Hey guys, I'm working on a 1990 F-150 4x4 with the 5.0 and the E40D transmission. I need to know where I can get the speedo drive gear, the one inside the tailshaft housing of the transmission, since they're no longer available from Ford. The speedometer works if I use a drill on the pinion gear on the end of the cable, but once I reinstall it in the tranny it no worky. Also, to those who've done it, how tough of a job is it to replace? I'm pretty mechanically inclined. Thanks.

 

It's not a separate gear, it's machined into the tranny tailshaft.
Did your tranny get rebuilt at some point in the past and did the builder use a tailshaft from a 93-96? Those years get the vehicle speed signal from the diff so they don't have the gear in the tailshaft.

 

It's not in the trans - it's in the t-case tailhousing, and it's a slip-on plastic gear. It's not shown in this '92-96 diagram because they used the rear diff, but it would be where 10 is shown, inside the tailhousing behind a snap ring. If you pull the VSS out of the tailhousing, you should be able to see the gear teeth with a flashlight & mirror. If they appear to have a crescent missing from each tooth, you've diagnosed it correctly.

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If you end up NOT being able to find that gear, then it's not very difficult to swap a '92-96 PSOM into your cluster & wire its output to your EEC so it can control the E4OD. But you may have to also swap to a '92 EEC for it to accept the PSOM signal - I'm not sure.

 

Doh!
I missed the 4WD in your truck description. The transmission related speedo drive you were asking about is all 2WD. Like Steve said, the 4WD takes it off the T/C