Small Block Mopar Thrust Bearing issue

[Mopar Mike]

Originally Posted by Mopar Mike

I haven’t ever seen this before, but the crank looks to be pushed forward from the torque converter and is wearing down the thrust bearing. This is a cast crank 340; there is about a 1/8 to 3/16 gap unbolted between flex plate and converter. Spins freely, and moves back and forth easily. The forged crank 340 has no problem with same Trans and converter. Any ideas?? Thanks,
Mike

Thanks to all that have replied, I was thinking converter and will look closer at other possibilities.
Mike

[Henry S]

There is a lot of info on the net. Do a search for thrust bearing problems. and look for the AERA paper on diagnosis and symptoms. most likely restricted coolers or cooler lines cause the torque converter to be pushed forward causing thrust problems. check your cooler line pressure.

[GTX JOHN]

I had problem with imput shaft on my 904 being significantly Bent.....Also I would dial indicate end of crank flange.....I have seen Cast small block cranks becoming seriously bent.

[Adger Smith]

Mike,
The drilling for positive oil is a good idea. I use a less labor intensive way to oil the thrust.
Take the top(block side) main bearing and use a file to make a small angle cut right at the parting line. You do it only on the back side of the bearing on the thrust side. I usually do both sides of the bearing. You slot it on the portion that the crank journal runs on so the oil goes into the cavity that makes the roll into the thrust face. I don't slot the thrust face. Take a little scotch brite and smooth the edge it rolls up on the bearing. It doesn't take much of a slot/angle to provide positive oil feed from the main bearing feed to the thrust. Get the converter fixed.

[Mopar Mike]

Adger, Thanks for the info on the thrust bearing modification. I like the less aggressive way you suggested. Is it possible for you to send an illustration to me? My e-mail address is mc340dart1@aol.com. Thanks again,
Mike

[Mopar Mike]

Originally Posted by Adger Smith

Mike,
The drilling for positive oil is a good idea. I use a less labor intensive way to oil the thrust.
Take the top(block side) main bearing and use a file to make a small angle cut right at the parting line. You do it only on the back side of the bearing on the thrust side. I usually do both sides of the bearing. You slot it on the portion that the crank journal runs on so the oil goes into the cavity that makes the roll into the thrust face. I don't slot the thrust face. Take a little scotch brite and smooth the edge it rolls up on the bearing. It doesn't take much of a slot/angle to provide positive oil feed from the main bearing feed to the thrust. Get the converter fixed.

Adger, Thanks for the info on the thrust bearing modification. I like the less aggressive way you suggested. Is it possible for you to send an illustration to me? My e-mail address is mc340dart1@aol.com. Thanks again,
Mike