The Stovebolt Site Forums The Shop Area Engine Shop Throw out bearing flops around

My throw out bearing makes a squeeling noise once in a while. I crawled under and noticed that if I knock the side of the bearing with a big screwdriver there's almost 1/2" of sideways movement of the whole bearing. What keeps the throw out bearing from floping around on the end of the fork? I'm wondering if I have the wrong bearing installed. I know there's supposed to be clearance, but there's a BIG difference between the outside diameter of the tranmission input shaft and the inside diameter of the throw out bearing. john.

From your description , it sure sounds like the wrong bearing.
The clearence of the bearing onto the bearing guide is just enough for a smear of grease.
You do have a nose cone on the g/box ?
The bearing does not run directly on the trans shaft.

What's the nose cone look like? In this pic below, the clutch is depressed. It's kinda hard to tell but does it look right? The tranny is on the bottom, pressure plate on top.
[img]http://img.villagephotos.com/p/2003-9/378428/throwin.JPG[/img]

From the looks of the pic, you've got the wrong bearing installed. It's obviously off-center. There should be just enough clearance for an easy slip fit on the bering retainer, not a sloppy fit.
Jerry

That's what I was begining to think, but I bought this bearing from "The Filling Station" and It's suppose to fit all 1938-1966 passenger and trucks. Is it possible that it supposed to "nest" into the fingers of the pressure plate? :confused:

I really can't tell from the picture but its possible the bearing is nestled around the input shaft housing but the bearing itself has come apart and the "slop" is in the middle of the bearing where it has come apart??? one thing for sure..... that doggie has got to come out of there.

The only way to tell for sure is to pull the trans, and do some measuring. The bearing part of the throwout should ride on the surface of the pressure plate spring, not inside. I'm assuming you have the diaphragm-type pressure plate, right? The 3-fingered Borg & Beck pressure plate would take a very different throwout bearing, but I don't remember them ever being used on a Chevy. The throwout bearing carrier should slide over the snout of the transmission with just enough clearance to allow it to slide freely, with no more than a few thousandths of clearance. The one in the pic looks like it's 1/4" or more too big.
Jerry

Thanks alot for the info. I'm not looking foward to it but that "doggie" is coming out for a closer look. john.

John , the nose cone on your tranny seems to be one of those without a bearing guide . It is a little difficult to tell in the photo .
I see these ocassionally , but I don't know what bearing setup is supposed to go with them.

The thrust bearing you are using looks just like the one that is designed to run on the extended nose cone/bearing guide ( I am sure there is a propper name for it ) .
I see you have a '45 truck , so if original , then it would have a diaphragm clutch , which that t/bearing is good for.
Maybe the box has been changed / repaired before you got it ?? And the nose cone is from another model...........

Dusty,
That must be the bearing retainer. It's a flange (with a 6 hole pattern) that has a cylindrical tube on it. It looks like the throw out bearing is supposed to ride on the tube. From what I can tell on my set up, it looks like the tube portion of the bearing retainer isn't there. Maybe it's broke off. That explains why the throw out bearing flops around on the end of the fork. :mad: I guess I know what I'm doing this week.

Hmmmmm- - - - -
Looks like I missed that in the pic! If the guide is missing, it would definitely explain the loose fit. Get it out of there and do some checking, and if it's a missing bearing guide, it's an easy fix. I think I'd install a new throwout bearing just to be on the safe side!
Jerry

Well, I got that problem solved. I removed the tranny for a closer look. From the looks of it, there's supposed to be a tube that screws into the front bearing retainer. And I so happened to have another tranny that I had for a backup. The extra tranny is a little different but it has a one piece bearing retainer with the tube allready on it. It fits perfectly on my existing tranny. I now have the tranny back in the truck and I have about another hours worth of hooking stuff back on and I'll be back to cruising. Thanks alot for the info. This website is too cool!!

Thanks for the update John , it's always good to hear a success story.