I know you guys are sick of seeing the same post from people and giving the same advice and I really did use the search but can't find a solution. 95 f150 shifting hard intermittantly, speedo bounces wild over about 65 mph, was far worse until I disconnected the ABS box - that helped a decent amount but this is the vehicle my teenage son drives and I don't want him driving w/o the ABS connected. Check engine comes on for a minute or 2 over 70 MPH on occassion.
Here is what I've done
Replaced VSS
Replaced PSOM (with a used cluster I bought on Ebay)
The rear end is completely rebuilt within last year and was done at a really good shop.
Could this be a bad wire from the VSS?
Is it more likely that I bought a PSOM that was also bad?
Could an aftermarket VSS be causing this issue rather than using an OEM part?
Sometimes the truck drives flawlessly and shifts like a new vehicle, other times it shifts hard. Speedo consistently jumps around at higher speeds. As I mentioned, very noticable improvement when ABS is disconnected behind the glove box.
Please help! My 16 year old son is driving me crazy

 

When you rebuilt the rear end did you replace the RABS/speed sensor on top of the rear differential?

 

I did replace the sensor on top of the rear end. I bought an aftermarket from oreilly's. I'm wondering if that may be a problem and if an OEM part would make a difference. it just seems weird that with a new rear end, a new sensor and replacing the cluster (just replaced the whole thing rather than just the PSOM) that the problem still persists. It seems like it's either got to be the sensor that I replaced or the PSOM that I bought used was also bad. Very frustrated.

 

Yeah sometimes these trucks are finicky about the motorcraft parts they like. I would pull codes and see what that gives you, seeing as your CEL is coming on. I would also hook up the old cluster (if you still have it and it worked.....that's basically assuming you bought a new cluster because the old one was ugly). Do everything you can before you start spending more money.

It's frustrating but generally these trucks tell us what is wrong with them if we listen to them....properly.

 

I replaced the old cluster because I was pretty convinced that it had a bad PSOM and rather than sending mine to be repaired, i just bought a whole used cluster and repalced it. I still have the old one and am considering sending it to get rebuilt (I'm assuming that's what they do to the PSOM when you send it for repair). I think i may try a OEM sensor first and see if that does the trick. The fact that when the ABS module is plugged in the issues are so much worse seems odd to me and makes it SEEM like it has to do the the RABS. I don't know though - I'm not a mechanic. I'm decent at monkeying with stuff but that probably just makes me worse than somebody that knows nothing. haha