Busy Shift

[DDD70]

2002 3500 D/A Ext.2WD No mods.
Just got home from 4500K-2820 mile
trip on mostly flat roads.Found that TX
shifted out of O/D excessively.
When I took it to two dealers,
they said there was no info on
excessive shifting.
My question is:This being a Canadian
truck,where can I get this info?
Only have 7030K's on truck and gross
out at 18500# am more than happy with
truck-nada problems other than what the
Tx does.My 97 Ex 2500Hd 5.7 vertex auto
would hold O/D a lot betterbut lacked
power on big hills.

[GMC-2002-Dmax]

DDD70,

Sounds like you need a different dealer :( .

The shift busyness is easily fixed with a reflash of your TCM for the Allison. Had mine done and much improved.

I also have the JUICE and that pretty much fixes the shift busyness as well.

Hope it works out.

GMC ;)

[hdmax(mike)]

I was under the impression that the busy shift problem was only on the 2001`s. Mine never shifts until I get down to between 40 and 45 mph. At 60+ I have to floor it all the way down to get it to shift to 4th. Other wise it just picks up speed very well in 5th gear.

[Jackmchome]

DDD70, The tcm flash you are looking for is to cure 5/4 shift busyness while in cruise control. It will also help with normal driving if you leave the cruise control turned on. Have your dealer look to cruise/shift busyness for the update. Actually that update might have been for 2001 models only. Can someone comment?

[ 09-03-2002: Message edited by: Jackmchome ]</p>

[TLA]

Had it done on my '02 - helps a bunch (as does the juice). The OD lockout is a good idea, as well, as there are too many times when it won't hold OD on a hill at 1600 rpm.

[Mic]

FWIW....this bulletin cover 2001-2002 ???

02-07-30-020; Harsh or Delayed 2-1
Downshift, Neutral Feel at Stop, Shift
Busyness, DTCs P0708, P0847, P0875,
P1711, P1713 (Reprogram TCM and if
necessary Reprogram PCM); 2001-02
Chevrolet and GMC C/K 2500/3500 Pickup
Models with Allison Series 1000 Auto
Transmission (RPO M74)

[DDD70]

Thanks MIC.
This is what this "OLD MAN" was looking
for.Will take to dealer tomorrow and see
what happens.
If this is all I have to contend with will
consider this unit to be the best we have
had in in 52 years.
If this truck last to 400K plus,the Better
Half and I will have live over 115 years at
the rate we drive.