I have a 2001 Chevy 2500hd silverado 4x4 w/allison transmission 5 speed & the 8100 engine. When speeds get up above 50 or so the truck drops out of 5th gear into neutral then downshifts into what they call "limpmode".When this happens the service engine light comes on & I loose reverse untill I reset the comp by disconnecting the battery & reconnecting after a while. Can you help me with this problem.

SOURCE: 2001 Chevy 2500HD Whining

these transmissions have three sets of planatery gears the whining you hear is simply the gears doing thier job. You have to remember the allison trans is basically the scaled down version of the heavy duty isuzu truck trans they are designed more for thier load capacity then for comfort

Harvey N Tawatao

• 3854 Answers
• Posted on Jun 26, 2009

SOURCE: Can anyone please tell me the location of the

The A/C service port is on the accumulator (Filter/Seperator i think is what you called it)on your Silverado. Good luck and keep me posted. Be glad to help.

SOURCE: I have a 2002 chevy silverado 2500hd with a 6.6l

The tag is about the only way to tell. But if it is push button you should have a 246.

SOURCE: I have a 2002 Chevrolet Silverado 2500HD with the

Hello. try a couple of things. make sure the rad is clean from any road debris or dirt. in fact, take a garen hose and pressure wash the rad and condensor fins real well. also miaght have both of the trans filters replaced. there is one inside the trans pan, and one spin on trans filter.

SOURCE: Where can I find or

those are sold on ebay in book for and on CD.