Peterbilt...

[buzzinghalfdozen24]

looking for references for adding auxiliary gear units onto semi trucks. Old peterbilt service truck needs taller gearing for higher speeds. Truck rpms out at 59 mph. Was hoping to find something similar to GEAR VENDORS unit, but specifically made for OTR semi trucks. Technically, changing rear diff gearing would work too, but liked this option...

Anyone have references?

 

[The patriot]

As far as I know, class 8's are going to need either the rears re geared, or transmission switched out to one with a taller high gear (possibly over-drive, or double over etc)

 

[Wayne M.]

Sounds like an older rig with a mechanical engine/ min electronics. The governed speed was determined by gear ratio mostly, especially in vocational work trucks. Swapping rear cogs would be the fix.

 

[buzzinghalfdozen24]

Yep, that's what I was thinking. Figure that'd be the simplest way. Thanks

 

[mwilson]

What engine and transmission do you have???

 

[Hoefler]

Adding an auxilary transmission is very doable, but would be expensive. What transmission do you have?? If a Road Ranger, you can have it made into an overdrive, if it isn't already, or a double over drive.