TH400 installed yesterday!! [Archive] - Chevelle Tech

: TH400 installed yesterday!!


scottrock
Jun 9th, 08, 8:06 AM
Hell yeah!! I'm stoked!

It's been about 2 years since my velle was last on the road~ due to a dying tranny. I had just put the new 402 in and, of course, the old transmission decides to take a crap after several rowdy trips around town. The car has been sitting in storage units and garages ever since.

Fast forward 2 years and I have FINALLY acquired a TH400. It's been checked out, serviced and had a shift kit installed. I cleaned it up, degreased it and put a purdy coat of black paint on it. :D

It's been sitting on my workbench for a few weeks now ready to go. Well, yesterday morning a friend of mine stopped in for a few hours and we threw it up in there. The install went pretty well considering we did it the hard way; no lift, no tranny jack. Just a few jackstands, a big floorjack to twerk the motor around and a little rollerjack with the tranny balanced on top. I had most everything ready to go, driveshaft dropped, crossmember off, fluid drained from old tranny, linkage removed. It took us about 3 hours and my back hurts like hell but it's in there. :hurray:http://i128.photobucket.com/albums/p175/rock_scott/DSCF2668.jpg

http://i128.photobucket.com/albums/p175/rock_scott/DSCF2666.jpg

Also wanted to ask any of you if the crossmember looks right. I could not remember if the orientation is right or not? It might be in backwards. If so, does it matter?

I will have to replace one of the cooler lines as one of the fittings would not break free & I ended up just cutting the line. Simple enough task there. I would like to install a drainplug in the pan (it doesn't have fluid in it yet) before I finish things up.

I almost made a mistake I've seen floating around in a few threads here and there. Where everything "looked" good and as such was being bolted up as it was... but at one point we realized the converter snout had come forward and was no longer seated fully into the transmission. Everything fit, it all looked good from the front, the converter bolted to the flywheel with no obvious problem (other than you couldn't spin the converter by hand, it was tight because it was in a bind!). That would have chewed it up real good! Sheesh! Anyway, we backed everything up and corrected the problem, allowing everything to bolt up nice and smooth.

Now I just need to get my driveshaft shorted, have the new yoke installed, fix the cooler line and I'm ready to drive!!:D:D:D:D:D

70ChevelleRagtop
Jun 9th, 08, 1:58 PM
Cross member looks correct to me. Also a good idea about adding a drain plug.

Whiskey
Jun 9th, 08, 7:21 PM
I think the crossmember is in backwards. Also if your converter was not lined up with the front pump and you bolted it up completely then is is possible that the front pump could be damaged. I have heard of it but have bolted em up badly too and got away with it. Good luck.
Bill

cmt454
Jun 9th, 08, 7:42 PM
Crossmember is correctly installed.

Mike
Jun 9th, 08, 8:17 PM
Scott ,do you still have the original trans mount?
Compare the height to the poly one you have installed as some are taller than original.

scottrock
Jun 9th, 08, 8:49 PM
I did keep the original mount. It was still good as I replaced it about 6 years ago when I put the shift kit in the old TH350.

I noticed the new mount is considerably taller. I hope it doesn't have clearance issues but if it does, I have a big hammer and I'm not afraid to use it. :D

scottrock
Jun 11th, 08, 7:00 AM
Ok, so yesterday morning I dropped the driveshaft off to be shortened, yoke installed, etc. Picked it up later in the afternoon and hauled ass to the house. Still not 100% together but 5 hours later and everything important was wrapped up to the point where I could take it around the block. :hurray::D:hurray::D:hurray::D Runs GREAT! Been missin that! No problems that I could see... No leaks (that's good) I do need to adjust the shift point/check my kickdown operation. Trans wouldn't hold first but I've heard that's a common issue. Maunually shifted into first- nail it and it shifts into second at about 4 grand- Isn't that adjustement tweaked with the vacuum modulator? I installed a B&M shift kit and went with the heavy duty setup. Should I have gone with the "street" setup?

Regardless, I am SOOO stoked to have my car back on the road. Today I will be picking up the tag for it :D it's gonna be a gooooood weekend.

scottrock
Jun 11th, 08, 7:38 PM
Alright folks, this salvage yard tranny works great. :hurray:

I've made a few trips down the street and back and everything sounds & feels real good. It feels a little different than the old TH350, but it pulls nice & strong. Hell all the difference in feeling could very well be that the old tranny was well on it's way out before I replaced the motor... it lasted just a very short time before it died.

Anyhow, I don't feel any slipping or notice any odd vibrations, etc. I can do nice smoky burnouts either in 1st or just in drive; power braking a touch or just mashin it to the floor~ but the darn thing sure does shift when it damn well pleases. :confused:

Now, I'm not saying that it's totally all over the place however it WILL do the following:

1. Shifts from 1st to 2nd while it is in 1st~ when you are laying into the throttle real hard. And it shifts too early at about 4k... I haven't had it out on the open road to see where the 2-3 shift occurs but I got the tag today so we'll see within the next day or two. Isn't that adjusted at the modulator?

2.At slower speeds, like between 15 to 25mph, I can manually downshift from 3rd to 2nd to 1st, but when I come back up it will only traverse between 1st and 3rd. It won't hit 2nd gear. Is this normal?

GasserNorm
Jun 14th, 08, 1:08 PM
Scott,

Install one of these, you have to tune it to get your shift point down but once you do you can race in drive.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=BMM%2D20248&N=700+4294925134+4294839071+4294849137+115&autoview=sku

Norm

scottrock
Jun 14th, 08, 1:52 PM
I'll do that, thanks!