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Main bearing and oil pan questions

SBpunk

NAXJA Forum User
Location
Enid, OK
Just wondering if you guys could take a look at my main bearing. I know its a shite pic with the flash but best I could do.



Secondly, how bad is this? Is it something I can beat flat again and be alright or do I need a whole new oil pan?




And lastly how much play should the timing chain have in it? Thanks folks
 
You're right, shit picture.
Run your fingernail across it side to side. If the grooves are deep enough to be detectable by your nail, they are too deep.

Hammer pan back into shape and all should be well if you get the surface flat.

The chain should have some slack in it, but if it's got 100k on it, throw on a new one.

-Ron
 
Thanks. I'll give it a shot. What problems will I have if its scared too much?
 
Thanks. I'll give it a shot. What problems will I have if its scared too much?

Theoretically the mains are supposed to run on a thin coat of oil and not make metal to metal contact (mostly). Scoring is an indication this isn't the case. Excessive heat (from friction) can destroy them quick. Blue/black spots on the steel is an indication things have gotten seriously hot, straw colored patches usually means moderately hot. The main bearings are usually layered and when the top layer is worn through (usually in spots), this can also be an indicator your clearances may be to large.

Most times your oil pressure will start to drop as the clearance in the mains and connecting rod bearings grows.

I've seen a lot worse than what you have. Most times I buy some plasti gauge and check the clearance. Plasti gauge is cheap, the only downside is whatever you are using plasti gauge on has to be oil free, oil melts plasti gauge. The plasti gauge will also show (highlight) the high and low spots on your bearings.

I find me a nice flat working area and use small wooden blocks around 3/4" thick, 2-3 inches wide and 4-6 inches tall and a hammer to straighten the pan back up. Just using a hammer takes more skill than I have. A nice flat piece of plywood works well as a base to hammer on, especially old plywood that has gotten really hard.
 
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Theoretically the mains are supposed to run on a thin coat of oil and not make metal to metal contact (mostly). Scoring is an indication this isn't the case. Excessive heat (from friction) can destroy them quick. Blue/black spots on the steel is an indication things have gotten seriously hot, straw colored patches usually means moderately hot. The main bearings are usually layered and when the top layer is worn through (usually in spots), this can also be an indicator your clearances may be to large.

Most times your oil pressure will start to drop as the clearance in the mains and connecting rod bearings grows.

I've seen a lot worse than what you have. Most times I buy some plasti gauge and check the clearance. Plasti gauge is cheap, the only downside is whatever you are using plasti gauge on has to be oil free, oil melts plasti gauge. The plasti gauge will also show (highlight) the high and low spots on your bearings.

I find me a nice flat working area and use small wooden blocks around 3/4" thick, 2-3 inches wide and 4-6 inches tall and a hammer to straighten the pan back up. Just using a hammer takes more skill than I have. A nice flat piece of plywood works well as a base to hammer on, especially old plywood that has gotten really hard.

Thanks! It was pretty smooth so I'm doubting it'll be a problem. The problem I ran into is getting everything back together and looking down to see a half circle piece of metal. Come to find out it sits in the bearing retainer :banghead: so everything came back out.

The oil pan got banged back into place as much as possible. If it leaks at least I'll know pretty quick. Going to put a thin coat of RTV on the spot just in case. These Fel Pro blue gaskets are pretty awesome so hopefully it'll pick up the slack.

Now the new oil pump/pickup is in place I'll be putting the pan back on tomorrow. Then I have to start worrying about the timing chain. Had a bit of slack :smsoap:. One step forward 10 steps back.
 
This looks all too familiar (just did my RMS and oil pan recently). For peace of mind you may want to replace the oil pan - advance auto typically has ours in stock and with the $40 coupon code you can pick it up in store for under $100. Mine had a similar deformity on the passenger side and while I could have bent it back into place I said eff it, do I want to be taking the oil pan off any time soon? The answer was a resounding "no" so I got the new pan.
 
Thanks! It was pretty smooth so I'm doubting it'll be a problem. The problem I ran into is getting everything back together and looking down to see a half circle piece of metal. Come to find out it sits in the bearing retainer :banghead: so everything came back out.

The oil pan got banged back into place as much as possible. If it leaks at least I'll know pretty quick. Going to put a thin coat of RTV on the spot just in case. These Fel Pro blue gaskets are pretty awesome so hopefully it'll pick up the slack.

Now the new oil pump/pickup is in place I'll be putting the pan back on tomorrow. Then I have to start worrying about the timing chain. Had a bit of slack :smsoap:. One step forward 10 steps back.

The half circle piece of metal you're talking about is the actual bearing. Your picture is of a main journal that rides in the bearing

The actual bearings themselves are the dull grey half circle inlays that sit in the caps. They are very soft so be careful with them. You can actually scratch them with your fingernail.

Bearing:
gMtcQLF.jpg
 
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