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My 68 427 (just got it) had a 454 flywheel
I think clutch was replaced and 454 FW was put on in lieu of resurfacing the 427 wheel
Engine is out of balance with the 454 but not real bad, some vibration above 3200
I have a service lift and car is safely up in the air.
I am installing a Tremic 5 speed, I have a new 427 flywheel and clutch.
Question:
Should I pull the rear main cap and inspect the bearing? bad vibration could cause damage however I do not think the issue has existed long.
Oil Pressure is good and consistent with good main bearings.
Is it possible to replace the main bearings from under the car? If so how?
In pulling the rear cap do I replace the rear seal?
Part of me says pull it apart, the other side says "the seals are good, the oil pressure is good, the engine is low miles since last rebuild and just leave it alone.
If I can not easily replace the main bearings then why bother looking.....
Tom, if you do decide to remove a few main bearing caps, be sure to check the clearance with some Plastigauge. It will give you a more definitive idea of just how much clearance you have.
If the rear main looks beatup, Can I replace it with the engine in the car?
Yes, very easy to do. You can do them all one at a time if you choose.
Details to roll out the bearing can be found in most motor repair manuals OR if you're lucky the upper will simply push around.
Removing/reinstalling the pan is the hardest part in my opinion.
If, If replacing 2-pc rear main seal, it's best to drop main caps 1 thru 4 a few threads and remove rear cap; effectively dropping crank a bit away from upper bearings. Otherwise there's a likelihood those sharp edges of block's grooves may peel/shave the back side of seal; leaving opportunity for leak.
if that's a recent rebuilt, leave the rear seal alone. Get something like a roofing nail and put it into the oil hole in the crankshaft. And then turn the crank over so that the tang end comes out first and then roofing nail will roll the bearing shell right out of the upper half.
Last edited by derekderek; 01-05-2019 at 06:35 PM.
OK so i will inspect bearings... Now... noob engine question (I have done many restorations and rebuilds..., but I always send the engine out for work...) if they look bad, do I need to order the right size? if the engine has been rebuild would the bearing size change do to machining? basically, what is to correct bearing or how do I determine it?
OK so i will inspect bearings... Now... noob engine question (I have done many restorations and rebuilds..., but I always send the engine out for work...) if they look bad, do I need to order the right size? if the engine has been rebuild would the bearing size change do to machining? basically, what is to correct bearing or how do I determine it?
Just take your time and don't take more than one cap at a time off,just loosen a couple and use assembly lube on the bearings.
once at a race ( in my misspent youth) I got saddled with changing a crankshaft in a c3 corvette drag car . Car was on the trailer it started to rain, I was in the low side of the parking lot.my buddies thought they would be funny an went to Kmart and got an air matress.and left it for me just when I was going to give up.it ticked me off so much I keep after it. At 2a.m I fired that 496 in the hotel parking lot and woke everybody in the place.I slept like a baby.
why do I tell this story? So you know it's no big deal.
What does crank surface look like? That is scuffed up, but I don't think it would lead to engine failure. At least not now that that wrong flywheel is no longer throwing that crank around. I would check all 5 mains. I would replace at least the rear one. Maybe all 5. You can't buy single mains anyway. Hafta buy whole set. Get this. Check rear main for run-out. Crank is a big hunk of metal. Probably ok. https://m.harborfreight.com/clamping...tor-63656.html
Last edited by derekderek; 01-08-2019 at 06:15 PM.
They are far from the worst bearings I've ever seen. Looks like it had some dirt in the oil,which could be from a normal type rebuild.or just running the oil too long the crank will probably be fine as the material is harder..I think you would be ok with the bearings.but I'm going on what I can see. Being hands on may change my opinion.
I'd check them all, however, I would go a little further than visual inspection. If you don't have GOOD tooling to do a formal check, via mic. I'd do at least the plasti gauge. The difficulty will be getting the oil off the top bearing shell. If oiled on either shell, you'll get a slightly smaller result. There looks like there may have been a little crap going through the engine, but like was said earlier, not nearly as bad as many have seen. Run a magnet over the oil remaining in your pan and see if there happens to be metal residue collected there. Often with an out of balance of a large amount there can be a pattern of wear as the over weight or under weight is in the same location every revolution. How many miles, did you say on it? Did the bearing shell show you if they are standard or oversized bearings? The oil pressure is a good indicator of excessive wear too.
01-04-2019, 03:09 PM
unbalanced - Main bearing inspection - engine in car
