please tell us you used a plastigage to check your bearing clearances...

 

Cool! I like it when a job is easier that what you expect. how did the thrust surface on the crank look? how did your bearings look? Find anything bad in the oil pan?

 

I didn't plastigage because the thickness of the new bearings were identical to the old ones & the crank service was smooth. The thrust bearing was the only bearing that had lots of wear on the one thrust side of it. There was a skinny piece of metal in the pan, I am assuming it was from the side of the thrust bearing.
Although the truck is up & running, I still don't know what caused the thrust bearing to fail with that small amount of miles. Being that it's an auto trans & all, there shouldn't be much pressure on the crank.
Any ideas what caused the bearing to prematurely wear out????????

 

Has the trans ever been out? If the torque converter isn't seated into the pump drive properly, it WILL put stress on the thrust bearing. (which side of the bearing was eaten up?)

 

No the trans hasn't been out. The thrust bearing was wore 30 thou on the tranny side. It had so much play that when you shifted from park to drive you could actually see the bottom crank pulley being pushed outward.

 

That's interesting. Wonder if at some point the engine was oil starved, or, just didn't get it changed often enough.......

If it eats this one as well though, gonna have to dig a bit deeper to find out why. If it never happens again, then "why" is just irrelevant.

 

I have a similar problem with end play on the crank. I was wondering how to go about determining bearing size. Do you pull the bearings and then size them? Do the old bearings have sizing information on them? When you plastigage, do you need to have a few different sizes available?

I can't afford a lot of down time so would like to get the parts ahead of time.

Also, how long did the job take you? Thanks in advance for the info.

 

Bearings come in undersize, but, that is more for if you have the crank turned. Other than that, its pretty much one size fits all..... (not like some foreign cars, where they have stampings on the crank, and on the block webbing, and you need to get SPECIFIC bearings...... that's always fun.)

tolerances on rods/mains are pretty tight, so, just one size of plasti-gauge should be good. Don't recall the exact color you need off-hand. Been a while since I had to deal with that kind of thing.....

 

I measured the old bearings & they were the exact same thickness of the new ones. The journals were in perfect shape as well so I just swapped all the bearings out with original standard ones. Got lucky that way but not so lucky in the way that I still don't know why the thrust bearing surface prematurely wore out......
The most time consuming & tedious part of the job was tapping the old upper bearings out. Even then it only took about four hours. Alot easier than pulling the motor!! lol
Oh ya, the pan does come off without raising the motor, you just have to turn it jussst right!
Good luck!

 

Thanks for the update. I got mine done over the weekend. I probably had 8 hours into it. I was trying to remove the top side bearings by myself. So I wasted a few hours on this. Once I got my son to rotate the crank for me, it was a piece of cake. I bought standard bearings as well, then measured thickness of old versus new and they were the same. Did not plastigauge but oh well. I guess technically, you should plastigauge the old ones first then adjust bearing size from there. I had a bunch of shavings clogging my oil pump filter as well. I decided to replace the oil pump and oil pump pick-up/screen as well. My oil pressure is back to normal. I was getting a check gauges warning message at stops due to low oil pressure.

Couple of tips from my job:

1) remove all bearing caps first, identify position to insure proper replacement.
(I tried just doing the thrust bearing by itself. top side came out, but new top side would not go in until all bearing caps were removed. Allows a little more wiggle room)

2) use two people, one to rotate crank.
3) I made a removal install tool from a large nail, cut 2 inches long with head on. The head should be larger than the worm hole. This fit into the worm hole/oil journal in the crank and catches the edge of the bearing and rotates it out or in whichever way you are going.
4) Oil Pan gasket. I bought 4 slotted (no head) 5/16 x 1.5 inches bolts. The same size as the pan bolts. use 2 on each end to hold the gasket in place. Pan fits right over them. Big time and frustration saver.