727 with 2/3 overlap

[Gr8polarbear]

Have a big block 727 with a cheetah 17156 reverse manual vb and when i bought the car it had a bad 2/3 overlap. Took it to a mechanic and told him just to rebuild the trans and fix the overlap. When he did he put a restrictor in the trans and it fixed the overlap but every now and then would slip going into 3rd gear at higher power. I assumed that it had a 5.0 lever in it but when we opened it up you could not see the number. I purchased a 4.2 to put in it and when we opened it back up sure enough it had a 5.0 lever in it. Now the 4.2 is in the trans and the restrictor gone. Now it has an overlap again. Originally the overlap was only at lower power/rpm, now the overlap is all the time. The mechanic nor i have any ideas what to do with it. Has anyone ever ran into this problem before and if so what is the fix?

 

[Illahe]

Have a big block 727 with a cheetah 17156 reverse manual vb and when i bought the car it had a bad 2/3 overlap. Took it to a mechanic and told him just to rebuild the trans and fix the overlap. When he did he put a restrictor in the trans and it fixed the overlap but every now and then would slip going into 3rd gear at higher power. I assumed that it had a 5.0 lever in it but when we opened it up you could not see the number. I purchased a 4.2 to put in it and when we opened it back up sure enough it had a 5.0 lever in it. Now the 4.2 is in the trans and the restrictor gone. Now it has an overlap again. Originally the overlap was only at lower power/rpm, now the overlap is all the time. The mechanic nor i have any ideas what to do with it. Has anyone ever ran into this problem before and if so what is the fix?

What servo do you have up front? Paul at Cheetah, is pretty sharp if you can get him on the phone, or call A&A.

 

[Gr8polarbear]

What servo do you have up front? Paul at Cheetah, is pretty sharp if you can get him on the phone, or call A&A.

I have no idea but i will try to call them this coming up week. I already planned on calling cheetah.

 

[GTX JOHN]

We run 4.2 and a HD Billet activator push
piece to eliminate a possible flex point that
piece we get from ProTrans as I recall. Sometimes
we have had to replace the Valve body and a
different brand or model has eliminated the issue.

 

[RustyRatRod]

What size band does it have? When you get past about a 3.8 lever, you need to run the widest band you can get in there. As far as I know, the only thing that used the 5.0 lever was the Hemi and they all had a wide band. I think the restrictor was a good idea. What's happening on the overlap is, the transmission is trying to shift into second and third at the same time and the restrictor delays the fluid flow just enough to straighten that out.

 

[Desoto291hemi]

Valve body .

Tommy

 

[Gr8polarbear]

What size band does it have? When you get past about a 3.8 lever, you need to run the widest band you can get in there. As far as I know, the only thing that used the 5.0 lever was the Hemi and they all had a wide band. I think the restrictor was a good idea. What's happening on the overlap is, the transmission is trying to shift into second and third at the same time and the restrictor delays the fluid flow just enough to straighten that out.

I dont know what size band it is. Do they make different size restrictors?

 

[RustyRatRod]

I dont know what size band it is. Do they make different size restrictors?

Not that I'm aware.

 

[19DUSTER73]

The first 727 I did had the same valve body. I was advised to run a 3.8 lever, all 15 springs in the front drum and .100" clutch clearance. It seemed to run fine but it was in a strip only car that was only ran a short time before I went through it and added a transbrake and a bunch of other goodies.