Suburban 2500 Buyers Guide?

Zippy1 · June 23, 2008

Hello all. I'm a newbie to these forums who is looking for some vehicle specific information. I currently own a 1996 K2500 'burb with the 454 vortec. It's getting on in years and I'm looking at trading it in on a 2004 K2500 Suburban LT Autoride with the 8.1.

After combing these forums for several hours, I have a few questions which still need some answers. First off, the Suburban I'm looking to buy is an 8.1 with 85,000 miles on the clock. From what I've found, the 8.1 doesn't need any real service, other than oil changes, for the first 100,000 miles of its life. Since the vehicle won't need plugs, wires, coolant flush, etc., what will it need? When should the diffs, transfer case, and tranny be serviced?

Speaking of transmissions, I had always been under the impression that all 8.1 motors were mated to the Allison. I've recently discovered that isn't the case in the Suburban. Do all Suburbans have the 4L80e (or some other 4 speed) or was the Allison an option? If the Allison was an option, how can I tell the difference? Also, are there any particular trouble spots that the Suburban is known for?

I've never been so impressed with the drivability of any large vehicle as I was with the '04 Suburban. It's like day and night when comparing it to our current Suburban.

Thanks all!

Sweathog62 · June 23, 2008

I've never been so impressed with the drivability of any large vehicle as I was with the '04 Suburban. It's like day and night when comparing it to our current Suburban.

We've gone from a 85/94/2002 and yes, currently working on the 2004 3/4 ton. It's been a good truck with only 48K miles. Gm gave no choices on the type of transmission. I've be running synthetic mobil 1 and dropped my tran temp about 25 degrees. The truck does and will use some oil about every 1200 miles but it seems to be well known and you need to just plan on it. Not a bad truck.. The only thing better would be the Allison Trans but you will have to go with the pickup options if you want it.

dewfpo · June 23, 2008

The Suburbans came with an upgraded 4L80E called a 4L85E I believe to better handle the 8.1L's power. If I'm wrong I'm sure someone will have the correct info.

DEWFPO

ATMINF · June 23, 2008

The big block burbans that did not have the ALLY had the 4l85E, its a good trans and can handle the power. If I were to get that Burban even though it says that it does not need service until 100,000, its close enough to do the 100,000 miles stuff. I would change all the fluids, coolent, plugs, wires, O2 sensors, air, fuel filter, diff fluids. I would also check all rubber bushings, hoses, belts etc.

Zippy1 · June 23, 2008

its close enough to do the 100,000 miles stuff. I would change all the fluids, coolent, plugs, wires, O2 sensors, air, fuel filter, diff fluids. I would also check all rubber bushings, hoses, belts etc.

This is exactly what I was afraid of. Even though one of these big gas engine vehicles can be bought for a song and a dance, there's always the maintenance items like this that will get you. I can pick this particular 'burb up for about $12K as it sits right now. From what I've seen, that's a good deal.

As for the transmission, does anyone know why the Suburban didn't get the Allison?

98silvz71 · June 23, 2008

They said it doesn't fit underneath the vehicle. And I could believe that. Our 03 1/2 ton Burb was a pretty tight underneath. The HD have a 2 inch body lift so I think that is what they did to accommodate the Ally.