Speedo correction for 6.14 gears

[wehring]

CAT tech just left and the LMTV now has an accurate speedo and a 330hp flash. When we changed the axle gears from 7.80 to 6.14 the speedo was off by 15mph.

Here is the info you need to give your CAT guy to correct ...

40291 pulses per mile
Found in vehicle speed cal in engine ECM configuration

hope this helps

justin wehring
979 997 3112

 

[Shark Bait]

CAT tech just left and the LMTV now has an accurate speedo and a 330hp flash. When we changed the axle gears from 7.80 to 6.14 the speedo was off by 15mph.

Here is the info you need to give your CAT guy to correct ...

40291 pulses per mile
Found in vehicle speed cal in engine ECM configuration

hope this helps

justin wehring
979 997 3112

I want the 330 hp!

 

[Strouty]

That is awesome. So you did not need to do anything to the transmission computer? I am asking because I would like to do something similar in a civilian truck with a similar setup.

 

[wehring]

That was it. 15 min on the CAT tech's computer and it was done. He had to use a calculator to come up with the correct pulses per mile but after he had the correct value to input it did not take him long.

justin

 

[Strouty]

That is great news, I love my cat dealership, but not so much the allison dealership.

 

[NDT]

Me thinks is info is only applicable on A1 trucks with C-7 power?

 

[wehring]

Good point Franz... And true. Will not work on 3116 powered trucks.

 

[Strouty]

I figured he was talking C-7 or 3126 since the 3116 is mechanical. My truck is a C-7 with an MD3060P so it should work for me.

 

[wehring]

I have a C7 truck. I assume this will work with the 3126 trucks but can not confirm.

justin

 

[Strouty]

What year is your truck? I think mine is technically a C-7 as well, I just like the sound of a 3126 better.

 

[wehring]

It was made in Dec 2006

 

[SIMXVertigo]

So the flash WILL NOT work on a 3116 powered truck but there should be no problem having the speedo changed with the gearing correct?

 

[wehring]

Correction..... 49,291 is pulse per mile value. Sorry folks. I try to check info before I put it out there but I missed this one. 40,291 from the first post is incorrect.

Justin Wehring
979 997 3112