I have a gmc 2500 hd gasoline engine transmission slipping can i out an allison transmission in it or are they just for diseal

may be time for a rebuild or replacement sounds like bands and or clutches are burnt or failing --try lucas trans mission additive may help for awhile but if internals are burnt up only repair will help

I don't know a "trick" but there are some youtube videos regarding allison transmissions.

Sounds like you should tow the motorhome with the 2500!!

seriously though, if it's a 4X4 make sure the front axle is not engaged, otherwise just make sure tranny is in neutral

just to be safe, check OM or nearest Allison warranty shop for advice

I'd be more worried about the motorhome drivetrain pulling that beast.....

ENGINE LACKING POWER CHECK TRANSMISSION FLUID TRANSMISSION COULD BE SLIPPING.YOU COULD HAVE RESTRICED AIR FILTER AND FUEL FILTER.TURBO WASTEGATE PROBLEMS.

Well the tchnical specs are available at
http://www.google.co.in/url?sa=t&source=web&ct=res&cd=9&url=http%3A%2F%2Fmedia.gm.com%2Fdivision%2F2004_prodinfo%2Fgmc%2Fpdf%2F04_GMC_Fleet.pdf&ei=VnjLSuPiNJze6AOg_JH9Ag&usg=AFQjCNFGSInnhC-fLTlqFE7yekGDKtwNCA&sig2=4uWnjikXApamQW-bb26Twg
However 202 I have assumed to be 2002 & if so then download the Users manual and trouble shooting tip from this site:
http://safemanuals.com/user-guide-instructions-owner-manual/GMC/SIERRA%202002. I hope this is what you are looking for...sodeep

No, have you changed the spin-on filter om the transmission yet? This may be the only trouble. I hope this helps. Good luck.

You may want to inspect the "pass-through" connector for water contamination, and/or related wiring for corrosion.

THERE HAVE BEEN ALOT OF PLOBLEMS WITH THE SHIFTER HANDLE/SWITCH. THE BEST WAY TO VERIFY CONCERN IS USE A DIAG. SCANNER & VIEW TRANSMISSION DATA DISPLAY WHILE ENGINE RUNNING. THE SWITCH IN THE SHIFTER IS FAULTY. IF YOU SEE NO INPUT CHANGE WHILE DEPRESSING SWITCH THIS IS YOUR CONCERN.

sure if you have all the computers and wire harnes.