Knez's Home

It took me 15 months to finally get around to installing Manny's one-ton front end. I thought this job would take me a few days so I waited for a long enough block of time which is hard to come by as a working father of 3. But that time finally arrived... in January... at well below freezing temperatures. I sure can pick them.

The job took me 4 days (~9 AM to 4 PM). After doing the first side, the other side went faster. This job could be done faster overall, but I was hampered by the weather and frequent trips to the auto parts store to get parts I needed, like a stronger longer breaker bar after I broke my old one on a wheel nut.

Overall I would say this job is very do-able by a moderate mechanic and can be done in your driveway. I had the HOA to worry about so I was hurrying, working day after day. It would have been much nicer to put in the same amount of work over a couple weeks.

Here are the relevant documents for the installation which were included with the kit and extremely helpful.

The 12 point bolts that attach the axles to the final drive that are included in the kit are garbage. Those bolts get tightened to 75 ft lbs. Out of 12 bolts, maybe 5 had the heads strip out before that torque. And now there is no getting them out easily. I purchased some genuine ARP 742-1000 bolts (12 point, 3/8", 24 thread pitch, 1" long, black oxide). Once I get those I will replace all the kit bolts I can. The kit bolts looked like ARP though, so I am curious to see if the genuine article holds up better.
The new hubs in the kit had paint in the ball joint sockets. One one hub I had a really hard time getting the upper ball joint seated far enough in. One second hub, I found the paint and scraped it out with the edge of a razor blade held perpendicular. That seemed to help.
The new hub's upper ball joint mount is super thick. So thick that going to 40 ft lbs on the upper ball joint nut won't fully expose the cotter pin hole. On the first hub, I went way way over 40 ft lbs to get a cotter pin through the hole. On the second hub, I went slightly over 40 ft lbs and instead settled for just one leg of a cotter pin through the hole. I wish I had done that for the first hub. The other option was to grind down the valley in the castle nut more so the hole was accessible earlier. This was the only part of the installation where it was clear this stuff wasn't made to fit together from the factory.
Once I was all done with the installation I set the ride height. 3 out of 4 corners had a good height. But one front wheel was fully an inch too high despite the pork chop bolt being fully out. I assumed the torsion bar must have been one rotation angle off. I took that whole assembly apart and got the lower control arm off so I could rotate the torsion bar correctly. After going back and forth a bunch on how to rotate the torsion bar before inserting it, I finally just read the maintenance manual from GMC which basically has the control arm and normal ride height, and the pork chop hanging down 1.5" from the cross member, then you can mate them. I did that, and upon reassembly the ride height was correct. So either my torsion bar was one rotation off before I even this project (possible, the front always looked high to me, I put it in one rotation accidentally (also possible, marker on greasy bar doesn't last), or the suspension wasn't fully settled. If I were to do this again, I wouldn't bother marking the torsion bar on dissassembly, I would just reaassemble per the GMC instructions, then I would drive around the block once before checking ride height.

I still need to get an alignment. All I have done is make sure the toe-in is close enough. I drove the RV back to the storage lot. Mostly 45 MPH but a section of 65 MPH. Here are my observations.

I would say the steering is improved. There was a big dead zone before turning the wheel had any impact. I would say over half that dead zone is gone. I did replace the inner and outer tie rods while installing this kit though.This is a pleasant change.
The wider stance of the front wheels just looks right, like it should have come from the factory that way where the fronts and the back's line up.
The suspension communicates more road imperfections now. I can feel more of the road. Again, I haven't had an alignment yet. And I am driving around in the winter with snow packed roads so don't quote me on this. But my first impression is I can feel the bumps in the front more. This might be down to replacing a bunch of soft worn-out rubber bushings with new ones. It feels sportier, though this obviously isn't a sports car.

Overall I am glad this project is complete. To not have to worry about the bearings, and to know literally everything up front is new gives me peace of mind. The larger brakes are nice too, though I can't comment on any change in stopping power yet. I am happy though to have modern part numbers for all those pieces. It will make it easier getting replacements later when I need them.

Here is a copy of the full one-ton front end parts list in case the link above stops working.

Parts list
1. 2, Knuckles (89-2000 Chevy 1ton 4x4 8600GVW)
2. 2, modified lower control arms
3. 2, bearing/hub  assemblies (Timken HA591339)
4. 2, aluminum spacers (3.5”)
5. 2, rotors AC/Delco 18A489A  GM 19241858
6. 2, axle assemblies GM8802
7. 2, axle washers (Dorman 618-057)
8. 2, brake hoses (Dorman H380-533)
9. 2, upper control arms
10. 2, upper control arm offset bushings ( K7104)
11. 2, upper control arm urethane bushings (ES3392)
12. 2, upper control arm ball joints ( K680)
13. 2, lower control arm ball joints ( K6291)
14. 4, lower control arm urethane bushings (ES3391)
15. 8, knuckle to bearing bolts (GM88891741)
16. 16, bearing to spacer wheel nuts (Dorman 611-110)
17. 16, spacer wheel studs (Dorman 610-189) GM3988538 AC/Delco 5739B
18. 12, 12-point flange head 3/8-24 x 1” cap screws.
19. 12, 3/8 washers
20. 2. ceramic pad kits (centric 106.3700)
21. 2, calipers GM 15976405, 15976406

Pictures