rack and pinion for our cars

[TheOldMan]

I have a 2007 Base model and want to know if the rack and pinion from a C5,C6 Corvette and our rack and pinions
are the same? Reason: I need to rebuild mine or send it in. If I send it in to Turn One, they only have Corvette rebiuld
kits and no XLR kits. Therefore, how is one with a XLR getting their rack and pinions rebuilt from someone?

Thanks for reading and replying.
Dennis

 

[mickeytee]

Theres several outfits on ebay claiming to rebuild the xlr. The corvette is not the same. Problem with rebuild is finding someone who does not just cean them, put seals in and call it done. Theres a guy in sc that gas rebuilt the xlr. He ssys the electronics in it get a leak that burns them out and he said there are no parts to replace the variable assist if that happens. I guess it depends on what wrong as the ones on ebay only sell for 4-500 after core exchange. Ive not bought on of those. Ive installed good used but not one of these.keep us posted what you find

 

[rexster314]

Theres several outfits on ebay claiming to rebuild the xlr. The corvette is not the same. Problem with rebuild is finding someone who does not just cean them, put seals in and call it done. Theres a guy in sc that gas rebuilt the xlr. He ssys the electronics in it get a leak that burns them out and he said there are no parts to replace the variable assist if that happens. I guess it depends on what wrong as the ones on ebay only sell for 4-500 after core exchange. Ive not bought on of those. Ive installed good used but not one of these.keep us posted what you find

This is what started all my troubles, the variable assist electronics on the steering rack. It was one thing, then another, mostly due to the ineptitude of David Taylor, now Sterling McCall Cadillac in Houston.

 

[RubyRod]

Also struggling with replacement steering racks. I had a rebuilt unit installed last June but it started leaking in November. The shop that replaced it won't tell me who did the rebuild. It was replaced again last month but the 2nd replacement has a problem. The steering requires WAY too much effort. Either the preload adjustment is wrong or the internal valve is screwed up. So it needs replaced a 3rd time. Waiting on the shop to work out the 3rd replacement with the rebuilder. Hopefully the 3rd time is the charm.

One thing that occurred to me after the first rebuilt unit failed is that the C7 vettes use an all electric steering rack. I suspect that the C7 rack will bolt right in to the XLR chassis. The trick is engineering an electronics module to insert between the ABS module and the C7 steering electric motor. Since the XLRs already have a "boost" electric motor in the steering rack it might only require a current amplifier. That wouldn't be too hard to design. I don't have any information on the C7 steering rack operation but if I can get my hands on some I'd like to see if my theory holds up. If so it might make a reasonable solution for a replacement rack for our cars.

 

[TheOldMan]

Can I ask where have the units leaked from? I understand the preload and hard steering, but also isn't there a
Magnasteer actuator or something in the input shaft housing that leaks from the wires that stick out? What happens if that goes bad?

 

[mickeytee]

The hard steering is why they cannot rebuild them. At low speeds the powersteering pump works as it shoukd. At higher speeds the powersteering pump is bypassed so its not doing anything at higher speeds the the rack actually requures resistance and uses less power steering assist. Its varaible due to speed. The ectronics inside get shorted out and tgey cannit repair them as they are sealed and there is no replacement. So a unit that is working fine but leaking might be repaired. One that has a little slop in it might be repaired but tgats about the limit.
To repair them properly you would need a test bench with a pump, a computer to simulate speed and a steering shaft set up to measure how much input is being used. And then if you find a problem there are no parts

 

[RubyRod]

Can I ask where have the units leaked from? I understand the preload and hard steering, but also isn't there a
Magnasteer actuator or something in the input shaft housing that leaks from the wires that stick out? What happens if that goes bad?

The original rack was leaking where the steering shaft connected to the input shaft of the pinion gear (where the electric motor resides). The second one was leaking where the electrical connector enters the pinion housing for the electric motor. I'm sure the grommet/gasket could have been replaced but the shop that replaced the rack it wasn't interested in repairing the unit. They simply arranged a replacement from the rebuilder and sent the first rebuilt back to him. (The original rack that was leaking was also sent to the rebuilder.)

 

[TheOldMan]

Mine is leaking in those same places, I am looking into repairing this myself.
been doing much research. Hope I can get it done. RubyRod, Thanks for the reply.

 

[mickeytee]

Let us know what you find. By the time it leaks out where the wire enters the housing it means it has leaked internnally into the magnetic assist and now leaking out. Its not supposed to have any fluid inside the electronics. Ive wanted to take one apart but having been told how jt works i know it is out of my scope to try and fix it. I used to rebuild volvo racks on the cars. They leaked out the seals of the rack tube. I could fix one in a couple of hours and a new one was 1000$ with parts and labor. I charged 100 and did them fir evey car lot in town. It would be good to try to build a used one and not yours but if you dont know what going on with the used one it would be difficult. Ive seen a several get broken where the fitting goes into the rack . the metal is very thin on that one line fitting and will break the corner of the rack when you try to remove it. It is very tight.

 

[RubyRod]

Mine is leaking in those same places, I am looking into repairing this myself.
been doing much research. Hope I can get it done. RubyRod, Thanks for the reply.

I wish you the best of luck. Let us know what you find. There are a few YouTube videos that should be helpful for disassembling the rack once you get it out of the car.

If you can find the seals and bearings it should be a job a DIY can handle. You should also see if you can find replacement brushes for the electric motor. Assuming you can disassemble it. The tricky part will be bleeding the steering system after you finish installing it. Based on the info in the Service Manual I don't think you'll be able to perform this step. You should be able to have the car towed to a GM dealer or repair shop that can bleed it for you if you get that far. One of the reasons I didn't attempt to replace the rack myself was because I don't have the pressure tools to bleed the system. Not the only reason but it was yet another issue.

 

[TheOldMan]

After much investigation and a teardown and rebuild of my rack and pinion I found out that there is power steering fluid that goes around and into the input shaft area that houses the magnet and resistor pickup. You know if the se are bad if you ohm the connections at the plug and it reads < 1.5 , > 3.5 ohms. My value was 2.0 ohms so I did not remove these parts. There are seals inside the input shaft, one at the top where the steering shaft connects to the input shaft and the other is just below the power steering high and low connections from the rack tube. That is also where the wires come out and that is the place that needs to be sealed up. I used JB Weld all around the rubber plug and wires to seal it.

There are no brushes that I found and there is a great video on the corvette site to explain how to get that part out of you need to.....but there are no parts available for that. Hope yours meters out okay.

More later.

 

[mickeytee]

If you have a link let us know. Ive not seen that video also ifanyone is working on this i tead the tech two has three settings on tge steering. Factory,firmer and less firm. Ive yet to look into this but input would be welcome

 

[TheOldMan]

Sure, here are a couple of videos;

Used this to see what is inside of the rack and pinion:

Used this to rebuild the rack but did not use the rebuild kit in this video. I used this one...Edelmann 8786 Rack Pinion Seal Kit:

DIY: C5 Power Steering Rack and Pinion Rebuild - CorvetteForum - Chevrolet Corvette Forum Discussion

C5 Tech - DIY: C5 Power Steering Rack and Pinion Rebuild - In this guide I am going to walk you through the steps I took to rebuild my 2001 Corvette Z06’s power steering rack and pinion. Note that you are responsible for your own rebuild, neither myself nor CorvetteForum are responsible for any...

www.corvetteforum.com

I just watched this for a better way to do the job. Took mine out from under the car not out the drivers side. Had to take out the power brake bracket to make it easier to get out but did not touch the upper control arm or the shocks.

 

[RubyRod]

Sure, here are a couple of videos;

Used this to see what is inside of the rack and pinion:

Used this to rebuild the rack but did not use the rebuild kit in this video. I used this one...Edelmann 8786 Rack Pinion Seal Kit:

DIY: C5 Power Steering Rack and Pinion Rebuild - CorvetteForum - Chevrolet Corvette Forum Discussion

C5 Tech - DIY: C5 Power Steering Rack and Pinion Rebuild - In this guide I am going to walk you through the steps I took to rebuild my 2001 Corvette Z06’s power steering rack and pinion. Note that you are responsible for your own rebuild, neither myself nor CorvetteForum are responsible for any...

www.corvetteforum.com

I just watched this for a better way to do the job. Took mine out from under the car not out the drivers side. Had to take out the power brake bracket to make it easier to get out but did not touch the upper control arm or the shocks.

Nice work. Curious as to why you chose the 8786 seal kit. The compatible vehicle list I found doesn't list the XLRs.

Were you able to disassemble the electric motor? Or is it a sealed unit? And do you know if it's the same motor or pinion assembly as in the C6 vettes?

 

[TheOldMan]

Not too much that I saw matched a XLR so I tried that kit. it had all the seals. There were no bearings with the kit.

The Variable Effort Steering (VES) system, or MAGNASTEER II is actually epoxied to the inside of the housing so I did not take that out,
However, a CorvetteForum member bradleyss14 shared very helpful information which I will re-share with you: first liberate the Magnasteer actuator, by carefully scraping away the epoxy which holds it in place. This epoxy runs the whole way around the actuator, shown here with red arrows:

Then the Magnasteer actuator can be slid out of the pinion housing (be careful with the wires). Also note that the connector at the end of the wires won’t fit through, so either the connector needs to be de-pinned or the wires cut and then spliced back together later.

 

[RubyRod]

Not too much that I saw matched a XLR so I tried that kit. it had all the seals. There were no bearings with the kit.

The Variable Effort Steering (VES) system, or MAGNASTEER II is actually epoxied to the inside of the housing so I did not take that out,
However, a CorvetteForum member bradleyss14 shared very helpful information which I will re-share with you: first liberate the Magnasteer actuator, by carefully scraping away the epoxy which holds it in place. This epoxy runs the whole way around the actuator, shown here with red arrows:

View attachment 15622



Then the Magnasteer actuator can be slid out of the pinion housing (be careful with the wires). Also note that the connector at the end of the wires won’t fit through, so either the connector needs to be de-pinned or the wires cut and then spliced back together later.

So the sealing material around the electric motor (aka VES) is actually an epoxy? A hardening epoxy? Or is it a non-hardening RTV sealant? Or maybe a non-hardening urethane sealant? Unfortunately there's no way tell what it is from a visual exam. Be nice to know what product to use if & when I have to do this.

I guess the next question is how are the wires that penetrate the pinion gear housing sealed? Since you didn't remove the VES I guess you didn't re-seal that area. This is what started leaking on the 1st rebuilt rack installed in my car so I'd like to know how to address this. The 1st rebuilt rack only lasted 4 months before it started leaking from the wires. Perhaps the rebuilder did just like you did and didn't remove the VES at all. He only replaced the seals that he could get replacement parts for. If so I'm not hopeful that the 2nd rebuilt rack will last any longer than the 1st one did.

Thanks for digging into this though. At some point it would be nice to have a thorough steering rack rebuilder's guide to put in the sticky section of the forum. I suspect that the only way to get a quality rebuild for our cars will be if we do it ourselves or have a step by step rebuild guide for a willing local repair shop/machine shop to follow. It may be the ONLY way to get a rebuilt rack at all in the not too distant future.

 

[mickeytee]

Id bet that no rebuilder that sells them for 400-600$ does anything but clean them up and put seals and boots. The one problem i see is that most list one rack for all cars. The 07-08 are not tge same as 04-06/07 middle year change. The gm part numbers so upgrades but that those two numbers do not interchange. 08 has different tie rods thsn other years. They no not interchange . 09 take a new number and shows to be a one year only. So throwing them all in a pile im not sure which one you woukd get. I assume most would be the older ones and they may not be compatible with the newer. There is some corvette rebuilders that look like maybe they can work on the assist but they get 1200-1500 for theirs. Several years ago the rebuilder i spoke with said there was no need to take the assist out as its not serviceable and no parts for it. Maybe things have changed

 

[RubyRod]

Id bet that no rebuilder that sells them for 400-600$ does anything but clean them up and put seals and boots. The one problem i see is that most list one rack for all cars. The 07-08 are not tge same as 04-06/07 middle year change. The gm part numbers so upgrades but that those two numbers do not interchange. 08 has different tie rods thsn other years. They no not interchange . 09 take a new number and shows to be a one year only. So throwing them all in a pile im not sure which one you woukd get. I assume most would be the older ones and they may not be compatible with the newer. There is some corvette rebuilders that look like maybe they can work on the assist but they get 1200-1500 for theirs. Several years ago the rebuilder i spoke with said there was no need to take the assist out as its not serviceable and no parts for it. Maybe things have changed

The comment on the VES unit is important. Since the wiring area leaks it seems that where the wires penetrate the pinion housing that this NEEDs to be addressed during a rebuild. At least it needed to be in the 1st rack I ended up with. If this section is "left alone" during rebuilds it's no wonder the rebuilt racks don't last. Be nice to find a way to address this. Seems like a common failure on all the MagnaSteer racks.

If the VES unit is not serviceable (sealed) then I can understand the hesitation to remove it. But in order to re-seal the wires it looks like it has to be removed in order to access the wire seal in the housing. I'd have to take one apart to find out for sure. Not thrilled about the prospect.

Thanks Mickey. Useful info.

 

[TheOldMan]

"So the sealing material around the electric motor (aka VES) is actually an epoxy? A hardening epoxy? Or is it a non-hardening RTV sealant?"

It is a hardening epoxy. In one video the DIY guy actually had his mechanic brother dig the epoxy out around the magnet and clean up the wire rubber and make a new place for an O ring. It is shown. Then he epoxied the unit back into the spot. Also because the wires are pushed into a connector they need to be cut before removal and spliced back at installation cause the connector (of course) won't fit thru the hole LOL.

Just remember, the people who rebuild these for $500-600 only clean them, put new seals and if needed bearings and that's all.
They also use epoxy or JB weld around the outside of the place where the rubber and wires come out of the body and seal that place up
the best they can.

Lastly if you use a multimeter and ohm the two wires and get a reading in between 1.5 and 3.5 then the resistor and magnet setup
is good and there would be no need to take it apart unless you will try and seal the rubber and wires from the inside.

 

[mickeytee]

Checking the ohms i do no believe confirms its working. Also check to see if its grounded to the housing. I saw a toyota unit video where neg volts was applied plus positve , i think 5 max in that case the rack was in a jig with springs pushing on the tie rod towards the rack.the torque to turn the wheel was measured. With no volts, then neg volts then positive volts.they had a pump set up runnng fluid thru it. I did see some manufactures offer the unit as a replacement. Ive read that the magnets are ceramic . they break easily. Old days you took a hammer to a starter and you could free it up. Today if you bump a starter housing you are very likely to crack a magnet , then its junk. So these magnets are fragile . Ive got a junk yard sending me a bad rack so it might be worth looking at and cutting up but there are no parts. A company in texas is supposed to call me. They say they rebuild the c6 which is close to ours.we will see what they actually do. 450 for a rack.
i was told that a leak is a result of other failure not the cause.