Hi I am installing a fully rebuilt 73 buick 455 in place of 71 350GS with a 4 speed. I did not realize that not all crankshafts have been drilled for a pilot bushing. Like to know if anyone had this problem and how to solve it. I am now thinking of either sell the 455 and build up my 350 to avoid all the problems. George
its no problem all. TA performance has the bushing you need. You may have to dremel the crank alittle so you can tap it in. heres a link that may help http://www.v8buick.com/showthread.php?t=126755&highlight=pilot+bushing Gord
George, Can you post a pic of the crankshaft in question. I want to document one of these cranks. Many have had problems with what appears as the cranks not being cleaned up to accept the bushing thus causing a smaller I.D. and distorting the bushing so as the the input shaft would no longer slide thru. Dennis Manner could not deny or confirm if all cranks were prepped or not when I discussed this with him last year.
I was one of them. The bushing was not concentric to the centerline of the input shaft. This caused the input shaft to spin when the clutch pedal was depressed. Made it almost impossible to shift into reverse. After about 500 miles, the bushing spun in the crank I.D. Pulled the engine and had the crank drilled properly - no more issues.
So your crank was drilled just not concentric? This sounds more of a machining error than not drilled "at all" I am not disputing anyones word, as we all know many things happended back in the day. I am just trying to document hopefully with pics for all in the future. Again thanks to everyone who supports this section of V8buick as we all have helped each other with our findings.
I know there's been a debate about the stock holes not being centered but I have no idea why the hole wouldn't be centered. On my 73 motor the hole was about .010 undersized for about half the depth and then stepped even smaller the other half of the depth. I machined a stock pilot bushing to match the hole I had with a .002 interfence and drove it in. After about 100 miles it's working good so far. This of course begs the question "Why are there two different diameters in some cranks?" Also for some reason my 73 block was drilled and tapped for a Z-bar stud.
I've seen 74 blocks drilled too. I think the 75 and 76 blue blocks were the only ones not drilled. Thank god they kept the boss though.
My 73 block was NOT drilled or tapped for a zbar stud, but the crank was machined properly for a pilot bushing. I just did my clutch 2 weekends ago and the bearing went in with no difficulty. I did use a Napa roller unit instead of a bushing if that changes anything. o No:
I'm currently fighting this problem of the two different diameters with the step half way in the hole right now:af: I'm going to mess around with it today, and if it fights me, Hello TH400:Smarty:
With the correct measuring devices it's really quite simple to have a bronze TO bushing turned to the size needed for light interference fit in the crank.
hi, I recently switched from auto to tremec in my 69 wagon. although the crank was drilled a pilot bushing didn't fit. dick millar racing makes a bearing that you tap into the torque converter recess of the crank. i had it in 5 days from the states to canada. i think it was about 30 bucks. pete
It's really not quite that simple for most people:Smarty: Two different diameters would be one thing if they were concentric with one another, but the step half way down is off center, almost like the flute on the drill broke as it neared the bottom, and when it broke, it pushed off center and took more out of one side off-center. I'm a laid-off Moldmaker, and I still have access to the shop to use machines,which I did. I put my bushing in a lathe, and modified it to work. Someone without access/ability would be screwed, or at the very least they would either have to remove the crank and take it to some machine shop. This other style bushing that fit's it the torque convertor pilot sounds like the way to go for most Buick people considering a manual trans, just make sure you have it on hand in advance.
