VSS Modules- Tire size correction

[TraceF]

Anyone have experience with the Superlift VSS Module or any other manufacturer? I want to correct for tire size change. Thanks!

[ccds]

here is some info on truspeed sensor:

http://forum.thedieselpage.com/ubb/ultimatebb.php?ubb=get_topic&f=5&t=000706

http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=7&t=003241&p=

http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=7&t=003602&p=

http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=7&t=003854&p=

hope this helps....search button works like a charm

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[ALLAMERICAN1]

The truespeed works as advertized. I put one on about 5 or 6 months ago. It took about an hour to install and about 15 or 20 minutes to get it adjusted. According to my GPS it is within 1 mph at 75 now.

[torque]

Just put one in this week. I'm in the process of adjusting it to match my GPS. It works as advertised.

[TBC]

How accurate is the GPS ground speed readin?5 I am not sure how you can really verify the GPS ground speed. I changed to 265's and then checked the speedometer against my GPS and was 1.5 to 2.0 mph faster than the speedometer indication. Best I recall before changing tires the speedometer was about .5 mph slow. According to the dealer the indications are within + or - 5% which is within the accuracy range.

The tech also said that the only way he could calibrate the speedometer was to call GM with the VIN # and see if the 265's are optional on my truck and if they have a software update for it. The way he talked about this was like some of the trucks had an option and some did not. He may have been confusing 2500HD's in general with the Duramax/Allison configuration. If at that he says I am within the accuracy range so an update would not affect anything. He did talk about the bulletin on oversize tires and the possible problems. He also indicated that 265's don't usually cause a problem. It is when you go to the larger tires that problems start.

I have not noticed any difference in performance. I did notice that the truck is taller. My $.02 worth for what it is worth.

[TraceF]

Thanks for the feedback and links.

One comment- sometimes I can't get the search engine to work at all. Is it on a different server maybe?

[BadDog]

What bulletin on problems with over-sized tires? This is news to me...

[TraceF]

BadDog-

The bulletin is #01-03-10-010B (10-14-2002)

This is D/A only.

Basically says not to try to diagnose driveability issues if the oem tire size has been changed.