I posted the following in another thread as a possible answer to my 2007 Z51 instability at speeds above 120. I thought that this issue was important enough to make it a separate thread.

I had to remove the steering rack for installation of an eight rib harmonic balancer. The outer tie rod connections must be disconnected. To my horror, the tie rod nuts where little more than finger tight! Worse yet, the tapered pins that fit up into the steering arms fell out on their own!!! Normally these must be pressed out or separated using a tie rod wedging bar. Aso, The tie rod nut is normally retained by some means such as a cotter pin, lock washer, lock tite, self locking nut, or some thing! These nuts are free spinning. Once loose, they are free to back all the way off. If one of these nuts backs off and the tie rod falls out You Are Screwed!

I don't know yet if this is part of the instability that I am experiencing but I am greatfull that I was able to tighten the nuts before the unthinkable happened.

The only torgue spec I currently have says to tighten the nut in two stages: 1st stage = 15 lb ft, 2nd stage = 33 lb ft. Does anyone know why a tie rod nut should be tightened in two stages? This is a brand new 07. No one has previously touched these parts. Matbe the factory somehow skipped the second stage. What ever, I believe it would be worth your time to check the torque on your tie rod retaining nuts.

 

My car is on a lift in storage, but I checked anyway and I'm happy to say my nuts are fine!

Good to know just the same, I'd keep an eye on your nuts to make sure they don't come loose again.

 

Thanks for the info. Gonna check my nuts when the weather warms up a bit. Seriously.

 

The 2006 service manual shows the outer tie rod to steering knuckle connection as having a slotted nut with a cotter pin. It's very unusual for such high risk fasteners to not get close scrutiny for obvious reasons. As I understand, there are no dedicated inspectors anymore...only hourly employees inspecting the product. Installing the wrong type nuts is virtually impossible at the plant level. If your tie rod end nuts are anything but a slotted nut, something is seriously wrong, and not by Bowling Green (Do you have any enemies that would like to kill you?).

IMO, it's more likely that this dangerous oversight occurred at the dealer. If the dealer has had numerous complaints about premature tire wear, and poor driveability, he may check the alignment on all Corvettes sold during PDI . If the dealer technician had to adjust the toe setting, he would have had to separate the tie rod ends from the steering knuckles...he may have forgotten to properly re-torque the nuts and cotter pin them. Even then, it still seems far-fetched that someone could make such a basic mistake.

As I interpret the service manual, torque is actually in three stages...first stage to 15 ft-lbs; second stage an additional 160 degrees of rotation; then third stage to 33 ft-lbs. Torqueing is in stages to allow the material of the steering knuckle and tie rod end stud to relax and stabillize under the applied stress such that the final torque will be accurate.

The torqueing process is pulling a tapered stud into a tapered hole; you are physically stretching the steering knuckle material for an interference fit around the stud...that's why a wedge or puller tool is needed to separate the joint when it's properly torqued.

 

jmpnjckflsh,

I agree with everything you say. But hear is the scary part. This car was a museum delivery. It has 1300 miles and has never been out of my sight. The nut is not a castle type. There isn't even a hole thru the threaded area to allow for use of a cotter pin. This may be unique to the 07. Maybe unique to only my car? ( Just called another club member. His car is a 2006 and has the same arrangement as mine - except his weren't loose!) I think GM has created a potentially very dangerous situation.

 

OK, NOW you have my full attention...I went out and checked my very early 2006.

I could never see the nut clearly, but I could feel it, and you are correct; it IS NOT a slotted nut as shown in some illustrations in the 2006 service manual. I don't know why I ever quote anything the service manual says...They've been making tie rod nuts like that for a hundred years, and as soon as I quote the service manual...WRONG!

Anyway, as I said, I haven't examined the nut closely, but it's likely a (intentionally per design) deformed "prevailing-torque" nut...it won't loosen up if it's properly torqued. However, if that's the case, it should not be "free-spinning"...it should be difficult to turn until the last few threads.

Ya' gotta watch those break periods...they could be a killer. I wouldn't worry if GM engineered it like that. Maybe NCM should take a look at their PDI procedures if GM is going to leave critical fasteners loose.

 

The doctors checked my nuts said all is fine..(cough)..

Seriously, I was wondering why your car was unstable at 120...Anyhow, an ounce of prevention worth a pound of cure.

 

I wondered when someone was going to comment about the condition of everyones nuts.

Seriously though, you can't properly check them without using a torque wrench. I may be an isolated case where something slipped thru QC. HOWEVER, since the nut isn't retained in anyway, it is in your best interest to take 5 minutes to put a wrench on them.

I ran my car hard last week end laying out a road coarse for a club road trip in two weeks. During a long 15 mile straight-a-way my car felt very unstable at 120 MPH. The steering wheel had excessive free play. My C5 doesn't feel like this. This car has something wrong with it. The loose tie rod bolts could certainly have been a contributing factor. I also found I had a bad wheel alignment (not the fault of GM). Anyway, I thought I would alert everyone to a potential problem.

 

Hummmm.. be checking this out this weekend! Thanks for the headups...

 

You all have my attention. After I write this I'm going out to the garge and check my nuts (I just can't help smiling throughout this entire thread!). I can't say that I have ever seen an unsecurred tie-rod nut and have great concern if the work shop manual dipicts it and the cars aren't built that way. Then again, since I have had my C6 I have had it re-aligned, one wheel replaced, another wheel re-balanced and a rear spring was improperly mounted at the factory. I guess I shouldn't be surprised, but it does get under the skin, if you know what I mean.

 

How was the rear spring mounted and how did you know?

..jack

 

Tight nuts here! No slots or cotter pin. Just two plane 18mm hex nuts.

 

I love it when we all start checking our nuts!

 

Now I have to go look at mine.