3rd gear issues on 727 after Tf2

[my5thmopar]

I removed the RMVB from my 76 727. I installed a 71 VB from my spare 904. It has a part time KD and I added a TF2. The governor in tail-shaft wasn’t removed. Reverse and drive is firm and immediate. The 1-2 is hard and will bark tires. 3rd will work if I go to neutral and back to 3rd. It seems it will drop back to 2nd with the slightest throttle. I went middle of the hole drilling, the ball was left in, accumulator is not blocked. Orifice pLug installed. I’m thinking I messed up the shuttle valve grinding or got spring wrong place. I adjusted the bands per the TransGo instructions. I overfilled just for testing and back to correct level. It’s not fluid level...I’ve had Mopars since the 70s.

Anything else I can try before I pull the pan?

I’m going to check Lokar shifter and Lokar KD cable adjustments today. Thanks Craig

 

[Oldmanmopar]

There are two different PTKD servos. Be very careful where you test that trans when at WOT. I had a PTKD servo in the trans of my Demon. I sold the car and he took it to a trans guy??? for a fluid change and the man talked him into a shift kit. Three days later his 17 yr old son was killed in That car.

Eventually he bought a 72 340 Challenger from me. They put that valve body in that car. The son-in-law was entering the interstate and kicked it down to passing gear when the trans shifted drive the rear tires locked up . He spun the car around a couple of times but did not crash. Just like it did in the Demon as per the paralyzed passenger stated that was in the Demon when he crashed.

This is just a word of warning. Trans failure is not always what you are ready for. If you are not sure of your mods that you have done. Start over with a fresh valve body . Do one mod at a time or you'll be in the dark as you are right now.

There are times when it is best to leave trans work to the professionals. You must ask your self is it worth the risk for the money saved. I usually add the lighter governor and add a PTKD. Turn the line pressure screw out a quarter turn to give a little harder shift. Beyond that I leave it to the pro's.

That valve body can not be trusted now. Send it off to someone who knows . There are plenty of builders on this site. I am sure they will not give you advice without seeing what you have done in person. Nobody wants the liability of trying to correct you mods without hands on.

 

[TrailBeast]

I removed the RMVB from my 76 727. I installed a 71 VB from my spare 904. It has a part time KD and I added a TF2. The governor in tail-shaft wasn’t removed. Reverse and drive is firm and immediate. The 1-2 is hard and will bark tires. 3rd will work if I go to neutral and back to 3rd. It seems it will drop back to 2nd with the slightest throttle. I went middle of the hole drilling, the ball was left in, accumulator is not blocked. Orifice pLug installed. I’m thinking I messed up the shuttle valve grinding or got spring wrong place. I adjusted the bands per the TransGo instructions. I overfilled just for testing and back to correct level. It’s not fluid level...I’ve had Mopars since the 70s.

Anything else I can try before I pull the pan?

I’m going to check Lokar shifter and Lokar KD cable adjustments today. Thanks Craig

Sounds to me like the TP is set too high.
First thing to check (like you said)

 

[my5thmopar]

Sounds to me like the TP is set too high.
First thing to check (like you said)

Thanks Tracy. That brings up a good point. Now I remember discussing about cutting the TP valve only 1/2 way. I do need to back it off some. I’ll report back after testing. Craig

 

[CudaFactHackJob]

You know you gotta pull the valve body and figure out your own mistake... so get busy haha.

 

[MileHighDart]

There are two different PTKD servos. Be very careful where you test that trans when at WOT. I had a PTKD servo in the trans of my Demon. I sold the car and he took it to a trans guy??? for a fluid change and the man talked him into a shift kit. Three days later his 17 yr old son was killed in That car.

Eventually he bought a 72 340 Challenger from me. They put that valve body in that car. The son-in-law was entering the interstate and kicked it down to passing gear when the trans shifted drive the rear tires locked up . He spun the car around a couple of times but did not crash. Just like it did in the Demon as per the paralyzed passenger stated that was in the Demon when he crashed.

This is just a word of warning. Trans failure is not always what you are ready for. If you are not sure of your mods that you have done. Start over with a fresh valve body . Do one mod at a time or you'll be in the dark as you are right now.

There are times when it is best to leave trans work to the professionals. You must ask your self is it worth the risk for the money saved. I usually add the lighter governor and add a PTKD. Turn the line pressure screw out a quarter turn to give a little harder shift. Beyond that I leave it to the pro's.

That valve body can not be trusted now. Send it off to someone who knows . There are plenty of builders on this site. I am sure they will not give you advice without seeing what you have done in person. Nobody wants the liability of trying to correct you mods without hands on.

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Are you saying that the ptkd was somehow responsible for the rear tires locking up?
Or just that the trans guy didn't know what he was doing?

 

[my5thmopar]

You know you gotta pull the valve body and figure out your own mistake... so get busy haha.

Probably but, not sure what it might be? I’ve had nothing but, transmission issues this year. Getting pretty tired of pulling them. Craig

 

[my5thmopar]

Sounds to me like the TP is set too high.
First thing to check (like you said)

First round of testing. Shifter was a little off but, I adjusted in the drive and checked all positions. It’s correct. 2nd round I backed off the KD cable. I now have 3rd gear. The concern is I have 1/4 inch slop in the Lokar cable. Not sure what if anything is wrong.

 

[CudaFactHackJob]

Automatics are unforgiving as hell. One little thing and no workee. Take it apart and post pics and I'm sure several guys on here will point out the problem immediately. (If you don't spot it first)

 

[Oldmanmopar]

Are you saying that the ptkd was somehow responsible for the rear tires locking up?
Or just that the trans guy didn't know what he was doing?

That ptk was on that car for 8 yrs never had a problem until that man went inside with his tricks after I sold it.

I myself can never give info on a trans except what converters worked for me. The only thing I would ever mess with was the PTK, governor, acumulator prop and the line pressure. After that I take it to a trans guy I know. I learned if you don't have the tools , knowledge or test equipment. Its best to keep your fingers off. Seen to many blow the floors out of cars and the Demon above confirmed I made the right choice.

My trans guy built the 727 in my Duster over 20 years ago like me he can't see anymore. I cannot count how many motors that were in front of i my 727. Being its out now I am sending it to ATI.

While at Carlisle, I told him it flares at 8000 3rd gear shifts when it gets heat in it. I was talking to him about a sprag and billet drum. He told me its only a matter of time and that thing will explode at those RPM's with what was in it.

Depending of the weight of the new car I might go to a 904 by ATI. Or a power glide race trans with a Neal Chance converter. Once you have a trans that is built. Any good trans guy can freshen it. Its the initial build that is critical. Its all about the Benjamin's. Pay now or pay later .

Like I said 20 years on the old school build but never these RPM's until this motor. Proper care, And the initial cost will be well worth the money.

I won't take the chance with my son's life with poor decisions. After talking some experts. I couldn't live with myself if something would happen to him.

 

[TrailBeast]

First round of testing. Shifter was a little off but, I adjusted in the drive and checked all positions. It’s correct. 2nd round I backed off the KD cable. I now have 3rd gear. The concern is I have 1/4 inch slop in the Lokar cable. Not sure what if anything is wrong.

It's supposed to have slack in it.
Remember how the TP rods had the long slot?
The slack in the TP cable is basically the same thing.

See here.
This is just a random pic I grabbed off Google of a lokar cable on another Mopar.
Thats why the attaching clip has a hole all the way through.

 

[CudaFactHackJob]

Was your 1-2 shift real late and hard before? Is the 1-2 too early now? Doesn't make sense.

 

[my5thmopar]

It's supposed to have slack in it.
Remember how the TP rods had the long slot?
The slack in the TP cable is basically the same thing.

See here.
This is just a random pic I grabbed off Google of a lokar cable on another Mopar.
Thats why the attaching clip has a hole all the way through.

View attachment 1715390429

Good catch. Yes, and on my 70 w/383 has the slot and there is some rod slack "slop". I was going through the fluid operation and trying to figure out what I could have done wrong. Makes perfect sense now that I've adjusted the TP back and forth. The diagram on Lokar instructions shows the same thing as the photo what you posted. I think the difference is, they don't account for a modified valve body. If I adjust per their instructions, there isn't any slack which contributed to the initial issues. I understand the operation and will adjust accordingly. Any good suggestions on rpm or mph for 1-2-D? Also, what about KD from 3rd to 2nd, suggested RPM or MPH? Maybe just set it by feel?

Was your 1-2 shift real late and hard before? Is the 1-2 too early now? Doesn't make sense.

Yes it "was" and not too early now. Yes makes sense. I've never used Lokar and I would say about right now. I just need to do some fine tuning. See above comment. Thanks guys!!!!!!!!!

 

[CudaFactHackJob]

ok l only saw where it was hard into second but not late.

 

[my5thmopar]

ok l only saw where it was hard into second but not late.

Ya, I should have clarified. The pressure was holding 2nd as long as I had my foot in it. It would only hit 3rd if I let off or went to N and back to 3rd. if I pushed the throttle again it would immediately drop in 2nd. I'm just relieved I don't have to pull another transmission laying on my back!!! Maybe I'll get some drive time before winter shows up!

 

[TrailBeast]

Good catch. Yes, and on my 70 w/383 has the slot and there is some rod slack "slop". I was going through the fluid operation and trying to figure out what I could have done wrong. Makes perfect sense now that I've adjusted the TP back and forth. The diagram on Lokar instructions shows the same thing as the photo what you posted. I think the difference is, they don't account for a modified valve body. If I adjust per their instructions, there isn't any slack which contributed to the initial issues. I understand the operation and will adjust accordingly. Any good suggestions on rpm or mph for 1-2-D? Also, what about KD from 3rd to 2nd, suggested RPM or MPH? Maybe just set it by feel?



Yes it "was" and not too early now. Yes makes sense. I've never used Lokar and I would say about right now. I just need to do some fine tuning. See above comment. Thanks guys!!!!!!!!!

I set them where I like the shifts and timing of them, there are no hard lines on this.
Right now I get my 1-2 shift around 15 mph and my 2-3 shift is about 30 minimum.
I have the low geared first is why so early on the 1-2.
Basically the 1-2 shift happens right after my back tires cross the farthest line of a crosswalk under normal cruising around conditions.
Of course the shift is more delayed if I'm into the throttle more.
Set yours where you like it.

 

[my5thmopar]

I set them where I like the shifts and timing of them, there are no hard lines on this.
Right now I get my 1-2 shift around 15 mph and my 2-3 shift is about 30 minimum.
I have the low geared first is why so early on the 1-2.


Basically the 1-2 shift happens right after my back tires cross the farthest line of a crosswalk under normal cruising around conditions.
Of course the shift is more delayed if I'm into the throttle more.
Set yours where you like it.

I kinda figured that and I know how to make adjustments with TP and governor, shift points etc. What I don’t know is about KD to 2nd meaning, is there RPM/MPH that you don’t want to drop back. I don’t want to tear anything up. It’s a 440 with 3.91 diff (future 3.23). When I was playing with adjustments yesterday, at one point it dropped back and felt like it was out of 2nd gear. As always thanks. Craig

 

[TrailBeast]

I kinda figured that and I know how to make adjustments with TP and governor, shift points etc. What I don’t know is about KD to 2nd meaning, is there RPM/MPH that you don’t want to drop back. I don’t want to tear anything up. It’s a 440 with 3.91 diff (future 3.23). When I was playing with adjustments yesterday, at one point it dropped back and felt like it was out of 2nd gear. As always thanks. Craig

I think what you felt was a no engine braking condition, which can be normal when the shift points are too high.
Also, the governor will not normally allow a kickdown after a certain speed.
It works the same way as if you went to manual low when going too fast for low.
You can move the shifter to low gear but an unmodified trans won't go into low until the road speed gets down to a safe speed for it to do it.

I say "unmodified" because an optional function of the TF2 kit allows the trans to be put into manual first at any speed.
I have this option in my car because the type of shifter I have makes it near impossible to go into manual low accidentally, but I can make it do it if I want it to.

You can test this with your car by doing about 30mph and dropping the shifter into manual low with zero throttle.
It probably won't downshift until you get down around 20-25 or so.
If it does downshift into first at 30 try 35 and see if it still does it.
Going into manual low at 30-35 won't be enough to hurt anything if it does it, because your car will probably go that fast in first anyway.

If you drop in first and it waits to downshift until you are at a lower speed you know the governor is preventing the engine from being over revved.
This answers your question about being able to kickdown into too high RPM's.
Kickdown will never happen too high to hurt something because the trans will go to third before it hurts an engine.
Manual shifting could, as I explained above with the manual downshift test.