Author Topic: Main Thrust bearings (Read 12276 times)

wannam42 · « **Reply #15 on:** January 01, 2010, 11:05:21 PM »

peerless (Robert) mentions that he uses the m20 bearings which are 360-degree but the original M42 main caps need to be machined by MM.

http://m42club.com/forums/showpost.php?p=66024&postcount=3

strypt · « **Reply #16 on:** January 05, 2010, 01:23:14 AM »

I use standard M50 thrust bearing, 360 deg and no problems so far.

KenC · « **Reply #17 on:** January 05, 2010, 01:37:44 AM »

Quote from: strypt;84058

I use standard M50 thrust bearing, 360 deg and no problems so far.

Part number or link to where to buy it online?

strypt · « **Reply #18 on:** January 05, 2010, 04:32:37 AM »

Sorry I don't have a p/n for it but it's a standard M50 bearing, bought it from my local dealer.

nicknikolovski · « **Reply #19 on:** January 06, 2010, 05:12:54 AM »

And the M50 bearing fits straight up to the M42 bearing cap?

strypt · « **Reply #20 on:** January 07, 2010, 03:08:01 AM »

wannam42 · « **Reply #21 on:** January 07, 2010, 08:50:39 AM »

The M42 only has half a thrust main bearing (i.e. the corresponding bottom thrust bearing is a plain main bearing with no thrust surface). Strypt, did you use the M50 thrust bearing for the bottom as well?

Did you use M50 main bearings all the way or just for the thrust bearing?

strypt · « **Reply #22 on:** January 07, 2010, 09:44:33 AM »

M42 and M50 use the same bearings except for that one half of the thrust bearing. The M42 "bottom" bearing is therefor the same as in the M50.

Nomadic · « **Reply #23 on:** January 13, 2010, 05:02:47 PM »

While we are on the subject of thrust bearings.... I was just inspecting the oil filter from my 200k oil change and found a bunch of "copper leaf" in filter folds. The shavings look quite flat to me. I'd expect crank bearing to have a slight curve to them, so I suspect these are shavings from the thrust bearing.

Any thoughts on what else these could be? How bad does this look?

Can the thrust bearing / crank bearings be replaced by pulling the pan w/ motor in place or is pulling the motor the best way to go at this. Any tricks for measuring the end play?

Thanks.

1991 E30 M42 · « **Reply #24 on:** January 13, 2010, 08:14:10 PM »

that is probably your rod bearings from my experiences with this engine

Nomadic · « **Reply #25 on:** January 14, 2010, 05:13:44 PM »

Upon closer inspection of the "shavings" found in the oil filter... I'm not sure they are metallic... They are very flat and thin, like 90min cassette tape and come apart easily. No metal slivers or "metallic dust" was found in the filter.

This was the first oil change after a timing rebuild and dose of AutoRx in the oil. I'm thinking the "shavings" are either from gasket compound or cooked sludge loosened by the AutoRx. I inspected the current oil filter w/ 300 miles on it and no shaving or debris was found... I'm keeping her on the road but keeping a very close eye on her....

Cheers,

quinn11m20 · « **Reply #26 on:** January 14, 2010, 05:37:20 PM »

Good luck.

1991 E30 M42 · « **Reply #27 on:** January 14, 2010, 10:15:18 PM »

Copper colored material is what you see after the other metal has worn away, I have seen it three times in this engine and several times with others. Did the oil look somewhat milky? I will dig around and see if I can find pictures of the metal shavings that came out of the three M42's that I blew up.

1991 E30 M42 · « **Reply #28 on:** January 14, 2010, 10:47:26 PM »

Here is a rod bearing that came out of one of my engines, you can see the copper in the picture and I wish I could show you how thick it it because it is only a couple thousandths thick

KenC · « **Reply #29 on:** January 14, 2010, 11:09:14 PM »

Quote from: 1991 E30 M42;84740

Here is a rod bearing that came out of one of my engines, you can see the copper in the picture and I wish I could show you how thick it it because it is only a couple thousandths thick

So there's a copper coating on them? I guess mine that are silver are toasted then...