: 99 Tahoe, Front end alignment "knockouts"

08-08-2009, 07:23 PM
My wife took our Tahoe to the local auto dealer for a front end alignment. I told her if there is any questions just have the dealership call me. Well, the call I expected came. This is where it gets interesting.
They claim in order to do the front end alignment they would have to remove the original factory knockouts in order to do the job. Around 300 bucks should cover it.
I have never heard of knockouts that have to be removed to do a alignment, but I'm not a mechanic either so I just dont know.
O.K, now this were it really gets interesting (still with me)? The vehicle was involved in a nasty collision 3 years ago with the right front axle taking a pretty bad impact. The right A frame was destroyed and had to be replaced. The aluminum mag was shattered and the frame had to be straightend,you get the picture right?
Here's my question, with the vehicle taking such a major impact to the frontend 3 years ago, How did they do a front end alignment then, with these so called knockouts still in place? Whats going on here? Ken

08-08-2009, 08:01 PM
I'm not a mechanic, have a owned a tahoe and a Suburban but have not heard of this before today. I found this info below....I'm sure GMC Jon will respond once he sees your post.

" These are little punchouts in the upper control arm(UCA) mounts on the frame. From the factory, offset washers are attached to the UCA bolts at the frame(Some poeple refer to these as "cams" because they make the control arm move back and forth similar to the way a "camshaft" makes a lifter move). That is how you adjust caster and camber on this vehicle- by turning these "cams" in or out to change the alignment. Now from the factory there is just a hole in the mount that these cams are in. You cannot turn them because there is no slot for the bolt to slide in. This is where the knockouts come in to play. In order to adjust the alignment, you need to remove the "cams", slide out the control arm, and viola, on each side of that hole in the frame is a "perforated" (I use that term lightly - some can be a bear to remove) outline in the steel. You need to use a special tool, air chisel, or in the real "bear" cases, a torch to remove the punchouts. What this does is take a 1/2" hole and turns it into a slot approximately 2" long, allowing for the in and out movement for adjustment. There are two of these on each side of the vehicle for a total of four knockouts.
If anybody with one of these vehicles had it aligned with these knockouts still installed....well you got a "toe-set" not an alignment-you can't adjust what you can't move."

Hope this helps,


08-08-2009, 08:02 PM
Even if it is legit, NEVER send a woman to get auto repairs. There's been several times my fiancee got a quote on a repair, then I got a quote or called them out and they were up to 50% different. Recent example. I had her call to get a price for tires on my truck while I was at work. Didn't even take it in. They quoted her $180/ea. Didn't get around to it until later in the week. I called to see if they had them in stock. Gave me a quote of $130/ea!

08-09-2009, 06:16 AM
Hmm. I've taken all my Chevy trucks to our local Midas Muffler shop for alignments. They've never said a thing about knockouts, they always adjusted toe-in/camber/caster and the price was always much less than $100.

I'd think removing the knockouts for first alignments would be averaged into the overall cost of alignments done at the shop. Charging separately for the knockouts sounds like a dealer-profit-improvement program, which you might imagine new car dealerships wanting these days.

Given the damage repaired on your Tahoe, unless your tires have worn very badly, assume the front end was completely re-aligned 3 years ago and if there were knockouts they were removed back then. At any rate, removing 2 knockouts, whether by air chisel or torch, doesn't sound like a job that would take $300 in labor- unless the shop does the work with a Dremel tool. :)

Take your Tahoe to an independent alignment shop- they can do just as good a job and will probably charge less.

08-09-2009, 06:29 AM
really depends. I have worked at Midas shops, dealers, etc.

If they can adjust the toe and the camber and caster are in spec, they wont touch the cams or remove the knockouts. Why create more work if its not needed? Many times on these vehicles its just to toe that is out of spec, or as we used to say "set the toe and let it go"

Also, its not just a matter of chiseling them off. You have to remove the control arm nuts, etc to get to them.

Its been years and years since I have done this, but its not as easy at it might seem like Dodge stated in his detailed description.

As far as the truck being in the crash, yes, this does sound suspect. I would think that the knockouts would have been removed somehwhere along the line but they could still be there

this is not done as a profit center for the dealers. They do this at the factory to make assembly faster and more accurate.

08-09-2009, 07:40 AM

If you've worked in shops doing alignments, you would know more about this than I do. I can say that I always call ahead and ask the price of an alignment, have never been asked if this is the vehicle's first re-alignment. I've seen the new shims in the suspension, so I expect caster/camber were adjusted.

I expect the knockouts are a factory assembly cost-savings step, not intended to increase later cost of service. Why would any company want that kind of black eye? I'm reminded of the Chrysler cars in the mid-70's that had no grease zerks on the front suspension- remember those? At the first lube job you had to pay the shop to install them and the cost varied widely.

08-09-2009, 07:46 AM
well if you have shims then you dont have cams, or the knockouts.

so that answers that question...

totally different setup

08-10-2009, 11:31 AM
If it was previously aligned, the knockouts should have been dealt with at that time. I guess there is a slight chance that the caster and camber were in spec after the frame was straightened and the new parts were installed. But I doubt it very much. There are no shims, just cams to adjust caster and camber. Book time is approx 2.4 hrs for the knockouts. Our shop only charges 1.2 hrs to do the knockouts and our alignments ($69)are priced in line with our competition. Does the $300 includes a 4 wheel alignment? $300 does seem a little high but that would depend on their hourly rate and alignment charge. I would probably take it to another shop and have them determine if they have to perform the knockout procedure, just to make sure the dealer is not trying to pull something. It is unfortunate if that is the case because it gives all dealers a bad reputation.

08-10-2009, 05:49 PM
GMC Jon, thanks for the reply. I wont claim to be a mechanic, but I have a really hard time believing that the knockouts werent dealt with last time, and if they weren't dealt with last time they certainly should have been. The damage was quite ugly to the right front axle.

Soon after the accident we were given the vehicle back and soon after that we started to notice issues with the front end. I took it back to the same dealer and they claimed they stretched the right torsion bar to far. The dealer and I called the insurance company to explain that more problems were found from the accident. The insurance company said no deal, these new issues could be from wear and tear or even a second impact to the front end. After a 2 month pissing contest I gave up. The insurance company would not budge and the dealer wouldnt step up to the plate either. That quickly ended a 10 year relationship with that insurance company.

As time went on the uneven wear on the right front tire was blatently obvious. As I said in my orignal post, when my wife took the tahoe in, I was expecting the phone call that certainly did come. Why did I have my wife take the truck to the dealer? Because I didnt want you guys to see me on the nightly news jumping over the service counter to get my hands around his neck!!!!!

The 300 dollars is the estimate for just a two wheel alignment, and no, I wont be having that dealer do it. Ken

08-10-2009, 08:59 PM
I own a body shop and a alignment shop, here is my opinion based on your statements.The $300.00 quote is high,this is strictly a labor operation.My shop procedure is to offer a printout of the frontend specs as it is now\before and then again after it is finished.I would guess that your repairs were done incorrectly after the collision,if you are experiencing tire wear and handling issues there is a problem! Most likely there will be caster\camber adjustments required,the age of the vehicle plus the accident assures you that.Not all alignment shops are equal,because C&C settings can be a pain some shops will ignore those specs and only do toe,forget them! I would suggest a shop that installs and modifys 4x4's,working on a stock truck is easy and they have experience with damaged parts and are quite capable of achieving the stock factory specification.

By the way a torsion bar cannot be stretched only replaced. As a side note if you are ever in a situation where a insurance adjuster refuses to pay for a job that is of a saftey concern demand a letter of warranty and an assumption of liability for that repair,that will usually change their mind.You might have to take the car somewhere else and have it done right and with the right documentation the insurance will have to pay.The contract states the car will be returned to a pre-accident condition.

At my shop I would estimate your job at $74.95 for the alignment and 2 hrs @$70.00\hr for the C&C adjustment,HOWEVER,I suspect there will be bent parts adding more expenses.

Good Luck; Mike Gibbs

08-11-2009, 11:24 AM
I remember when I bought my 2003 Yukon new, a buddy of mine who did the wheel alignments for the dealer (they didn't do them in their own shop) told me to tell them it pulled to one side or the other before it was a year old so he could line it up and charge them for the knockouts. Then he said the next time I got it lined up, I wouldn't have to pay for them.