I was performing the initial break-in for my TKO when after a few minutes, the cluch failed to fully disengage. It was shifting fine, and then, bam, wouldnt go into gear. It just came out of nowhere. When the clutch is disengaged, the rear wheels can be turned by hand, but there is a noticable ammount of drag. When the wheels are turned, there is no unusual noises, but a slight stick-slip is felt when theyre turned at a very slow speed.

What could it be? I thought maybe the clutch disk could have been put in backwards, but I distinctly remember checking to be sure that it was in correctly, and it seems that it would have been an issue from the get-go, rather then suddenly appearing.

I know its not misaligned. I spent LOTS of time making sure that it was within tolerances. Thats what killed the auto and damaged the crank and I didnt want to waste another good trans. The absolute worst case scenario would be the trans being .004" off.

Could it be the pilot bushing being too tight? Maybe an issue with the hydrolics? Bellhousing and hydrolics are stock and I have a centerforce clutch and throwout bearing.

Im stumped. TOB, clutch where installed correctly. Trans is on center, everything is torqued to spec...

 

What kind of pilot bushing did you use? Brand new I take it? With the brand new trans?
Maybe a too tight pilot bushing started to grab the tranny input shaft... I think there's only a small chance of that.

pressure plate and friction disc are both brand new? If they are new, and you're pretty sure the friction disc is right way on, and you aligned the clutch, then pushed motor->trans together, then those are most likely not a problem.

the stick-slip makes me think hydraulics, along with the fact that the problem came up rather than being there right away.
So i'm thinking either hydraulics thing, or something is brand new, kinda tight, heated up as you were using it, and started to catch. When it's cold again, is the problem gone? Easy way to test that theory.

 

I was thinking pilot bushing or clutch hydrolics.

Cant rule out the clutch disk being in backwards, but I remember checking it on installation, and to me it seems that it would be an issue from the begining.

Ill have to check it later now that its cool and see if it still binds.

 

Theres litte doubt that its the pilot bushing. I can distinctly feel the cutch engage as soon as contact is made with the pressure plate and the flywheel as the pedal is let out. Instantly locks. Probably the small ammount of lube between the input shaft and bushing was driven away, and the excess friction. is causing the problems

How the hell am I supposed to fix this!?!?!? This is a Mustang TKO, so I doubt a pilot bearing is available for this application. Like everything else, Mcleod probably mis-machined the bushings What a disaster...

 

oh, a mustang TKO, different sized tip on it then? And a normal SBC pilot bushing?

If it's yer basic copper style of solid pilot bushing, you can always just drill it out to the right size. I mean, grab a ford pilot bushing and caliper it in the store, then run home and drill out your chev one. I think the chev one is the smallest ID one, so drilling it out is probably an option.

 

Its the right size, but the tolerances allowed are probably too tight. Like, just a few thousanths too tight. The shaft still turns in the pilot, but the drag is enough to pull the trans along with it in neutral. I noticed that the fitment seemed close when I put it on the input shaft.

Stupid me, I actually assumed that it was ok when in fact I should have measured and adjusted as needed. God forbid if something I buy actually works without extensive modifications.

 

Something that works out of the box? That's just crazy talk, go back to soviet russia you crazy communist!
Well good luck modding it I guess

 

Its been like this for every single little thing. Not one aftermarket part so far has fit properly. And now, on top of it all, the whole thing has to come back out because of that damn bushing. Its like, you finally get to the finish line, and you look down and realize that the finish line is really the starting line, and you have to do it all over again.

 

So before the tranny was in the car you tried putting the pilot bearing on the input shaft? Did it have clearance then, or was it to tight to turn?

Have you driven the car yet? How does it behave then?

Are you sure you adjusted the slave travel enough? It seems weird that it would all the sudden start to bind up like that? Maybe there wasn't enough grease on the bushing/input shaft and it got too hot?

I don't know what the correct clearance is supposed to be between the bushing and the input shaft, I'm sure you can look that up. Is the pilot bushing the one from Forte's for the conversion? You could probably get a new one, measure you input shaft diameter, and ream the bushing to get the correct clearance.

I know what you mean about aftermarket parts. The manufacturers either don't know how to tolerance things, or have horrible quality control.

Well, whatever you do good luck.

 

If it's a forte's modified mustang trans, it uses a modified input shaft with the stock GM 26 splines to take a GM clutch, along with a stock GM pilot bushing. Did you use the factory GM roller pilot bushing or the old school brass/copper/whatever one?

 

The mustang Tko and the GM tko have the same number of splines. The bearing retainer shaft is larger for the mustang than the GM version, but he puts on the GM style for the conversion for our cars. The overall length of the input shaft is longer for the mustang tko. I believe the end of the input shaft that fits into the pilot bearing is larger for the mustang as well. When I received the "special" pilot bushing in the kit, a quick comparison showed it had a larger ID than a GM stock one. Also the GM stock one would not fit over end of the input shaft. The picture has it circled, I don't know who makes it, but it definitely has a larger ID than a stock GM one.

 

I guess dimented will have to post what kind of pilot bushing he has, because I'm running a mustang TKO that was modified by fortes, and I'm using a stock GM roller pilot bushing, stock hydraulics, and a GM style clutch and everything fits fine.

 

I have the same kit that Thomas has. Its an actual mustang TKO with only machining to the housing. It also has that speacial pilot bushing.

This reminds me. I did actually measure the clearance between the input shaft and pilot bushing. IIRC, the inner diameter of the bushing was .005" larger then the input shaft, which should be correct. Im really stumped now...

 

I don't know the clearance specs, but I find it hard to believe that even if the bushing was a little tight, it wouldn't self clearance itself in a matter of seconds. When I've changed stock ones before (the solid metal ones you beat in) there was never any lube inside them, nor any way for them to be lubed if you get my point (no lube neccessary). I still think you have another issue if it worked fine for a couple minutes and then had a problem. You could always pull the trans and put a sand paper roll on a drill and ream it in and out a couple times and give it a little extra clearance.

 

I found out why it wasnt working. The input shaft was binding up in the pilot bushing. Why is it doing this? There arnt any burrs on the shaft, and teh bushing feels fairly uniform. Is it possible the trans is out of parallel with the motor? There are wear marks on most of the pilot on the input shaft, but it seems like the part with bronze over it is being forced into the bushing.

I checked for all of this, and the concenricity as well as the out of parallel seemed to be ok. The worst was .0045" and +/-.002" respectivly.

 

Did the tranny slide into place when you put it in or was it really tight going in the pilot bushing?

I don't see how the bushing could have .005 clearance then all the sudden get tight enough to bind up on the input shaft?

Is the ID of the bushing tapered at all?

This might sound like a dumb idea, but could you check the runout of the input shaft? Maybe its too much?

I really don't know what to say man, sorry. Good Luck.

(You're starting to get me worried about my TKO...haha)

 

I do believe we have a winner.

I just got done checking that very thing wrapped a layer of tape around a socket so it was teh same OD as the input shaft and it was just that. It feels ok until it hits that spot that the input shaft was rubbing on, and gets stuck, like really stuck. The bushing was clamping down on the input shaft and not allowing it to turn freely.

Is it possible that the fit in the crankshaft is too tight?

 

Quite possible, I used a small brake caliper honing tool to clean out the cavity for the pilot bearing. After cleaning it with the tool, the pilot bearing went on very smooth. You can rent the tool or buy it. It is less than $10

 

Hey, I wonder if this would work?


Lakewood Pilot Bearings: LAK-15975 - summitracing.com


Says itll adapt a ford trans to a chevy motor. I wonder what the ID is?

 

Its supposed to be a fairly tight fit in the crankshaft, but you shouldn't have to beat it into oblivion to get it in.

I'm with Nelapse on getting a honing tool or a reamer(much more precise) to get the diameter you need.

Do you have a set of calibers to maybe get a rough idea on how much its tapered?

At least these aftermarket parts are keeping with their stellar reputation.

 

Sweet. They say the ID is .669" and intended for use with the ford 3550/TKO. Im going to order one and try it out.

 

I didnt have to beat the hell out of it. I basically grabbed a hammer and a block of wood and drove it home. It doesnt want to come out, though, so its certainly possible that the fitment is too tight. I tried the extention and grease method to remove it, but all that happens is that hot grease comes flying out from around the extention and the outside of the bushing at the speed of sound.

 

As for the taper, its smaller then the dia. of the input shaft from what I could feel. The socket with tape was the same OD as the input shaft, and it wouldnt pass through the bushing.

 

Thomas,

Since you have the same kit as me, make sure you check the clearance between the retainer bolts 0on the trans and the adapter plate if your using one. The adapter plate wont clear those four bolts.

 

Its sounds like its an ok fit with the crank. I bet it was just machined wrong.

Tell me how that roller bearing works out. The pilot bushing wasn't my first choice, but I was under the assumption that I didn't have any other option.

As for removing the bushing, I rented a tool from Autozone that attached to my slide hammer and worked real well.

Whats the OD of the Input shaft? I would measure mine, but its already in the car.

I hope it works out for you!

 

Actually, I didn't have a problem with the four bolts for the retainer shaft. Hmmm. The adapter plate (another fine piece ) fit flush against the trans, but not flush against the bellhousing. The plate had a fillet that interfered with the bore in the bellhousing. I had to chamfer the BH bore to get it to sit flush.

 

The adapter plate issue mustve been an issue with select TKOs. On mine. It almost fit flush but not quite. I had to enlarge the chamfer on the BH like you, and cut four clearances for the bolts (multiple times b/c not all the plates where machined properly). They missed clearing by a 10th of an inch or so. I know someone here got burned by that bolt issue not too long ago.

As for the OD of the input shaft pilot, I measured .665 inches. The pilot bushing is .670" to give the proper operating clearances and limit potential deflection of the input shaft. Easy way I found to check the bushing is to stick it in first and turn the wheels with the clutch pedal in. If it doesnt turn completly freely, the trans wont shift.

I hope the pilot bearing works and the trans lasts. Its been a year now and its still not in the car yet...

 

I got the pilot bearing. Its basically a generic, off the shelf made in china sealed bearing assy. with a knurled sleeve pressed over it. It does fit the trans, and looks like itll work. Not the best thing in the world but at least it should allow the input shaft to spin freely.

I got a pilot bearing puller, but they didnt have any slide hammers, and there isnt a slide hammer for purchase/rent to be found in all of south jersey at the moment. Typical...

 

Well, figured out what the problem was. Theres a step in the crank, I would assume to keep the roller pilot bearings in place. I saw this when I installed it, and assumed that all would be well just driving the bushing in untill it was flush with the crank, and not all the way in. Wrong... Still to far. Drove it past the step and it compressed the bushing. Lots of fun getting it out. Took about a zillion hard *** whacks with the slide hammer to finally break it loose.

 

Are you talking about the new bearing you just bought? Or the reason why the old one got messed up? The bore in the crank where the bushing gets pressed into shouldn't have a step in it? Do you have a picture or anything I'm having a hard time visualizing that.

 

I think its the reason the old one got messed up. If you where to look into the bore for the pilot bushing, there is a step there for some reason on my motor. It looks like about an 1/8" of the bushing was driven up onto the step, causing it to taper.

 

Wow, I've never heard or seen that before. Yea, I would say that would cause the bearing to taper some. Well, I hope this new one works out for you and the Tko gets some miles on it!

 

Lol, me too. Im tired of pulling this damn trans out to fix this and that.

I got it back together and it seems to be working much better. It shifts ok and the wheels can be freely turned in gear with the clutch pedal in.

One thing that I did forget to do was replace the lube in the bearing with a good high temp moly-free synthetic. Knowing Mr. Gasket, they probably spec'd the cheap **** that will run out at high engine temps and foul the clutch.