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main bearings what part #

Posted: May 2nd, 2011, 2:14 pm
by Zjdamien
ok ive got about 12,000-15,000 miles on my 4.6 stroker and ive got my crank walking and pretty good bit im going to drop my pan next weekend im going a head a ordering and set main bearings to get a new thrust bearing and im not shur to get mains for the 4.2 or the 4.0 my machine shop put the rotating assy together for me and i dont know what bearings they used thanks and the crank has been turned .010-.010

Re: main bearings what part #

Posted: May 2nd, 2011, 5:31 pm
by SilverXJ
You want the bearings for the 4.0L.

Re: main bearings what part #

Posted: May 2nd, 2011, 6:10 pm
by IH 392
The main bearings must match the block, there are two sets, the year split is '90/'91.

Re: main bearings what part #

Posted: May 3rd, 2011, 10:26 pm
by Cheromaniac
Zjdamien wrote:ok ive got about 12,000-15,000 miles on my 4.6 stroker and ive got my crank walking and pretty good bit im going to drop my pan next weekend im going a head a ordering and set main bearings to get a new thrust bearing and im not shur to get mains for the 4.2 or the 4.0 my machine shop put the rotating assy together for me and i dont know what bearings they used thanks and the crank has been turned .010-.010
You'll need Clevite main bearings MS-1947P-10 if it's a '91+ HO block or main bearings MS-704P-10 if it's an '87-'90 Renix block.
You might want to ask yourself why your crank has so much endplay. If you have an auto tranny, the thrust bearing (no.3) can wear out prematurely due to torque converter issues. Just hope that the crank itself hasn't been damaged.

Re: main bearings what part #

Posted: May 6th, 2011, 5:27 pm
by Zjdamien
you think the tq converter could cause it ive heard of manual transmissions could cause thrust bearings to wear out over time but never a converter

Re: main bearings what part #

Posted: May 6th, 2011, 6:46 pm
by SilverXJ
Its possible, but the torque converter would have had to balloon.

Some reading:

http://www.enginebuildermag.com/Article ... ilure.aspx

Page 22: http://www.engineparts.com/publications/CL77-3-402.pdf

Re: main bearings what part #

Posted: June 25th, 2011, 2:04 pm
by gradon
So my brother and I attempted to mock up the 4.9l bottom end to make sure the machinist decked the right amount. The block is a 96nvh and the Clevite ms1947p10 bearings(91-01) have offset locating tabs. The lowers fit in the caps fine, but there is no offset notch relief in the block, just a center groove. Do I cut the notch off the bearing? Clearance the block for the bearing?

Re: main bearings what part #

Posted: June 25th, 2011, 3:45 pm
by SilverXJ
The bearings for the block side have a center tab. The bearing for the caps have offset tabs. If both your halves have offsets you have the wrong or misboxed set.

Re: main bearings what part #

Posted: June 26th, 2011, 5:19 am
by Cheromaniac
gradon wrote:So my brother and I attempted to mock up the 4.9l bottom end to make sure the machinist decked the right amount. The block is a 96nvh and the Clevite ms1947p10 bearings(91-01) have offset locating tabs. The lowers fit in the caps fine, but there is no offset notch relief in the block, just a center groove. Do I cut the notch off the bearing? Clearance the block for the bearing?
The MS1947P main bearings have locating tangs in the center so you were obviously given the MS704P main bearings for the 4.2 and Renix 4.0 blocks by mistake (packed into the wrong box). Just return them in exchange for the correct ones.