Pilot bushing installation
Thread Starter
Pro
Joined: Jul 2004
Posts: 711
Likes: 61
From: Waterford CT
Pilot bushing installation
I just finished removing the pilot bushing from the crank of my '71 LT1 by jacking it out with a threaded rod and some nuts. It was tight. Now that I have it out and the hole cleaned up it's obvious that the new bushing won't simply slide in. My question is, just how tight a fit is this thing? I don't have snap gages and my dial caliper won't reach that deep so I can't measure the ID of the crank. Will freezing the bushing make a significant difference? Do I just line it up and start tapping it in with a mallet and big drift pin?
I've been doing my own wrenching for a long time but this is the first time I have had to do this. Any advice is welcome.
I've been doing my own wrenching for a long time but this is the first time I have had to do this. Any advice is welcome.
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
I always just use a socket the same diameter as the pilot bearing , turn it around backwards and put the flat side toward the bearing. Hold it as straight as possible and give it a couple firm blows with a hammer . Once you get it started straight, it will tap right in . just tap it until it is flush with the crank. A trick to take the old one out if you don't have a puller is to fill the hole with heavy grease and use a steel rod the same size as the hole . Drive the rod into the hole and the hydraulic pressure will drive the bearing out.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Measure the depth of the bore and dont drive the bushing in any deeper.If you drive it deeper the ID of the bushing will become smaller and the trans input shaft will fit too tight and cause the bushing to fail.I generally leave the bushing sticking out around 3/16"
(the force needed to drive the bushing is substantial and feeling the bushing bottom out against the very small lip can be hard to feel)
(the force needed to drive the bushing is substantial and feeling the bushing bottom out against the very small lip can be hard to feel)
Thread Starter
Pro
Joined: Jul 2004
Posts: 711
Likes: 61
From: Waterford CT
Thanks for the tips. I put it in tonight by tapping it in with the old bushing as a hammering surface. I also left it proud of the crank surface about 3/16" because that's how I found the stock bushing before I pulled it out. It left shaved bronze under the hole so it was definitely a tight fit.
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
Thanks for the tips. I put it in tonight by tapping it in with the old bushing as a hammering surface. I also left it proud of the crank surface about 3/16" because that's how I found the stock bushing before I pulled it out. It left shaved bronze under the hole so it was definitely a tight fit.
