Here's the latest:
Since I've gotten responses from two different people saying that the vehicle speed sensor (VSS) is on the differential, I decided to jack up the truck's rear end and crawl under and take a look.
I could not get a look from more than one angle, but it looks like this (click here
) is probably the appropriate VSS because it has the same sort of "L-head" for the two-pin connector, assuming that the one show here is also two-pin with exactly the same fit.
The only Motorcraft speed sensor I found is this one (click here
), but the head is not L-shaped, and besides it looks like it is designed with two different connector heads. Conceivably, one of the two connectors might match my F150 plug, but the "business end" of the speed sensor looks very different from the "business end" of the L-head speed sensor. So it cannot be that both of them are replacements for the one I have.
It also appears that the first one above -- the one with the L-head connector -- is simply a magnetic pick-up head with no moving parts. So it is hard to imagine how it could fail or wear out, etc. So if that is the right part, why would I be getting a 29 trouble code? Also, the warranty info on that link suggests that the speed sensor shown there is an ABS sensor associated with the rear brakes. That too is puzzling.
I also googled for 'Motorcraft 1988 F150 "vehicle speed sensor" ' but could find no Motorcraft speed sensor with an L-head.
And neither AutoZone nor O'Reilly (local parts stores) have either a Motorcraft or a L-head speed sensor on their web sites.
Can anyone positively identify the part I should order? Is it the one with the L-head at the first link above (Raybestos example shown)?
I also felt around behind the one on my differential housing, and it seems that there is probably an obscured bolt fastening the sensor into the differential housing.
After unplugging the sensor, is this a simple matter of using a wrench to remove that (supposed) bolt by feel and then a simple matter to pull the old one out and then insert the new one and replace the bolt and then reconnect?
Are there any tricks to doing this? Is it likely that the bolt may be hard to break loose?
Any particular torque I should use to re-tighten?
I guess I should use anti-seize lubricant on the bolt if that is how the VSS is fastened.
But I should note that now another person says I have two VSS's. (I guess that's not counting the likely ABS speed sensor associated with the rear brakes.) So that makes more sense vis-a-vis the available parts found. So now I should ask: Which one of the two VSS's could cause a trouble code 29? Or can either one of them cause code 29?
I have a hunch that the VSS I should pay attention to is on the transmission, especially since the one shown here ( http://www.oldfuelinjection.com/?p=33
) is also more easily available at parts stores.
It also happens to be like the one at the link above for the Motorcraft VSS.