[chuckies76ta]

Where’s Cliff when u need him. !

[Scott Stoneburg]

Originally Posted by chuckies76ta

I’m getting confused. Rear band or front band?

Front band. The issues I'm having are related to the front band. No gear / engine braking in 2nd gear.

[chuckies76ta]

Ok. That’s kinda what I was starting to think. . I’m not familiar with the front band as I don’t have it in my training and I don’t have engine braking.
That band must grab the forward clutch drum. You don’t need that for racing..

[Scott Stoneburg]

I don't need it. But my valve body was not designed to "not" have gear braking. So the fact that it doesn't work makes me wonder if the trans will hold up. Or is something wrong?

[Cliff R]

My guess is that it woln't hurt anything IF the fluid path to apply the servo is blocked someplace or the servo pin/band set-up is applying but not effectively grabbing the drum.

If the circuit is open and leaking it may take some fluid/ apply pressure away and could cause intermediate clutch slippage/failure.

If it's hitting quick/firm/hard on the 1-2 upshift at heavy/full throttle with decent RPM's you'll probably be fine. If it feels "soft", or "slide-bump" on the upshift you're in trouble.......IMHO.....

[chuckies76ta]

Cliff, What about down shifting from 3-2 if he has no band or engine braking? My Hughes instruction remove the front band and then go on to caution you to not down shift shift the transmission under load or moving and not to put in neutral. My Wife will shift to second when on return road after 1/4 mile run with the car moving very slow and no load on transmission. Haven't had any issues.

My instruction say no neutral as it can cause an over speed in the direct drum. And no 3-2 down shift as it can shock the intermediate sprag.

[chuckies76ta]

Scott, https://transmissioncenter.net/shop/...e-front-64-98/

[Cliff R]

For sure it wouldn't be a good idea to manually downshift when the car is going over 100 MPH and the drum is spinning really fast.

At low vehicle speeds to get some engine braking it woln't hurt anything.......

[Scott Stoneburg]

I don't pull it down into 2nd to help with braking at the end of a run. But if I'm cruising...in Mexico...and someone comes up next to me I would like to be able to pull it down to get in the right rpm range to make a hit. Otherwise I don't really care if it doesn't have gear braking. But it's supposed to so something isn't right. My concern is that what ever is wrong will cause premature failure.

[Scott Stoneburg]

I sent the valve body off to Turbo Action to have it checked for operation. I am confident it is ok. But better to be sure for a small diagnostic fee . I pulled the trans apart. Checked the clutches and forward drum. There was no bleed hole in the drum which I have read it should have. So I drilled it. 1/16" hole. Also while checking the forward band it was just as I expected. I removed the spring and manually pushed the pin as far as it would go. It did engage the band but would just barely touch the drum. I was still able to spin the drum easily by hand As I have read, the pin needs to be about .250 longer for use with the 4L80E band. I tried welding the end of the pin and added about .075 to the length. When manually depressing that pin I was able to engage the band enough where I could no longer spin the drum. I ordered the correct length pin today and will see how it operates when it arrives.

[chuckies76ta]

Good you found your issue with the front band. https://www.turboaction.com/24142A%202-04.pdf Is this your instructions for your valve body? Any chance while you have the valve body opened, that you can post a pick of the gaskets and the separator plate? Thanks

[Half-Inch Stud]

After 4-Pages, Post #2 nailed it. HIS

[Scott Stoneburg]

Yep..Cliff nailed it quickly. I could not get the builder to even think that he was wrong. His ego was in the way. The new servo and pin should be here soon and hopefully the valve body back pretty quickly too. I have learned a lot about TH400 builds through Cliff's book and many videos. I will be doing my own from here on out.

[Half-Inch Stud]

Scott, fantastic to know you will "own the build" from now-on. If you ever go to the factory Iron VB, then i can be a resource to help.

[Scott Stoneburg]

Originally Posted by Half-Inch Stud

Scott, fantastic to know you will "own the build" from now-on. If you ever go to the factory Iron VB, then i can be a resource to help.

Thank you. I will most likely take you up on that offer, either late this year or early next year. My brother an I will be building a mostly street 81 Grand Am. Going to use a mild 400 build in place of the non running 301 4bbl motor and we will build the spare TH400.

[Cliff R]

"Yep..Cliff nailed it quickly. I could not get the builder to even think that he was wrong. His ego was in the way."

You'll have that "ego" thing a lot with transmission stuff. "Builders" know that most of the crowd is scared to death of transmission building once they drop the valve body and check balls are rolling all over the floor.

The TH400 isn't fussy, and really doesn't need a lot of help. Just improve things in a few areas and it's ready for the street or track.

I would add that some of this new stuff is pretty complicated. Dive into a Subaru transmission/transaxle sometime if you want to test your skills sets at automatic transmission rebuilding and get a lesson in humility..............or any of this new 6, 8 or 10 speed stuff......there is a LOT going on in there for sure!

About the only thing I haven't tackled to date is a CVT, and don't plan to.............

[Scott Stoneburg]

Made it back to the track last night. The car would not hook at all. Even rolling into the throttle created tire spin. The track just didn't have any bite. But the transmission worked perfectly. So I can close the chapter on this trans rebuild. Now I have to start working the shock settings to try and get it to hook. But I think a lot of last night's issue was the track more than the car.