I just replaced the differential in my truck, gears went from 3.31 to 3.55
Do I need to reset the computer for the transmission?

 

Yes

 

If you're 4 wheel I hope you replaced the front gears too, otherwise no more 4x4.

 

Can I ask a stupid question from the OP-How does he do that, disconnect the battery or ?

Reason I ask is my 2wd '97 had 3.55's and one shim ate my carrier housing, then I installed a '2000 rear w/different gearing.

Thanks,
Jim

 

Only stupid question is the one not asked. The op didn't give any info on his truck. Tackle recently made a thread called details for this exact reason. Anyway you can't just disconnect the battery. On '97-'98, the speedo was operated by a driven gear. To get the correct reading on the speedometer the driven gear would have to be replaced. On '99-'03, the speedo is operated electronically. If the ratio is changed to a factory ratio, you can reflash the PCM. If its not a factory ratio ie: 4.10's. A programmer is needed or a chip with a custom tune.

 

Ok thanks-did the tranny gear. Didn't know about the computer. Guess I need to figure out how/whom to get the computer done.

Thank you,
Jim

 

No problem! If you replaced the gear you don't have to mess with anything on the PCM, being you have a '97. '99-'03 are the ones that have to have the PCM reflashed because there is no driven gear. Everything is electronic.

 

Sorry, I thought all of the info was in my signature. Anyway, truck is a 2wd, swapped diffs as I switched tire sizes from 29 - 31.7"

Would have preferred 3.73 but got this rearend for $60. As for resetting the trans, I was just planning on disconnecting the battery for a while. Will that do the trick? Thanks

 

Signatures don't show up on the mobile app. What year is your truck? And I pretty much summed everything up you need to know with Rollbar. And no, disconnecting the battery is not gonna do anything for you.

 

SS he has a 99 4.2