Hydraulic Throw Out Bearing Issues

[Bolted to Floor]

Hi Guys need some insight here. It’s a 67 Mustang with 390 and TKO 600. The clutch pedal went to the floor this afternoon and left a puddle under the car.  Fluid was leaking from the bottom of the scatter shield. Pulled the transmission and got a look at the hydraulic TO bearing.

It looks like the adjusting collar had adjusted itself into the housing increasing the distance that the bearing had to be pushed out to engage the clutch. Is that possible? Thought it was supposed to go the other way. I didn’t realize this until the bearing separated from the housing in my hands.

Looking down in the housing, it appears that the internal seal / gasket has twisted. The orange colored seal looks to be in good shape. Are these things rebuildable? What’s my chances with untwisting the internal seal and slapping it back together?

I have no experience dealings with these things. Any help is greatly appreciated.

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This is the best picture while it's still in the car.

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[preaction]

It looks like it may have over traveled and leaked or the seal may  have twisted from being installed dry either way I would install a new seal ( buy two ) before putting it all back together.

[cammerfe]

I've found that local supply outfits are quite willing to give knowledgeable advice. I don't know where you're located, but Bearing Supply here in Livonia is my usual 'go-to' place.

KS

[My427stang]

With the grunt work involved with pulling the tranny, I'd be hard pressed to just reseal without a cause.  What determines it's location during initial setup?  Could you have made a mistake?  Is there a threaded adjustment without a lock nut or loctite, etc?

The toughest part about rebuilding it is likely finding the parts versus buying another TB, but I'd want a cause first

[Bolted to Floor]

I was tired the other night when I was making the post and left out details I probably should have included. The car has been driven about 180 miles to the TO bearing issue. Mostly on side streets. On the freeways where I can maintain some speed, there is a vibrations in 5th gear that is noticeable at 1500 RPM and 50 MPH. It seems like it’s there in 4th gear at 1500 RPM, but it’s really hard to tell with the rest of the car noises and exhaust. Dam Flowmasters!! The new Borlas XS Pro’s have arrived to replace them.

When pulling the transmission, one of the bolts that holds the rubber mount to the transmission was gone. The other was half way out. I don’t know that they worked loose or I never tightened them. I also found rubbing / contact marks on the transmission case and the cross member.

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The drive shaft was built about 2006 by Houston Drivetrain. I have since changed out the yoke to fit the 5 speed. The receipt didn’t indicate balancing, but I will take it and have it checked this week.

I’m in agreement on the over travel. I found my pictures from when I set it up last year.

image

It was set up according to the instructions to have .125” of clearance between the TO bearing the clutch diaphragm fingers. Here is a video from Modern Driveline’s web site.

https://youtu.be/0X2JAoHhy0A

As far as a cause, could the vibration I’m feeling through the car be a possibility??

Mistakes – I’ve made plenty, but I try to limit myself to 3, the first one, the last one, and the next one. Keeps me from having to count too high. XX But I think I had this set up correctly.

The bearing is supposed to be self-adjusting to allow for wear on the clutch disc. If I understood correctly, the bearing will move back toward the transmission as the clutch disc wears and the fingers move out and away from the flywheel. The adjusting collar by the transmission will rotate itself into the Tilton body.

It looks like a seal kit is available, will have to see if I can find a video on the rebuild. 

Edit to add details

[C6AE]

I have seen notable vibration from a misaligned bell housing. Many seen to accept that these things are aligned "good enough". But having been "bit", I always check them and perhaps now I get them closer than required. (Like .002-.003" concentricity, they are usually square except for excess paint)

[jmlay]

When it let go did it blow fluid into/onto the clutch? If contaminated you may need to replace the disc as well..

[Bolted to Floor]

I have seen notable vibration from a misaligned bell housing. Many seen to accept that these things are aligned "good enough". But having been "bit", I always check them and perhaps now I get them closer than required. (Like .002-.003" concentricity, they are usually square except for excess paint)

I have those measurements. I will dig them up. I thought all was good.

[Bolted to Floor]

When it let go did it blow fluid into/onto the clutch? If contaminated you may need to replace the disc as well..

I think I got lucky with this. All I can see around the flywheel is dry along with the clutch fingers.

[Chrisss31]

What did you use for a bellhousing?

[Bolted to Floor]

What did you use for a bellhousing?

It’s from QuickTime.

[C6AE]

I have seen notable vibration from a misaligned bell housing. Many seen to accept that these things are aligned "good enough". But having been "bit", I always check them and perhaps now I get them closer than required. (Like .002-.003" concentricity, they are usually square except for excess paint)

I have those measurements. I will dig them up. I thought all was good.

Probably not that then...
 I once did a transmission conversion in a Mustang and didn't check it and it was basically undriveable!

(I have to check this on large truck engines whenever we install a clutch and believe it or not, a factory bell-housing is usually within just a couple of thousandths.)

[Bolted to Floor]

I’ve spent close to 2 hours on the phone with MDL and Tilton. They both said close to the same thing on all accounts. Like the collar shouldn’t have adjusted inward that far that soon. Spent a lot of time discussing how I set the clearance between the bearing and the clutch fingers to make sure I did it right to begin with. Sent them both a bunch of pictures of how it went together and how I found it after the fact. I also got to confirm that the runout was within spec for the transmission into the scatter sheild.
 
MDL wasn’t a fan of Centerforce when I ordered the kit in 2013 for the 5 speed. They both had the same story on the weights interfering with the bearing in some but not all applications. Mine shows no signs of contact. They also talked about the Tilton TO bearing not liking the how the weights caused varying clamping force depending on RPM.
 
MDL has made some changes to the kit since I purchased mine in 2013, like a .500” shim at the transmission isolation mount to raise the back end up to get the drive line angle right. I asked the questions before buying the kit in 2013. Will I have to cut the trans tunnel, no. Will the drive line angle be right, yes. I did test fit the transmission before body work was complete. I didn’t check the angle though.  Shame on me for doing half of the work. My boss talks about “trust but verify”, it works for this.
 
If the angle isn’t right when I get it back together, I don’t think I have the room to install .500’ worth of spacer. That should put me in contact with the tunnel. I will have to install the angles on the rearend to roll the pinion.
 
Neither was overjoyed with the idea of staking the threads on the collar to prevent or slow adjustment, but understood if I went that route. The Tilton rep did offer up using urethane on the threads to really slow the adjusting ability.
 
Tilton did ask about tire age when I mentioned having them re- balanced. Could they have flat spots?? At just over a year old, I don’t really think so.
 
After all the talk, there’s no smoking gun on what caused the collar to adjust inward other than speculation on the vibration!!
 
A new seal kit for the TO bearing is coming, it should be here on Friday. The drive shaft checked out on balance, it’s not the problem. I will get the tires to the shop this weekend.
 
Contrary to what I said above, I am looking into a new clutch. I found several stories about the weights on a Centerforce causing vibration issues. As I was laying under the car talking with Tech support, I noticed one of the counter weights hanging below the others on the high side of the circle! I pushed it up and it stayed, but for how long. I can only wonder if that’s the problem. The down side to this is I think I pushed in the clutch at speed and the vibration continued, just don’t remember for sure, too much going on lately. I didn’t get enough time to troubleshoot before the TO bearing failed.
 
Still looking to get it to the Mustang Steve Bash in Glenrose Texas on September 15th. At this point, Sheryl has little faith in it and wants to trailer it up there. She doesn’t want to be stranded on side of the road. I can’t say I blame her.

[My427stang]

Although I have installed a few CF clutches over the years without issue, mostly in import 4x4 trucks, I am not a fan.  I just think the weight design is cheesy.   I think a swap to a McLeod or Ram, I like McLeod better but only a little, is a good move.  Long style or diaphragm, they both work great, I have one of each in my 2 vehicles

As far as the spacer, when I did my TKO swap, I used a Dark Horse crossmember, and I deeded to raise it about 1/2 inch.  Look close at the vent in the front, it likely will take a whack of the hammer on the floorboards to clear, and honeslty, if angle is right, I do not know how you can avoid cutting the seat cross brace unless it is one of the modified transmissions for that purpose.  I proudly cut mine, it's no big deal, you just notch it

As far as angle, don't trust anyone, it should be 3 degrees down compared to the frame, and the pinion should be slightly steeper 1-1.5 degrees as an estimate, as the pinion will rotate up and needs to be parallel during acceleration.  Use a cheap angle checker or with an Iphone you should have a compass app that has a second page with angles

[Bolted to Floor]

Thanks Ross.
I prefer a diaphragm  style. I developed a phobia to long style clutches after changing so many of the Borg and Beck parts house reman-ed units when I was 16-21. I could have been a wee bit abusive to them also. 

Even though it’s an area no one will see unless they are working under the car, screwing up the nicely painted underside is more of an issue than the actual cutting.

I will check the angle as soon as I can get it all back together.