Another Pilot Bushing question?
Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
Another Pilot Bushing question?
M20 tranny nose measures .590. The guide that came with the luk clutch set is .590. The inside measurement of the pilot bearing that came with the Luk clutch set is .583. The guide that I ordered from Summit (before I knew one came with the set) measures .579. The pilot bushing that I purchased from Advance Auto (before I knew one came with the clutch set) and have installed I cannot measure but the .579 guide fits it perfectly whereas the .590 guide will not insert w/o extraordinary efforts (that I've not attempted). Don't have part numbers on hand but all were correct for the application. Regardless, based on what I presented, is the installed bushing incorrect? If so, is the one provided by LUK correct?
PS. LUK pilot bushing o/d is 1.099 and ht. is .747. The pb installed is Federal Mogul PB-656-HD.
PS. LUK pilot bushing o/d is 1.099 and ht. is .747. The pb installed is Federal Mogul PB-656-HD.
Last edited by Brumbach; Oct 9, 2010 at 10:06 AM.
Race Director
Joined: Apr 2005
Posts: 11,277
Likes: 2,139
From: Bowling Green, Kentucky
M20 tranny nose measures .590. The guide that came with the luk clutch set is .590. The inside measurement of the pilot bearing that came with the Luk clutch set is .583. The guide that I ordered from Summit (before I knew one came with the set) measures .579. The pilot bushing that I purchased from Advance Auto (before I knew one came with the clutch set) and have installed I cannot measure but the .579 guide fits it perfectly whereas the .590 guide will not insert w/o extraordinary efforts (that I've not attempted). Don't have part numbers on hand but all were correct for the application. Regardless, based on what I presented, is the installed bushing incorrect? If so, is the one provided by LUK correct?
PS. LUK pilot bushing o/d is 1.099 and ht. is .747. The pb installed is Federal Mogul PB-656-HD.
PS. LUK pilot bushing o/d is 1.099 and ht. is .747. The pb installed is Federal Mogul PB-656-HD.
Although this advice is a bit late, you should test fit the pb over the transmission input shaft nose to check clearance before installation in the crank.
It is also possible that the pb was a very tight fit in the crank (don't know ?) and that it slightly squeezed down the pb inside diameter during installation.
Bottom line, I would install a new pb and make all my checks to ensure it will fit the second time.
Larry
Le Mans Master
Joined: Feb 2008
Posts: 6,498
Likes: 1,922
From: Folsom CA
The PB 656 HD specs are.
ID .592
OD 1.096
W .755
Rather than pull the new Pilot bushing out I would look at my drill bits and see if one matched the .592 ID and run the drill in to clean it up. The Bronze is pretty soft and would drill out very quickly. I think the drill would try and follow the existing hole as path of least resistance. Best would be to remove it and do this on a drill press where you could maintain the straight hole perfectly. If this one shrank on install the next probably will also. If this was wrong right out of the box you have mis boxed product.
ID .592
OD 1.096
W .755
Rather than pull the new Pilot bushing out I would look at my drill bits and see if one matched the .592 ID and run the drill in to clean it up. The Bronze is pretty soft and would drill out very quickly. I think the drill would try and follow the existing hole as path of least resistance. Best would be to remove it and do this on a drill press where you could maintain the straight hole perfectly. If this one shrank on install the next probably will also. If this was wrong right out of the box you have mis boxed product.
Race Director
Joined: Apr 2005
Posts: 11,277
Likes: 2,139
From: Bowling Green, Kentucky
The PB 656 HD specs are.
ID .592
OD 1.096
W .755
Rather than pull the new Pilot bushing out I would look at my drill bits and see if one matched the .592 ID and run the drill in to clean it up. The Bronze is pretty soft and would drill out very quickly. I think the drill would try and follow the existing hole as path of least resistance. Best would be to remove it and do this on a drill press where you could maintain the straight hole perfectly. If this one shrank on install the next probably will also. If this was wrong right out of the box you have mis boxed product.
ID .592
OD 1.096
W .755
Rather than pull the new Pilot bushing out I would look at my drill bits and see if one matched the .592 ID and run the drill in to clean it up. The Bronze is pretty soft and would drill out very quickly. I think the drill would try and follow the existing hole as path of least resistance. Best would be to remove it and do this on a drill press where you could maintain the straight hole perfectly. If this one shrank on install the next probably will also. If this was wrong right out of the box you have mis boxed product.
The OD can be machined to fit, since it seals against the steel crank and does not need the oiling pores open for lubrication purposes.
Brumbach needs to remove the incorrect pilot bushing and install one that fits his transmission input shaft without modification.
Larry
Le Mans Master
Joined: Dec 2007
Posts: 8,000
Likes: 659
From: Puget Sound
Jim
Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
If you don't mind destroying it in the process, use a tap one size larger than the hole and thread it into the bushing, when it bottoms out, keep turning it and the bushing will walk right out. Total time = 1 min. Next time, check the fit of the bushing on the input shaft first, but you know that now don't you?
Jim
Jim
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Safety Car
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From: St. Joseph Mo
If you don't mind destroying it in the process, use a tap one size larger than the hole and thread it into the bushing, when it bottoms out, keep turning it and the bushing will walk right out. Total time = 1 min. Next time, check the fit of the bushing on the input shaft first, but you know that now don't you?
Jim
Jim
