Got the Transgo 1-2 shift kit, any suggestions before installation?

By "short", do you mean early? or harsh (quick)?

-BC

 

So your 2-3 shift was so early that your car barely spent any time in 2nd gear?

I assume you are talking about during light-throttle driving, and not WOT?

I guess I wouldn't want to shift into 3rd much before 20 MPH or so, so maybe I'll include it.

Thanks for the insight.

-BC

 

Ya,
Skip the little spring that goes on the modulator valve. I've never seemed to need them, they bring the part throttle shifts down and seem to cause an almost "stacked" shift scenario.

A .125" 2nd feed hole is what I use on racing units with a 34 element sprag.
I wouldn't go any bigger than .135" and I would recommend staying with .120-.125".
If you do the accumulator valve mods in the VB, drill the feed hole to .125", install 5 checkballs, it will shift to 2nd plenty firm enough at throttle and still be pleasant at light throttle.
I've used the .125" 2nd feed up to around 900 Hp without issue, no problems with the 2nd gear clutch life or sprag breakage. It seems to be a very good compromise.

You DO NOT need a fancy clutch or steel. A stock steel and stock Borg Warner smooth tan friction is good to 750+ HP. I typically upgrade to a Hi-Energy friction in the directs and intermediates at 700+ HP but not necessarily because there is an issue with the stock plates.
The Hi-Energy frictions I use are from a 4L80E application, OEM, not a "racing" clutch that is good for taking your money.
I also like the Alto Reds but at about $4 per plate vs. $2-2.50 per plate, there is no reason to use them.
Beware of the green waffled plates. These are the typical transmission shop and supplier "Hi-Performance" friction. They are relatively inexpensive, and they themselves do seem to hold up OK, but they tear up the steels, and then the clutch pack starts slipping.
I've never torn down a Th400 with the waffled plates that the steels were in good shape.
A local "Performance" trans shop built a Th400 for a gentleman who is now my customer.
It had those plates in it, behind a 540 BBC in a '67 Buick Skylark.
It lasted exactly until the first WOT shift into 3rd gear and slipped to the rev limiter.
It wasn't only the clutches fault, but they didn't do it any good.

 

Either use the heavy direct return springs or drill a .060" bleed hole in the outer circumference of the direct drum. I prefer to drill the bleed hole as I feel it allows the air to escape on clutch apply, and prevents centrifugal apply.

.140" is good for the 3rd feed.

I block the 2-3 accumulator feed hole as shown in my article on NastyZ28. It makes the 3rd gear shift crisp.
IIRC the TransGo kit limits this feed so the fluid gets to the clutches faster, and this is an Ok method too.

If you're at or over 500 HP, don't use the Transgo seperator plate, save it for a milder build.
If you are over this HP you want to dual feed the trans internally by leaving the center seal off the direct drum, sealing ring off the center support, and blocking the reverse feed.

 

I assume you are talking about the 2nd feed hole, not the 3rd accumulator feed hole. I'll stick with 0.125" then.

Whoa! Great information. I don't know if the waffled plates are going to be used or not, but I'll make sure they don't get used.

I assume you mean this article - http://www.nastyz28.com/forum/showthread.php?t=58578

Do you mean this plate?



Jake, like I said previously, thanks a million for your contributions to the Buick community.

-BC

 

Yes,
.125" on the 2nd feed hole.
.140" on the third.

If you do the internal dual feed mods, you can use the stock seperator plate, and the trans actually works better. The fluid feed is faster than through the sandwiched Transgo plate.
I've had problems with the TransGo plate in 500+HP applications that were mainly drag raced.
I've traced the issue down to the plate itself, although it is a great kit, the plate becomes a restriction to the fluid feed to third at elevated power levels.