Can anyone suggest a source for oversized main bearings for my 1990 Cadillac Fleetwood (front wheel drive) ?
VIN 1G6CB1336L4274368
Engine is 4.5 Liter
Here is what I am looking for:
An oversized #1 Main Bearing which was identified by a blue edge color on the original GM part.
An oversized #5 Main Bearing which was identified by a black edge color on the original GM part.
Thanks for your help!
Can we assume you have tried a GM dealer, if so and they are discontinued, I am sure Napa has engine bearings, you just need to focus on the under/oversize of course.. Why are you replacing just 2 bearings, is the for the noisey number one main?
Hi and thanks for replying!
Yes these parts discontinued long ago at GM dealers.
Reason for replacing is of course to correct the #1 main bearing knock.
Engine has high milage and I am thinking that I will need the oversized bearings for #1 and #5.
In the aftermarket replacement parts market, bearings generally come in .0100"
increments, for re-ground craks, while the factory had .0005" increments.
Any idea where I might find these OE versions?
You will not need #5, that was never an issue, number one wore because of the common practice of over tightening the belts, I would check Napaonline for the proper bearing, you need .001, and .002 over/undersize. to correct the thumping in the front of the engine, which btw was a customer complaint but really did affect the engine. When the pan is off you must plastigage #1 to determine which bearing you need, to do this you must get upward pressure on the crank to get an accurate reading. Napa does have sets in 001 and 002 over/undersize.
Understood. I am very grateful for you sharing this with me :)
Quote from: kj4821 on November 29, 2011, 11:23:48 PM
Understood. I am very grateful for you sharing this with me :)
Your welcome, always feel free to ask for advice, the people here are the best.
DJAKES
I have a 90 SDV 4.5 V8 .If you are pulling the engine just for the bearing knock, don`t waste your time. Mine had bearing knock at 65K, & it still has it at 171K. Use 10w-30 oil, not 5w-30, & don`t use Mobil 1. Use GM oil filter, or better.
This is NOT a function of belt tension- it is a serpentine setup with a spring tensioner.
The big problem you might have is a leaking front seal & pan gasket. I fixed that by ignoring it, & washing the engine & driveway occasionally. Don`t misdiagnose PISTON SLAP for main bearing issues. These engines had it, on cold start.
Of course, if you have torn down the engine & are rebuilding it, GOOD LUCK, you will need it.....
c chleboun #20099