727 Hard Shift from 1st to 2nd...smooth into 3rd

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Tjhoward84

Tjhoward84

1969 Barracuda Convertible
Joined
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I just had the transmission (Torqueflite 727) rebuilt because the reverse servo went out and also took out the reverse band. While the transmission was a part the shop also changed out the valve body so the reverse lights would work with the roster and neutral switch. Now, the transmission shifts incredibly hard from 1st to 2nd (around 1,500 rpm) but then it's really smooth from 2nd to 3rd.

Going from 1st to 2nd you would think the trans and rearend were left in the middle of the street. The car (1969 Barracuda convertible) has a Dana 60 rearend with 3.54:1 gears.

We've tried adjusting the kickdown cable (Lokar SS cable) but that has not done much (really hasn't done anything).

Any ideas?

Could it be the valve body?
 
Tjhoward84 said:
I just had the transmission (Torqueflite 727) rebuilt becuase the reverse servo went out and also took out the reverse band. While the transmission was a part the shop also changed out the valve body so the reverse lights would work with the roster and neutral switch. Now, the transmission shifts incredibly hard from 1st to 2nd (around 1,500 rpm) but then it's really smooth from 2nd to 3rd.

Going from 1st to 2nd you would think the trans and rearend were left in the middle of the street. The car (1969 Barracuda convertible) has a Dana 60 rearend with 3.54:1 gears.

We've tried adjusting the kickdown cable (Lokar SS cable) but that has not done much (really hasn't done anything).

Any ideas?

Could it be the valve body?
Click to expand...

Most assuredly it can.
Problem is, we don't know what was done to it or how.
You need to talk to the builder, and if he won't or you can't for some reason you might as well just look for a stock valvebody.
(Unless you want to pull the valvebody, open it up and take a bunch of pictures anyway)

It sounds like some mods were a little over done, but who knows.

Ball left out, drilled separator plate, drilled dams, sticky 1-2 shift valve bore, and any of these together.
 
TrailBeast said:
Most assuredly it can.
Problem is, we don't know what was done to it or how.
You need to talk to the builder, and if he won't or you can't for some reason you might as well just look for a stock valvebody.
(Unless you want to pull the valvebody, open it up and take a bunch of pictures anyway)

It sounds like some mods were a little over done, but who knows.

Ball left out, drilled separator plate, drilled dams, sticky 1-2 shift valve bore, and any of these together.
Click to expand...


Thanks for the reply. The shop is very reputable and do great work. I will talk to the manager and see if they are willing to drop the pan and check the valvevbody. I'm pretty sure they put a new stock valvebody in the transmission when they fixed the reverse issue. The only thing different was they had to find a valvebody that would work with the neutral/reverser switch so the reverse lights would work (i.e. go off when not in reverse). The old valvebody/neutral switch/rooster would not turn off the reverse lights when in drive or nuetral. They would stay on all the time except if the car was in park.
 
Yeah, somebody put the wrong spring in the 1-2 valve, or its stuck, or the accumulator is stuck or blocked. That'd be my guess. In any case,the VB needs to come down.
Unless the 2-3 shift is also way early. Then there could be multiple problems.
On further pondering; I suppose the line-pressure could be cranked, as well as the throttle pressure, and the 2-3 is wrong.
Same conclusion; VB needs to come down.

In any case TB is on the money.
 
AJ/FormS said:
Yeah, somebody put the wrong spring in the 1-2 valve, or its stuck, or the accumulator is stuck or blocked. That'd be my guess. In any case,the VB needs to come down.
Unless the 2-3 shift is also way early. Then there could be multiple problems.
On further pondering; I suppose the line-pressure could be cranked, as well as the throttle pressure, and the 2-3 is wrong.
Same conclusion; VB needs to come down.

In any case TB is on the money.
Click to expand...

I was going to guess blocked accumulator or the line pressure is just too high.
 
AJ/FormS said:
Yeah, somebody put the wrong spring in the 1-2 valve, or its stuck, or the accumulator is stuck or blocked. That'd be my guess. In any case,the VB needs to come down.
Unless the 2-3 shift is also way early. Then there could be multiple problems.
On further pondering; I suppose the line-pressure could be cranked, as well as the throttle pressure, and the 2-3 is wrong.
Same conclusion; VB needs to come down.

In any case TB is on the money.
Click to expand...

Thanks for the info.

The trans shifts from 1st to 2nd around 1,500 rpm and then from 2nd to 3rd at 2,500 rpm. It think the shift points are OK. It's got 3.54 gears in the rear end.

We've tried backing off on the line pressure by adjusting the kickdown cable (Lokar) but that just doesn't seem to do anything for us.

I think it's in the valvebody. It's the only piece that was replaced other than the reverse servo and reverse band when the transmission was out of the car.
 
Tjhoward84 said:
Thanks for the info.

The trans shifts from 1st to 2nd around 1,500 rpm and then from 2nd to 3rd at 2,500 rpm. It think the shift points are OK. It's got 3.54 gears in the rear end.

We've tried backing off on the line pressure by adjusting the kickdown cable (Lokar) but that just doesn't seem to do anything for us.

I think it's in the valvebody. It's the only piece that was replaced other than the reverse servo and reverse band when the transmission was out of the car.
Click to expand...

"The trans shifts from 1st to 2nd around 1,500 rpm and then from 2nd to 3rd at 2,500 rpm."

At what throttle does it shift at those RPM's
If it's at a light throttle that's not bad at all.
If that's at full throttle that's not good at all

Also those shift points should vary depending on throttle used. (do they and about how much?)

A stock TF trans shifts earlier than that a light throttle and later than that at heavy.

That is pretty much exactly what I am working with in my part throttle kickdown thread.
(And it's almost kinda pretty close to perfect now) :D around town in traffic but now I need to deal with the throttle pressure adjustment and governor to move the shift points higher in the RPM range when using more throttle.

It shifts perfect for my tastes around town (a little late and firm) but to early at wide open throttle.
Lightening the governor valves and lessening the throttle pressure adustment should level out right about where I want it for both.
 
A 1000 rpm disparity between those shifts, if at the exact same throttle setting is too much, or rather would be too much for me to live with.I like moderate upshifts at 2800 to 3200, and lazy upshifts at 1800ish. And each about the same as the other. Your shifts should be much closer together. But really its the other end thats more important;ie the WOT upshifts.
Those shift-points are a personal preference, and at one time,I spent whatever time I needed, to get that. I currently have a 904 set-up like that and I built a cloneVB.
 
I am having similar issues with a rebuilt trans and lokar setup. Could it be that the throttle pressure doesn't have a return spring (at the trans)? I noticed mine was was not returningcompletely and built a simple bracket to attach a spring to. Have not tested it yet though.
 
seabee said:
I am having similar issues with a rebuilt trans and lokar setup. Could it be that the throttle pressure doesn't have a return spring (at the trans)? I noticed mine was was not returningcompletely and built a simple bracket to attach a spring to. Have not tested it yet though.
Click to expand...

That's a good thought and should be checked of course, but I think if that's was the case his shifts would be a lot higher in the R's than they are.

Did you happen to lube those Lokar cables?
Right out of the box I have always heard they tended to bind because they were not lubed.
Getting these things to shift how and when we want is a bit tricky and a lot time consuming, and trial and error.
A tougher 1-2 shift valve spring can move those shifts higher in the RPM's and better match the 2-3 shift and THEN lighten the governor to move both up if wanted but we don't normally have the option of multiple springs to try.

Shoot, it took me probably 6 tries just to get my shifter cable adjusted right again after using a thicker pan gasket.:D
Test drive, then just one more quarter of a turn on the cable adjustment, then test drive and adjust again until it feels as perfect as it's going to get.
 
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