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crackling on the volume knob?

Posted: Thu Apr 05, 2007 12:01 am
by kassim503
I have this old radio- its old and should be tossed but I just cant part with it quite yet.

Uhhh, well the volume knob crackles, just like when it has corrosion on the contacts of the switch, now I cant get to the switch if i open it up, they glued a circuit board right on top of it and i dont fancy ripping that out because ill mess it up somehow, Al said somewhere back that it can be cured for a while by cranking the knob across its range 30-40 times. But ive been cranking this for so long and there is no change in the crackle/ dead spots.

Is there any kind of chemical or household solvent I can jet into there to make it stop crackling? Or is it time to pull it apart to replace the switches with newer ones?

Also, if anybody can please explain "electronic" transfer case "shift on the fly" works? Can you engage it while in drive and moving? Im gonna keep stopping and doing the neutral thing until I figure out how it works. If anybody understands Long Island ORV activities, you will understand why shift on the fly can make a big difference

Posted: Thu Apr 05, 2007 5:51 pm
by 83_maxima
I have used some silicone spray in there and that took care of the crackle for a short period of time. It eventually came back though.

Re: crackling on the volume knob?

Posted: Thu Apr 05, 2007 9:55 pm
by asavage
kassim503 wrote:Is there any kind of chemical or household solvent I can jet into there to make it stop crackling?
Tuner cleaner might melt surrounding plastic, so you can't spray it in from the front. I would try Tri-Flow from the front, but you'll have to deal with lube dripping out for weeks.

Tri-Flow is mainly (I think) silicone oil.
can please explain "electronic" transfer case "shift on the fly" works?
I am no expert.

Both Ford Explorer (old) and Chev S10 (old) that use electric shifting use an electric motor on the transfer case and a set of contacts on the shift quadrant to provide the feedback lights on the dash or switch. Yes, if it's a push-button shift, you can shift on the fly (AFAIK, but I am no expert). I've had to replace the switches (GM) and the shift motor (Ford) at least once on each.

The system does not shift immediately. It winds up the shift motor and puts torque on the shift quadrant, the shift will occur when the driveline detorques. If you are not on loose stuff, it might take quite a while, which is why the manual says to shift from reverse to forward a couple of times if it won't disengage (4WD light stays on after requesting a switch to 2WD).

The GM system can also have vacuum-servo-operated front hub decouplers. Yeah, they're as trouble-prone as that sounds. Mainly, you must exercise them every so often or they won't couple/decouple when you need them, which is really a pain. Engage it on dirt every so often, even if you don't need 4WD right then. And don't drive on pavement in 4WD, you excessively stress the whole geartrain from the wheels to the transfer case.

I'm sure a real 4WD person will jump in here and correct me now ;)

Posted: Fri Apr 20, 2007 3:28 pm
by kassim503
Tri-Flowed all the crackling volume knobs that crackled, it solved almost all the crackling, occasional corrosion spot here and there that I cleaned up by cranking the knob a million times. Nice n clean and im happy

Oh, so shift on the fly dosent sound anything like I thought it was, I thought it was a more special setup.

Probably still gonna stop and pop it into neutral every time I gotta shift from 4wd, that sounds kinda shaky