Speedo Recalibration
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Joined: Aug 2005
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Speedo Recalibration
I put BFG 315/70R17's on my 2005 F-250 SD Crew Cab PSD (which I love!) and of course my speedo is 7-8% off. I've read in other posts that the dealer can recalibrate the speedo, but I just contacted mine and was told (after checking with the service manager that they can't do that "anymore". Ther person I talked to didn't know what "anymore" meant, but suggested I contact a local tire shop to see if they could do it. It was recommended that I have my PCM reprogrammed to adjust the transmission shift points. Does anyone have any experience with speedo recalibrations? Have you had dealers do it or someone else. What about PCM reporgramming?
Postmaster
Joined: Jun 2004
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From: Milky Way Galaxy
Speedo calibration is a function of the PCM, so you're recalibrating the speedo/PCM/tranny/anything else that uses that data all at the same time. Unless you use a device like the Superlift Tru-Speed. The PCM, from what I understand can only accept revolutions per mile as low as 600, but 315's wouldn't be a problem. I don't believe it's a FMC policy not to recalibrate the PCM for larger tire's, but things may have changed since I last asked my dealer.
Posting Guru
Joined: Jul 2005
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From: Denver, Co
Tell the dealer that you swapped tires, and would like to get the new tire revolutions per mile value programmed. In addition to what Envirocon has already stated, you will also be correcting ABS behavior, as it too uses this data.
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No Luck so far
Trucks at dealer for service today and I was told by their diesel tech that no way do they do reprogramming. I've got a contact at a different dealer. I Think I'll ask him to see what he can find out. Thanks for the replies!
