STUCK IN THIRD ALLI

[TEXASTOUGHDMAX]

My Allison is sick also. Somewhat similar to TexasDmax. Mine seems to be stuck in third gear, forward and reverse. It started this after I cranked it back up after a quick stop at the grocery store yesterday. My "Service Engine Soon" light came on also. No other lights or messages. I changed the filter today. The magnet was clean. Cut the filter open and found a small amount(less than 1/4 teaspoon)copper colored material that I'm guessing is clutch material from normal wear. It never got hot, I was not pulling anything, and the fluid looks and smells OK. Any thoughts from you guys???

[hoot]

That is what happens when you go into limp mode.

It should go away once you shut it down and restart it.

[TEXASTOUGHDMAX]

Thanks for the reply Hoot.

After several times of shutting it down and starting back up(even after sitting overnight), the service engine soon light is still on.

I plan on taking it to a dealer tomorrow. They claim they have seen problems similar to this before, but did not say what any of the "fixes" were.

Would driving it about 30 miles in this condition damage anything?

[hoot]

The service engine soon light will go off before you get to the dealer.

[big dipper]

TTDMAX,

Copper is not clutch material. If it is copper, metallic, could be one of the thrust washers in the planetary. If you still have the stuff and the filter, take it with you to the dealer.

George

[TEXASTOUGHDMAX]

After closer inspection of the filter, what first appeared as clutch material is actually the epoxy/glue that binds the paper to the metal part of the filter. It is hard as a rock!

Sorry for the misinformation. I'm so distraught I can't even see straight!!!

[GMC-2002-Dmax]

Originally posted by hoot:
That is what happens when you go into limp mode.

It should go away once you shut it down and restart it. Limp Mode, what's that tongue.gif tongue.gif .

If I have a little too heavy right foot I either get 3rd gear or neutral. :eek:

Yes the light goes out after a while. Should you worry, that depends on what is causing it.

Mine is self inflicted.

Just ask Mackin, he'll tell ya straight up.

Better check your clutches :eek: smile.gif tongue.gif


GMC ;)

[blakmax]

TEXASTOUGHDMAX and Members!
Allison Transmissions can have electrical glitches that cause "limp mode" or self protective mode. Get the computer scanned and chances are it could be one of many sensors that lost there values!I see it everday. ;)

[dmaxalliTech]

TexasTough, See me thread on what good be your problems...

Allison wiring problems

[TEXASTOUGHDMAX]

It's Fixed!!!!

Picked it up this morning.

Here are the Tech Comments: "System Diagnostic Check, Code P0708 and found PRNDL flashing. Found Bulletin 02 07 30 011D. Performed Diagnostic Check. Shift point erratic. Replaced Park/Neutral switch (P/N 29540479) on transmission. Cleared code. Test drove OK".

Cost:

Parts: $157.50
Total: $277.01

Thanks for everyones input.

[pinehill]

My intent is not to make you feel bad, Gary, but go to your dealer's parts department and ask for an NSBU switch for an '02 HD. I think that you'll find that it costs less than $60 RETAIL (at least it does at an Allison service center). The labor charged for diagnosing the problem, changing out the switch, and doing the test drive should be no more than 1 hour if your Tech knows what he's doing. I'm assuming that you're past the 36K warranty period.

You may want to ask for an adjustment and, in any event, you might want to find another dealer to do your service work.

[ 07-12-2003, 07:12 PM: Message edited by: pinehill ]