1995 REXHALL AERBUS speedo

[Hangfive]

Hi all, when my 1995 Aerbus speedo quit and transmission shifting became very erratic, research suggested the sensor to be on the park brake assembly attached to the rear of the tranny. My park brake shoes were worn-out also, so I decided to R&R the unit. FORD claims the unit is not serviceable, and will provide a new unit for $1800. OUCH! So I figured out how to disassemble it, found a new internal speedo gear, shoes, bearings, and seals for less then $300. Tricky to reassemble, but I got it. The little gear (also worn-out ) on the sender that sticks into the hole, has to be the correct one to match your diffy gear set, and are provided marked and color coded. Mine is black. The wrong one will cause your speedo to lie.

[Hangfive]

Hi all, months after having accomplished the previous post, I encountered my speedo intermittantly jumping around, accompanyed with poor shifting. I did a ton of research on this and narrowed it down to the module on the back of the speedo. In the mean time I encountered a problem with my ROADMASTER dinghy brake system. It has the old style using an air compressor on the RV. The compressor was staying on all the time or not turning on at all. Trouble shooting found the pressure switch had no voltage coming out of it. The relay turns on the compressor using the signal from the pressure switch. This signal was at the switch intermittantly, so I traced it down to coming from the ignition on. Turns out the pressure switch was shorting to earth. This in turn was shorting the Powertrain Control Module to earth, and was causing the erratic speedo and transmission shifting, not the speedo module. It's working normal now. Also replacing the compressor for being worn-out as it has a hard time getting to the 135 PSI shutoff point. Installing a 200 PSI unit that won't have to work so hard.