Powerglide TC bushing\seal leak.

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JasonL
Posts: 15
Joined: Fri Apr 08, 2016 1:30 pm
Location: Bemidji Minnesota

Powerglide TC bushing\seal leak.

Unread post by JasonL » Fri Sep 08, 2017 8:17 am

My transmission has had a leak since I have had it and I suspect even before I purchased it. I have had it for 11 years and rebuilt it 8 years ago. When i got it it was coated in oil and crud from several leaks including the TC seal area. I tore it down cleaned it up during the transmission and engine rebuild.
The torque converter bushing was replaced as well as the seal on the differential. I purchased the parts from Clarks.
I have put 8K miles on the vehicle since the rebuild and the leak has been there the entire time. It is a slooooow leak I have put in 1 quart of transmission fluid over the 8K miles. It is the only leak I have and it is making a mess of the engine and causing my heater to stink. I power wash the area every 3 months or so which helps. The car also marks it territory with a drop of transmission fluid here and there when parked.


I pulled the engine and torque converter last night and have found that the fluid is coming from the TC to Diff area. My TC bushing is in good shape and the shaft on the Diff that the bushing rides on is smooth. The TC bushing has an 1.412" interior diameter and the shaft has an 1.410" outer diameter. ??? Shouldn't .002 be tight enough??

Also the seal on the Diff is in good shape and the OD of the torque converter collar is 1.76". I could not measure the seal before pulling it. After pulling the seal (and bending it a bit with the seal puller) it fits tightly on the TC collar.
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Does anybody know what the outer diameter on a newer Diff should be?
What is the ID on a new TC bushing?
Should .002" be tight enough to seal the transmission?
I'm not ready to just throw in another bushing and seal to have it leak again.
Why would the transmission fluid leak inside the bell housing and not into the Diff if the seal\bushing were bad?
Could the TC be out of round or cracked causing the leak? I don't see a crack but perhaps there is a small one that opens while driving and up to operating temp.

A local transmission shop can get me a rebuilt torque converter for $175 I'm thinking of changing the TC, and the seal so I don't have to tear it apart and clean it again. It is from a place called precision transmissions in Iowa.
I was considering the high stall TC from Clarks, but that is a lot more than $175.

Does anybody have any advice or experience with this issue that may weigh in with another option?

It is on a stock built 65 Monza with a 140.

64powerglide
Posts: 1251
Joined: Tue Mar 25, 2014 9:18 pm
Location: Kalamazoo Mi..

Re: Powerglide TC bushing\seal leak.

Unread post by 64powerglide » Fri Sep 08, 2017 10:57 am

I had the same problem with the 64 I bought 4 years ago. I also have a local trans shop that works on Corvair's & last year I was told the TC hub was worn so I got a TC for the same price & a new seal & it hasn't leaked for over a year now. The guy also cleaned out the plugged up vent. I think your thinking is correct, replace the TC & seal.
64Powerglide, Jeff Phillips

Kalamazoo, Mi..

User avatar
JasonL
Posts: 15
Joined: Fri Apr 08, 2016 1:30 pm
Location: Bemidji Minnesota

Re: Powerglide TC bushing\seal leak.

Unread post by JasonL » Fri Sep 15, 2017 10:17 am

I am replacing the torque converter and seals. I was able to buy a rebuilt torque converter that is rebuilt to a high stall TC for $210.
It is coming from precision transmissions out of Iowa.

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