Changed transmissions now speedo is off (1 Viewer)

[jaymundy]

A friend changed out the transmission (A440 I think) in his 75 series, and now the speedometer and odometer are significantly off when compared to GPS figures. Anyone have a clue? The new transmission is from a newer truck but is otherwise the same as far as we know. My first thought was a difference in the diff ratios between the donor and receiving vehicles.

 

[Clint79]

Isn't the a440 a auto ,all 75 series come with the h55 5 speed manual box bar the fzj 75 from late 92-99
are u sure the new box is from a 75 series

 

[jaymundy]

No, not sure at all.

 

[Dieseler]

Just change the speedo gear in the trans tailend

 

[Radd Cruisers]

Just change the speedo gear in the trans tailend

There are two parts to this, the drive gear and the driven gear. Both will need to be changed back to the ones that were in the original transfer case that came with the vehicle.

~John

 

[Greg_B]

If you are not splitting the case any time soon, or are not inclined to change out both gears that John mentioned (or you are playing with t-case/diff gear ratios) contact this fella here: CANWEST TACHOGRAPH INC. Canada, BC - Kenworth Speedometer, Peterbilt Speedometer, Kenworth RPM Guage, Custom Built Speedo Cables, VDO Guages

He has supplied a number of ratio adapters (screw onto the t-case speedo output) for me over the years.

jaymundy, see if there is a company closer to you which does the same thing. Most ratio adapters have been a one shot deal, but I have had one I had to send back a couple times to fine tune. He was great to deal with.

gb