I need new tires on my '03 Silverado (2500hd/Duramax/Allison). I currently have the factory 245/75/r16's but would like a bit taller tire ie: 275's mainly for looks.
--Any input or suggestions as to adverse performance and/or voiding Allison warranty if I do so??? I tow a 20ft runabout boat (@ 3000lbs in the Colorado mtns)

Hello Wade:

You ought to fill out the member information so we know where you are from, and tell us more about your Duramax.

I don't think you will void the warranty, but you will not be able to get warranty service/diagnostics on the Allison without having 245 tires on the truck when you show up at the dealer. Apparently all the diagnostics and codes can be thrown off by having oversized tires.

Partially for this reason, I have a set of 245 snow tires that I keep on separate rims.

Somewhere on this site is a service bulletin about this, and it has been extensively discussed before. You should be able to find it with the search function.

A lot of people have gone up to 265 tires as a small but uneventful upgrade.

I put on 285's and tow a tournament ski boat in the mountains here, I didn't tow before with the stock tires on but the Dmax has absolutely no problem with the taller tires and a boat behind it.

As far as warranty goes just keep your 245's and if you break something in the driveline put them back on before you go in for warranty work.

Wow if they wont warranty work on the allison without 245s what do the SWR 3500HD guys do with their factory 265s when they have to get work done? I have had 265s on my truck since I purchased it and never had a single problem and had the tranny worked on 2 times.. Of course they werent anything nuts like 315s or anything...

Dre

Hmmmm....I wonder what my stock 245's would look like on the truck with a 6" lift. Do you think they would notice if I brought it in for warranty work? LOL

You think that is good... Let's see what happens when I arrive with my stock 245s and the fore and aft have been re-geared to 4.56. Besides I would need to slip them on a block from the dealership. There is no way they are likely to get a correct reading on 245s.

Of course they werent anything nuts like 315s or anything...

Dre

):h Wouldn't know anything about that, personally.):h

One thing to add,
My mileage dropped a little (19.2mpg to 18.5 highway) by going to 265x75x16 tires over the stock tires. I was running the ole 125hp Edge at the time. My mileage went back up to about 19.5 when I added the Quad 215hp box.
No adverse affect on the tranny that I know of and I'm a little rough on this rig sometimes :rolleyes:

I know this has been brought up before, and I think there was even a bulletin from GM regarding this, but when I bought my truck, there were 2 other diesels that had 285's on them. They were brand new trucks and were trimmed. What would happen if I had bought that truck and took it in for warranty work? Do they have extra sets of tires that they would mount for troubleshooting? Or would they just find a way of not warranting it?

Now that the H1 Hummer has the D/A with 37" tires how can GM say anything about tire size:confused: :confused: :confused:

I know this has been brought up before, and I think there was even a bulletin from GM regarding this, but when I bought my truck, there were 2 other diesels that had 285's on them. They were brand new trucks and were trimmed. What would happen if I had bought that truck and took it in for warranty work? Do they have extra sets of tires that they would mount for troubleshooting? Or would they just find a way of not warranting it?

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I believe that the bulletin said it was the owner's responsibility to bring the truck in with the right size tire.

My interpretation of what that means is that you cannot go in and demand they do transmission diagnostic/warranty work if the truck does not have the right size tires on it, and if they have to put some on (and then perhaps let you drive around for a week since the transmission is a learning, "adoptive" transmission) they can charge you for it.

Has anybody gone through this?