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Cam bearings removal & installation

Posted: Sun Aug 30, 2015 7:46 pm
by Juro
Today I drove out the first cam bearing. But the bearing has no way out, that is, I am trying to extract it.
The design of the engine won't allow it, since there no opening large enough to extract the bearing.

Now I''m also wondering how the heck I'm going to install the two middle cam bearings.

1992 3.1 engine.

Thanks.

Re: Cam bearings removal & installation

Posted: Mon Aug 31, 2015 10:54 am
by 3X00-Modified
Cam bearings are designed to be installed in a specific way... each bore is not the same size as the other one. On a GM 60* the two center bores are the same diameter, the outers are slightly larger and equal to each other... So when removing you pound the outers into the engine then remove the tool and proceed to crush the bearing to squeeze it through the opening you just pounded it out of... You don't need to remove it in one piece so crushing it is perfectly fine. You will have to do this for one of the inner bearings as well. When installing the bearings should be numbered or lettered or simply placed in a box in the appropriate order to the block From the front of the motor it's 1, 2, 3, 4. When you go to install you would install #2 from the front of the engine, then #3 from the back of the engine and then #1 and #4.

This is pretty basic and similar to how you would install cam bearings on many different engines. I feel like you dive into thing's a bit too quickly and don't do any research on them before hand... and then just post here asking for help.

I'd be really surprised if there is absolutely nothing in the book on how to do this.

I also thought this motor was together and you had been doing oil pressure tests by priming it and whatnot... now it's apart again and your doing cam bearings?

Re: Cam bearings removal & installation

Posted: Mon Aug 31, 2015 7:18 pm
by Juro
Thanks very much, that makes sense. The service manual has only a very brief description of the procedure.

But how do I crush the bearing? with a hammer and long chisel?

Also I changed my mind and decided to do this cam bearing replacement. The tool cost $150, and I wasn't sure.

Re: Cam bearings removal & installation

Posted: Tue Sep 01, 2015 6:07 am
by 3X00-Modified
Just grab it and pull it back through the opening, it will squeeze through... It's soft material.

Re: Cam bearings removal & installation

Posted: Wed Sep 02, 2015 9:00 pm
by Juro
No problemo, I was able to remove them intact.

Re: Cam bearings removal & installation

Posted: Sat Sep 05, 2015 7:22 pm
by Juro
Today i installed the two inner cam bearings with my $150 tool. But the two outer bearings are the hardest to install.
My tool set includes a nylon cone which is helpful in centering the long aluminum tool while I drive it in with my ten pound plastic hammer.
This is possible only for the two inner cam bearings.

The two outer bearings get driven at an odd angle, even when I used a short pipe as a driver. The bearing gets out of round,
and the camshaft will not fit through the bearing. The bearing is destroyed at this point. The only part of the tool set I am
using is the expansion driver, which consists of four aluminum jaws that fit together to form a circle, surrounded by a rubber
tube, and a quarter inch thick washer.

So, I am ordering a new set of cam bearings, but how will I ever install these outer bearings?

Re: Cam bearings removal & installation

Posted: Mon Sep 07, 2015 8:07 pm
by 3X00-Modified
Read the directions on the tool on how to do it.

Re: Cam bearings removal & installation

Posted: Tue Sep 08, 2015 12:07 pm
by 3X00-Modified
Looking at the tool you may have purchased (guessing here) you will have to install the driving extension on one side of the expander assy and the main driver bar on the other side to put the expander in the middle of the two and in a position so you can drive it from the back as well as have the longer driver bar forward of the bearing install direction and go all the way through the cam galley to have the centering cone at the other end... you may need a second hand to hold that in place to keep it centered... This is all a guess since I've never used that tool and from the sounds of it I'm glad I don't have it.

You need to be able to think outside the box and re-engineer tools since 90% of stuff you want to use on this motor is not designed to work with it and you need to figure out these funky details before you start. Installing a cam bearing with out having the driver supported is a huge no no and you should have stopped right then before even attempting it. Would have saved you some money and headache in the long run.

Re: Cam bearings removal & installation

Posted: Wed Sep 09, 2015 3:55 pm
by ronaconda
I have one of these tools and it was a fairly simple, straight forward procedure. It requires a great deal of patience though. As Jon previously stated, the inner bearings will be thinner than the outer bearings so that the inner bearings will go through the outer bearing provision. I can take a peek at mine, but IIRC, there should be a shoulder on the tool attachment that matches the thickness of the bearing. And it should be made of a material that will not damage the bearing. The outer bearings are the most time consuming and require the most patience. Small taps of the hammer are needed to make sure they are square with the block. And make sure the oiling holes are lined up correctly.

Re: Cam bearings removal & installation

Posted: Thu Sep 10, 2015 6:15 am
by 3X00-Modified
You should be able to use the centering cone when installing the end ones to ensure they are straight... My $50 tool had the provisions to allow use of the entering tool and install those bearings as I described.