I recently had my differential blow in my 2005 3.3 caravan. as a result I figured why not rebuld the tranny at the same time. Everything is back in and running properly. Shifts beautifully, and have no problems...save one. My speedometer is out by 15kph at 100kph or roughly 8-9 mph at 60 mph. The real problem is that it is not to my benefit. I am actually speeding when I think I am not. I have no codes stored at all, and have replaced the output sensor as I was told by the guy that rebuilt it that it was probably bad. Still though I have the speed problem. I am looking for any suggestions as to what it could be.
Thanks
Brad.

 

Only guessing but you may need to have the pinion factor reset by by your local dealership and their DRB scanner.

 

my local highschool did my pinion factor with a snap-on mt2500 (aka red brick). i put a different size tire on and needed pinion factor changed so the speed read correctly.

 

What if there are no High Schools close by with a $4000.00 scan tool?

 

I agree, you need to have the pinion factor reset. I wouldn't know if a lot of auto shops in high would have a scanner. Your best bet would be the dealer.

 

snapon mt 2500 scanner was under $2000 when brand new. they are used all over ebay for under $600.

every autoshop I know has a scanner capable of doing pinion factor. snapon mt2500, snap on solus, snapon modis, OTC genisis, Monitor 4000. and many more can easily program in pinion factor. I see no reason to have to go to any dealer. besides EVERY highschool with an automech program has some type of quality scanner. The highschool I went to (only 130 kids per grad class) had several quality scanners. We learned on the MT2500, OTC genisis, Mac 4000, solus, and we had a DRB3 and GM tech2, and ford super star.

 

I guess as a follow up to this, why would the pinion factor be wrong? Is it because it was disconnected from the battery for a long time...like 2 months? does everything just kind of get reset when that happens? Also, what should the pinion factor be? Whatever it reads now, do I need to go higher or lower with that number? Does anyone one know for sure if the mt2500 will do this, as I have access to one for free. I also have the K-13 key needed to read the chrysler vehicles.

 

Ok, this is frustrating. I managed to find the pinion factor setting with the MT2500. It only gives me 3 options for tire sizes and nothing seems to make any difference. or at the very least negligable at best. Any other ideas?

 

If you have access to a DRBIII, there is an option "Body Interior">> "MIC" >>"System Tests">>"Cluster Calibration Points" where you can calibrate each guage to certain divided points. In the case of the speedo, it's 20-40-60-80 I think. Don't know if the MT can do it. If your battery was jumped at any time then it can sometimes joggle the cluster calibration. Not saying you jumped it but the battery could have been dead at the shop, it happens all the time.

 

yes, the MT2500 can do a cluster calibration test.

yes the MT2500 can change tire size (pinion factor) yes it does work

yes, the mt2500 has over 30 tire sizes to choose from to change 'pinion factor'