Pulling a TH350

[Linz]

I apologize if this has been covered but I did a few searches and didn’t find any definitive answers to some of my questions.

I have a 72 with a 350/350 combo witch in its present form runs and drives just fine. The problem I have is that the transmission is an oily greasy mess that seems to be leaking from everywhere. I read the other recent thread on the guy that is tacking leaks on his and it was suggested by some to just pull it and clean it up out of the truck. This is the route I think I’m going to take.

I’m also thinking while it’s out I may as well rebuild it then I know what I have?

So my question is.

Is it a simple enough process to pull the transmission and leave the engine in place? I see no reason to pull the engine as well. Are there any special steps that I need to take? I didn’t really find a step by step process but perhaps most guys pull the whole lot engine included. Im assuming the engine will need supported somehow also? Or will it be simpler to let the transmission shop pull it if I rebuild it? I’m sure I’m capable of doing it I’ve pulled a ton of semi transmissions and installed clutches etc. I’m just lacking a few of the finer points on the smaller stuff.

And secondly if I was to overhaul the transmission are there any things that I should do or ask for? Upgrades make it stronger etc etc

Thanks

[truckster]

First things first - 4WD or 2WD? 2WD is relatively easy. Remove the u-joint, pull the driveshaft (have a drain pan under the transmission tail shaft). I like to use 3-inch bolts as guides to remove and install the transmission. I cut the heads off and cut a slot in the end so I can remove them with a screwdriver. One on each side will do. Remove the torque converter bolts. Place a jack under the transmission with a block of wood to protect the pan. Remove crossmember bolts and drop the crossmember out of the way. Now you can slide the transmission out. The engine should be fine sitting on the motor mounts.

If we're talking 4WD, you're going to have to remove the transfer case - they're very heavy and awkward. I would definitely recommend a transmission jack if you're dealing with a transfer case.

[AussieinNC]

To add content to the response from truckster....

Disconnect battery first
Remove distributor cap and rotor button You will break both if the engine mounts are not perfect...)

Jack up the truck so the bottom of the chassis rails is at least 14" off the ground, support with four car stands on the chassis

Remove the trans pan and drain the fluid
Remove the rear uni bolts and remove the driveshaft
Remove the shift linkage rod from the shift lever on the trans
Remove the flywheel convertor cover
Remove the bolts securing the convertor to the flexplate and push the convertor back...wire the convertor back against the case with tie wire...
Remove the passenger side upper trans case to engine bolt and remove the filler tube and dipstick
Jack the trans up slightly and remove the trans mount to cross member bolts
Remove the cross member
Lower the trans support jack approx 4 inches (keep jack under trans!) and remove the cooler lines from the trans....plus the ends with plastic caps
Remove the vacuum modulator pipe at rear of trans
Remove speedo cable
Remove lowest bolts from each side between engine and trans ad install studs as "truckster" indicated...
Remove the remainder of the bolts between trans and engine....
Lower trans a little and slide the trans back to clear the ends of the studs...
Lower the trans and slide out from under truck...

The only reason you would want to do all this is if the trans is malfunctioning or the convertor pump seal is leaking...if the pump seal is leaking, IMO, it should get an overhaul while its out...

You can pressure wash the trans fro the top and under the truck and replace most gaskets and seals without the need to R&R so long as the pump seal is not leaking...

Hope this helps...

"truckster" great response...just felt the need for more content and some safety suggestions etc...

[truckster]

Originally Posted by AussieinNC

"truckster" great response...just felt the need for more content an some safety suggestions etc...

Thanks. I guess I've done it enough times that I wasn't thinking in enough detail. Your response is spot-on.

[jondancer]

Good info, I’ll be pulling my turbo 350 to swap a 2004r

[AussieinNC]

Originally Posted by truckster

Thanks. I guess I've done it enough times that I wasn't thinking in enough detail. Your response is spot-on.

35 years of it for me...and I still get roped into assists...albeit, I dont work of the floor anymore...2 post and 4 post lift saves this old mans back....

[AussieinNC]

Originally Posted by jondancer

Good info, I’ll be pulling my turbo 350 to swap a 2004r

Make sure that 200R4 has been beefed up...and is setup correctly....then add am isolated cooler system for the trans...

[Linz]

Sorry forgot to add yes a 2wd

Great informative replies so far thanks guys that’s exactly the sort of info I’m after

[projectking]

If it’s “leaking from everywhere” I’d first inspect the vent to see if it’s plugged before pulling the trans out.

[hotwls13]

Originally Posted by AussieinNC

To add content to the response from truckster....

Disconnect battery first
Remove distributor cap and rotor button You will break both if the engine mounts are not perfect...)

Jack up the truck so the bottom of the chassis rails is at least 14" off the ground, support with four car stands on the chassis

Remove the trans pan and drain the fluid
Remove the rear uni bolts and remove the driveshaft
Remove the shift linkage rod from the shift lever on the trans
Remove the flywheel convertor cover
Remove the bolts securing the convertor to the flexplate and push the convertor back...wire the convertor back against the case with tie wire...
Remove the passenger side upper trans case to engine bolt and remove the filler tube and dipstick
Jack the trans up slightly and remove the trans mount to cross member bolts
Remove the cross member
Lower the trans support jack approx 4 inches (keep jack under trans!) and remove the cooler lines from the trans....plus the ends with plastic caps
Remove the vacuum modulator pipe at rear of trans
Remove speedo cable
Remove lowest bolts from each side between engine and trans ad install studs as "truckster" indicated...
Remove the remainder of the bolts between trans and engine....
Lower trans a little and slide the trans back to clear the ends of the studs...
Lower the trans and slide out from under truck...

The only reason you would want to do all this is if the trans is malfunctioning or the convertor pump seal is leaking...if the pump seal is leaking, IMO, it should get an overhaul while its out...

You can pressure wash the trans fro the top and under the truck and replace most gaskets and seals without the need to R&R so long as the pump seal is not leaking...

Hope this helps...

"truckster" great response...just felt the need for more content and some safety suggestions etc...

Great write-up. I was thinking of doing the same thing, but I'm back to just leaving the trans in until I'm sure it's not good.

Trying to picture pressure washing the trans from above or below though. Better be wearing a head to toe plastic suit. Haha

[AussieinNC]

Originally Posted by hotwls13

Great write-up. I was thinking of doing the same thing, but I'm back to just leaving the trans in until I'm sure it's not good.

Trying to picture pressure washing the trans from above or below though. Better be wearing a head to toe plastic suit. Haha

Grab yourself a mylar painter coverall from a big box store...$15 well spent....

Couple cans of engine degreaser spray and a pressure washer that has a soap injector on it....

Yep its messy, but its fun !!!!!!