JohnD60

I replaced my steering rack a few months ago and have been struggling getting back to the same level of steering feedback I had with my previous rack.

Originally thought I just needed to get use to the new rack but after two track events and a couple months of street driving it's clear to me there's something wrong.

It feels to me like the current rack is "over powered". The effort required to turn the wheel is always the same --- really easy.

I suspect the problem is with the Magnasteer on the new rack. The company I purchased it from said they were replace it if I have a dealer test it with a tech2 and verify the issue is in the rack.

Does anyone know what exactly I should ask the dealer to look for?

Thanks,

John

Bill Dearborn

Why not run the codes on the DIC and see what you get. The steering rack gets its speed info from the EBCM. If the rack isn't getting the proper data it will provide maximum boost at all speeds instead of reducing boost at higher speeds.

Bill

JohnD60

I checked the DIC. No codes present.

I'm assuming the same thing as you. The system is giving me the same power assist at speed as it is when I'm going slow.

John

davidfarmer

does the power steering set trouble codes????????? I've blown a few pumps and racks and never seen it show up on the DIC?

Anyway, did you also replace the pump?? Pretty much anytime a rack is damage, good chance schrapnel has gotten into the pump (and vice versa)

Bill Dearborn

I believe there is a code for the magnasteer function but I am visiting family for a couple of weeks and do not have access to my Service Manual.

Bill

JohnD60

I replaced the pump with a turn one unit at the same time. It was the second pump replacement but the first for the rack.

When I installed the rack I made the mistake of turning the steering wheel when the rack was out of the car. I did get TCS error codes after that. Had the dealer replace both the steering wheel position sensor as well as the air bag clock spring and the codes went away.

My understanding is the only sensor left in the magnasteer system is the one in the steering rack that actually varies the pressure.

john

yakisoba

I would call Turn One, if you have not yet done so, and ask them. The guy that runs the place knows PS systems back to front.

JohnD60

Hi Tim. I did that too. Jeff at Turn One said he thought it sounded like the magnasteer components in the steering rack. Apparently some magnets are engaged (or disengaged) over 45 mph that reduces the power assist. Sounds like my magnetics are not doing their thing.

Not sure how a Tech2 sensor check is going to be able to tell but the guys at ZIP indicated they will send me a replacement rack if I have the test done. I'm guessing the dealer is going to tell me everything looks fine. Everything is probably commanded correctly, it's just not responding.

Lesson learned....I should have removed my original leaking rack and had it rebuilt instead of buying a reman one. No way for the companies getting these rack core returns to know what the rack as been through.

I never knew how much I would miss that little shiver in the steering wheel before the rear slicks let go....... :-)

abc 123

The guys at Zip are dodging the bullet.

Tech 2 is only going to enable a test that will vary the current to the coil so you can check for a change in steering effort when turning the steering wheel. A simple test drive can also be used to confirm any problems with the system. At low speed, the steering should require minimal effort and feel the same in both directions.

As speed increases, steering effort should gradually increase. If the steering feels lighter than normal at high speed and/or unusually stiff at low speed, Magnasteer isn’t working. But if the steering feels stiff at all speeds, the problem may be hydraulic.

If an electronic problem is suspected, the first thing to check would be the electrical connection to the coil on the Magnasteer unit. Coil resistance between terminals A and B can be checked with an ohmmeter, and should read about two ohms (the actual GM spec is 1.6 to 3.1 ohms). An infinite (open) reading indicates a bad coil (requires replacing the rack since the coil is not serviceable). Checking for shorts between both sides of the coil assembly and rack housing is also recommended. If the coil is defective, the entire Magnasteer unit must be replaced

JohnD60

Thanks ABC.

Zip Corvettes

Hold on here, nobody is dodging bullets here. All we are asking is for the problem to be diagnosed and not what someone thinks might be wrong. That is easy for someone else to say when they are not paying for it. I do not mind replacing a rack if that is the problem. A warranty is a warranty, I will replace the part if it is defective no problem. But what happens if the part gets here and it is not defective? Then who is liable for it, so for the sake of the customer and Zip the problem needs to be diagnosed and see if it is the rack or a ebcm before parts just to going out at no charge. I am sure John that if I got the rack back and it was ok, that you would not be ok with paying for the new rack also. This protects you and us. If there is an issue you are having call me back, but nobody is dodging bullets here.
Justin

abc 123

Justin, the issue is the diagnosis does not need a tech 2. It is easily felt. Not many people have a Tech 2 at their disposal, and going and paying a shop for additional service just adds to the customers grief. You going to reimburse John for the fees in checking the magnasteer unit out?


So what part of the signal from the EBCM controls the rack?

JohnD60

Hey guys. It was not my intent to say anything negative here and I apologize if it came across that way. I was simply trying to determine if someone knew the specifics on what I should ask the dealer to check.

I don't have a problem with diagnosing the real issue and fully understand Justin’s position. As I stated earlier, I appreciate the situation the reman companies are in. I was simply after an explanation of how the dealer or I can determine this failure mode.

My understanding is if the megnasteer sensor had electronically failed, I would get a TCS fault code (there are no codes present). I believe the Tech 2 tool allows the dealer to independently command the magnasteer to adjust the assist level. However, it would not be able to determine if the assist level actually changed (i.e., it would not be able to determine if there was an issue with the mechanical part of the rack).

Because of my installation error, the car had already been to the dealer to get the steering position sensor (and air bag clock spring) replaced. They performed the Tech 2 steering calibration as part of this repair. The power steering pump, wheel bearings and control arm bushings were replaced since the install as well as two professional alignments (granted these were to my specs that included 1.5 deg negative camber). In addition, there were no other fault codes.

I was trying to do diligence against all the possible failures options.

When I took it to the dealer today I told them to figure out why it felt over powered at higher speeds.

1) If it was something other than the rack, they should fix it.
2) It if was the rack, they should let me know so I could follow up with Justin to get a replacement.
3) If they didn’t find anything they should align it again and I would drive it to see if things felt better.

I suspect tomorrow morning the dealer will tell me they did number three. If it works I’ll be happy. If it still feels over powered, I’ll call Justin and am sure we’ll figure something out. Who knows, maybe they’ll find something else.

I’ve made several purchases from ZIP and am very happy with their products/service. They were even very responsive to me when I call with this service request. I expected them to be vacation this close to the holidays! This situation will not change my opinion.

Zip Corvettes

I did not say the EBCM controls the rack, what I said to the customer is with a Tech2 you can see if everything else in the system is operating properly and that the problem is not a sensor. Just because that was replaced at the same time as the rack does not mean it also is not bad. I don't have any problem replacing any part that is bad. As far as who pays, I don't pay to figure out what the problem is, that could change if the problem is indeed our part though. So to shoot the question back to ABC who should be liable if the part is not bad and we shipped a replacement rack that is now installed on the car. The reason we have a policy is not to just protect us at Zip but also the customer.
ABC the other part of this you stated that you can feel it, well what does the steering in a car feel like that has 1 1/2 degrees of negative camber and postive toe feel like on the street. I would still want a Tech2 on the car to see what everything is doing on a street car, but because this is a track/street car with this alignment it is an absolute must. So what you are telling me is that by not feeling the magnasteer work, you are 100% for sure that it is a rack and nothing else. I see you are deep inside GM, do they replace items like this or do they figure out what the problem is first.
Justin

JohnD60

I'm really sorry I started this debate. I got the car back from the dealer today and now understand what Justin was asking.

Via the tech 2 the dealer was able to verify that the voltage sent to the magnasteer was correct and did vary with speed. This was the tech2 capability I was not aware of. If this was not correct the problem would have been with some other system on the car and not with the rack.

Makes sense to verify this for this type of problem. I made the assumption a commanded voltage error would generate a fault code but that is not correct.

The dealer also re-did the alignment and stated some settings had changed so it's also possible this contributed to my light steering feel.

So in essence you both are correct. The ultimate diagnosis in this situation will come down to feel but we now know for certain the rest of the compoents are not suspect.

I shared all this with Justin in a voice message today. Told him I would drive the car for a few days and get back with him if things did not improve.

I again want to state that Justin and ZIP have treated me well in this situation. They have been very responsive to my service need.


Hope everyone has a great Holiday!

Zip Corvettes

John,
Did the dealer say if the rack actually tightened up when he applied the voltage to it. The great thing about the Tech2 is that it has bilateral control of the system, in otherwards you do not need the speed to increase the voltage. You should be able to feel the difference as soon as it is commanded. The rack does not generally fail soft, but you still have to rule out anything else that could be causing it. You did not start anything here, all you were doing was asking a legitimate question, it is just too often that people jump in with usually the wrong solution even though they are trying to help. It is always best to try and put yourself in everyone position, that is what I try to do. If you initially called me with this problem in your rack and you knew what the Tech2 could do, you would have also wanted to diagnose it instead of just replace it. Not to mention withe rack you don't want to be wrong because it is not like it just bolts right in. Hope you had a nice Christmas, and I will talk to you when I get back Monday.
Thanks
Justin

JohnD60

Justin,

To my knowledge the dealer did not test it in a static condition. What they told me was they test drove the car with the Tech 2 attached and verified the voltage was commanded correctly.

I haven't had the opportunity over the holiday to drive the car enough to tell you if the alignment made the difference. I'll have time this weekend to take it out and see.

John