06 transmission slipping

[rick19v]

Shifts into 2nd fine, but when the t/c kicks in it slips. Back off throttle, ease back into it and it acts fine. Only in 2nd & 3rd gear. No codes.

 

[rick19v]

Any suggestions? Anybody have an idea what's wrong?

 

[fox]

3 minutes between your posts?? And at 4 am. Some of us sleep.

Now, when was it last serviced? Miles on it? Is there no slippage at 60 mph?

 

[rick19v]

The 2nd post was an add-on to the 1st post, 9:45 my time. Wasn't expecting a reply until today. 65,000 miles, I put the last 10,000 on. It was supposed to have been serviced not too long before, I'm checking on that tonight. As far as I can tell it doesn't slip at 50-60mph. Thank you for your response.

 

[rick19v]

It's a 06 dodge Cummins automatic 4x4.

 

[cerberusiam]

but when the t/c kicks in it slips.

What exactly does than mean? You said it shifts to 2nd fine the you say it slips in 2nd and 3rd. If it was slipping it would not shift into 2nd fine and likely jump right to drive then shuttle back and slip some more.

The TC doesn't lock until you get into drive unless you are shifting manually so the "t\c kicks in" is adding massive confusion to what you are describing.

 

[rick19v]

Thank you for the information, now I understand what I'm experiencing more clearly. I pull away from a stop light, it shifts into the next gear fine, then a few seconds later it starts slipping. I just tried manually shifting to see what it would do and when I shift into 2nd it doesn't change until I shift to drive. transmission fluid is not burnt smelling and looks clear. I'm learning a lot from this forum, thanks for your input.

 

[cerberusiam]

Ah, so when you shift into Drive manually it does feel solid and the engine wants to rev up? 2nd feels good but drive feels really sloppy and bad? If you ease off the throttle then back on the throttle will it then hook up and feel solid in drive? With OD locked out and in drive with the TC locked does it feel like a manual trans when push and release the throttle quickly? Can feel the TC positive lock in drive?

 

[rick19v]

Drive feels good. O/d feels good, I can set the cruise on 70mph and the speedometer stays at 70 and the tack stays around 1950, neither one moves, even when I travel up or down small grades. It hunts at around 20mph when driving in neighborhood. It's 2nd and 3rd that the issues are in. Gonna do some more research so I have more accurate information to post.

 

[cerberusiam]

If it is just 2nd that feels strange try adjusting the band and see if it is off a bit, or, you have a broken band mount. The mount the band strut sits in will shear a rivet and allow it to twist when applied and that messes up the shift timing. The band struts will bend and casue it also. The band anchor will break a side out of it showing a lot of the same symptoms.

Since oyu are not seeing any slippage whne in drive or OD it sound slike you have a timing issue on the 2-3 shift.

 

[rick19v]

So I should just service the transmission, adjust the bands. Do you know the specs for adjusting the bands? Should I replace the transducer and the governor pressure solenoid as well?

 

[cerberusiam]

If oyu have not replaced the the gov solenoid and transducer in the last 40k miles it is time. If you have replaced the gov solenoid with the GM style and the custom gov manifold just do the transducer.

Front band adjsutment:

Loosen lockut so ther ei splent of space to tighten set screw

Tighten set screw to 72 INCH lbs

Back set screw off 1 3/4 turns

Tighten locknut while holding set screw in position.


If oyu have some wear int he band and clutch pack you might have to tighten the set screw setting a bit. If it doesn't shift right tighten a 1/4 turn at a time to test if that helps. When you have the pan off inspect the band anchor and band ends for any problems. You see then by looking up past the VB to the front of the trans.

 

[rick19v]

Thank you. Do you adjust the rear band the same way? And what is the custom gov manifold?

 

[cerberusiam]

Rear band is a different spec but it is adjusted the same way. You have to do it with the pan off. If manual 1st and reverse feel good I would not even bother with it. The band is much more massive and rearely needs service unless are backing heavy trailers a lot.

The custom manifold is part of the aftermarket kit that uses the GM solenoid. Part of the problem with the stock gov solenoid is the design of the gov manifold and its tendencies to get crud buildup in it causing issues. The tendency of the stock steels to make metal ends with a fine sludge that interferes with the smaller passages and sharp corners in the manifold. Evidently the updated solenoid for the stock housing has as many windings as the GM, but, the GM is much more massive and the manifold redesigned to stop the buildup issues.

 

[glenalt]

Great info on adjusting bands. Thanks.