Torque Wrench spec when reinstalling wheels

sonydst · Post by **sonydst** » 31 Oct 2010, 10:17

Hello Forum members,

I am replacing the pads and rotors on my 1995 Volvo 850. The rotors are warped. Does over-tightening the lug nuts when reinstalling the wheels lead to warped rotors? I want to prevent these new rotors from warping. If so, what should the torque reading be?

Thank you in advance for your response.

Jim

Post by **Ozark Lee** » 01 Nov 2010, 18:59

Uneven tightening can lead to warped rotors. The book spec is 81 lb/ft but I go closer to 100. The important thing is that is even on every stud.

My torque wrench is a real pile and I don't really trust it. I evenly torqued the front wheels on the platinum to 81 and dang near lost a wheel - I did lose a lug stud and the rest of them were loose. Fortunately the brakes started to make weird noises which alerted me to the problem.

...Lee

FCPEURO · Post by **FCPEURO** » 01 Nov 2010, 19:17

Ozark Lee wrote:Uneven tightening can lead to warped rotors. The book spec is 81 lb/ft but I go closer to 100. The important thing is that is even on every stud.

My torque wrench is a real pile and I don't really trust it. I evenly torqued the front wheels on the platinum to 81 and dang near lost a wheel - I did lose a lug stud and the rest of them were loose. Fortunately the brakes started to make weird noises which alerted me to the problem.

...Lee

+1

I torque my wheels so at least 100 lb/ft.

On a side note, it is funny Lee that you mention loosing a wheel. I myself at first only torqued my lug nuts to 81 ft/lb on my 850. The only difference is that I did loose a wheel, on the highway, at night, at 70 mph. Thank the lord for the way volvo designed the front sub-frame. If it wasn't for that, I would have been toast.

I found the wheel about a half mile away leaning up against a guard rail. You can actually read about it and see pictures of what happened under the FWD section on the Volvolution Forum.

Post by **Red-Arrow** » 02 Nov 2010, 05:28

I don't have a torque wrench but I just use my best judgment. 81 ft/Ib seems lowest to me for such a big power car.

Most people can repeat the pressure they apply over 5 reps. Just tighten the nut until it won't turn anymore and just squeeze it nicely. I always preform a sort of deadlift motion with the wrench. Arms straight no bend in the elbow and its all lower back and legs doing the work. The wrench is only 12 inches for a reason. if it was say 24 inches you could over tighten the nut. The average man or woman can muster more than 81 ft Ib with very little effort, 100 ft Ib takes a lot more effort in comparison.

I don't personally think you warped your disc by over tightening unless you when gorilla on the nuts.

Post by **jblackburn** » 02 Nov 2010, 07:02

I once saw a guy chasing his wheel down the road. It was rolling pretty good, through the median and over into the other lanes of traffic, which started swerving and skidding trying to avoid it. I was so amused I almost rear-ended someone myself.

They won't warp unless they have at them with the air guns at tire shops. After trying to change a flat tire where I couldn't budge the lug nuts they were so tight, every time I take it to a tire shop now I loosen all the nuts when I get it back and re-tighten them myself.

C@lvin · Post by **C@lvin** » 02 Nov 2010, 07:17

jablackburn wrote:They won't warp unless they have at them with the air guns at tire shops. After trying to change a flat tire where I couldn't budge the lug nuts they were so tight, every time I take it to a tire shop now I loosen all the nuts when I get it back and re-tighten them myself.

+1 on re-torqueing after a shop puts the wheels on.

I torque all of my vehicles by the mfg spec and have never had any problems with the lug bolts/nuts loosening up.

Post by **Red-Arrow** » 02 Nov 2010, 15:40

I have no problem with air tools and impact wrenches but if your a homer like me then you need a big tank and decent gun to get consistent pressure and torque. I normally use impact wrenches for removing stubborn nuts. On the wheels I will always check the nuts after a day or two or 30 miles.

WoodEye · Post by **WoodEye** » 05 Mar 2015, 11:22

I lost a lug bolt and almost the wheel on my "94 850 Turbo Wagon. I had torqued all of them to 81 when I had them off to paint the wheels. Now after reading everyone else's stories I am going to re torque to 100.

Post by **scot850** » 05 Mar 2015, 11:37

I have torqued my wheels to 81ft/lb or110NM for years and never had a problem. I always make sure the threads are clean and the seating faces are clean and shiny to ensure the torque is good. I do recheck each lug bolt after I have tightened.

Not sure why the torque spec is what it is, as the XC70 we have is 120NM and our Saturn is 100ft/lb. All have alloy wheels, 5 lug bolts/nuts. Not sure what determines the setting chosen. Don't think 100ft/lb would be an issue, but wouldn't go higher.

Neil.

Post by **abscate** » 05 Mar 2015, 12:03

There are a couple of threads on this but we should report torques as either dry or lubricated.

Lug nut specs are usually dry, and you torque less if lubed