Trans is slipping--now what??

[sixpack_sid]

I just finished rebuilding my 68 Dodge Charger and took it out for a drive a handful of times. First of all some info: It's an AT 727 trans with a 440 BB engine-both came out of a 77 Chrysler NewYorker.  The engine and trans were NOT rebuilt before installed, but I did hear the engine run before I bought them.
The trans seemed to be slipping and each time I took it out it became more noticeable. When I would accelarate, the trans would slip and if I let off the gas and then step on it again, the trans would kick in. I took it for a drive tonight and I was at a stop light. When I started to go, the car seemed to slip into neutral and did a line lock. I left some rubber on the street as the tranny kicked into gear. Then, it wouldn't shift at 55mph. I continued down the road and as I slowed down and then accelerated, it wouldn't shift at 40mph. I started to worry I wouldn't make it home since the road to my house is a mile long uphill slope. It started out slow, then eventually did shift up the hill and I was able to pull into the driveway before it started slipping again. Do I need a new trans?? I was wondering about getting mine rebuilt, but am not sure how much it would cost. Anyone know if there is a quick fix I can try to get it running decent? I just got it on the road-it sucks to not be able to drive it.

[c00nhunterjoe]

You can always check the band adjustments but if it locked in 2 gears and is slipping it sounds like she is toast. There is a very slim chance that one of the bands is out of adjustment.. if one is too tight and the other too loose it can hang up between shifts. Its worth a shot. I'm sure mr kunkel will chime in shortly with more in depth procedures. I'm pretty good with the torqueflites but I would definatly call him the expert!

[cdr]

sounds like its low on fluid,wrong dipstick???   also it has to be running in neutral to ck it

[John_Kunkel]

The failure to upshift could be a simple TP linkage adjustment.

The slipping is a more serious matter, if the fluid level is correct and the filter is clean the slipping is probably the rear clutch...time for an overhaul.

[440]

I'd try the easy things first, check fluid level (flat ground, engine running in neutral), make sure modulator vacuum is hooked up correctly and check kickdown lever adjustment.

If that fails I'd check the bands, and failing that it's overhaul time. 

[c00nhunterjoe]

There's no vaccum modulator on a torqueflite.

[440]

  Ignore that comment of mine...

In saying that though how does the torqueflite monitor engine load etc ?

[c00nhunterjoe]

Lever on driver side of tranny connected to the throttle via 3 linkages and 2 pivots on the bellhousing and intake.

Assembled as though you were looking from the left side of the car.

[Cooter]

One thing to remember is the fact that many of the LATER model BB 727's came through with only 3 clutches in high gear. NOT the most strongest set up if you've added a few Ft. Lbs of torque to that 77 440.

I always modify the high gear clutch drum to handle at least 5 clutches.

[c00nhunterjoe]

One thing to remember is the fact that many of the LATER model BB 727's came through with only 3 clutches in high gear. NOT the most strongest set up if you've added a few Ft. Lbs of torque to that 77 440.

I always modify the high gear clutch drum to handle at least 5 clutches.

I upgraded mine to a single clutch.........

[sixpack_sid]

I checked the fluid, she was a pint low. I put more fluid in and now she's shifting better. When I checked the fluid before, I checked it in park. I'm glad that's all it was! Thanks!

[cdr]

I checked the fluid, she was a pint low. I put more fluid in and now she's shifting better. When I checked the fluid before, I checked it in park. I'm glad that's all it was! Thanks!

i would do a filter & fluid change

[440]

Check the dip stick again... does the fluid on the end smell burnt ?