Okay, this question sounds a little stupid even to me, but please realize that this is my first Jag and the first time I've dealt with this type of lug nut.

I removed a tire the other day for the first time. I expected that once the lug nuts were unseated, they would just come off with my fingers (like on my American cars). They didn't. I had to use the wrench until they were almost completely off. Once the wheel was off, I tried to run a lug nut back on with my fingers, but with the same results.

My question is, are these supposed to be real tight like this? Is it because these do not use the tapered seat like I am used to with our American cars, and therefore the resistance is needed to keep them from loosening while driving?


Can I or should I use anything like anti-seize on the threads for lubrication?

Thanks for your help and again, my apology if this is a stupid post.

Scott Wilson
1995 XJS Convertible
Ghent, NY, USA

 

They should not be tight like that. I'd investigate and correct immediately.

 

I've battled this many times on 80s-90s vintage Jags with alloy wheels and the pass-thru type lugnuts

Almost certainly the holes have developed a bit (or perhaps a lot) of corrosion which prevents the lug nuts from turning easily. A conical wire brush driven by a drill motor will usually clear the corrosion but I've had a few where I had to actually use a pocket knife to scrape away the worst chunks first. Naturally you want to avoid, to the largest extent possible, actually removing any wheel material. IOW, you are not trying to enlarge the hole but just remove the crusty corrosion.

A tiny dab of wheel bearing grease smeared in the holes will prevent this from happening again.

You may well find the that wheel-to-hub mating surfaces have corrosion as well. Clean it all off and smear some grease on the areas as well. No need to go hog wild. Just enough to coat the surfaces. Some use 'anti-seize' products to accomplish the same thing. That's fine, but ordinary wheel bearing grease works perfectly well.

Cheers
DD

 

On second reading, it sounds like you're saying the lugnuts won't thread easily onto the wheel studs. That's a different matter than what I mentioned above.

The threads are likely stripped or corroded. Clean everything up and tell us what you see.

Cheers
DD

 

It's a common problem on XJS if the wheels have ever been refurbished. The paint (+ any corrosion as mentioned by Doug ) can make the wheel nuts slightly tight. The problem then arises that this very slightly misaligns the nut and repeated use very slightly damages both the nut thread as well as the stud thread. Happened on my car when I first had it. I ended up having to use a tap and die just clean up both threads and then relieve a bit of excess paint from the wheel holes.

They shouldn't really need copperease or grease on the threads to be able to hand tighten. This can also give you conflicting torque readings when you tighten them.

Paul

 

Points taken and Thanks. I will look into it by this next weekend. Just for reference, I may buy a lug nut at the local auto parts store to see how it runs on the studs.


Does anyone know what size/thread I will need?

 

1/2-20 thread size


Cheers
DD

 

Thanks Doug. I was thinking they would be metric... Shows how little I know, but I'm learning!


Thanks again.

 

Well, I finally got back to working on the lug nut issue. It turns out that some of the square shouldered lug nuts are extremely tight fitting just into the wheels (the original factory 5 spoke alloys). This is with the wheels off the car.

The lug nuts have a good snug feel when I hand thread them all the way down the stud length, without the wheels.

Then I tried to insert the lug nuts from the back side of the wheel. They easily fit in most the way but bind as they reach the outer rim of the holes. I'm talking about the outer side/point where the wheel and lug nut's square shoulder make contact, when the wheels are installed as normal.

Both the nuts and wheels show some scalding where they bind against each other. Most of the metallic buildup seems to the on the inside of the wheel holes, near the outer surface (the visible surface when installed).




Before I take any corrective action, let me ask you this:

1. Has anyone else encountered this problem?
2. Could the alloy wheels holes have distorted from the nuts being too tight?
3. Since the lug nut still have a good snug fit on the stud, it's not likely they have stretched, causing their diameter to expand, right?
4. If you were going to use a fine grit emery paper on one or the other, would you choose to dress the wheel holes first?

Thanks for your advice... I have so much to learn about this beautiful machine.

Scott

 

1. I'd try a stiff brush ala gun tube cleaner to clean the holes in the wheels.


2. Can't disagree with Doug as to wheel bearing grease. Stays in place on high temperatures.


3. I use the silver antiseize. Just a dab'll do ya". I don't worry about wet vs dry torque values on this application.


4. I do use my impact to remove lug nuts. The electric one. Adequate, but not over whelming torque like the air powered one.


5. But, I spin them up snug with an "X" manual lug wrench, then torque to spec. with the rachet.




Far more sophisticated since getting the added toys!!!


Carl

 

I've encountered lugnut-to-wheel fit problems many times, but typically due to corrosion, as mentioned above


Certainly sounds plausible.....



Seems to me that 'stretching', if it occurred, would reduce the diameter.


Personally, I'd dress both the nuts and holes...in hopes that removing a small amount of material from both (rather than a lot of material from just one) will restore a good fit of the nut in the hole

Cheers
DD