Shift Kit

[BigRandy]

I've got a leaky pan gasket on my TH400 and have decided to go for a shift kit while I have it off. I've used a B&M shift improve kit before on a TH350 but that was years ago and I don't remember how I set it up.

While reading up on current options I found some favorable threads on TransGo but not sure which one I should get.

I'm not looking for anything that will knock my fillings loose under normal driving but I do want it to firm up under acceleration. Wouldn't be opposed to a little tire chirp either.

Are TransGo kits better than B&M?

TransGo has kit number SK400 which I've found in the 30-$40 range and then a reprogramming kits which sell for more.

The B&M Shift Improver kit that I used years ago is now in the $70 range.

The transmission is fine. Just want to firm it up a little while I have the pan off.

Thanks!

[AcampoDave]

Never used a B&M it have used Transgo twice. Worked great and the trannys lasted a long time. I just used what they called back then "taxi/police" firmness.

[cadillac_al]

Personally, I never put shift kits in th400s because they shift firm enough already. Correction, I did put one in a th400 in my Cutlass and my body unconsciously trained itself to brace myself for the 1-2 shift. It was pretty annoying getting slammed every day. That would have been a B&M shift kit because I just recently found out Transgo is better.

[sweetk30]

just did my first ever my self kit . trans go sk400 . easy to do .

and evilbal has them 3 different sellers now shipped for under 18.00 bucks .

the trans go it just fixes the bad points and a tiny bit firmer shifts .

[crazy longhorn]

I have used both B&M, & Trans go.....Trans go, is my choice Longhorn

[YoungPup1977]

Is this for the truck that got a used differential not long ago that you had to get a u-joint to fit ?

[BigRandy]

Originally Posted by YoungPup1977

Is this for the truck that got a used differential not long ago that you had to get a u-joint to fit ?

It is.

[YoungPup1977]

reason I asked is because you were a bit afraid of doing the differential at the time and now you wanting to get into a shift kit.

Being under the truck with ATF dripping in your face trying to figure out how to keep the checkballs from falling out and aligning the new separator plate/gaskets/manual valve/gov tubes all at the same time can be a real pain.

But if you are up for a challenge, getter done !!! Can be done!!!!!
Go buy a th400 TransGo shift kit, pan gasket, filter and around 6 QTS of ATF.

Also, I suggest to buy a adjustable modulator and replace the old one.

also you need to buy something to keep the checkballs in place.

[sweetk30]

1 tub of trans goo .

1 red stripe modulator .

1 sk400 shift improver kit .

1 fiber pan gasket . way better than cork gaskets .

1 aluminum acumulator pistion for he valve body to ditch the plastic one thats known for cracking . and leave the spring out of it when reinstalled . ( 20+ year trans guy said leave out )

dex III fluid .

un interrupted time .

good long reach small needle snap ring pliers .

dont us the orange spring in the valve body for truck use . ( 20+ year trans guy said not for truck use )

i was lucky on mine . the trans was out so i hung it on a engine stand for easy work .

[BigRandy]

Originally Posted by YoungPup1977

reason I asked is because you were a bit afraid of doing the differential at the time and now you wanting to get into a shift kit.

You are correct. I don't have the tools or experience to confidently set up a diff. I'd sure like to give it a shot some day but not when I only have one set of gears. I needed something already set up.

When I got the second diff I was very tempted to try it anyway. Figured that with 2 complete diffs I could take a chance, but now I'm satisfied that I did not. Everything is smooth, dry and quiet. At least it was this morning and I hope it stays that way.

Mistakes cost money. I was laid off for the third time in 35 years, and until this old man finds employment again I'm on a "small mistake only" budget.

The shift kit might be a challenge. About 40 years ago I worked in a transmission shop after school and I remember some but not a lot. The guy I worked for was a transmission wizard so I never worried about getting in over my head as long as he was around.

In the 74 I've changed the vac mod with a red stripe and flushed\refilled the 400 with type F fluid, as advised some 40 years ago by the "wizard" who told me that type F would produce a slightly firmer shift.

When I had my new 77 Silverado (see avatar) I swapped the cam at about 35,000 miles, added headers and the B&M S-I kit. The truck had 308's and was essentially a dog off the line but would rip once it got some RPM under it.

I'm embarrassed to admit this but more than once I shifted from 1-2 at 55-60 MPH and barked the tires. The 2-3 shift was around 80. It would still chirp the tires when I sold at 168,000, and except for the cam swap, never opened the motor, trans or rearend for anything other than fluid changes. The valve seals were leaking though.

I was a little hard on it because I expected it to blow early and wanted a reason to build it up. It never did. Those 350's are bullet proof when k//ept maintained

But I'm way past my 20's and have zero intention of trying that with this old truck. It looks like hell but runs and drives well. I'd just like to feel it kick

Thanks.

[YoungPup1977]

Well Big Ran.... after reading your latest book I would suggest that you just leave the trans alone. If the trans is working and not slipping I would not put the shift kit in it. Drop the pan change the filter since you have the pan off and fix your pan gasket leak. Please don’t use the rubber gasket with a tube of sealer.
I hope you don’t take this wrong but I tell it like I see it. I know there are several people on this forum that like to hear what they WANT to hear and are offended very easy. But for this old dude I am only trying to help and not worry about being PC

[BigRandy]

Originally Posted by YoungPup1977

Well Big Ran.... after reading your latest book I would suggest that you just leave the trans alone. If the trans is working and not slipping I would not put the shift kit in it. Drop the pan change the filter since you have the pan off and fix your pan gasket leak. Please don’t use the rubber gasket with a tube of sealer.
I hope you don’t take this wrong but I tell it like I see it. I know there are several people on this forum that like to hear what they WANT to hear and are offended very easy. But for this old dude I am only trying to help and not worry about being PC

Thanks. Your posts do have some bite to 'em but I've got thick skin and a brain and appreciate an honest opinion.

[sweetk30]

the type F fluid trick is cause it has friction modifyer in it for more grip like when you add the special lube to the posi rear .

i to have been told this trick .