Need scoop on changing Thermostats

[DURAMAN]

Hello,

I have an 02 2500HD 6.6 Allison that needs a new t-stat. I don't know which is bad so figure I'll change both while I'm in there. I bought the t-stats at NAPA because they were much cheaper then the dealer. The guy said there were no gaskets which seemed odd, but I assumed he knew something I didn't. If anyone could offer suggestions for changing these it would be much appreciated?

Thanks in advance!

Shane

My apology to the powers that be. I also posted this question in the Members forum by mistake. I haven't visited in years and things are quite different....

[DmaxMaverick]

The stats should include seals, but no gasket is needed for the housing.

[jared D.]

I have a 02 LB7 and need to change the thermostats also, I think? In the past with the cold weather covers on it would hit operating temp.(205) in about 5 miles. Now Im lucky if it gets to 180 during a 100 mile trip at 30 degrees outside temp. Coolant is full, not making oil. I think a thermostat change is worth trying. Where are they located? I noticed a oval housing on the front top of motor that looks like it is it. What part # are the seals? Is it better to get the thermostats and seals from GM.

[DmaxMaverick]

The seals are part of the stats and will come with them. The dealer or GM supplier is probably the best place to get them, but they are not cheap. I don't think I'd trust a non-GM parts house for these, unless the parts are GM or Delco. Napa lists them also, but they don't specify mfg. You may want to check with www.kennedydiesel.com or other TDP Advertiser (http://www.thedieselpage.com/vendors/main.htm) for advice on availability.

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[DURAMAN]

Thanks for the info. I think I'll take the NAPA stats back as I've also heard from others that it's best to use the GM parts if possible.

Shane