GM8100 & Allison experience ?
 

I’m looking at a 07 Kodiak 5500 with 8100 GM & Allison driveline. Normally I’d prefer a diesel but the price is attractive. It has under 50k miles and was garaged and used exclusively for pulling a horse trailer to shoes. Is this a good power train and is it powerful enough to handle a 5th wheel camper through hills ?
No, the gas mileage isn’t a concern, it won’t be a daily driver. Just a toy hauler for vacations and hauling my off road toys.

We used to have a 2007 duallie with that power train. Used it to pull a heavy gooseneck horse trailer with living quarters. Much better torque than a 454. Not as much as a Duramax but we were happy with it. It actually got a little better mileage than the 454's because you need less throttle and would stay in closed loop most of the time. High % throttle position throws the computer into open loop and the fuel injection richens significantly.

FWIW,
Eric

Only thing I remember hearing about them was they tend to use a little oil. I considered this combo years ago, but they never stayed on the market very long. Ended up with an 09 Duramax.

The 8.1 Allison combo is a great setup. The diesel would be more powerful, but the 8.1 can hold its own.

The Allison trans is an absolute unit.

Great combo! I had the 5 spd. I think the newer 6 spd would be even better. It did use a little oil & a lot of gas but that’s to be expected.

Murf

496 is a great engine. I would put a larger transmission cooler, and change the spin on trans filter when you get it. This is mandatory.
There are Threads on this set up on GMTRUCKS.com.

+1 on that. I forgot to mention that I installed a larger cooler and did the 3 change routine to switch it over to synthetic trans fluid. The later ones may have come with synthetic, I don’t know.

Murf

My buddy has a 2004 GMC Sierra 2500 with that powertrain and he loves it. Fuel economy is not great but it sure pulls nice. He has not had an trouble with his. He maintains his vehicles well and has over 100,000 miles on it.

For heavy hauling this is a nice combination. As I see it, the primary advantage over a Duramax is the lower cost buy-in and the much less expensive maintenance and repair costs as the vehicle ages. Of course it won't have the torque and power of a Duramax but a set of new injectors won't set you back 8K either. Anyone who is a good GM car technician can work on an 8.1. Duramax takes some more advanced skills and scan tools. Duramax is perfect for people who put allot of mileage on their vehicles year around. Then the cost per mile is very attractive. For the use you describe, the 8.1 should give you good service. The Allison synthetic fluid situation has a specific VIN break where they changed from Dexron III, to full synthetic Dexron VI. You should be able to find the VIN break info on-line. The issue is seal compatiability on early units when Dexron VI is used in the early Allison 1000's. I think you will like it.

I have that combo in an 02 2500HD - I've had it 16 years and no plans to get rid of it anytime soon. I think I'm around 180k now - still uses a quart of oil between changes, but no worse than it did 130k ago when I got it. No major drivetrain issues but did have to replace the crank position sensor at one point which was a major PITA.

Love mine. 2005 Gulfstream Super C motorhome. It's been my tow rig for my 28' enclosed trailer since 2007. Been to Norwalk and back to Maryland every year since 07, except for 20 of course.
Many trips down south also. 58000 miles and no complaints so far. 8.1L, 5spd Allison.