This thread is a follow up to my original thread Rack and Pinion Question and Advice. Wanted to separate the two and keep this one as more of a true installation guide for future DIYers. I also referenced the Hummer H3 Service Manual's Power Steering section quite a bit. Rack and Pinion replacement begins on page 56 but found other helpful information throughout.
*Note: this is the process I followed for a full rack and pinion swap on my 2008 H3 3.7L. You might have alternative methods or additional steps based on your specific needs.

Replacement rack: OEM ACDelco Rack & Pinion w/ inner and outer tie rods (16mm) – GM Part #25957397
Distributor: RockAuto
Cost: $357.99

Replacement Steps

1. Flush power steering fluid. Won’t include those steps but this power steering flush process video outlines the flush and bleed process well. Goal is to eventually drain as much fluid as you can before disassembly.
   https://www.youtube.com/watch?v=GCKzCBMgB84&t=328s&ab_channel=CarsandRoads
2. CLEAN! If you’re replacing the rack due to a leak like me, you will most likely need to grab some brake parts cleaner and clean up the entire area around the rack, diff, secondary air injection pump, etc.
   
3. Center/confirm centering on new R&P and record tie rod measurements. My GM R&P came centered out of the box and I measured the length of the threads connecting the inner and outer tie rods at 1.15cm (about 9 individual threads showing) for both sides. Use this to compare with the rack/tie rods you are replacing. *Note: The threads on my stock tie rods measured approx. 1.38cm. I decided to not adjust the new tie rods on the rack and leave it at the original measurements. If you have doubts, this video on How to Center a Rack & Pinion has you covered.
   www.youtube.com/watch?v=ZQfMJHboXBo&ab_channel=DetroitSpeed
   
   
   
   
4. SECURE THE STEERING WHEEL AND LOCK IN STRAIGHT FORWARD POSITION! This is arguably the most important step. If you rotate the wheel while the R&P is off, you could find yourself with quite a few issues that are easily avoidable. GM makes a Steering Column Anti-Rotation Pin J-42640 and the service manual recommends using this tool to lock the column. It’s not expensive but I did not want to pay for/wait for shipping so I followed other’s advice and locked it down the best I could with bungee cords and the seatbelt. *Note: Once the wheels are straight, you might want to go ahead and remove the negative battery cable. If you copy my setup below, the horn will start blasting if the battery is still connected.
   
   
   
5. Get your H3 up on jack stands if you haven’t already and remove front wheels (OPTIONAL). Another good video to watch on YouTube is Installing Steering Rack Reinforcement Kit from Outfitter Design. I did not get the reinforcement kit used, but it’s a pretty nice guide for how to remove everything. In the video, he did not remove the wheels but because it was already jacked up and easy to remove, I figured I could use the extra room.
   https://www.youtube.com/watch?v=Xgzuioaf2ew&t=381s&ab_channel=CarsandRoads
6. Remove outer tie rod bolts (13/16” socket ended up fitting the best) and then knock tie rods free from bushing. A few knocks with a hammer where the tie rod fits through the bushing freed them both.
   
7. Remove steering rack bracket top bolt (15mm) located on passenger side right in front of the differential.
   a. HELPFUL TIP: Since you already have the air box removed when you flushed the power steering, access the top bracket bolt from above. It was so much easier to fit a ratchet onto the bolt by looking down through the engine bay. Even got my thick cordless to fit once I knocked it loose.
   
   
   
8. Loosen the bottom bracket bolt (15mm) if you want but don’t remove completely. You need it to support the rack once the horizontal and vertical rack bolts come out.
   
9. Remove the power steering gear inlet and outlet hose retaining plate bolt (10mm). Gently pry off the plate if needed. I used my metal trim removal tool and it popped right off. Might be a good idea to check the O rings on those as well. You’ll also want to clean up the hose ends and connection points before reinstalling as well.
   
10. Remove the horizontal and vertical rack bolts. You’ll need locking pliers or something similar to hold the nut in place while you turn each bolt.
    
11. Separate the rack and pinion from the steering shaft (one 11mm bolt located on driver’s side).
    a. HELPFUL TIP: Since the wheel is already off, remove the fender liner on the driver’s side to get easier access to the bolt. It’s a tight fit coming from underneath with a regular size ratchet and swivel joint. When you reinstall, the bolt should be torqued to 33 lb in and there was no way I was going to fit my torque wrench on the bolt by coming from the back side behind the rack. Tried for a long time before going through the wheel well. After that, it was done in a minute. Since the bolt connects vital parts to steering the car, I wanted to be sure that I torqued it to proper spec. Here’s a shot of my torque wrench coming through the wheel well.
    
    
    b. HELPFUL TIP #2: When you go to reinstall the rack and link the R&P and steering shaft, note that it fits together in a specific way. There are notches in R&P input shaft that allows it to fit properly into the steering shaft. I spent some time trying to rotate the input shaft on the rack to line it up perfectly. Be mindful, though, because the more you rotate and move those pieces around, the more it gets out of alignment and off-center.
    
12. Everything should now be disconnected except for the lower bracket bolt. To remove the bracket and bushing, push/pull from the top. The bottom part of the bracket has a notch that sticks up and you won’t be able to push it off from the bottom. Shouldn’t be difficult at all since the rack is basically free at this point. You might need to support the rack with one hand and pry the bracket off with the other as well.
    
13. Slide the rack and tie rods (if still attached) out. You will need to adjust/rotate the rack a bit to get it out from its position. Once freed, I slid the entire thing out towards the passenger side wheel well. I think it helped having the tire and wheel removed to give me the extra space needed.
    
14. Clean the area where the rack and pinion was housed and then slide the new rack in place. Reverse the instructions for installing the new rack. Don’t forget to make sure the new R&P is centered the best you can prior to installation.
    
15. I essentially followed the power steering flush and bleed process when refilling with P/S fluid. Skipped a good bit of the flush part since that had already been done and just made sure everything felt good when bleeding the system. I used Prestone Synthetic Power Steering Fluid.
    
16. Take it straight in for an alignment once you’re done and verified there are no issues. Might be helpful to schedule that in advance and not risk the shop having no availability.

Additional Thoughts
When it comes to locking the steering wheel, I would probably recommend getting the J-42640 anti-rotation tool if you can. If not, it’s fine as long as you’re careful but here’s a picture of my steering wheel when driving to the shop in a straight line for the alignment.



Even after locking it down (or so I thought), the wheel still ended up pointing at 1:00 when driving straight. I think this happened when I was reinstalling the steering gear to the steering shaft. I ended up moving it around more than I wanted to. Some of this was necessary in order to fit the two together and get the bolt in, but this should tell you just how important it is to lock the steering column. It drove just fine for me, and the shop is right up the street so I thought it would be alright without taking everything apart and making adjustments and just let the shop fix it during the alignment process.

Here is the before/after printout once the alignment process was complete. And for reference, my last alignment was only 40 days ago after I had the torsion bar out to install a new catalytic converter. So before the R&P install over the weekend, my alignment was near perfect.



Hope this helps the next person who is thinking about doing the rack replacement themselves. It’s absolutely doable and you don’t need to go waste money at a local shop that will likely charge you almost double what you paid for just the rack. Just remember to lock the steering column and go get an alignment right after.

 

Not what I meant by CENTER/(((SECURE))) the steering wheel. You need to prevent it from rotating side to side. Btw, you would have seen 1 o'clock after install, it's obvious looking at the alignment before specs, it moved to the passenger side. You could have adjusted DIY to correct(video below). Lastly, your alignment shop did NOT adjust CAMBER/CASTER, and they didn't give you the proper +TOE?

 

@hummerz appreciate the info. I had to rush to get it up to the shop when I wrapped up on Sunday and I must have not paid close enough attention when I got everything free on the steering wheel. I'm sure it was there but what I meant was I didn't notice it until I was already driving for a minute. But thanks for the alignment specs. I have a one year unlimited alignment plan at the local shop and I think I will call them and schedule another appointment to see about making the proper adjustments.

 

Fyi, I can drive My3 straight, without hands on the steering wheel. Your alignment specs show pull to the right. Btw, the alignment machine allows adjustment to tolerances to show GREEN. You need increased caster right front, increased positive camber left front to 0(zero), and MORE +TOE. Then you can drive straight without premature tire wear.

 

Thanks for the write-up, KU. Nice work! You are all over it.

 

KU1525, THANK YOU for taking the time to make this thread. I am sure it will help others over time. KUDOS to you!