmission is out and make sure they don't look bent or warped from the collar pressing on it. I'm not sure of the best way to check them - you can slide them on the input shaft and spin it to look for any runout. Usually they will have a little wobble play in them from the clearances between the hub and the shaft but it should be uniform enough that it can be checked with a dial indicator. And just visually inspect the area around the hub to make sure it's still looks flat and straight. If any question - you may want to consider replacing the outer or both disks. It would be a shame to put it all back together again and end up with a bad clutch shudder/chatter and have to pull it apart a 3rd time.

[ERA Chas]

I think Brent would have been aware of flywheel thickness with the 2 discs he spec'd.
If he sent it that way, I think it's the right part-he did preassemble before shipping parts.

[DanEC]

Originally Posted by ERA Chas

I think Brent would have been aware of flywheel thickness with the 2 discs he spec'd.
If he sent it that way, I think it's the right part-he did preassemble before shipping parts.

Chas - I'm not saying the flywheel choice was right or wrong - but flywheels come in a wide range of thicknesses. Pick a thicker flywheel and throw in a dual disk clutch and the accumulation of dimensions with a TKO6 600 transmission may raise up and bite you like I'm suspecting here. Probably never create an issue with a single disk clutch that represents most of the market. I don't imagine that Brent had the transmission in his shop to test fit. I'm still sort of surprised that Tremec doesn't caution about checking retainer clearance in their installation instructions since they have a big aftermarket.

[ERA Chas]

Originally Posted by DanEC

Chas - I'm not saying the flywheel choice was right or wrong - but flywheels come in a wide range of thicknesses. Pick a thicker flywheel and throw in a dual disk clutch and the accumulation of dimensions with a TKO6 600 transmission may raise up and bite you like I'm suspecting here.

Your point is good-I just think Brent would have accounted for that. Hopefully he'll weigh-in on this point.
And yes, no matter what the cause, Jeff has paid his dues thrice over with this problem. It's just not fun like this.
Hope the answer appears before he needs back surgery.

[lippy]

One more question (I really want to make sure I get this right):

When I put the trans in neutral and turn the rear wheels by hand, it is fairly smooth and easy.

Now that I've backed out the trans on its bolts 3/32", when I put the car in gear and depress the clutch, I can turn the rear wheels by hand. The clutch releases. But I do hear something rubbing a bit (sounds like the clutch), and there is a bit more resistance compared to turning the wheels in neutral. Of course, I'm spinning the internals of the trans when I do this, so this may be normal.

Does this sound right?

[blykins]

Dyno day today, been a long day.

Ok, let's see....

This is an all McLeod setup, flywheel, clutch, and fork. Their flywheels are thicker than the RAM flywheels I've used, the bolts don't stick through the back of the crank flange like they do with the RAM. With that being said, this is a combo I've used multiple times over, with both FEs and 385s. I've never ran into this issue before. Didn't have the trans here, Jeff received it several months ago.

Jeff, it's going to be different when the trans is in gear and the clutch is engaged. Lots more stuff turning, like the discs, synchros are locked to the gears in the trans, etc.

[DanEC]

If I remember right - his build used an aluminum block also. Could be a few hundreds of an inch difference in crank flange to rear block machined surface distance than original Ford. A few hundreds more flywheel thickness. Quicktime bellhousing overall depth could be slightly different than stock Ford. Lots of tolerances that could go a little this way or that way - or all in one direction.

I don't remember ever spinning a transmission from the rear wheels. Makes sense it would feel a little different in gear. I think in neutral the countershaft and gears are primarily turning only. In gear it's picking up the input shaft and the clutch disks may be lightly touching on the clutch plates as they spin because they haven't been fully seated in. I know that putting a new bearing retainer on a Muncie there is a lot of drag on the input shaft before installing. After it's been run a little bit the input shaft is back to wobbling around as loose as a goose because of the front ball race bearing. But, really need to check the back disk plate for any damage.

[patrickt]

Lippy, I ran across this Mcleod dual disk on a TKO thread over on the FF forum. Kind of interesting.
Duel Disc clutch question - FFCars.com : Factory Five Racing Discussion Forum

[blykins]

The street twin is an entirely different clutch kit than the RST that we are using here. I've never had to trim with this application before which is what's weird, but I've come to accept out of the ordinary stuff with aftermarket parts.

[lippy]

I pulled the trans and measured all of the clearances. It does look like there is interference between the bearing retainer and clutch splines. I'll take the retainer to the machine shop Monday and take 9/32" off, which leaves 0.100" for clutch wear plus a slight margin for safety. Hopefully it does the trick.

[frdfver]

You may already know to be careful when pulling the retainer that the input shaft stays put, makes life easier.

[DanEC]

Originally Posted by frdfver

You may already know to be careful when pulling the retainer that the input shaft stays put, makes life easier.

I'm curious as to what ight happen? Pulling the retainer on a Muncie of Toploader doesn't disturb the input at all. What's different on a Tremec?

[blykins]

Originally Posted by DanEC

I'm curious as to what ight happen? Pulling the retainer on a Muncie of Toploader doesn't disturb the input at all. What's different on a Tremec?

On a Tremec, the input shaft is just "clocked" when installed. That's why it's so easy for an end-user to install a short input shaft by himself. You literally pull the bearing retainer, turn the input shaft a little bit to a keyed position, then pull it out. It's not like a Toploader where you have to drop the countershaft to get the input out.

I've already reminded Jeff, but the bearing retainer goes on in one direction, as it has a feed hole in it that oils the input shaft bearing.

[DanEC]

Originally Posted by blykins

On a Tremec, the input shaft is just "clocked" when installed. That's why it's so easy for an end-user to install a short input shaft by himself. You literally pull the bearing retainer, turn the input shaft a little bit to a keyed position, then pull it out. It's not like a Toploader where you have to drop the countershaft to get the input out.

I've already reminded Jeff, but the bearing retainer goes on in one direction, as it has a feed hole in it that oils the input shaft bearing.

Thanks Brent - I was wondering if unlike older transmissions, the Tremec main drive gear wasn't machined integral with the input shaft. Apparently it's not.

[patrickt]

Lippy, take pics of the work before and after and then post a new thread, with descriptive words that show up easily on a Google search. Even showing how you pull the retainer. I know this sounds like an unusual case, and maybe it is, but for the next guy that is using those components, and they are pretty typical after market parts, an informative thread by you would be worth its weight in gold. And this is not just a "Cobra related problem." When I was looking around, I found similar problems to yours on every niche-car-forum you could imagine. You have to detail it in a new thread though, you can't leave it all buried here.

[ERA Chas]

Although I agree about the value to others, that's a ton of work for a guy that's been hammered by this problem.
I'm sure he just wants to get the fix after the now-third trans-out in a residential setting. Think he's paid his dues.

[frdfver]

Lippy, Looks like Brent is taking care of things with some good info. Agree with patrickt, other problems with trans, pilot brg, bellhousing mismatch or interference. Even where the clutch disc input splines are contacting the pilot brg. Best of luck...

Paul T.

[lippy]

Hey, these things happen. Patrick has a good point. I'll put up another post, but I want to make sure this is solved first.

[blykins]

Originally Posted by patrickt

And this is not just a "Cobra related problem." When I was looking around, I found similar problems to yours on every niche-car-forum you could imagine.

I'd be interested in seeing the threads that you found that involve RST clutch kits, not Street Twins. Those are separate clutch kits, with the Street Twins being much larger.

I'm not an "installer", just an engine builder, but I will say that I've sent out engines with these RST clutch kits for BBF's, FE's, and SBF's, and have never heard of anyone having any trouble. All TKO-spec bellhousings from Quick Time, no matter if they are for a 460, FE, or SBF, are all the same depth. The TKO input shaft and bearing retainer are all the same length. The RST pressure plate is the same for all RST kits, and the discs are all the same, with exception of different hubs for different input shaft specs.

It's certainly an interesting scenario, but it doesn't surprise me...

[patrickt]

Originally Posted by blykins

I'd be interested in seeing the threads that you found that involve RST clutch kits, not Street Twins. Those are separate clutch kits, with the Street Twins being much larger.

I'm not an "installer", just an engine builder, but I will say that I've sent out engines with these RST clutch kits for BBF's, FE's, and SBF's, and have never heard of anyone having any trouble. All TKO-spec bellhousings from Quick Time, no matter if they are for a 460, FE, or SBF, are all the same depth. The TKO input shaft and bearing retainer are all the same length. The RST pressure plate is the same for all RST kits, and the discs are all the same, with exception of different hubs for different input shaft specs.

It's certainly an interesting scenario, but it doesn't surprise me...

Well that's just it. A lot of times the threads don't specifically state exactly what the parts are or who made them. They just list the symptoms, the fact that they're using a Tremec, or a Mcleod, or what not. That's why Lippy needs, assuming he fixes it, to start a new thread that includes his exact parts, his exact problem, and his exact fix. And not have it all hidden under "Clutch Fork Travel." A found a couple of different threads that sounded close, like this one: Transmission: Problems installing Tremec TKO but none of them were exactly what Lippy was using.