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Old 10-18-2014, 09:12 PM   #1
scrappy's 69
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TH350 Trans Leak

I know this has been asked before, but I haven't been able to find the thread. My TH350 is leaking around the speedo cable, what can be causing this and what do I need to fix it? Thanks for any help.
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Old 10-18-2014, 10:54 PM   #2
dmack91
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Re: TH350 Trans Leak

Should be an O-ring on the speedo gear portion that goes into the trans.
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Old 10-19-2014, 01:50 AM   #3
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Re: TH350 Trans Leak

Quote:
Originally Posted by scrappy's 69 View Post
I know this has been asked before, but I haven't been able to find the thread. My TH350 is leaking around the speedo cable, what can be causing this and what do I need to fix it? Thanks for any help.
Get one of these
http://www.ebay.com/itm/GM-TH350-Tur...7503bc&vxp=mtr

And then if you need a new speedo gear (seal groove worn into the shaft or worn shaft) count the gear teeth and note the color of the gear and get a new gear: scroll down this page a pick out a new one, not used.

http://www.ebay.com/sch/i.html?_odkw...r&_sacat=33726
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Old 10-19-2014, 10:07 AM   #4
Lee H
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Re: TH350 Trans Leak

A new bullet will likely solve your problem. Be sure the lip seal is seated. The last few I've gotten the seal was only pressed in a little and it leaked worse than the old. You can get these bullets at your local auto parts house. You can also get the the lip seal and o-ring if you have a local trans parts house and replace them your self. If your speedo if off nows a good time to get the correct speedo drive gear.
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Old 10-19-2014, 08:02 PM   #5
scrappy's 69
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Re: TH350 Trans Leak

Thanks for the info!
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Old 10-19-2014, 08:33 PM   #6
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Re: TH350 Trans Leak

I don't know about the TH350, but some transmissions (like the TKO-600 as an example) have both an inner and outer o-ring and if you forget either, it'll leak.

I'm sure someone will chime in here if, in fact, there are two on an old hydramatic.
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