TH350C Removal Method

[garzas23]

I have an 85 gmc pickup and I need to remove the transmission just enough to replace my flexplate. I have a good 3ton floor jack, does anyone have any tips or advice for using a regular floor jack? or should I just wait and get a transmission jack? Im concerned about where to place the jack for stability.
Thanks in advance.

 

[350runner]

I'm sure you could do it with out a trans Jack, but I'd get one. I got mine from harbor freight. The cheap scissor lift one (red and white) this allowed me to angle and feel comfortable at the same time. I do remember having to use a small car Jack at some point though o on the trail to fit the bellhousing to the engine block. Tho it's not a two man job, having an extra hand to help would be nice.

Sent from the dust in front of you!

 

[towjoe]

I wouldn't attempt it without a trans jack. To hard to get lined back up without the angle and to narrow of a top on a regular floor jack to stabilize transmission on

 

[garzas23]

Ok im going to go ahead an wait an use a trans. jack. Ive heard it was a bit tricky to get the transmission stabbed back in. Any tips? Ive also read that you shouldn't leave it in park, not sure why..

 

[350runner]

I left mine in park. I did need an extra hand tho. It is a bit tricky getting it back on the pins and what not.

Sent from the dust in front of you!

 

[chengny]

Transmission jack for sure.

Put the truck up on jack stands - both axles.

Use your floor jack to lift the front of the engine a bit - use a block of wood and lift at the balancer. This will tilt it down in the back.

Set up the transmission jack so that the transmission is angled in line with the tilt of the engine (or as close as you can get it).

Make 2 studs about 3 -4 inches long (out of 3/8" - 16 all-thread) and screw them into the lower engine block/bell housing bolt holes:

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These studs will serve as guide pins to help line the bell housing up to the block. When the bell housing is on the studs, thread nuts on them and bring the engine & transmission together. After you have installed the normal bolts in the other holes, back the studs out and put in the regular bolts.

 

[garzas23]

I appreciate the help and tips everybody. I plan to get to it in the morning if all goes as planned so ANY tips are helpful and much appreciated.

 

[MadOgre]

Are you guys serious? I have changed too many trannies to even remember how many. I have never once used a transmission jack or even thought of buying one. If I was using a hoist to elevate the vehicle that would be different.

No need for a transmission jack. Just use a piece of plywood or a 2x6 that is about the same size as the transmission pan and place it between your floor jack and the transmission pan.

Un bolt the torque converter and inspection cover, Un hook transmission cooler lines and shift linkage, Remove driveshaft and the speedo cable, un bolt and remove the rear transmission crossmember, remove the top 4 transmission bellhousing to block bolts.

You may or may not have to remove your exhaust to get access to the transmission.

Now place the floor jack under the pan with the wood in between and slightly to the rear of the pan at 90 degrees so when the transmission is lowered you can simply pull the jack out to the side from under the vehicle. Remove the lower bolt on the bell housing opposite to the side you are working from with the jack.

Place a jack stand with a piece of wood in between, under the oil pan of the engine to prevent the engine from dropping down and bending the distributor on the firewall, when the transmission is removed.

Now apply a little upward pressure with the floor jack just enough to move the transmission up a hair. Remove the last bell housing bolt that should be right beside you now. Now lower the transmission until the engine is resting on the jack stand and then a little bit more. Grab the tail housing of the transmission and give it a wiggle to separate the transmission from the block. There bare 2 dowel pins that align the transmission to the block so you have to pull the transmission back about an inch to disengage the bell housing from the engine block.

Now simply keep one hand on the tail housing and use the other to lower the jack and pull it out from under the vehicle. An assistant can be quite useful.

You will see that the transmission actually balances quite well on the floor jack if you get it in the right spot. So when reinstalling the transmission just balance it well on the floor jack and then maneuver it back into position and again wiggle the tail housing and push forward to get it back on to the dowel pins. And reinstall the bellhousing to block bolts first. An assistant is quite useful.

 

[350runner]

As a heart attack...
Would seriously recommend someone asking how to do something. Do it in an unsafe manor? And the trans slips off the Jack... bish is heavy under truck.

Sent from the dust in front of you!

 

[MadOgre]

Oh be sure that the vehicle is raised enough to be able to have room to slide the transmission out from underneath it.

I have a 6 inch lift so I never have to worry about that issue but if you have a low rider its kinda hard to jack up the vehicle for clearance when your transmission is sitting on top of your floor jack under the vehicle lol

 

[MadOgre]

and ALWAYS CHOCK THE WHEELS!

 

[MadOgre]

Oh and don't forget to remove the dipstick/filler tube before removing the transmission.

 

[garzas23]

Thanks everyone for the help!! Got it out today.. Wasn't to hard but definitely tricky by myself. I WAS just join to replace the flywheel but I figured I might as well replace the front and rear seal while its down, and it needs some major cleaning and degreasing. So ill be doing all that over the next week or two then ill get it back in there.

 

[MadOgre]

Right on! Glad it worked out for you.

 

[1low4x4]

Yeah.....nevet used a trans jack and ive changed lots of transmissions...lol

Board and floor jack is good enough