.Rocket.Man.

I got a 68 442 with mostly stock 400 engine, TH 400 and posi 3:42 rear. I'm having tranny rebuilt and was wondering if/what I should do shift kit wise? I'm just looking for an improvement over stock not looking to build a race car. Any opinions are welcome, Thanks!

442Harv

Every time I had a tran rebuilt, I put in a mild shift kit. I like a positive shift feel.

BangScreech4-4-2

Just so long as you're doing a rebuild. I have been told by more than one source that to install a shift kit on an older transmission is asking for trouble, as the increased line pressures will play havoc with the seals.

Fun71

TransGo is my choice.

The first one I installed was in my '70 Supreme with ~90,000 miles on it and nothing bad happened.

Canadian Greg

I put a Trans-Go II kit in mine back in '87.
Still shifts like new. Very impressed with its longevity.

droldsmorland

X10 on the trans go kits.

https://classicoldsmobile.com/forums...h400+dual+feed

http://www.jegs.com/p/TCI/TCI-Street...46476/10002/-1

http://www.transtar1.com/contact/loc...ew-York-Branch

Be sure the builder is familiar with all the upgrades that need to go into a TH400. Make sure he re-bushes the whole case (bearings). Make sure you get a new pump, use top of the line frictions & steels, band and soft parts. Think about a looser converter say like 22-2500 stall. Install the manual/automatic valve body option. This allows you to up shift when you want to verses allowing the governor to govern it.
Install a TM-50 modulator. Dial it up (tighter) for firmer shifts. USE TCI Synthetic clear trans fluid and their high perf filter. Run a cooler pre-radiator, not post.

Build it similar to the TCI Street Fighter specs with the trans go dual feed(if you so desire). Look for it in Jegs catalog.
Trans go stuff is available from Trans Star Industries.

Warning: you will get rubber on 1-2 & 2-3 upshifts! NICE! Tame it down with the modulator adjustments.

rootney

Dr Olds,

I need some advice here.
I've recently been trying unsucessfully to get rubber and hard shifts in 1-2 with a transgo reprogramming kit (1&2) . My tH400 just got completely rebuilt including new pump and B&M perf. clutches. Same shop installed the transgo kit. I even had them speak to the tech support guy at Transgo. We did the "competition" build.
Even when shifting manually and winding the motor to 3500 I get no chirp. It doesn't even feel agressive. The TC is new 2800-3200 stall. My motor is fresh built 455/ 10.3:1 comp/home ported "C" heads/performer intake/Holly 850/.640" lift roller cam. The motor pins you to the seat, but the tranny's not shifting hard.
One more thing that I'm gonna try is putting my old narrow radials back on just to see if I can feel anything. I now have MT 12x30x15 sportsman radials. Oh, my rear is a 3:42 posi.

This is very frustrating. I would expect the tires to at least give a solid chirp from first to second.
The car used to have a mild built 350 and a TH350 with shift kit. That setup would bang 2nd pretty good.

Help

George

BlackGold

You answered your own question. Maybe the shifts could be made firmer inside the transmission. But they'll never feel as neck-snapping with a high-stall converter as they do with a stock converter. I'm not saying the high-stall converter is a bad thing; it really helps an engine stay in its power band. But there's no getting around the fact it will cushion the shifts somewhat.

droldsmorland

Yes the high stall will cushion the shifts and is likely your problem. But it also depends on many other factors, cam, rear gear etc... Did the trans builder "dual feed" the direct drum? Did you install heavier direct clutch return springs? Did the third feed hole get drilled out? Drilling out the 3rd feed hole = more fluid volume in a shorter period of time to apply the piston quicker, giving a firmer shift and "improved high gear oiling".
Here's the deal on the TH400,
TransGo is the ONLY kit that dual feeds without doing the internal mods. So it is the only kit you can install for dual feeding with a trans in the car...
They do so by using a sandwiched separator plate assembly... it is a patented component that has 3 plates riveted together, the center one performing the same function as all the TH350 kits "transfer plate" but it is a little more complex due to the nature of the TH400's fluid passages in the worm casting area.
On a TH400 going into a pretty stout car drill the feed holes out to the upper end of TransGo's suggestions. ~.130-150"...
Lastly try dialing up the vac modulator. You may have to turn it in quite a bit. This will move the shift points up thus increasing the line pressures which may get you to where you want to be?

rootney

Doc,
I'll check on the drill size ~.130-.150".
As far as the modulator, I'm leaving that out of the equation by manual shifting. When I get firm shifts manually, I'll consider the auto behavior. Actually when driving in automatic, I wouldn't care about shifts being firm unless it felt like a lot of slippage.

Again, my trans. shop had transgo tech support on the line to make sure nothing was missed. In the end though, you have to trust in what the shop says or know when it's time for a second opinion.

I did an internet search and found that many guys that have changed to a higher stall converter, AFTER driving with a stock converter and a shift kit, felt dis-appointed. So, thanks for setting me straight on that one. My shifts are no doubt faster, but the seat of the pants feel is not dramatic.

George

Fun71

The shifts in my car softened considerably with the 2500 RPM converter so it doesn't rip second as much as it used to.

Hmm, I do not call 3500 RPM "winding" it up, but that's me.

I have noticed that mine shifts harder and chirps 2nd more often in Drive than when manually shifting. I don't know why but the auto shifts feel firmer. I learned I can get part-throttle 1-2 chirps if I push the throttle just enough to run the auto shift into the 3000 RPM range, and it almost always chirps 2nd. I can't make it do that when manually shifting. Also, it's not just the RPM level, I have to operate the throttle to push it just into the secondaries so the engine's making torque and not just winding up at light throttle.

Another thing to look at is the vacuum modulator adjustment. I haven't played with it a whole lot, but loosening the adjustment screw results in lower RPM and softer automatic shifts, while tightening it raises the RPM and firms up the shifts. When I got my trans back form the shop the screw was all the way in and the trans would run fairly high on part throttle shifts - they were firm, but to too high. I backed the screw out several turns and the RPM came down to where it was before the rebuild and this is where I can get part throttle chirps ~3000 RPM.

droldsmorland

I wonder if your clutch packs were "packed tight" or a little loose? The stack up tolerance is critical on the clutch packs. What is your line pressure readings through out the ranges? Thats the best way to tell if the builder did it right. Higher means harder shifts. But not too high as that will be too wild and it wont stay together without some race parts installed. Go from there. If they are low or stock spec pressures then the builder didnt do what you wanted.