Tips on Installing TH400 in 68 Lemans?
 

So I rebuilt the 455 and TH400 and I'm pretty sure I stabbed them in together but that's been about 10 years ago. Trans gave up the ghost in 2018 or 2019 so I pulled it out, but I had a 4 post lift in the garage at the time, so it was an easy day.

Have since gotten rid of my lift and now I have to reinstall the trans. Since it's been a while, I figured I'd check with y'all to see if you have any tips.

Engine is in the car, trans is ready to install, I have a Harbor Freight trans jack.

I have a pair of floor jacks (3 ton) and four 6 ton heavy duty jack stands.

My main concern is getting the car high enough; not sure if I'll be able to do that unless I put a wooden block on the floor jack.

Wondering if I should slide the trans under the car on a piece of plywood and then put it on the trans jack? Going to be tough to wrassle it in place under the car, but I should be able to handle it.

Also, should I lift the car up front and back or just in the front?

Thanks in advance for any info/tips.

Scott

Definitely lift it front and back. The trick is getting car high enough to wheel trans in on the jack, then its easy to pump it up in place while on the jack.

I hobo it; Tip the bellhousing by raising tail, then slide bell-first under frame to reside in position to go up.

then tip onto jack (i never had a trans jack so how i got em up is particularly forgetful).

Do yourself a favor and forget the jackstands, here’s a video to build your own out of 2x4’s. When your done you can stack them in corner. With these no problem getting car high enough getting trans under car. I built some similar and used 2-4 and the 2x6. And stacked them.

https://youtu.be/aCqfHligDSQ?si=R13KSpX6aNDHifkm

I just don’t trust the jackstands. Especially the ones that are available today

I made these and love them. These are the best.

https://youtu.be/GUNYVgEyoXU?si=74yLyFqmcfMmeZgn

I like those. Only sketchy thing is getting the vehicle high enough to get them under the tires.

You can, take a block of wood and put it on the jack itself. Like a piece of her 4x6. Then you can it it high enough. I like the ones in second video better I made 2 with 2x6. Then 2 with 2x4. So if you add the 2 together stack. It’s like 9-10” under tire, and give you almost 2’ under the car.

https://youtu.be/GUNYVgEyoXU?si=74yLyFqmcfMmeZgn

I painted my pink…LOL just kidding…I absolutely love these. Cheap and easy to build.

https://youtu.be/GUNYVgEyoXU?si=74yLyFqmcfMmeZgn

I also used the matchstick boxes to get the car up nice and high and stable.
An additional pair of hands, a friend, makes installing a transmission a lot easier. That would be my recommendation get a friend to help.

I've always double blocked mine. Older jackstands,and rims under tires blocked up. I've had 2 guys I know get crushed by cars falling. Trans jack is very nice. I just made a steel adapter plate for my floor jack. It's nice to get in place just a pain to crawl out to release.

"Have since gotten rid of my lift and now I have to reinstall the trans. Since it's been a while, I figured I'd check with y'all to see if you have any tips."

I'd get rid of my wife before my 4 post lift! Not really but I get more work out of the lift these days for sure.

Seriously, good advice given and it helps to take some bolts from the hardware store and make alignment pins to help guide the transmission to the engine. Simply get some long 3/8" bolts, cut the shank at the desired length, round the ends some, then slot them with a hacksaw for easy removal with a flat tip screwdriver. You may not be able to use them in the upper holes but at least one on each side really helps getting the trans to slide in place while you are wrestling with it laying under the vehicle.......

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I start by jacking up the back and put 2 3 ton stands under the axle. Move to the front and jack up put 2 more 3 ton stands under the front. Back to the rear to finish jacking up put wood stands under rear tires then back to front to finish jacking up to rest front tires on wooden stands.

The first time I was very very cautious, but found that is was not scary to do and felt safer than previous ways I've raised the car to work under.
I just reverse the process to let car down. I didn't measure under to see if a 400 Transmission would fit for installation. Low profile jack might be necessary.Good luck.

I recently installed a trans using the smaller ~$100 harbor freight trans jack, I do the same thing for raising the car as I do for header installs... put ramps under the front tires by either jacking the car up or driving on to them, can put a 2x4 across the top for added height... or bigger jack stands to get the same height as the ramps, then jack the rear up using bigger jack stands under the rear end axles, i have an older set that have triangle legs and use the pin through the shaft, extended they can be 28-30+" tall and are very sturdy, especially under the rear of the car thats lighter than the front.

Once the car is raised up, the trans is able to be put on the jack & wheeled under the car, then its easy to use the adjustable pan of the jack to tilt it to match the engine angle and slide it forward to engage the dowls on the engine, didnt need to make studs or any other extra tools, once it meets the trans you can make fine adjustments to the pad on the jack if needed & then just start the bolts.

The smaller HF trans jack works great for this and the car doesnt need to be that high up, if you cant get it high enough, slide the trans under the car on cardboard then with a helper lift it onto the jack while in the center of the trans tunnel area. I did this in a 2nd gen firebird and had no issues jacking it up high enough to slide the trans on the jack under the car.

I use my drive on ramps for the front you can add a 2x12 under if you want to go higher or two depending on how high you want to go. I know everyone here hates Jack stands but that’s what I use under rearend most of the time or another set of drive on ramps sitting the other way ( car can’t move forward or back that way) anyway I use jackstands for rear so after trans install you can run the car in all gears and check for leaks before you ever put it down. If you do it like this make sure to push brakes hard and make sure wheels are not spinning before you put it in park or reverse. My2¢

Picked up seven 2x4x8's at Lowes along with some 2.5" screws. Will make a pair of the log cribs and if I like they way they turn out, I'll see about making a second pair.

Thanks for all the input.

Scott

What does a 2 x 4 go for at Lowes these days ? I bet seven 8 footers was not cheap.
If any of you make it to these parts I can get you a pickup load of mill ends long enough to do what you need to. Free, just need advance notice for planer schedule.
2 x 4s, 2 x 6s up to 2 x 12s. Even 6 x 6s up to 6 x 12s. And they make great firewood.
When I show up for night shift there is a couple dumpsters full of them that end up in a giant chipper if no one takes them home for firewood.
Nice side benefit. Heated my home for decades with free wood.

Well, let's see...

2x4x8 are $2.78 each at Lowe's. I used seven, so that's around $21 with tax.

Humboldt County is 2,011 miles from me, so 4,022 round trip. My Yukon drinks premium fuel at $3.76 per gallon and gets 22 mpg, If my math is right, that's 183 gallons at $3.76/gallon, or about $688. Add in hotel expenses, and that would be some damn expensive free wood! ;)

Real expensive ! The offer was for someone closer but I am pretty far from most all of you.
2.78 is pretty cheap. The price must have come down since Covid when it went way up. Almost tripled for awhile.
I just bought enough 2 x 4 and 2 x 6s to make a 5 foot picnic table and it was over 200$ !
Plywood is nuts too. Building a big deck and just the 2 x 6 PT 18 footers are over 100$ each !

Got the first one built. I added 4" blocks on the sides where the tires will sit so it spreads the load to the ground better.