Allison shifting funny.

[Lonewolf867]

I have 6400 miles on my 2003 D/A.
I love the truck,BUT I am having a few concerns. The tranny is shifting rather funny as of late. The last few days I have noticed that it is taking longer to shift.
Here is a description.
goes from first to second ok. Nice shift. Firm but not too hard.
Then I will feel the initial shift from 2nd to 3rd. At which point it will start the shift hold for a second or two or three then finalize the shift.
Same thing for 3-4 and 4-5 shifts.
It is a funny feeling, It is not slipping that I can tell, and it doesn't do it all the time. My tranny temps are always around 200 no matter what when or where I am driving.
I also noticed that a few have stated that their RPM's are 2k at 70 mph. Well my rpm's are 2k at 65. and 2400 RPM's at 70. I still have the stock tires on it. I am sorry to say it is BONE stock at the time. But not for long. ;)

Any suggestions for this?

Mike

[Lonewolf867]

Boy looks like there maybe trouble in the near future.
In stop and go traffic today...I would slow down but not come to a complete stop. When I would hit the go peddle to move up a little the truck would clunk pretty hard. Like it was out of gear and had to rev before it would hit a gear.

I have never had a truck do this before. Checked the fluid and all was fine. Time to change the tranny filter I know but this is starting to concern me.
Looks like a trip to the dealer if you guys have no suggestions.
Mike

[mackin]

Lonewolf867


Perhaps you should have it checked out .....

But ;)

The clunk may have been it was getting ready to downshift and you unexpectedly forced it .....

The "now" sluggish shifts maybe a result of your driving habits and the Allison adapting "memory" .....

People forget this is not your ordinary Rubberband tranny you've become a custom to ..... The Allison is an electronically controlled Heavy Duty Transmission ..... I mean this in a good way not sure if your aware of this or not ....

Bring it to the dealer have them check it out and reset your tap cells .....

Good luck keep us posted ....

Mac
:D :D

[Allison Jettester]

I changed my fluid to transynd, full flush, before I went to Canada. I filled the fluid to just below the full line cold and took it for a drive. I had the most horrible harsh shifts up and when I stopped, it shifted down with a bang so bad I was knocked against the steering wheel. I kept draining fluid at half pints at a time until shifting was normal. The fluid ended up about 1/4 of the distance above the minimum fill line hot ( 180 degrees) and the same cold. This transmission is really senstitive to fluid level.

This is before I put the cooler on.

[ 09-16-2003, 05:33 AM: Message edited by: Allison Jettester ]

[mark45678]

2 things I would like to add to this.... first the Alli if it doesnt come to a compleat stop with the brakes on will stay in 2nd gear then when you start moving it down shifts to 1st and bangs in HARD! 2nd you will notice a little differance if the trans temps get over its normal operating temp.

[Allison Jettester]

Mark,
You may want to adust your fluid level. Mine did that also as I was lowering it. It does not do that now.

Joe

[Geerrhead]

Mike,

The Duramax will spin 2300-2400 rpm at 70 mph with the torque converter unlocked. Have you verified this at the at 180-210 degrees? From your description, I am wondering if the converter is locking on your 2-3 3-4 shifts, maybe that is what you are feeling.

[Lonewolf867]

I was wondering the same thing. Yes I have shecked the speed at 200 degrees. At 70 mph I am running 22-2400 rpms all the time. It never drops below that. even down hill with a tail wind.
I now have 7945 miles on the truck. Still only getting around 14-17 mpg. That will include around town and longer trips all in one tank. Do you think there is a posibility that the torque converter is not locking up in 5th. I do not feel the lock there. Just in the other gear.
hmmmmmmmmm ;)
How could I check to see if it is locking?
Could I reset the pcm by disconnecting the battery and have the tranny relearn?
hmmmmm
Will darma ever get back with greg? oops sorry wrong board.. :D
Mike