any one know how to fix a speedo that bouces all around. only does it above about 50 mph. just had the e4od rebuilt and they said they replaced the sensor in the rear end. it has always been 5mph off but now it bounces around a good 15 mph. it's on a 94 f150 351w e4od tires 285-75-16 gears just swapped to 4.11 to compensate for large tires. speedo is still off

 

If it didn't bounce before they did the rear end re-gear and replaced the sensor, there's a good to excellent chance that they somehow screwed up mounting the tone ring or the sensor.

The speedo is off because it needs to be reprogrammed for the larger tires. The VSS reads the rotations of the carrier so the ratio is irrelevant, only the tire size affects the speedo reading.

 

285/75R16 is only ~33", which isn't enough of a change to necessitate gears. I have them on my Bronco with stock 3.08 gears, and it's far from sluggish, even with the little 4.9L .

Read the TSB at the bottom of this caption:



But SR is probably right about the gear installer screwing up the tone ring.

 

it did it when i had the tranny rebuilt and they said they put new sensor in it how do you reprogram the speedo. i had thought with the big tires and 4.11's it should get it back to about a stock rear end ratio

 

Read that caption.

 

my speedo started flying off the wall...and thennnn the gears in my rear end ground each other up hopefully that isnt your problem

 

Why did you have your tranny rebuilt? I am guessing error in shifting patterns and neutraling-out when in OD. The problem problably stems from the pickup ring in the rear when they changed the gears + Psom needing reprogrammed. The real culprit is probably your PSOM to begin with possibly saving you a lot of money. I replaced the whole cluster from a Lightning after replacing all my sensors and finding they weren't the problem (did tighten my throttle response as the Throttle Control Module had some dead spots). Solved the shifting problem. Of course I found out why the lightning was in the yard in the first place as the cluster has a different problem, causing the 4x4 the engage irradically, so off the yard again. The short of it is replacing the PSOM (or cluster is easier) seems to solve a lot of the shifting problems with the E4OD. Good Luck with the particular problem.

 

There is no "Throttle Control Module" on a '94 F150 or Lightning; do you mean the Throttle Position Sensor?



The cluster can't affect t-case shifting; at most, it can hold the indicator lights on, but the t-case will still respond to the buttons & shift normally.

 

sorry, yes you are absolutely right (I have a hard time remembering things, lol) the TPS (throttle position sensor) that was a fun one to change but not too difficult :-)

 

Ya I would think the same as it shouldn't affect my 4x4 at all. However the shifting problem was fixed right after I replaced the cluster, and the 4x4 lights began to flicker at a stand still or moving both on the cluster and on the switch. Really weird is it is both 4x4 hi and lo flickering. I could have sworn it actually engaged the other day (or I hit something in the road) because something jumped up into my drivetrain while I was moving down a smooth road. wasn't sure but I pulled over and the lights continued to flicker without any kind of rhythm. I just disconnected the switch and thought that would solve problem but (the truck is posessed) the dash lights continued to flicker...lol, thankfully the switch light went out though, hehe. so I either got a short in the line, a bad sensor, or I got problems with the cluster (probably a short there). Any ideas. By the way Steve, your the man, been watching the forum for about a year and a half while I diagnosed the problem with my shifting, lol.

 

[/hijack] If you want to discuss problems specific to your truck, start a new thread in this forum.
This thread is for bouncy PSOMs like the original post.