My xj8 has recently started making a grinding noise when the antenna is all the way up. It goes up and down smoothly, but when it reaches the top, it runs for a few extra seconds like it doesn't know when to stop, and it makes a grinding noise at this point. Any ideas why this would be happening?

 

If this is the original antenna then it could be suffereing from wear.
The mast should be wiped with a cloth containing silicon spray and wipe from the bottom to top and not bacward as it forces muck into the joints.
Should be done after every long trip or at least once week.
The crunching noise is the operasting mechanism going past the stop switch.
You can easily remove the entire antenna from the car and work on it to check gears have not worn or, just replace it, they are not expensive.
They are easy to work on, just take cover off and check the gear wheel and rack mechanism
See if their is plenty of lube...look for worn or broken teeth.

 

I agree with cleaning it. I took mine off and made it worse but after several weeks it fixed itself and has been working flawlessly for many months.

 

Mine makes a slight grinding noise when retracting. It works fine though, and I do keep it clean. It may be on the way out, but it's been doing this for a couple of years at least.

 

Not wishing to hi jack this post, but my antenna has a slightly different issue, The car can't get it up all the way" (I've tried wiping the antenna with a solution of silicon and Viagra). Seriously though I assume this is a faulty stop switch since the motor doesn't run on. Are they repairable? Or should I look for a replacement?


Steve

 

I took it apart, and everything looked fine, and I added some grease just to be sure.

SBryant, I'd say you should take yours apart as well, after taking mine apart I could see how yours would stop too soon if some of the plastic teeth were worn down

 

I had exactly the same issue with my 2001 XJ new-to-me. I pulled it and put in a used replacement which works like a champ. Then I pulled my old one apart and it looks good. BTW, I did install another mast but it had no effect and the old one's gears were fine. So, I'll clean this one up and re-lube it and test it and keep it as a spare... assuming it works OK.

 

WD 40 stops the noises for me. The car is happier if it is driven daily. I lube it every few months. Each car has it own personality though and what works on one does not work on another car.