Tips for In-Engine Bearing Replacement

desertred · Jan 27, 2004

I'm in the process of replacing the rod and main bearings of my 4.0. Got the rod bearings done, but having a bit of trouble with the main bearings. They are not in bad shape, but have worn to .001" below the maximum clearance specification. When trying to replace bearing inserts (same size as current configuration), I couldn't get the new inserts to rotate around the crank. It is just a bit to tight to try it by hand. I fret at trying to force them around the crank by other means. Does anyone have some tips on what I can do to drop the crank enough to get the bearing insert around the journal without binding the insert? TIA

XJguy · Jan 27, 2004

desertred said:
I'm in the process of replacing the rod and main bearings of my 4.0. Got the rod bearings done, but having a bit of trouble with the main bearings. They are not in bad shape, but have worn to .001" below the maximum clearance specification. When trying to replace bearing inserts (same size as current configuration), I couldn't get the new inserts to rotate around the crank. It is just a bit to tight to try it by hand. I fret at trying to force them around the crank by other means. Does anyone have some tips on what I can do to drop the crank enough to get the bearing insert around the journal without binding the insert? TIA

Ive done this twice unfortunatly with bad results...new bearings went bad in no time even with thicker ones. But I was able to slide them in once all the bearing caps were off.

I read somewhere to use a little dish washing soap so as to lube things up so that it will slide better....I never tried this nor do I know if it will work. Not good to use oil since then you might have a bearing rotate once the engine is running, I assume the soap will just dry up with the heat. Good luck. Maybe someone else will chime in.

XJguy

cubes · Jan 27, 2004

I usually loosen all the main caps to allow the crank to drop down slightly, then replace them one by one.

desertred · Jan 28, 2004

Thanks, I will try and loosening all the bearing caps. Did doing this allow the replacement inserts to be rotated around the crank by hand, or did you have to use the crank to rotate the upper bearings in place?

XJguy said:
Ive done this twice unfortunatly with bad results...new bearings went bad in no time even with thicker ones.

Interesting. Any idea why your replacements went bad so quickly? Did they gage as being in tolerance?

.

cubes · Jan 28, 2004

desertred said:
Thanks, I will try and loosening all the bearing caps. Did doing this allow the replacement inserts to be rotated around the crank by hand, or did you have to use the crank to rotate the upper bearings in place?

Interesting. Any idea why your replacements went bad so quickly? Did they gage as being in tolerance?

.

normally once the caps have been loosened all you need is a flat head screwdriver to push the upper shell out and to install the new insert without having to rotate the crank.. (be careful not to damage the new inserts or the crank journals!)
I've done a few of these and they all turned out o.k.
good luck...

XJguy · Jan 28, 2004

desertred said:
Thanks, I will try and loosening all the bearing caps. Did doing this allow the replacement inserts to be rotated around the crank by hand, or did you have to use the crank to rotate the upper bearings in place?

Interesting. Any idea why your replacements went bad so quickly? Did they gage as being in tolerance?

.

Yes I bought the bearings according to what I gauged...but the crank was just too shot; out of round.

XJguy

Tips for In-Engine Bearing Replacement

desertred

NAXJA Forum User

XJguy

NAXJA Forum User

cubes

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desertred

NAXJA Forum User

cubes

NAXJA Forum User

XJguy

NAXJA Forum User

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