2eXceL

iTrader: (2)

I recently picked up my '99 GS400. It has 88K miles and after reading a lot of the posts on here decided it would be a good time to invest into Front Suspension upgrades. I purchased all OEM replacement parts from Sewell Lexus and installed them my self. (Use ClubLexus Discount).
I think this replacement is a big upgrade and although I did not yet have the loud knocking noise, it has given me better alignment and sense of security that the LBJ will not fail pre-maturely. I still have some creaking noise from the brakes, but that should be fixed a my next Brake job.
Parts List:
No.2 Lower Control Arm '03-'05 GS400
Front Lower Ball Joint '01 GS 400
Front Tie-Rods '01 GS400
All new nuts & bolts for these parts

As mentioned in some of the DIY's for this work already, it is a job you can do if you regularly do your own brake jobs, oil, changes, etc. Its not too difficult if you have never done this before, but will require you to know tools and suspension parts. I would advise to review this 2nd Gen GS sticky thread with the links to the Repair Manual and get familiar with the parts you will be replacing/removing.

Materials/Tools:
Print out of all Front Suspension Torque specifications
Breaker Bar
Long and Short Sockets 17mm, 19mm, 15mm, 14mm, 12mm
Short/Long Ratchet
Long Wrenches, crowfoot and/or box-end
Pitman Pullers (small and large)
Jack Stands & Wheel Chocks
PB Blaster Lubricant Spray
Flash light

As discussed at length the main wear item that causes GS front suspension problems is the No. 2 Lower Control Arm bushing. You can replace just the bushing, or just the entire arm. At the price of new arms from Sewell and the installation process I recommend replacing the entire arm with '03-'05 GS arms.
Here is a link to my pictures of the job. http://tinyurl.com/7vq4q5r

My No.2 LCAs were not to the point of making loud knocking noises but did show cracking and tears.


I followed this sequence to do the install. Note: (Keypoints / Tips)
1. Jack up Car, use wheel chocks and Jack stands to work under front of Car
2. Disconnect 12V Negative Battery terminal
3. Remove Tire/Wheel
4. Remove ABS / Speed Sensor (Cover with bag, prevent dust and particles from contacting sensor)
5. Remove Brake Caliper (Use bungie cord, keep relief of Brake tubes, Note position of brake lines around suspension Arms to prevent twisting or wrong position during install)
6. Remove Rotor
7. Remove Under Body Chassis Brace (Big triangle assembly under car, about 6 bolts.)
8. Remove Nut and Bolt from Shock to Shock Bracket
9. Remove/Disconnect Sway Bar link from Sway bar (you can also try just removing the nut from the Shock bracket. IMPORTANT- during re-installation I completely sheared off the bolt on the Sway bar link and had to buy a replacement, make sure you tighten BOTH bolts slowly hand-tight first, then torque, I ended up only doing them hand-tight since I am not sure if the torque spec was set correctly on my wrench)
10. Remove 3 Nuts from the Engine bay for the Front Shock, remove Front Shock from the Car.
11. Remove Bolts for Lower Ball Joint to the Front Knuckle.
12. Break loose the Nut to the Lower Ball joint and the Front knuckle. Use Large Pitman Puller to push the Lower Ball Joint stud out of the Knuckle.
13. Break loose the Jam Nut on the Tie-Rod from the Steering rack. (Mine was very tight, also before breaking loose the Jam Nut you can Paint-mark the position if you will not be able to do an alignment soon.)
14. Remove Nut from Tie-Rod to Knuckle and use PitMan puller to push Tie-Rod off
15. Turn Tie-Rod and spin it off from the Steering Rack. (Need to hold the Steering rack with a wrench to help turn)
16. Remove Two Bolts for No. 2 LCA to the Lower Control Arm, these are under the Shock Bracket
17. Break loose the Nut at the Upper Ball Joint to the Knuckle, use small Pitman Puller to Push Ball joint stud out.
18. At this Point the complete Knuckle will come free and can be Removed from the Car.
19. Start complete removal of the No. 2 LCA, buy breaking free the Nut on the Stud to the Body.
20. I bought a new Stud for the No. 2 LCA so I had to remove the Old stud (Requires lots of PB Blaster and large breaker bar.)
21. Installed New Stud to the Body for the No. 2 LCA.
22. Set the New No.2 LCA on the LCA, under the Front Shock Tower. (This is where it becomes trick to align the new arm to the Stud and the LCA)
23. Use a friend or something to hold the No.2 LCA just barely engaging the Body Stud and try to align the two bolts to the LCA. (Ensure it is aligned and you may need to push the LCA down to help. HAND-START the bolts, if alignment is not correct you can STRIP out the LCA if you keep tightening.)
24. Tighten the two bolts at the No.2 LCA to the LCA, then push the LCA up completely to the Body on the Stud. (Ensure Brake caliper line and hose is routed the correct way before you push up the No.2 LCA to its home)
25. Install the plate and Nut for the No.2 LCA to the Stud.
26. Install New Tie-Rod to the Steering Rack. (Line up to previous paint mark you made.) Tighten the Jam Nut.
27. Install New Lower Ball Joint to the Knuckle.
28. Re-install the Knuckle assembly to the Upper Ball joint
28. Re-install Tie-Rod nut to the Knuckle
26. Re-install the Front Shock Absorber
27. Torque all the Nuts and bolts on the Lower Ball Joint and the No. 2 LCA, some of these are high torque (Align the nut to allow the re-insertion of the push pin clip through the Nut/Stud)
28. Re-install the Sway Bar Link to Sway bar or Shock bracket
29. Re-install the ABS Sensor to the Wheel hub (make sure sensor is clean)
30. Re-install Rotor and Brake Caliper
31. Double check all ball joints and bolts ensure you have torqued everything to spec.
32. Re-install the Wheel/tires
33. Do the Other Side
34. Re-install the Front Chassis Brace.

I'm sure I could've mixed some steps in the process and some of these could be done in a different sequence, but just want to give others out there a starting road-map on how to do this. Overall the whole process took me about 8 hours over two days. Of course the first side took me longer. This is just a guide and as always I am not responsible for any damage or negative unwanted consequences of using this DIY. Use at your own risk.

Other than that let me know if you have any questions.

JLAWS

Thanks for this detailed and valuable write up!!! It will come in handy.

Man I wish I had a GS400 with only 88K miles. Truly a rare car.

GS714

Just curious, was your car pulling to the right or left before you replaced those mentioned items. My car is currently pulling to right at and above 50 mph. I am thinking of replacing the Caster Control Arm or (Lower Control Arm #2, S-Arm) and the outer tie rods. If that doesn't worked, the Upper Control Arm and Lower Control Arm #1 should be next. I have had car aligned and looked at many places but no one seem to give a definitive recommendation. My guess is that would prefer to do the parts replacement and figuring it out a long the way.

2eXceL

iTrader: (2)

My alignment was good before the replacement but like I mentioned the bushings were just starting to crack on the No. 2 Lwr Control Arm. In your situation they are most likely the culprit for bad alignment. I would replace No. 2 LCA and lower balljoints.

2eXceL

iTrader: (2)

Yea it was a rare find at low miles, I plan to slowly build it up to a DD sport sedan. I hope the write up helps.