The Stovebolt Site Forums The Shop Area Engine Shop pilot bearing question

I have a 53 6400 series and am in the process of installing a 61 235 motor that has been rebuilt. I had a machine shop do all the hard stuff, and put the motor back together myself. I have a shop manual for 1953. In the manual they show the procedure for replacing a pilot bearing. In several catalogs from several suppliers: Chevs of 40's, Jim Carter, the Truck Shop, etc. they show a bearing and a bushing, that they all say goes in the end of the crank shaft. I don't remember seeing anything like that, and I certainly didn't put one in. We used an alignment tool to line up the clutch,and it seemed to fit perfectly in the end of the crankshaft. I don't know where we would have put a bearing or a bushing. I don't understand this. Is it possible the bushing was in the crank, and I simply didn't know what I was seeing, or have I missed something important. Thanks for your help. Allen

I need to do this yet, but as of yet I have not. The pilot bushing is a brass bushing in the end of the crank. I have not removed my old one yet, but I recall someone saying that you can remove it by filling the hole inside of the bushing with grease and then using a similar size rod or dowel to tightly fit in the hole filled with grease and strike the rod/dowel with a hammer and the bushing is supposed to pop out. Let me know if this works for you.

If your alignment tool fit, then the bushing was in there. The machine shop may have put one in for you or the old one was never removed. If you're gonna remove it, I have heard that a 9/16" or 5/8" tap works good. It digs into the bronze and when it bottoms out on the crank it pushes out the bushing. I have not tried this but have heard it works well.

cujo8: Now is a bad time for me to be finding out about all this. I have put the motor back together and have it in the truck. The thought of going back and working on a bearing isn't something I'm looking forward to. I think that what happened is that the machine shop didn't do anything about the bushing and I didn't know about it, so the old one is still in there. As I said earlier, the alignment tool fit perfectly, and I think I would have noticed if something was missing. Based on this, I think I am going to go ahead and assume the old one is there. What do you think about this? Am I risking doing some awful damage if I'm wrong? Allen

If the pilot shaft fit snugly in the hole in the rear of the crankshaft then in all likelyhood the bushing was in there. Sometimes they want be brass colored and if you weren't looking for it you moght not see it. Now does that reasure that you have one in ther I don't know. Did you stick the pilot shaft in to check for a tight fit before you ever put the clutch or pressure plat up to the flywheel? If you did and thought it was fine then you probably have one....Ronnie

Shipwright: Thanks for the info. You just made me feel a lot better. Allen

I wouldn't worry about it if it's not making any bad noises. It's just an oil impregnated bronze bushing with no moving parts. Should last a long time. I think you would have noticed if it was the needle bearing style. I believe that style was only stock on the GMC motors.

Shipwright: Again thanks. I'm almost sure it would have been a bushing and not a bearing. All the catalogs indicate the year motor I have would take the bushing. Based on all the quick help from everyone, I'm going to proceed. After thinking about it more, I believe the machine shop would have replaced it if they had taken one out, so either way I believe one must be in there. If I don't hear anything strange when I finally start it up, I'm going to give a big sigh of relief and forget about it. Allen

When I had my engine work done I had my crank polished and the machine shop did not remove the pilot bushing. I think mine is probably OK, but since I have not put the engine back in my truck yet, I will put a new pilot bushing in just for the warm fuzzy feeling. Yours is probably fine and you probably would have noticed if it was missing when you used the alignment tool to install the clutch. I still need to get one of those alignment tools to install my clutch. I picked up a new clutch and pressure plate off ebay for my 54 GMC, but there was no alignment tool included. I thought they usually included this in these kits. Anyway good luck and happy truckin'.

cujo. I had my work done at a Carquest Distribution center, and machine shop, and got the clutch, throw out bearing, etc. there also. They did not supply the alignment tool but the store had one on hand, so I got it when I picked up everything. It was one of the few thing that did not cost a lot. Again thanks. Allen

Alignment tools are best but you can make your own with a dowel rod and masking tape. Just build up the difference between the dowel rod and the bushing by wrapping the tape around the rod until it is the right diameter. Then do the same for the clutch plate. Doesn't take long and works very well.

The best clutch alignment tool is an input shaft from a transmission like the one you are installing in your truck.

Joe

Try it out and worse case is that it'll squeal when you release the clutch from a stand still.
I too didn't replace the pilot bushing when I helped my son install a 350 in his '60 Burb. Yep...it squeals :mad: .
Fortunately, I have a 2 post lift that will help the replacing process a little easier .

I've done this many times, fill it with grease and use a spare front trany shaft and hit it with a hammer. If you have someting with the same diameter, it will work just as well. :-) Lothar

i switched my 70 chevy from auto to a manual so i had to put in a new pilot bushing (one was included in the kit) but thing that surprised me was there was also no alignment tool in my Napa clutch kit either problem i had was you couldn't put the truck in gear with the clutch engaded so i would shut it off and put in gear and push in the clutch and it would take off on its own so i was getting pretty ticked cause i thought something wrong with the clutch or tranny but turns out my pilot bushing was to tight, had to put it in gear put the clutch in and hold the brakes and start it worked perfect and then it was alright "sigh" what a relief that was
Nate