need help on cruise/vss....

[3-StarJ.R.]

posted this on the "other place" a few days ago with no response, has anyone run across these problems before?

Heres my story, I do a LOT of interstate driving due to my work being out of town. Traveling I-75 between Atlanta/ chattanooga you can safely cruise 80+ 'cause if you don't, your gonna get run over! Set the cruise on 80 mph ....perfect....set the cruise @ 83+ it starts to surge 2 to 4 mph up and down, speedometer rock steady following the surging......no difference in any chip setting.... no speedo jumping with out cruise up to 90+....Changed the VSS this weekend, now speedometer is all over the place from 75 mph up, can't even use the cruise.....anybody got any suggestions? I was thinking possible metal on the old vss, it was clean and no metal when I pulled it...When I stuck in the new one, pulled it back out thinking I didn't get it seated properly and it was coated in fine cuttings from the rear gear...cleaned it and stuck it back in....think that might be my problem? More metal? I'm gonna pull the chip on my trip home tomorrow to see if that has an effect on the new vss which I won't clean again until I see if the chip is having an impact.........

 

[powerboatr]

if your running 80 plus with 4.10s your spinning that puppy arent you, very familiar with that stretch of 75, 65 is just as bad over here WOT.
anyway, the filings/cutting on the new vss, NUMEROUS or just some? filings size?
when was the last rear end fluid change?
whats the fluid level?

i would contribute the possible surge to the flinging of metal onto teh vss screwing up the reading, however you said it was clean when you removed it?

 

[3-StarJ.R.]

Boater, what was strange to me is the old vss had no metal sticking to it @ all, it's supposed to be magnetic right? so on it's removal I figured I found the problem....New vss picked up a good amount of fine cuttings on the first insert. Motorcraft syn lube about 25,000 miles ago after changing out a rear hub seal. Fluid level good. I think I'll pull it out aagain after work today to see about more filings and inspect them closer....Thanks for the insight.....

Update: Yep 85 mph 2700 rpm Pulled the vss sensor again, and again very fine cuttings attached in a few gear oil "spikes".....may have a bearing going south or worse yet abnormal gear wear.... when I did the hub seal on the left side I changed out both bearings while I was there. So the right side bearings is where I suspect bearing problems...looks like I'll be pulling the rear cover and checking things out. Regardless if every thing is ok, Ill still be spending mucho denaro for a fluid change.....-mad -mad . Then start over chasing the cruise problem.....

 

[tubzz]

hey jim,sorry your haveing problems,i don't have nothing to add but maybe check the wireing to the vss with a meter and check them for rubbing up against something.whats the plug look like?

 

[95_stroker]

Jim,

We recently covered something very similar to the problems you describe. I'm going to insert some links to old threads and one link to an external website that eneded up solving the last users problems. Read it all and see if it sounds like what you have going on.

Speed sensor thread.

Speed sensor thread update.

Offsite resource.


Good luck and let us know if this helps.


Mike

 

[JOAT]

Metal particles on the VSS is bad. That means there are probably a significant amount in the gear oil, which will cause VSS fluctuation, not to mention accelerated wear

There should be a VSS connector under the center of the dash. Usually near or attached to the trailer brake connector. Grey 3 post connector but 2 wires, one red/something. If you have a multimeter with frequency capabilty, you can connect it there and watch the frequency reading. Should increase with speed but hold at a steady speed. Odds are you'll see it jumping with metal in the final drive.

One thing to consider, if it needs a new gearset. With 2wd it doesn't cost any more to change the ratio if you want.

 

[3-StarJ.R.]

Guys, thanks so much for the links and suggestions, i'll practice up on the search engine here so that you'll won't have to repeat yourselves on the same subject every fifteen minutes......looks like little Jimmy has found a new place to play!!

 

[3-StarJ.R.]

whats the plug look like?

Terry, first time it's ever been touched. Looks good, rubber seal is- good, wires into the wiring harness on the frame rail is good...(no road hazzard damage, unlike my running boards....'nother story...)....will throw the meter on it this weekend....

 

[94f450sd]

mine does the same thing.dont know what it but its been doing it since the installation of the stage 2s.i just figured it was something that happens when you start adding power.

 

[3-StarJ.R.]

Hey Rich! hows it going man! I think my problem is like Don said, I got a bigger problem than just the cruise being goofy, it's all the cuttings I got floating in the gear oil, got to make the time to ppull the rear cover and check out the gears for abnormal wear....so far no odd noises or bad bearing vibrations......I got a bad feeling the rg/pin is living on borrowed time......