Rear end speed sensor

[MBRPCrazyford]

I was driving down the road the other day, and the truck started slamming into gear. So, at the next stop, I pushed er to the floor, it held to about 30mph, then slammed into second, then a little better into third, and so on. Took it to my tranny guy today, and he put it on the computer, and it told him that the rear end speed sensor was bad. I was wondering if anyone else had this problem before. Also, the OD off light was flashing, he said that it could be a soleniod in the tranny, but today the computer just said that it was the speed sensor . Then I was almost home, and it wouldn't shift out of first-mad . As i said before, it only shifts real hard sometimes, and omly from a dead stop. Like if I'm doin about 30-35 in second or third and get on it, it's fine. Any help would be appreciated. Thanks

 

[94f450sd]

OD light will blink if the speed sensor is junk.replace it and all should be fine

 

[95_stroker]

I would also recommend draining the rear differential and taking the cover off, your sensor might be good but covered in fine metallic shavings. Get the pumpkin cleaned out and clean the sensor, put fresh gear oil in and see if the problem still exists. If so....change the sensor but in the mean time you will have also taken care of one of the yearly maint/inspection items also.

 

[MBRPCrazyford]

ok, thanks

 

[drillin001]

i have the same problem with mine, i took it to a shop they said the speed sensor was shot, replaced it so i picked it up and on the way home it started again, i took it back and they said it could be a broken wire somewhere in the harness, so at 60.-80. bucks an hr. i decided to live with it. ive put about 6K on it so far and it hasn't left on the side of the road yet,

 

[94f450sd]

i have the same problem with mine, i took it to a shop they said the speed sensor was shot, replaced it so i picked it up and on the way home it started again, i took it back and they said it could be a broken wire somewhere in the harness, so at 60.-80. bucks an hr. i decided to live with it. ive put about 6K on it so far and it hasn't left on the side of the road yet,

go through the wireing yourself.much cheaper.again as the traitor above(sorry mike)stated pop the cover off the rear end.but im gonna add to it by telling you to jack the truck up,put it on stands.put tranny in neutral and turn the wheels and wath the carrier while it turns.pay attention to the tone ring,its the ring of teth between the carrier and ring gear.see if its missing any teeth or if some are smashed.i had an issue with my dually doing this when i snapped the spider gears into 6 pieces .the tone ring was 30 bux i think.

 

[BIG JOE]

I would also recommend draining the rear differential and taking the cover off, your sensor might be good but covered in fine metallic shavings. Get the pumpkin cleaned out and clean the sensor, put fresh gear oil in and see if the problem still exists. If so....change the sensor but in the mean time you will have also taken care of one of the yearly maint/inspection items also.

What Mike sez.

I just R&R'd one for a guy Monday, on a 96. Pop the Diff cover and drain it. While its drip draining replace the speed sensor.

The one I took out looked like a Fuzz Ball. (metal from normal wear)

An indicator of a speed sensor going bad is: Shifting issues or, when on CC yer truck will "Hunt" trying to maintain set speed.

JMO, but wipeing it clean and re-installing it is, in a few more K miles, a Bandaid. It's a 30 dollar part, Just replace it. It's a magnet.. prolly Weak & Tard ?

 

[MBRPCrazyford]

Ok, thanks, took it to the shop and he cleaned it, replaced front and rear diff fluid, trans case fluid and all that good stuff. Still wanting to stick in first for a littlewhile, but then it's ok. Taking it to transmission shop Mon. Thanks for all your help and I'll keep posted the outcome!!