TH 350 Seal Leak
Thread Starter
Racer
Joined: Feb 2002
Posts: 378
Likes: 19
TH 350 Seal Leak
Trying to correct a major front of trans leak, (and yes, it's a trans leak, not a mtr rear main seal issue), the TH 350 was dropped and the front pump seal removed revealing that the front pump body bushing is shot, and has to be removed. This means the pump has to be removed.
Was wondering if anyone out there has ever done this job, removing the pump from case and tearing down a TH 350 oil pump?
Thanks for any response.
Was wondering if anyone out there has ever done this job, removing the pump from case and tearing down a TH 350 oil pump?
Thanks for any response.
Le Mans Master
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
I pulled the pump out of my TH400 transmission several years ago.
It was leaking all around the circumference of the pump because the o-ring seal was old, shrunken, and hard as a rock. I actually had to break it to get it out of the groove.
I replaced the o-ring and the front seal, but I did not tear the pump apart at all.
That fixed 99% of my transmission leaks.
It was leaking all around the circumference of the pump because the o-ring seal was old, shrunken, and hard as a rock. I actually had to break it to get it out of the groove.
I replaced the o-ring and the front seal, but I did not tear the pump apart at all.
That fixed 99% of my transmission leaks.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
No trick. Well, the toughest part is getting the pump ot of the case after it's been in there for XX years. Pull the bolts, with the pan off you can stick a big pry bar between the direct clutch housing and the pump and wiggle it around until the pump pops out. Then with the pump setting front down on a vise, take out the 5 bolts that hold the halves of the pump come apart. The 2 gears in the pump go in one way- note how they are in there for later. Dot on the outer ring (stator) up, and lugs on the center gear(rotor) up. Take the old seal out, replace the bushing. Before you put the pump back together, slip the housing with the new bushing over the snout on the convertor and rock it around. That gets the bushing back to round and cleans up any burrs. Install the new seal, set the halves of the pump back together and start the bolts. The 2 halves of the pump have got to be exactly lined up- get a couple of BIG hose clamps and put them around the OD of the pump, tighten the bolts and drop it back in with a new o-ring and paper gasket, new seals on the bolts and go.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
How many miles are on that transmission? If it has more than 100K miles on it, you should just go ahead and buy a rebuild kit and a new converter for it while it's out of the car. If the front bushing is shot, it's got to have a lot of wear on all the internal seals and plates.
