Wheel Nut Torque?
 

BACKGROUND:

The workshop manual calls for 65-87 ft-lb torque for the wheel nuts. Service Bulletin 02-002/04 (http://www.finishlineperformance.com...02-002-04.html), dealing with a snapping noise associated with the front wheels, indicates that a torque of 108 ft-lb should be used when reinstalling the wheels on cars with this problem. The key phrase, in my mind, is: "...but for a field counter-measure against this noise, be sure to torque the lug nuts to 147 N.m (108 ft-lb)."

QUESTION:

What is your opinion on torquing the wheel nuts to 108 ft-lbs? In my opinion, the implication in the TSB wording suggests that the high-torquing instruction applies ONLY to cars that have exhibited the snapping problem. And it is an expedient procedure, intended as a "quick fix" for the problem and to quickly send "happy" customers on their way.

I'm uncomfortable using that high a torque on my wheel nuts, and plan to stick with the high end of the workshop manual recommendation. I think 108 ft-lb could actually damage the cast aluminum wheels, especially over the long term. What do you think?

108 is ok. Why... ?
I always torque lugs w/a torque wrench.
After installing the MS suspension this weekend, I found out that I somehow left the socket I needed for the wheels at home. Thus I had to use a regular lug wrench to tighten the lugs until I got home.
When I got home, I checked and all but 1 were already 100 ft-lb.
I loosened and re-torqued to 100.

Since I hit 100+ on 9/10 lugs with the regular lug wrench (just trying to tighten normally), 108 sounds ok to me.
If you consider how many times a shop will air-gun your lugs off and on over its lifetime, and they are hitting over 100 I guarantee, 108 is fine.

My opinion of course.
-B

Since I've never heard the snapping noise on my car, I decided to stick with the original lower wheel torque cause' of the damage concerns you mention.

I don't own a torque wrench, but have changed a few tires in my 25 years of driving. :rolleyes: Am I now to assume that when I removed my wheels to paint my calipers and rotor hubs, put the wheels back on using the stock lug wrench, tightening them the way most fathers and shop classes teach, I've screwed up my wheels and ergo my car?? :eek: Aren't we getting a tad bit anal about owners manuals and foot pounds? It's a lug nut for chr*st sake.
Just my opinion. . . :p

In those 25 years how many of those wheels were 18" aluminum ? I used to not worry about it, but after a few years of 'winging it' with my Miata's aluminum wheels, I noticed the tapered lugs were damaging the wheels, digging into the stud 'holes' pretty noticeably. I have a few torque wrenches now for various tasks (in/lbs, ft/lb's in 3/8", and ft/lbs in 1/2"), including lug nuts.

Okay, point taken, none were aluminum wheels. :o Nevertheless there are some tasks, changing a tire for example, that shouldn't be "nuked" (pardon the Navy slang). I just believe that if Mazda wanted me to use a torque wrench they would have provided one with my spare tire kit. If they didn't think the average driver was skilled enough to change a tire, they wouldn't have provided the tools to accomplish the task. I dunno, this is just one of those topics that make me go huh?? No offense intended to Go48, he had a legit question and I'm not helping.

I agree with you- the average joe isn't going to be taking their wheels on and off often enough to make it a big deal... in fact, since the 8 doesn't come with a spare tire standard, I doubt Mazda expected many people to touch the lug wrench. However, for people like us that rotate our own tires, swap summer/snow tires, paint our calipers, do our brakes, etc... the overtorquing can take it's toll after a while. I also don't like to see how easily these wheels crack with curb impacts (from other member's pictures/postings)- it doesn't instill a great deal of confidence in their strength.

Good discussion guys. Appreciate your input.

I don't consider torquing nuts to spec as being anal, but I can appreciate why you might say that. I've been changing wheels on cars for neigh on to 50 years now (I'm REALLY old :) ), and didn't pay much attention to torque specs until I began paying $30K-$40K for my vehicles. And as was pointed out, I, too, remove/replace a wheel here and there fairly frequently when I change oil, install aftermarket items or just crawl under the car to enjoy the view. :o

So as long as my wheels don't exhibit the snappy sound, I will continue to torque them to the originally stated specs.

I use a Snap-On flank drive socket. I nip it up hard, and then add a bit more......
You're not going to damage these wheels doing your wheel nuts up by hand.

"So as long as my wheels don't exhibit the snappy sound, I will continue to torque them to the originally stated specs."

I torque mine to 90 ft/lbs and have also never experienced the snapping sound. I also autocross so for eight months out of the year my lugs see two to four (or more) wheel changes per month. Lug nuts and stud will wear out. And a little grease on the thread of the lug will go a long way to keep a partially stripped lug nut from siezing and making your simple tire change a nightmare.

I also used 90 ft-lbf when I recently swapped my wheels.

I take the included wrench and tighten them as much as I can by hand. Then I give it a little extra by throwing all of my weight on it.

I did this probably 20 times on my old enkei aluminum wheels without any problems but after seeing pics of these wheels cracked, I would hate to lose a wheel at high speeds so it got me thinking about buying a torque wrench or 3.

I have always torqued to 108 -- no problems. My pick-up specs are to 110. I really don't think 108 is that big a deal.

A small investment in a torque wrench to a great idea for those who don't have one. If you ever plan on going to the track -- you really need to check the torque and re-torque after each session run.