Speedometer help please - Diesel Forum

MHG · 11-19-2012, 04:56 PM

We re working on a '91 4X4 w/ E4OD and a B-W transfer case. Both the speedometer drive gear and driven gear need to be replaced. The vendor mentioned in a thread here is out of stock on the drive gear, yellow 7 tooth. Anybody have a source? Is it available from Ford, if so part number? Thanks in advance. MHG

chuckster57 · 11-19-2012, 05:27 PM

I thought the E4OD equipped vehicles used the VSS in the rear differential.

drinkypoo · 11-20-2012, 01:45 AM

That might be 1992+, I don't have the right book to prove one way or the other.

MHG · 11-20-2012, 08:28 AM

This '91 has one on the rear end and one on the transfer case

chuckster57 · 11-20-2012, 09:16 AM

Have you tried LMC, Rock Auto, and maybe 4Wheel Off Road.

drinkypoo · 11-20-2012, 09:49 AM

I wonder if they send the same signal

chuckster57 · 11-20-2012, 09:54 AM

If I had to guess, I would bet the VSS in the rear end is electrical and signals the TCM for shifting, and the transfer case VSS is cable driven for the speedo/ODO.

drinkypoo · 11-20-2012, 10:08 AM

Probably true. I wonder if one could upgrade to a 1992+ cluster. I imagine it wouldn't fit without heavy modification anyway.

LMJD · 11-20-2012, 10:21 AM

Quote:

Originally Posted by chuckster57

If I had to guess, I would bet the VSS in the rear end is electrical and signals the TCM for shifting, and the transfer case VSS is cable driven for the speedo/ODO.

Yep, unless the auto trans has a bearing on it, my '91 (5 spd) speedo is 100% old-time cable driven with the gear driven odometer. The diff sensor is for the ABS system. In '92 they switched to the digital mileage display.

chuckster57 · 11-20-2012, 10:39 AM

Thanks for clearing that up.