I've noticed recently that when the RPMs reach 5500 with the tranny in manual 1st, it really bogs down suddenly until shifted to 2nd. At first I thought it was the engine loosing it at 5500, but since have verified that the engine will pull to 6000 RPMs in 2nd without a hickup. So, something most be going on in the tranny, like attempting to go into 2nd while still in 1st, if that is possible.

Mods in sig, particulars about the shift kit are fuzzy after 2+ years.

 

Centrifugal application of the 3-4 clutch?

 

i thought centrifugal apply was only an issue above 6500?

 

I searched on that (have to admit that's the first time I've heard that term), and Dana of Pro Built Automatics fame indicated it can be a problem in the range I'm speaking of. From an almost 4-year-old post: "If you install the Trans-Go Performance Shift kit it will give you all new heavy duty springs for the forward and 3rd gear clutch packs, these springs prevent accidental 3rd gear clutch from trying to come on in 1st or 2nd gear (due to centrifuge) up 7,800 rpm. I use these springs, Trans-Go Shift kits and boost valves in all my transmissions and have no problems with 3rd gear apply." Since this is a new development, wonder if one or both of those springs has/have finally given up on me.

As you can see from the sig, I also have the no 2-3 shift at WOT problem, and the Transgo kit didn't solve that (assuming I enlarged the proper hole - everything was done to the valve body, nothing to the case except .5 valve & Vette servo).

 

As the springs age it wouldn't surprise me if the point at where it occurs started happening at lower and lower RPM.

IIRC, the heavy duty clutch springs aren't included in the TransGo kit, they're a separate item, P/N 7-CS or some such thing.

 

Oh, it goes away immediately as it is shifted to 2nd.

 

Whether it's the problem or not, here's what I found in the filing cabinet of doom.

 

For grins last night I tried holding the tranny in 1st to see if it "got over it" - not! Later, when going about 25 mph in 2nd, I dropped it in 1st and it did the same thing. Final test, left the shifter in 2nd from standing start, it shifted fine from 1 -> 2 at 5000 RPMs, then of course wouldn't shift from 2 -> 3 w/o backing off the throttle as normal. This 169k mile tranny is on its last legs performance-wise, although it operates just fine in "normal" commute driving.

I've got two TH700's sitting tail-up on the garage floor - one for the Camaro, the other for the '57. The one currently in the Camaro is barter fodder - fellow racer rebuilds trannies for a living, is looking for a TH700 for his El Camino.

The one destined for the Camaro supposedly has been rebuilt for performance but has a bad front pump (former owner didn't have the converter properly seated before installing, broke the pump rotor). The rebuilder says he'll fix the front pump with a 13-vane unit gratis. When the Camaro is up and running and verified, I'll give him the current unit in exchange for building the tranny for the '57 (labor only - I'll supply the parts). I'll look into getting those springs as part of the rebuild parts - I'm sure Dana will fix me up.

Thanks for your assistance. This thing has frustrated me since late 2001 (did I mention the spurious TCC lock-up when in manual 2nd after the Transgo install?).

 

I keep the spring kits (7-CS) in stock, they go for $17.50.

 

Well, the tranny (and engine) are out now. A rebuilt '83 tranny with Transgo stuff is going back in. A check ball fell out of the pan when I was draining the "new" tranny (converting from 27 spline to 30 spline so I can reuse my converter), so I took the whole thing (including an '87 tranny for the 30 spline stuff) to the guy who rebuilt my TH400 4 years ago. He was trying to figure out where the ball was supposed to go, and I was trying to find the Transgo instructions from 3 years ago, and found the remains of the kit I got from you, Dana. Low and behold, the spring kit was in there - I hadn't used it because I didn't remove the tranny when I put in the shift kit. So, I had it available and didn't know it (didn't remember it, anyway).

I'll be rebuilding the '86 tranny for use in the '57. Now I need to get the rebuild parts for it put together.