Conical Washers

Status
Not open for further replies.
Joined
Aug 30, 2004
Messages
31,869
Location
CA
I need to purchase a set of conical washers so that I can measure rotor runout. Does anyone know where I can purchase a set?

Thanks.
 
I'm not sure of a good source for the conical washers but you can use a stack of flat washers if you have acorn lug nuts, or if you have or get some open lug nuts and install the flat side towards the rotor. That should work acceptably. Or you could cut out the center section of a junk wheel and use that
lol.gif
.
 
Originally Posted By: yonyon
What about just buying some ordinary hex nuts and using those with some flat washers?

How would you tighten those nuts to 80 lb-ft (or thereabouts) per the service manual directions to measure runout?

The conical washers allow you to use the factory lug nuts so that you may use a torque-stick and an impact to tighten all of the lug nuts before measuring runout:

http://www.youtube.com/watch?v=SSxCNbjKi-0
 
I wouldn't. I'd just tighten them to maybe 60 ft. lbs. with a torque wrench. It's not an ideal solution, but it will work without having to wait for those washers. If the measurement taken that way is different than the measurement taken at 80 ft. lbs. with the conical washers there's a serious fitment problem that needs to be addressed.
 
Originally Posted By: yonyon
What about just buying some ordinary hex nuts and using those with some flat washers?


That was basically my suggestion too and seem to work for me before, but I guess the critic wants to do it exactly as described with conical washers, factory lug nuts and torque sticks.
 
Originally Posted By: Trav
This maybe a dumb idea but couldn't you just get deeper lug nuts?


Actually, that's a good idea except this would not work on cars that don't belong to me.
 
Originally Posted By: The Critic
Originally Posted By: Trav
This maybe a dumb idea but couldn't you just get deeper lug nuts?


Actually, that's a good idea except this would not work on cars that don't belong to me.


Now I understand the purpose of the conical washers. It's so you can do multiple car brands without having to buy an extra set of nuts for each model. And, torqueing the OEM nuts onto flat washers might bung up the OEM nuts or get uneven torque.

Interesting.
 
I am curious how many techs actually measure lateral runout on brake jobs; I am guessing not many. The used set I purchased from an out-of-business GM dealer looked practically unused. Considering that GM recently revised their brake service bulletin to state that measuring LRO is no longer necessary, perhaps this has become an obsolete procedure for routine service.
 
I'd say probably not many. They'd just fudge the run out numbers for warranty purposes. Turn the rotors on the car (not bad) or slap on new rotors (not so good) and send you down the road. I think it was mostly a run out problem on some of the hubs that is now being held in line.
 
Originally Posted By: mechanicx
I'd say probably not many. They'd just fudge the run out numbers for warranty purposes. Turn the rotors on the car (not bad) or slap on new rotors (not so good) and send you down the road. I think it was mostly a run out problem on some of the hubs that is now being held in line.


If anything, the issue is due to people not cleaning all of the rust build-up on the hub flange. That is why I bought one of these kits:

http://multimedia.3m.com/mws/mediawebser...5002-8161-5.pdf
 
Yeah corrosion/rust/debris on the hub and the back of the rotor hat if the rotors are going to be reused and/or machined can definitely be a factor in run out, especially where salt is used. But there was still a hub run out problem. The 3M kit is nice. If budget is a concern a less expensive wire wheel can be used, as could hex nuts of proper size and thread pitch in place of the speciality conical washers.
 
Status
Not open for further replies.
Back
Top