8.1L vortec?

[STORE500]

Does the 8.1L vortec in a GM suburban come with the Alison Tranny?

[Blaze]

I believe it does - I think all the 8.1's were paired up with Allisons.

My Bro-in-law had a GMC crew cab with the 8.1/Allison. What a beast! It would pass anything but a gas station. He got about 12 on the hwy and 9-10 in town. Could pull a house off it's foundation, tho.

[jerkin'm]

That is my understanding too..I have a burban w/ the 8.1 and it is a beast...LOVES the gas too..I average around 9 mpg with it....Great truck though..

[wayner]

The Suburbans, Yukon XLs, and Avalanches that came with the 8.1 did not have Allison Transmissions. They came with the 4L85E which is a beafed up 4L80E. Only the 2500HD and 3500 were available with the Allison. That is why the heavy duty trucks sit 2 inches higher, to make room for the allison.

The 8.1 was only available from 2001 to the early 2007s, it is no longer available. The 8.1 is an awesome engine. The only known common problem with them besides poor gas mileage is the crank shaft position sensor failure. This has recently been made an official recall on the 01 models although it is common on early 02s as well.

The 01,02 allisons were a 5 speed with tow/haul. The 03-05 added the overdrive lockout feature. The 06 and up allisons are 6 speed with manual mode.

I don't work for GM and I'm no expert. I'm just an enthusiast who happens to own an 02 8.1/Allison and so far I'm very happy with it...It's an awesome machine!