Tow/haul...no fifth gear shift

[chrisinkanata]

Noticed today when pulling our 5th wheel trlr that when in tow/haul, the trans won't shift into overdrive unless I disengage the tow/haul at about 60 mph. Shifts right up then and I flick it back into tow/haul. Kind of a pain. Works perfectly in 'normal' and 'til today, worked fine in TH. Usually shifted between 58 & 65 mph depending grade, wind etc. even at 70 down a slight grade today, no up shift in TH. 02 GMC 2500HD D/A. Any thoughts?

 

Chris

[02suburbanZ71]

Its designed to work that way.

[gmtech4]

Trust me if that transmission is unhappy it WILL turn on that little light ........

[Prokopchuk_9]

It's all good brah [emoji106]

[redwngr]

Did you find out what the issue was?

 

Obviously, if it used to shift but doesn't now, then something changed.

[Cowpie]

You could always take it to a Allison specific shop and have it checked and change some of the parameters. Go onto Allison's website and check service locations and find one in your area. Most servicing Allison shops take care of every product in the Allison line. Just like it is usually better for a Ram owner to go to a Cummins specific shop for engine work, someone with an Allison usually comes out ahead by going to a Allison shop. There are many parameters like shift points and such that can be changed to meet user needs, of course, up to the design limits of the transmission itself.

[gmtech4]

You could always take it to a Allison specific shop and have it checked and change some of the parameters. Go onto Allison's website and check service locations and find one in your area. Most servicing Allison shops take care of every product in the Allison line. Just like it is usually better for a Ram owner to go to a Cummins specific shop for engine work, someone with an Allison usually comes out ahead by going to a Allison shop. There are many parameters like shift points and such that can be changed to meet user needs, of course, up to the design limits of the transmission itself.

 

There was nothing to check cliff ., it's working as designed ,

 

Getting a tune is different but going to an Allison shop is not required for that as the do not deal with series 1000 Allisons ...

[Cowpie]

I think you had better check the Allison site. Most Allison shops do service and support the 1000 right along with the other models. You make my contention, that many folks just have no clue that the Allison shops support the transmission that GM throws in these pickups, and probably better than a GM dealer ever could. And Allison can set a lot of parameters that a GM dealer never would or, in most cases, wouldn't have a clue that they could. It is part of the design and no need for a "tune". Just because Allison was started by GM decades ago doesn't mean that GM knows as much or more about the products than Allison themselves or their servicing shops. But hey, no one is forcing anyone to take advantage of the Allison shop option if they are more comfortable going someplace with only a GMC or Bowtie on the sign. I just have learned over the years that it is sometimes better to go to the specific shop that represents the folks who actually built the component I need repaired or changed.

 

Just did a quick search at the Allison website and sure enough, Inland Truck Parts near me, as I already was aware, is an Allison specific shop near me that services, remans, sells, etc the 1000 right on up the Allison chain to the new Allison TC10 TS, including TCM reprogramming across the entire product line. And Interstate Power Systems near me as well, also a Authorized Allison complete servicing shop, services the 1000 and the rest of the Allison line. But hey, what does Allison themselves know that a car and pickup dealer doesn't, right?

[gmtech4]

I think you had better check the Allison site. Most Allison shops do service and support the 1000 right along with the other models. You make my contention, that many folks just have no clue that the Allison shops support the transmission that GM throws in these pickups, and probably better than a GM dealer ever could. And Allison can set a lot of parameters that a GM dealer never would or, in most cases, wouldn't have a clue that they could. It is part of the design and no need for a "tune". Just because Allison was started by GM decades ago doesn't mean that GM knows as much or more about the products than Allison themselves or their servicing shops. But hey, no one is forcing anyone to take advantage of the Allison shop option if they are more comfortable going someplace with only a GMC or Bowtie on the sign. I just have learned over the years that it is sometimes better to go to the specific shop that represents the folks who actually built the component I need repaired or changed.

 

Just did a quick search at the Allison website and sure enough, Inland Truck Parts near me, as I already was aware, is an Allison specific shop near me that services, remans, sells, etc the 1000 right on up the Allison chain to the new Allison TC10 TS, including TCM reprogramming across the entire product line. And Interstate Power Systems near me as well, also a Authorized Allison complete servicing shop, services the 1000 and the rest of the Allison line. But hey, what does Allison themselves know that a car and pickup dealer doesn't, right?

 

Haaa , who knew , right on , you're right ,at the dealer we don't go n to the module and change parameters , busy enough without doin that lol

[BlackZ71Silverado]

The Allison shops will know everything. Any one of their employees will know much more than anyone of those mechanics working in a GM service dept. that's for sure.

 

If you think something is not right, take it to one of the Allison service shops and let them take the truck for a spin. They will be able to tell from a short drive, your dealership will not. It does seem fine from your description but wouldn't hurt to have the guys who know that transmission in and out feel what's going on. Better safe than sorry.

 

 

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