just bought a 04 and problems already

[johnb1686]

I have been looking around for a while and finally bought a 04 dmax, auto with 60k on it. I test drove the truck and everything felt good. The next day I drove it for about 40-50 miles then I stood on the gas and the the rpms went all the way to 3 k but the truck slowed down.:confused: It felt like the trans was slipping between gears.The trans never went into the next gear untill I let off the gas. I went back to the car lot and they said that the truck was still under gms 100k warranty and to take it to them and they will fix it. Is this covered under warranty? Any ideas what might be wrong? I have only had this truck for 4 days and I can't afford a new tranny :mad:

[Mark Rinker]

First of all - WELCOME ABOARD! (Also, relax...there are a few simple things that could cause what you describe.)

Q1: You didn't mention any Service Engine Soon light illuminated - is this the case? If there is, head to the dealership and have them pull the trouble codes. If not...

Q2: What happens when starting out from dead stop when you only apply (and hold) enough throttle to make 2000 rpm, with the transmission in D?

Based on your description, the 'slippage' you felt at high rpm between shifts was likely the computer de-fueling on your behalf to LIMIT transmission slip. This is normal. Revving your diesel to 3K or more is not.

Q3: Will it shift through all the gears? If not, how many upshifts do you get? What final (max) ground speed at 2K rpm?

Q4: Any strangeness to the digital gear selection indicator on your dash?

You should count 4 upshifts - 1st through 5th. If you are still experiencing a 'hang' in any gear - by all means take it to a dealership and have them troubleshoot. It would be interesting to know if the spin-on external transmission filter has ever been changed. That might be a start, but its unlikely to be plugged. Unless you have a service history indicating a tranmission fluid service, this would also be a good thing to have done.

Another culprit based on your problem description may be a nearly plugged fuel filter. Another good one to change out now, especially if you don't know the service history.

Good luck - let us know what you find out. Don't worry about the transmission just yet, its VERY unlikely that you have a mechanical problem in that department.

[johnb1686]

First of all - WELCOME ABOARD! (Also, relax...there are a few simple things that could cause what you describe.)

Q1: You didn't mention any Service Engine Soon light illuminated - is this the case? If there is, head to the dealership and have them pull the trouble codes. If not...

Q2: What happens when starting out from dead stop when you only apply (and hold) enough throttle to make 2000 rpm, with the transmission in D?

Based on your description, the 'slippage' you felt at high rpm between shifts was likely the computer de-fueling on your behalf to LIMIT transmission slip. This is normal. Revving your diesel to 3K or more is not.

Q3: Will it shift through all the gears? If not, how many upshifts do you get? What final (max) ground speed at 2K rpm?

Q4: Any strangeness to the digital gear selection indicator on your dash?

You should count 4 upshifts - 1st through 5th. If you are still experiencing a 'hang' in any gear - by all means take it to a dealership and have them troubleshoot. It would be interesting to know if the spin-on external transmission filter has ever been changed. That might be a start, but its unlikely to be plugged. Unless you have a service history indicating a tranmission fluid service, this would also be a good thing to have done.

Another culprit based on your problem description may be a nearly plugged fuel filter. Another good one to change out now, especially if you don't know the service history.

Good luck - let us know what you find out. Don't worry about the transmission just yet, its VERY unlikely that you have a mechanical problem in that department.
Q1: no check engine lights
Q2:It will shift through all gears as normal
Q3:yes
Q4:no
the only time that I have seen any slippage is at 3/4 to full throttle other than that it is ok.
It will slip so bad that I think the truck would come to a stop under full pedal.
Is it normal for a whine from the trans when rolling to a stop?
I will put a new filter on tomorow and see what that does.
Thank you for you help

[Mark Rinker]

What is your transmission temp after these incidents? Sounds like a trip to the dealership may be in order. No, a whine while rolling to a stop would not be 'normal'.

What do you know of the truck's work history? Stock wheels and tires? Any power adders or intake/exhaust mods present? Gooseneck ball?

How does the transmission fluid look? Should smell new and be translucent red or pink. No burnt brownish color or bad odor.

[Kennedy]

Good possibility that it just needs a fuel filter change.

I'd suggest that you change ALL fluids and filters (except internal Allison) to known quality products so that you know what is in there and when the last service was. This should be SOP on any used vehicle purchase...

[johnb1686]

What is your transmission temp after these incidents? Sounds like a trip to the dealership may be in order. No, a whine while rolling to a stop would not be 'normal'.

What do you know of the truck's work history? Stock wheels and tires? Any power adders or intake/exhaust mods present? Gooseneck ball?

How does the transmission fluid look? Should smell new and be translucent red or pink. No burnt brownish color or bad odor.
the truck has stock wheels a tires , no mods, no gooseneck or signs of ever having one.
The fluid looks red and has no odor
What type of warranty is on the allison?

[Mark Rinker]

Covered under 100K drivetrain warranty.

Are you still driving the truck? Any filter replacements?

The more I re-read your description, the more I agree with JK. Get a new fuel filter on this truck, first.

[DmaxMaverick]

Covered under 100K drivetrain warranty......


There isn't a "drivetrain" warranty until 2006. Prior, the 3/36 B to B warranty is the only coverage, other than extended.

The 100K warranty only covers the engine on a 2004 Diesels.

[Mark Rinker]

Ooops...my bad. I have made that mistake before, confusing the 3/36 with the 100K engine warranty. Then there is the 200K injector warranty, but only for 2001 - 200?...etc, etc.

[johnb1686]

I bought a fuel filter and a trans filter today we will see what that does
thanks for your help

[Mark Rinker]

There should be a particle magnet on the transmission filter when its removed. It has to be moved from old filter to the new filter. If its missing, they can be purchased at an Allison dealer or at a GM parts counter.

Look for instructions for replacing the fuel filter here on TDP. If its beyond hand tight, you may be scrambling for the right filter wrench to remove it.

[johnb1686]

After going to the stealership they told me that the trans is bad. :( I started to save my money. Then I changed my fuel filter with my oil change and the trans is fine no problems at all. I am so happy:) :) :) :) :) :) :)
thanks for all of your input

[rob from bc canada]

Sounds weird to me - if the engine was hitting 3000 rpm and no power was going to the wheels, I would expect the problem to be tranny/converter.

Seems strange that the engine could rev up, and not put the power through the trans.

In any case, sure glad that worked for you, I would have never guessed.