My transmission seems to be slipping...torque converter??

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weaverjsnw

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Ok here is the situation. I have a 1964 dodge dart gt. I recently had the slant 6 bored .040 over installed new pistons. Also had the head done with new valves, springs and had the valve seats hardened. Otherwise the engine is stock to my knowledge. I also changed out the 13" stock wheels for 14" wheel and new larger tires 215/70/r14. Since then I've had slipping issues. I recently had the transmission out and found the clutches and bands to be in good condition. I did replace the clutch piston seals because of leakage during the air test. Put everything back together. The shifting did improve but still slipping. Car is slow taking off and builds speed slowly. The torque converter was put it about a year ago. Everything ran great until i lost compression on cyl #4 a few months ago. Thats when i had the block bored and head done. Along with the new wheels and tires replaced the windshield. So I've just spent over 2k on this car. Would the bigger displacement and larger wheels cause the tourqe converter setup to be off?
 
Yes it was. Started noticing the shifts getting soft. Oh I also found my kickdown lever snapped in half so I had no kickdown linkage hooked up for a while. It is repaired and hooked up properly.
 
Yes it was. Started noticing the shifts getting soft. Oh I also found my kickdown lever snapped in half so I had no kickdown linkage hooked up for a while. It is repaired and hooked up properly.

Running with no kickdown lever, that is the pressure valve in the transmission. No pressure, no good for the trans.
 
Yes it is full. Seems to be slipping in all the forward gears in drive. Slips more with throttle. Car still moves just much slower acceleration. Shifts seem solid at about the right speeds. No flare when shifting. Just feels mushy on accelerating. Like i said clutches and bands were fine. Bands were torqed to spec. The valve body was clean. Did notice some wear on the separator plate where the check balls sit. Shift linkage may be a little off. 1st gear on the pushbuttons doesn't push in. I lined it up in neutral on the safety switch. So does anyone know if the changes I made would affect the stock tourque converter setup? I'm not so sure its the trans. Everything looked good when I was in there but I'm no expert.
 
None of those changes can affect the torque converter. Take the pan off; for several reasons. See if the detent is centered in the proper notch while in D. Check pan for debris. All this slipping probably fried the forward clutch.
 
Running with no kickdown lever, that is the pressure valve in the transmission. No pressure, no good for the trans.
I Ran without a kick down linkage back in the seventies for a short time doesn't take long and you be slipping for sure
 
You really shouldnt just look at the clutches. The clutch basket should be measured for clearance when assembled. Sounds like clutches slipping or a bad seal to me. Doubtful its the converter.
See post #10 about checking the shift detent. It is possible it may not be snapped fully into gear.
 
smell the oil you will know if it is slipping . i have seen transmissions fry in 5 min without a kick down hooked up .
 
No one picks up on this but a misaligned pushbutton-system can cause funny things too.
That, and the neglected in hooking up the throttle pressure lever awhile ago it's not surprising the trans is acting up.
 
All this started with1-2 and 2-3 flaring. Found the kickdown band loose. Tightened it back up and repaired the lever. That helped for a bit. Then began doing it again. The fluid smelled burnt. Dropped the pan found some debris. Cleaned it out put new fluid.in hoped for the best. Seemed ok for a bit then began slipping. I tore it down expecting find fried clutches or bands. They were not. The frictions measured about the same thickness as when they were installed. There was leakage when I did the air pressure test. I did replace the seals and tested again it was much better. I will drop the pan again and get the shift linkage centered in drive. I suppose at this point that seems like the most logical culprit. I really don't want to pull it out again but I'll do what I gotta do to make it right. Thank you for your help.
 
How many different transmissions are you working on? I ask because in post #15 you say that this all started with a 1-2 and 2-3 flaring, but in post #9 you said no flare when shifting. Check post #10 about clutch pack clearance.
 
Sorry i meant the flare was gone after taking it apart. Just trying to give all the info I can. So I guess I just need to pull it out then?
 
Yes i will do those suggestions. You mentioned measuring clutch pack clearance and I got confused. Ok I will report back with my findings.
 
If the fluid smelled burned, the damage is done. Build it. Again.
 
Ok just dropped the pan. The detent was off a bit. Pretty sure I have it right. The fluid did not smell burnt. It was recently changed. I did notice however some fine metal flake in the bottom of the pan. Nothing chunky. The car was driven twice since I last had it apart.
 
Also the kickdown lever broke because of my floorpan job. It would come into contact with more throttle eventually caused it to snap in two. Luckily still had both halves so was able to tack weld it together.
 
So question now is do I button it up put some fluid in it and see how it is with the linkage adjusted or do the metal flakes mean it needs an overhaul again? Hoping for the easy one I'm getting too old for this. Especially since I'm working on gravel...
 
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