TH350 Question

[low budget]

Just rebuilt my transmission and have about 20 miles on it.  It has started leaking out of the front seal.  I put a new seal in when I rebuilt it, but can't believe it is leaking already.  Any ideas of what could cause this?  I read somewhere that there is a vent tube that comes out of the top that could be plugged and it is building up pressure, could that be true???  Any other ideas???

[Lt.Del]

did you put a new torque converter in?  sometimes they crack and will show same leaking symptom.  when the truck is cold and fisrt cranked up, a crack will leak crazy, since it is full of fluid, until converter heats up a bit and closes crack for for the most part. 

[low budget]

Yes, I put a new converter in.

[rsandusky]

Did you replace the bushing inside the front pump housing? The bushing helps support the torque converter

[VileZambonie]

When you rebuilt it did you replace the pump or rebuild it? Which pump do you have?

[low budget]

I just used the same pump that was in it.  I took it apart to make sure it was ok, replaced the seal and bushing, aligned it, and put it back together.  I thought it went together without a problem.  The pump is just a stock pump, and the transmission is a nonlock-up, pre80's th350

[VileZambonie]

So is it a crescent gear or variable vane?

[low budget]

crescent gear.  That is the only type of pump I have seen on these tranys...

[VileZambonie]

OK -Did you replace the bushing? The gear isn't upside down is it?

[low budget]

I made sure that the gear was in the way it came out.  I knew that was vary important.
I replaced the bushing also.  I talked to a friend of mine and he said it sounds like that bushing might have spun on me.  I am going to try to get the trany out today to look at it.  I have another seal, but still need to get the bushing.

[low budget]

well, the verdict is in, my friend was right.  The bushing has spun on it, need to get a new one.  He told me you have to be careful when you put them in.  He has had that problem with them before...

[VileZambonie]

When you replace the bushing you need to make sure it's free of burs and not pressed too far in. Use some emery and clean the neck of the converter. Lube everything up with trans jel or vaseline and test fit it. Another common mistake people make is leaving the converter installed on the trans which will warp the seal.

[low budget]

I took it today to a trany shop and they installed to new bushing and rear seal for me.  I had the seal already, but they only charged me $10 for the bushing and labor.  I thought that was pretty cheap and I don't have to worry about it.

 Vile, as always, thank you for all your input.  I feel comfortable doing any job on my truck with the help of you, and many others.