Speedometer Fluctuation

[TXDSLSHOP]

My speeedometer is erratic on my 93 D-350 and I was wondering if anyone has any insight on this. I just bought it and haven't even looked under it to see if the speedo is electronic or cable driven. Also, the rear brakes lock up pretty easy, so does this thing have rear anti-lock brakes? Thanks!

 

[DPKetchum]

Yes it has rear antilock called RWAL. AS far as speedo goes I've had this problem with a 1990 and 1993. I get a headache just thinking of this. Anything from speed sensor to poor grounds ,speedo head etc. Theres been lots of discussion on this subject with lots of differant opions,repairs etc. First the truck should have a brake light and a antilock light come on when key turned on and it showed go off as truck started and ran. Also can check by locking brakes up at moderate speed etc. and rwal should come into play. As far as speedo I'll let someone else jump in on that. I went round and round with Chrysler on late issue for four years on the 90 model with no real success. Yes speedo is elec.

 

[dwalker151]

I had the same problem on my 93. Man... was it fun with the cruise control on. I solved it using the K. I. S. S. theory of mechanics. In other words I cleaned all the connectors with contact cleaner that hook up to speed sensor at the transfer case. On mine there was two an hook up to the speed sensor and a short adapter cable. It might not work but it's easy to try!



Dean

 

[BushWakr - RIP]

My speedo issue was simply this... if I did a "granny" start/accel. then no problem, but if I got on it at all it would thrash around like it had a mind of it's own. When it spasm'd up and down the transmission would drop out of OD into 3rd. That really sucks when your doing 65 MPH.....

Anyway I pulled the speed sensor assembly out, then the removed the speedo gear from the transfer case for inspection.

The gear can be a cause and will show it, if it's bagged. In my case the gear was good, so I replaced the speed sensor. So far this has cured my problem and I'm good to go.

You do need to make sure that your speed sensor is either indexed or not, depending on the truck year.

You will see the little "two fingered" bracket on the sensor if it is indexed for your rearend gearing, which makes it read correctly.

If you replace the sensor put the new one on in EXACTLY the same place as the old came off of. I may be able to post a pic of it if you need one.

Let me know and I'll dig it up in the manual



edit: I scanned and posted the two pics of this in a new pic gallery under my nickname.

bob.

 

[cguthrie]

Hey i'm having the same problem with my speedometer and my transmission started shifting out of O/D into third today. So if i replace the speed sensor that should fix it?

 

[BushWakr - RIP]

Well it did for me. The speedo gear and the sensor are the most common cause of this problem.

As I mentioned, first you check the gear inside the transmission, if that is ok, then it's very likely the speed sensor that is at fault.

If your speedo thrashes around, or twitches with the just the key on and engine off, then you've got other problems.



Bob.

 

[cguthrie]

Bob,



hey thanks allot it was beginning to annoy me do you know about how much the sensor and the gear cost? are they easy to install.



Thanks allot,



Chris

 

[BushWakr - RIP]

I don't know about the gear but I paid around $87. 00 Can. for the sensor.

Piece of cake to install, including inspection of gear etc.



bob.

 

[DPKetchum]

Well I hope this works,my 90 never got fully repaired it started all of the above at 6,000 miles and ever 3 to 6 month's would go from twitching to full blown sweeps of hand to ok in a matter of minutes to several day's. I kept D. C. on the hook by call 1800d. c. and keeping a file open for 50,000miles and four years. They claim they had almost 4k in speedo type repairs in it. Sold that truck bought a used 93 4x4 and had it 6 months or so and it dosen'nt do as often or as obvious but it does and is worse towing. It's had a new updated gear and a new speed senor and may be ok for weeks and then twitch's etc. Never drops a gear but with cruise on it surges when this occurs. Several years ago I talked to a SPEEDO shop and they said that system had a gremlin in it and was Junk!!!!and did'nt care to every get involed in another repair on one of these!Had told D. C. about this and they claimed not to have heard about speedo problems. THe tow services I inquired with that had them as wreckers/flat beds etc. said not a speedo in a one of theirs worked or worked correctly all the time. Enough from my end. KInd of a thorn in my side for more then a decade!

 

[Mark_Kendrick]

I have the same problem with mine. I had the folks that did my oil change grease the fitting at the speedo gear and that cleared it up for a while but it stl spazzes out now and again. I'll have to break out the brake clean and check the grounds on the truck next.



Later,

Mark

 

[robiR]

Same thing here, I did however have the speed sencer replaced twice by dodge, when the truck was new-it would kill the cruse control completely. One of the dodge places said it would produce a noise that the coumpter would pick up, when the bearings would loosen up (they replaced it under smogg, after warenty passed). I have however cleaned it in parts cleaner and tryed to lub it a few times after this. Now it is effecting the speedo causeing the OD to kick out and in, in time with the speedo. So I guess it is time for a new one-I just hate giveing Chysler more money: I think they have gotton enough from me.

 

[DPKetchum]

On my first truck whick I bought new,they replaced speed sensors,pcm's,wire harness from sensor,turnsignal light switch,o. d. buttons all several,several times over the course of 40k or so and each item would fix it for a while. Once at about 10k they had it two weeks,finally said repaired and had driven it 60 miles and i got in it and withen a Qtr. mile it dropped to 0 and would'nt work at all. My 93 once in a while is real jerky,big wide sweeps ,most of the time little twitch's. What really gripped me was D. C. and I mean REP's on up in command saying there wasn'nt a problem but a used car saleman in a dealer in 93 said they did'nt trust mileage on none of them. When i looked at used one's I did'nt eaither!!When 1994 came around I was told they really did'nt give a rats butt because their concern was new body style and that was their focus. AS i said a thorn in my side. IT still pop's up.

 

[BushWakr - RIP]

Ok you guys, knock it off eh ... . your makin me nervous, besides if mine hears you guys talking you know what will happen don't ya...



fingers crossed... .



bob.

 

[TXDSLSHOP]

Thanks!

Thanks for your Help! I am going to check it out tomorrow!