: Lug Nut torque on V2



vperl
07-28-09, 08:39 PM
Yes, this has been worn to death on the forum.

My vehicle is at dealer for some work, I mentioned to them to make sure that the lug nut torque was set at what the 09 CTS-V owners manual is printed as, 140 pounds torque.

After hanging up I wondered if other tire stores would have the correct information. Checked 4 stores got to a recommended Tire Rack installer and he gave me 140 pounds of torque, the other three insisted 100 pounds torque was correct even though I expressed the fact that they were way too low.... and I gave the car information over again so that there was no confusion what model the car was.

All three claimed they were right, the tire rack installer was the only one that had 140 pounds torque.

Beware of shops that do not have the correct information, what ever it is

jwa999
07-29-09, 12:09 AM
My vehicle is at dealer for some work, I mentioned to them to make sure that the lug nut torque was set at what the 09 CTS-V owners manual is printed as, 140 pounds torque.

Tonight I just checked out the torque on on my wheels.
Rear wheels where torqued at the factory at 100lbs.

Front right wheel was at 140. front left wheel was fixed twice by dealer.
The torque was at 158. And it was a bitch to get loose.
I had to lean on the wrench with all my weight, and 4 out of 5 literally popped loose so violently, it popped the wrench in reverse.
So, i'm going to keep them at 140. I haven't had the clicking from the front wheels in a long time.

Hans.

cavillac
07-29-09, 03:41 AM
i think you will be lucky to find a tire shop checking torque before the install. The tire techs get paid like crap. Based pay plus 1 or so per job at most places. Speed is key. If they are using a set torque extension, at least all of the wheels with be the same. otherwise it on with impact until it stops ratcheting.

Hawkeye2
07-29-09, 06:42 AM
I read here somewhere that now 158 is correct - particularly if you have the clicking wheel syndrome.

jvp
07-29-09, 09:08 AM
158 is the right number. Tight or not, that's the value you should be torquing the V's lugs to.

jas

DiamondWhiteCTS-V
11-16-09, 07:42 PM
What about for after market wheels used for winter tires? Should they be torqued to 158 on all 4 as well? Or is 158 only for factory oem wheels?

Short-Throw
11-16-09, 10:29 PM
What about for after market wheels used for winter tires? Should they be torqued to 158 on all 4 as well? Or is 158 only for factory oem wheels?

158 spec is required due to the thickness of the stud/size of the lug nuts.

Mike

DiamondWhiteCTS-V
11-16-09, 10:33 PM
What is the danger in them not being torqued properly to 158? Other than wheel clicking - is there a danger that the wheel will come off?

They used aftermarket "tuner bolts" on my aftermarket wheels that easier to fit a wrench into. They are 19mm. Should I be worried that these bolts are not to spec? thanks Short-Throw.

Short-Throw
11-19-09, 11:41 PM
What is the danger in them not being torqued properly to 158? Other than wheel clicking - is there a danger that the wheel will come off?

They used aftermarket "tuner bolts" on my aftermarket wheels that easier to fit a wrench into. They are 19mm. Should I be worried that these bolts are not to spec? thanks Short-Throw.

Diamond,

The torque setting set by the engineers is not arbitrary. Now, granted, the spec for the V2 is higher than most cars, but it's for a good reason, it's strictly dictated by the hardware employed. The proper spec ensures the wheel being held to the hub with no vibration. Of course over tightening a lug can stress a bolt and with the required 158 spec it is higher than most cars are set to. Truthfully many techs at the dealership aren't even aware of this and I suspect as more V's hit the market this will subside. This anomaly has too many people self-proclaiming it's too high which is utter nonsense.

If you under torque the lugs, you can introduce vibration. Vibration will eventually reveal the weak link in the chain and may cause a failure, which could be the stud, the lug or even the wheel depending on the situation.

To be clear, when you say 'tuner bolts' you are referring to the lugs correct? They did not replace the studs?

What is the torque level of your lugs now? Why would the shop deviate from the required spec?


Mike

Prof
11-20-09, 06:05 AM
Minority opinion here...

I torque them to 90 lbs. They come off weekly to clean the wheels, I have no vibration, no clicking, and have never found one to be loose. Approximately 10, 800 miles...

I have another performance vehicle with the same size lugs and nuts...those have always been at 90 lbs and no problems...it regularly sees three digit speeds on the track...the rear tires are consistently subjected to torque in excess of 700 ft lbs...those lugs have never come loose.

I guess if I was driving at 150 and not pulling the wheels weekly or at least monthly, I might reconsider my approach, but to me 90 is fine. My opinion (no expert here by any means) is that this is vehicle manufacturer massive overkill in search of a solution. While I see no problem with the average (never check the lugs) driver having this kind of torque...but in my case, I think 90 is fine.

lavaman
11-20-09, 09:50 AM
Minority opinion here...

I torque them to 90 lbs. They come off weekly to clean the wheels, I have no vibration, no clicking, and have never found one to be loose. Approximately 10, 800 miles...

I have another performance vehicle with the same size lugs and nuts...those have always been at 90 lbs and no problems...it regularly sees three digit speeds on the track...the rear tires are consistently subjected to torque in excess of 700 ft lbs...those lugs have never come loose.

I guess if I was driving at 150 and not pulling the wheels weekly or at least monthly, I might reconsider my approach, but to me 90 is fine. My opinion (no expert here by any means) is that this is vehicle manufacturer massive overkill in search of a solution. While I see no problem with the average (never check the lugs) driver having this kind of torque...but in my case, I think 90 is fine.

Please there is no disrespect intended here but I must disagree with your approach to this. It's your car and your free to do as you wish, but I will put my trust in the engineers responsible for building this car not the opinion of one who does not have all the information Cadillac engineering has. Torque specs are not random. They are reached as a result of good solid engineering and should be followed. I have my wheels torqued to specs... (140 or 158 if clicking is present.)

140 is where mine are set. I did find though that my car was delivered to me with the wheels at ~ 100 ft lbs. (So much for the engineering dept. relaying their findings to the factory floor!)

Prof
11-20-09, 10:06 AM
Oh yes, I would never advocate people do as I do! I have never stayed in a Holiday Inn Express.

My position was provided as perspective from a cantankerous old fart, who enjoys detailing his rides, and has hands that are too big to get to the inside of the rims through the spokes!

I don't think that there is much chance of warping the rotors at 140 or 160 unless you tighten your lug nuts incorrectly.

I usually defer to the engineers, with the caveat that they will probably add a considerable hedge safety factor.

chopmeat
11-20-09, 10:37 AM
140 or 158?
I have to look at the book again but where did 158 come from??

tedcmiller
11-20-09, 04:26 PM
I believe the lug nut torque figure of 158 lb-ft appeared in a CTS-V TSB referenced in an earlier post about wheel clicking. It was part of the procedure for eliminating the wheel-click - which it did, but only temporarily.

lavaman
11-20-09, 07:27 PM
That is correct. Our owners manual states 140. A TSB pertaining to those experiencing the "Wheel clicking" instructs to remove the front wheels, clean the wheel/hub mating surface and reinstall the wheels increasing the lug torque to 158. That is where the two different torque numbers come from.

DiamondWhiteCTS-V
11-21-09, 01:38 AM
Diamond,

The torque setting set by the engineers is not arbitrary. Now, granted, the spec for the V2 is higher than most cars, but it's for a good reason, it's strictly dictated by the hardware employed. The proper spec ensures the wheel being held to the hub with no vibration. Of course over tightening a lug can stress a bolt and with the required 158 spec it is higher than most cars are set to. Truthfully many techs at the dealership aren't even aware of this and I suspect as more V's hit the market this will subside. This anomaly has too many people self-proclaiming it's too high which is utter nonsense.

If you under torque the lugs, you can introduce vibration. Vibration will eventually reveal the weak link in the chain and may cause a failure, which could be the stud, the lug or even the wheel depending on the situation.

To be clear, when you say 'tuner bolts' you are referring to the lugs correct? They did not replace the studs?

What is the torque level of your lugs now? Why would the shop deviate from the required spec?


Mike

Yes the tuner bolts are the lugs. On the outside they are 19mm rather than 3/4" - the tire place called them tuner bolts but not sure why. I don't know what the torque is which is why I'm worried now. Especially now that I understand that regardless if it is the oem wheel or winter wheels the lug torque should be 158.

Are most everyone out there with winter wheels ensuring the lugs are torqued to 158?

lavaman
11-21-09, 09:44 AM
I am confident that factory specs are the same regardless of which wheel or tire is on your car.

If there is any doubt check the torque.

Prof
11-21-09, 02:18 PM
Diamond,

The torque setting set by the engineers is not arbitrary...


Mike


Concur with this...but I believe that the initial specs were more like most of us were used to seeing. It was only after there was an issue with the wheel clicking that the TSB was issued increasing the torque...so in my mind the hardware dictated the initial tq specs. Only after there was a problem was the specification increased. So the new specs are not driven by the hardware rather the new number is due to another issue...but I am often wrong, all of my wives have made that very clear.

OldRoadDawg
11-21-09, 03:06 PM
...but I am often wrong, all of my wives have made that very clear.
:highfive:

Gary Wells
11-21-09, 03:49 PM
.......but I am often wrong, all of my wives have made that very clear.
The CTS-V will not sue for non-support / alimony when you trade it in on a younger model. Just thought that you should know that.
J/K, Prof.