I am replacing the clutch in my 72 next week. It will be a Centerforce dual friction and a CF throwout bearing. I am going back to the conventional GM style fork and adjuster rod, and will be using a Lakewood adjustable pivot ball. Since so many have had problems with the pilot bearing fit I was going to go with a Dick Miller racing unit. But, I noticed Summit is now selling a Bronze bearing from RAM (pn RAM-BU75) for Olds/Pont/Buick/Chevy that looks like the same type of design size wise as the DMR bearing, but it's still a conventional bronze unit. Looks like the best of both worlds to avoid potential problems with unfinished cranks. I ordered it so it should be here on Tuesday or Wednesday. Has anyone used one of these? o No:
It's shorter because it doesn't install in the conventional pilot bearing recess. It fits in the center area on the crank where the torque converter would usually align into. If you have seen the Dick Miller sealed pilot bearing it will probably make more sense. I have picked up a conventional bushing as well, just in case this guy isn't what I'd hoped it would be.
I ran a conversion bearing in a 442. It failed after 800 miles. It was measured and installed correctly. I pulled the engine, and found out that the torque converter recess was out of concentricity with the center line of the crank. I would not trust that bearing. It looks to be a cheap chineseum unit...:blast:
Well since I do already have a conventional Chevy style bearing installed in my crank, I'll probably not risk experimenting with the olds piece.
Mike, after you install the bronze pilot bushing, lift up the tranny and pre-fit the input shaft to make sure it fits in the inside diameter of the newly installed pilot bushing. If you have an old input shaft, you could use that for checking also. I did not have success with the RAM brand pilot bushing, I used the roller from NAPA. Hope that helps!
Thanks for the info. Funny you mention the Napa roller, because I have 2 of those besides the Ram bushing.
Mike, I had issues with the bronze one too. First I had to slam it in there with a hammer and punch. When I did, it squeezed the ID of the bushing so the input shaft was really tough to fit in. So much so, I was worried when I had to use the four bolts on the tranny ears to draw it in to the bellhousing. I found mic'ing the ID of the crank and the OD of the pilot bushing helped. They were way off and I turned the bushing on a lathe to help both ease the bearing install and the tranny install. I went 5 thou over the ID of the crank on the bearing.
I had a roller in the former BBB 4X4. Nice piece. But, I had the crank hole checked during the rebuild. If your crank hasn't been checked, you could tear a roller up. I've heard tales that automatic engines cranks were left a bit sloppy there, but I can't verify it. I can't remember if my crank needed anything or not.
There is a bronze bushing in the crank right now. I am swapping it out only because I need to change the clutch and I don't want to tear this damn thing apart again. :laugh: My hope is that the guy who had the car before me and did the original butchered 4 speed swap at least did this one part of the conversion right. o No: I'm still kicking myself for not changing the clutch and pressure plate when I originally repaired this mess 2 years ago. ou: Oh well...live and learn
Mike, I had to perform the same procedure Paul did with my pilot bushing to get it to go in. Just took a little off the OD to get it to tap in nicely. My first bronze bushing was a fight to get it to go in. I should have known something was'nt right especially when the plastic clutch alignment tool would not go in the pilot bushing. Paul is exactly right on the money. :TU:
Now I'm wondering if I should try and find a machine shop and have them turn down the O.D. of one of my bearings before I dive back into this. I'm still hoping that by some miraculous act of compassion by the Buick gods that the stock size bearing will fit. :laugh: I have to ask. What would all of us misfits who actually prefer to row these Buicks do without this board? A big :TU: to all of you guys!!!
The other thing you could do, which I have done in the past is buy bronze bearings in mass quantities. Right now I have 6 or 7 of them. And they don't all mic the same. You could take the smallest one and try that one and return the rest. Luckily I had access to a lathe and took it down myself. All of us misfits would be throwing good $$ out the window without this board. Or at least more then we already do.
