Crankshaft End Play

M

Mongo

Member
Noticed considerable end play on my engine - notice the movement when the clutch is engaged - guessing aapprox 40- 60 thou movement. What is the cause, consequences and fix for this problem. Otherwise running great. Engine has about 5000 miles on a rebuild.
 
That is a lot of end play and will put way too much stress on your piston connecting rods. With ONLY 5000 miles on the engine since it was "rebuilt" this should not be unless the rebuilder did not pour new babbit. Do you know the rebuilder?

With a running engine I assume you are measuring the end play at the crank pully, which is OK place to measure unless you have a loose two piece crank pully. If indeed you have 40-60 thou movement then all your mains are impacted and surely it is now stressing the connecting rods.

I only had 30 thou endplay and Brent in 10-Uh-C was able to fix me up in short order.

I would strongly reccomend you email Brent and see what he says ( you can find him on this web site). If you live near Penn. Ora Landas can also fix you up. I have used both and can recommend them highliy. In the photo you can see what a nice job Brent's team does. They even added the center main oiler tube to help furture problems in the area..
 

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Hi Mongo, You need to fix this! You've lost the thrust portion of the poured babbitt bearing at the rear main, or, is this an inserted engine? In any case, you're missing some of the thrust bearing, and you need it replaced immediately. Good Luck!
 
I thought I should mearsure this rather nthan guessing at it. At the clutch access hole on the face of the clutch assembly I measured 20 when I apply and release clutch pressure. Is that too much end play?
 
That's too much. Spec is .003-008 end play for the crank. As said, something is wrong with the thrust bearing.
 
Mine is somewhere between a 1/4 and a 1/2 mile.. The engine was done in 1961, is quiet except for valve lash, runs good and doesn't leak a drop of anything.. I'm going to keep running it until it decides it doesn't want to do it any longer..
 
I measure it at the front pulley.I move the crank back and forth with a pry bar.
I put the test indicator magnet on the block and the tip on the pulley.

I would think the clutch cover might flex. Also you need to push the crankshaft in both directions to get an accurate reading.

Mine has .007,but when you clunk it back forth and by hand, it sure looks like a lot. I would suggest measuring it carefully before you do anything.
 
Mongo said:
Noticed considerable end play on my engine - notice the movement when the clutch is engaged - guessing aapprox 40- 60 thou movement. What is the cause, consequences and fix for this problem. Otherwise running great. Engine has about 5000 miles on a rebuild.
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If it does have babbet bearings, the only way to fix it is to take it all apart and re-work the main bearings. It may be because the crank has too much side clearance or the mains were machaned incorrectly in the first place. It may run a long time just like it is without doing any harm. The rods have a lot of side clearance on the pins and the crank can move forward a lot before the rods will contact the inside of the pistons. If you do have babbet bearings and if the engine is running well, I would be inclined to keep an eye on it and only take it apart if the end play keeps increasing.

Be sure the clutch is properly adjusted and do not leave the clutch pushed in for long periods of time, such as waiting at stop lights etc. You may extend the life of your main bearing end thrust for a long time, especially if you do not drive the car a lot.

It will take the same work to fix the problem if the end thrust surfaces of the mains are a little worn out or a lot worn out. If you do start to here any strange noises or anything like that, I would definately look into it further.

This is what I would consider.

Chris
 
Excellent advice! It's good to have some perspective, and not get too caught up in what is "perfect". BUT....if perfect is your goal please disregard previous sentiment.
 
I had one where the owner was putting the flywheel on a rebuilt engine and he used the wrong bolts and broke the rear main oil catch.
I had another cap rebabited and guessed at how much babit to put on the thrust.
As it turned out it fit the crank nicely but the end play was .031"!
It sounded ok and didn't seem to bother the clutch so we left it that way.
That was about 8 years ago. I saw the car this 4th of July and the owners said it's been ok.
But that's not good to have them turn out with that much play.
 
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