New 8.1L / Allison Owner Questions...

[esbstuff]

Just bought today an 2003 3500 4x4 with an 8.1 with an Allison trans. 145k on the clock and appears to be a decent used truck. This truck needs to be a long termer. I plan not to sell the truck till at least 250K and would like to keep till it rolls 300K.

My questions are...

1) Outside a once over and a oil and filters change is there any known problems with this combo that I should look at?

2) What should I do as far as preemptive maintenance? What is about to go? Basically, what can I change now, to save myself a breakdown later?

Thanks in advance!

[Daubs]

Congrats! Good looking truck.

I purchased 2004 CC 8.1/Allison new, and it was my daily driver until about 5 years ago. Mine has 112k on it now.

The 8.1 was known to burn oil, up to 2 qts per 3000 miles. Mine never did. Service guy and message boards say this is pretty common for the 8.1.

The Alison is rock solid!

I've done some research on message boards and chatted with a few peeps.

Ran in to one guy who helped develop the 8.1L V8. He told me it was originally designed for medium duty trucks, generators and such...was never intended for use in light-duty pickups (2500HD's and 3500's). He said it might burn a little oil, but will run forever

Another guy worked marine applications in Florida. Said he works on 8.1's in off shore boats all the time...and never seen one fail.

My only issues have been with electronics (radio's been replaced under warranty three times, Auto AC sensor replaced, and replaced the instrument cluster), and rust coming from inside out on rockers (ugh!).

Aside from that, my truck has been fantastic!

I installed 285's, jacked up the front end, put in Volant intake, and had Westers mod the CPU. I'm getting 10.5 MPG around town, and 12.5-13 MPG highway. Just towed 3,000 lb trailer with ATV's to Colorado and got around 9 MPG. The Alison was wonderful, downshifting on steep grades to keep me at steady speed.

When i ordered my truck, gas was $1.85 a gallon, and the Duramax was a $6,000 option. Test drove both and liked the feel of the Big Block. The D-max had CRAZY mid range power, but the Big Block actually felt stronger right off the line.

One other thing...my 8.1 knocks like a diesel at cold start (the dreaded cold-start-knock). My dealer offered to replace the short block, but said since mine doesn't burn any oil, that i should just learn to live with it. It quiets down after about 30 seconds.

It's been a great truck. Daubs