What allison does the 4500 come with? I looked at the GMC website and it has the vocational models listed. Which would have the same internal gearing as the 2500/3500 models. Thank you.

Apparently the Allison in my C4500 is the 1000. There is nothing in the manual, or the sales literature to suggest this, but a rep at Allison told me this was the transmission in my truck, when I called to find out about it.

From GM media release this past August...

"Enhanced calibration and warranty coverage for Allison transmissions

To better meet the needs of vocational applications, many of the Allison transmissions have been recalibrated, and they’re now backed by longer warranties for 2005. For example, the Allison 1000 PTS and 2200 PTS, used for pupil transportation and shuttle series on C4500/C5500 models, feature a unique calibration for lock-up in third gear – versus lockup in second gear for the previous model. Both transmissions now feature a three-year, 100,000-mile limited warranty.

The Allison 1000 EVS – used with Fire Rescue and Ambulance packages on C4500/C5500 models – features a five-year, unlimited mileage limited warranty. The Allison 1000 MH and 2200 MH – featured on C4500/C5500 motor home series – meanwhile, are backed by a two-year, 100-percent parts and labor coverage warranty, plus a three-year extended transmission coverage. Mileage coverage is extended to 200,000 miles.

Allison vocational transmissions also are added on C6500 and C7500 models for 2005. A 2500 HS Allison transmission replaces the 2000 Series transmission in all applications. Thanks to the 2500 HS, the Gross Vehicle Weight Rating (GVWR) is increased to 33,000 pounds for 2005 versus 30,000 pounds for 2004. The Allison 3000 RDS close-ratio six-speed automatic transmission becomes the base transmission on C8500 models and is available on C6500 and C75000 models. A number of other transmission choices are also available. (Please see the accompanying specification pages for a complete listing of engine and transmission choices.)"

But, when you look at the specs sheet, it only lists the 1000 and not the 2200 as an option for the C4500/5500 so it is rather confusing...

"Transmissions
ZF S6-650 (M50)
Allison 1000 (M74)

Type:
6-speed manual
5-speed automatic


First:
5.79
3.10

Second:
3.31
1.81

Third:
2.10
1.41

Fourth:
1.31
1.00

Fifth:
1.00
0.71

Sixth:
0.76

Reverse:
5.23
4.49

PTO (optional):
6-bolt SAE

Final drive (axle) ratio:
5.13
4.88 / 5.13"


Edit: Yep the application sheets show the 1000 line for 45/5500 series and 2000 line for the 65/7500 so GM Media needs to get their facts straight.

So, what are the facts of the warranty on the transmission - the people who sold me it, had NO IDEA of anything about the truck. I do not know what the warranties on the duramax or the allison are, and do not know who to call to find out. I make a suggestion. Anyone thinking of buying a C4500 or C5500 Medium duty truck... DO NOT BUY IT FROM A CAR / PICKUP dealer - they know NOTHING about it. I made that mistake, but fortunately I like the truck. Imagine what it would have been like, if I didn't like the truck......

Mylash

What allison does the 4500 come with? I looked at the GMC website and it has the vocational models listed. Which would have the same internal gearing as the 2500/3500 models. Thank you.
This is a little late but here ya go. I just happen to have a GMC Med Duty brochure in front of me and it says that the Allison 1000 or the ZF 6 speed are the only trans choices for the 4500/5500. The C6500/7500 gets the Alli 200/2400, 3000MD, Eaton Fuller manual or the TTC manual depending on engine/torque combo selected.

JP

if you have the ISP scheduling system build sheets you can find out the trans and axle ratio there you should have 2 copyies of these sheets fan fold approx 15 pages they even give part numbers for nuts and bolts.

Local GMC Commercial Dealer says that the Ally 1K is for GVW up to 19500 and a new ALLY 2200 is for C5500's with 23K and 26K GVW (GCW remains the same...26K Max) for either trans. choices.

Cutaways (For Class A or Class C Motor Home) get the MH version (1000/2200) of the Ally Trannies, depending on what is spec'd by the MH manufacturer. If rails exceed 24', expect the 2200 MH, as GVW must certainly be 26K (if not...walk away from that deal...the 1000 wont hold for long).

Hope this helps clear this up.

By the way, forget the Pontiac/Chevy car dealers. They are Morons. They only want the commission from the sale and see the body outfitters as competition to "steal-away" part of it from them. Find and use the commercial dealers, and you will be able to enjoy your toys as you intended to use them.