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Old 12-06-2018, 07:34 PM   #1
Linz
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Pulling a TH350

I apologize if this has been covered but I did a few searches and didnít 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 Iím going to take.

Iím also thinking while itís 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 didnít 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? Iím sure Iím capable of doing it Iíve pulled a ton of semi transmissions and installed clutches etc. Iím 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
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Old 12-06-2018, 08:07 PM   #2
truckster
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Re: Pulling a TH350

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.
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Old 12-06-2018, 09:15 PM   #3
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Re: Pulling a TH350

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...

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Last edited by AussieinNC; 12-06-2018 at 09:50 PM.
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Old 12-06-2018, 09:39 PM   #4
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Re: Pulling a TH350

Quote:
Originally Posted by AussieinNC View Post
"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.
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Old 12-06-2018, 09:46 PM   #5
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Re: Pulling a TH350

Good info, I’ll be pulling my turbo 350 to swap a 2004r
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Old 12-06-2018, 09:47 PM   #6
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Re: Pulling a TH350

Quote:
Originally Posted by truckster View Post
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....

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Old 12-06-2018, 09:49 PM   #7
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Re: Pulling a TH350

Quote:
Originally Posted by jondancer View Post
Good info, Iíll 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...

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Old 12-06-2018, 09:59 PM   #8
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Re: Pulling a TH350

Sorry forgot to add yes a 2wd

Great informative replies so far thanks guys thatís exactly the sort of info Iím after
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Old 12-06-2018, 10:08 PM   #9
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Re: Pulling a TH350

If it’s “leaking from everywhere” I’d first inspect the vent to see if it’s plugged before pulling the trans out.
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Old 12-07-2018, 03:29 PM   #10
hotwls13
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Re: Pulling a TH350

Quote:
Originally Posted by AussieinNC View Post
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
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Old 12-07-2018, 08:49 PM   #11
AussieinNC
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Re: Pulling a TH350

Quote:
Originally Posted by hotwls13 View Post
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 !!!!!!
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