727 slipping

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charger426

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Have a feeling I need to overhaul the 727 I got out of basically a Mopar junkyard but want to see if I'm missing something first.

Before putting the trans into the car I put a cheetah Manual Automatic valve body and a deep pan. I adjusted the bands per the cheetah instructions and filled with new Amsoil Signature Series AFT and a bottle of Lucas stop leak (has a leak that appears to be coming from between the case and tailshaft). When I first took that car our it actually shifted pretty good. But around the 3rd or 4th time through the gears its started to slip when shifting 1-2 and 2-3. It doesn't have any delay going into R,D, or 1 only has issues when up shifting. It doesn't matter if I have it in D or go through the gears myself it slips every time, sometimes worse than others.

Fluid is between add and full when hot and in neutral. Is it maybe mis-adjusted bands, wrong fluid (its ATF+4), or just time for a rebuild? I don't have any history on the trans past it came out of a working car.
 
if you tranny is slippin even a little bit your oil will be dark and smell burnt if not its not slippin
 
when you put the valve body in there are different length bolts did you put them in right?
 
do a search lots of good tranny threads and you will likely find a thread with the same problem /
 
Why on God's earth would you put stop leak in a transmission and then install it?

Stop leak is designed to be used if you are going to sell something and you want it to stop leaking in the now. In the long run, stop leak will cause major hemorrhaging of every seal in the transmission. The seals will continue to swell until they turn into goo and disintegrate.

It is meant as a quick fix on cars rolling through auctions and whatnot. Nothing more.

If the transmission is slipping, there is already damage done. No amount of adjustment or stop leak will fix that.
 
RustyRatRod said:
Why on God's earth would you put stop leak in a transmission and then install it?
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Its not like I knew it was leaking when I put it in. If I had a crystal ball to know what things are going to do I wouldn't have this thread right now. Its called Uncle Sam is shipping me off in a few weeks and I want things to work for my mom to drive the car around while I'm gone. Thanks.
 
charger426 said:
Its not like I knew it was leaking when I put it in. If I had a crystal ball to know what things are going to do I wouldn't have this thread right now. Its called Uncle Sam is shipping me off in a few weeks and I want things to work for my mom to drive the car around while I'm gone. Thanks.
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Putting stop leak in the transmission just assured you 100% that it will FAIL on her.
 
RustyRatRod said:
Putting stop leak in the transmission just assured you 100% that it will FAIL on her.
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You are honestly the only person that I've ever heard say/type that. There is a reason you were on my ignore list. Shame on me for thinking you had something helpful to say vs just bashing or being negative.
 
charger426 said:
You are honestly the only person that I've ever heard say/type that. There is a reason you were on my ignore list. Shame on me for thinking you had something helpful to say vs just bashing or being negative.
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Nobody is bashing anything. I am telling you from years of experience and seeing what it does.

Simply trying to tell you what you are in store for. I am sorry it's not unicorns fartin rainbows or anything else you want to hear.

If you think I bashed anything, please read again. That was not my intent and still is not. Just because you don't want to hear it, doesn't mean it is bashing.

That's what stop leak products do. Swell anything rubber. That's what they are made to do. There is no secret power that makes that action stop. They swell until they are so soft there is nothing left.
 
If its slipping, then the servo or clutches are not holding. 3 things could be happening. Either the frictions are no longer bonded with friction (worn out) or the seals that are on the servo/clutch pack are bad and are not able to hold the pressure to the actuators, or the pump is shot and is not generating enough line pressure to do its job (this could be lack of fluid (not likely as you checked it) or a stuffed filter that COULD cause something like this. Im sure the deep pan came with an extension and a filter, may not be an issue depending on what you did in there.
 
pishta said:
If its slipping, then the servo or clutches are not holding. 3 things could be happening. Either the frictions are no longer bonded with friction (worn out) or the seals that are on the servo/clutch pack are bad and are not able to hold the pressure to the actuators, or the pump is shot and is not generating enough line pressure to do its job (this could be lack of fluid (not likely as you checked it) or a stuffed filter that COULD cause something like this. Im sure the deep pan came with an extension and a filter, may not be an issue depending on what you did in there.
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Yeah deep pan came with new filter and extension peice. Just seemed odd that it seemed to shift fine the first few times and all of a sudden started slipping when shifting. Generally I've had people bring slipping transmissions over that have gotten progressively worse vs all of a sudden. Does the kickdown lever adjust pressure even when shifting manually? Could that not being adjusted right cause lower pressure and lead to slipping?
 
RustyRatRod said:
Why on God's earth would you put stop leak in a transmission and then install it?

Stop leak is designed to be used if you are going to sell something and you want it to stop leaking in the now. In the long run, stop leak will cause major hemorrhaging of every seal in the transmission. The seals will continue to swell until they turn into goo and disintegrate.

It is meant as a quick fix on cars rolling through auctions and whatnot. Nothing more.

If the transmission is slipping, there is already damage done. No amount of adjustment or stop leak will fix that.
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he is right you know .
 
The kickdown linkage does play a part in the shift duration. Are your shifts dragging out at a high rpm? If so, it may be your KD. The adjustment is all the way in at WOT, then let it fall back to wherever it does. If your KD is not hooked up (worst case) your trans will shift into 3rd before you go under the traffic signal, and itll do it softly. If you wire the KD back, itll run up to the shift point and should shift pretty fast regardless of your speed. Give that a shot. That should test a few systems.
 
pishta said:
The kickdown linkage does play a part in the shift duration. Are your shifts dragging out at a high rpm? If so, it may be your KD. The adjustment is all the way in at WOT, then let it fall back to wherever it does. If your KD is not hooked up (worst case) your trans will shift into 3rd before you go under the traffic signal, and itll do it softly. If you wire the KD back, itll run up to the shift point and should shift pretty fast regardless of your speed. Give that a shot. That should test a few systems.
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I'm using a Lokar cable set up for the kickdown and throttle linkage. I tried to set it up like the factor service manual advises setting up factory linkage. Looking around it sounds like other Mopar guys have had good luck setting up Lokar kits by going to WOT and adjusting the kickdown lever to be all the way back at that position. I'll re-adjust my cable and see if that helps.
 
charger426 said:
Yeah deep pan came with new filter and extension peice. Just seemed odd that it seemed to shift fine the first few times and all of a sudden started slipping when shifting. Generally I've had people bring slipping transmissions over that have gotten progressively worse vs all of a sudden. Does the kickdown lever adjust pressure even when shifting manually? Could that not being adjusted right cause lower pressure and lead to slipping?
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Probably the remaining old fluid in all the cracks and crevasses that still contained friction material. Once you drove it around the friction material was diluted = slippage. That is why you hear story after story of transmissions failing after a fluid change. Out the drain plug comes fluid and friction material in a worn transmission.
 
How come it took until post #16, for the KD adjustment to be questioned. That should have been post #2.
KD is a misnomer. It should really be called Throttle-Pressure Adjuster.Cuz that's what it does. Sure it provides a kickdown, but that is secondary to it's function.It's primary function is to increase line pressure, which directly increases the holding power of the clutch packs and servos. Secondly, it delays all the upshift speeds, by suppressing the shift commands coming from the governor.
If there is insufficient line-pressure, the clutches slip, and the tranny shifts softly,and very early. With line-pressure maxed out, the shifts will be harsher and much higher up the speed range. The end result is that you, with the gas pedal, can control the shift timing and harshness, right from the driver's seat, in accordance with the current driving requirements. Yeah it kicks the tranny down a gear, but that is just the pressure balancing act going on inside the VB at all times.

Long story short is, get after the TPA, ASAP. It may already be too late, but it's worth a shot.
 
AJ/FormS said:
How come it took until post #16, for the KD adjustment to be questioned. That should have been post #2..
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well AJ I will tell you why . any cheeta manual valve body I have used never had a kickdown maybe they were all reverse shift pattern if it makes a difference .
 
I'll check on the kickdown today if the weather breaks. For the record the stop leak I used was Lucas Transmission Fix. More of a re-newer than a stop leak product. Know people that use the stuff as preventive maintenance too. Either way here's hoping its the kickdown just not being adjusted right.
 
jimjimjimmy said:
well AJ I will tell you why . any cheeta manual valve body I have used never had a kickdown maybe they were all reverse shift pattern if it makes a difference .
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Yep it does. As I said in the first post mine is one of there manual automatic VBs. It acts like a normal auto in every way but will got to or stay in 1 or 2 as long as you have the lever there. No override like a factory VB.
 
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