15 speed Road Ranger Transmission

[baleflipper]

I recently bought an older truck with a 15 speed Road Ranger transmission.This Transmission has a selector valve on the shift knob to changes ranges. The selector is air powered. I can not get into lowest range. Any one know how to fix this? How many air tubes should be behind the selector valve? 3 or 4?
Truck will pull dozer but needs the lower range gears.

 

[Angus Cowman]

I recently bought an older truck with a 15 speed Road Ranger transmission.This Transmission has a selector valve on the shift knob to changes ranges. The selector is air powered. I can not get into lowest range. Any one know how to fix this? How many air tubes should be behind the selector valve? 3 or 4?
Truck will pull dozer but needs the lower range gears.

if it is a 15 over then it will be in low until you shift it out of low if it is a 15 under then you shift it to low range
you should be able to look under the truck and find the air changers on both boxes
disconnect the lines and make sure you have air going to the selectors
I am thinking IIRC you will have 1 supply line to shifter and then a line going to each selector so a total of 3 on the shifter itself

you can also unhook the lines at shifter and find out which is supply then hook it back up and hit selector and find which line is feeding whenre and when

are you sure someone hasn't swapped it out for a 10 speed at 1 time

 

[denvermartinfarms]

should just be three lines on the shifter i have never seen one like this that had four. i have been around this kind of problem before but i can not remeber what exactly it was i will think about it some more and ask someone and get back with you.

 

[baleflipper]

There are 3 lines on shifter knob,Red,Black and Blue. All 3 lines go to the transmission. There is only one transmission gear box on this truck. The air lines all are hooked to a shifter mechanism,one is at the front of the transmission the other is at the rear,what I take to be the supply air line is on right rear center of transmission. There are several larger hoses on this transmission. I think there might be a gear pump to supply oil to the shaft bearings in this tranny.
If this was only a 10 speed I don't think there would be a need for 3 air lines. I have never been in one of these transmissions. It looks to me like it is standard 5 speed shift pattern with a reduction on the input shaft and a reduction on the out put shaft. The lowest gears would be the input reduction engaged as well as the out put reduction. Mid range would be the input shaft reduction in the direct position and the out put in reduction.
High speed would have input direct as well as out put direct. For some reason the chart in cab says do not split shift in lower gears.
I suspect that the transmission was let get low on oil and the input reduction shaft got scarred. The rough shaft might not let the gear slide on it to engage reduction. No problem seeing transmission,this is a cab over. You can walk right up to it!
I may need to install an elevator to be able to get in the cab. My knees don't take the climb too well.

 

[Lawson Farms]

Also make sure that the lines are cleaned out from the shifter to the transmission. We've seen some pretty good gunk clog up the lines to the shifter.