- 10-25-12 03:15 PM #1
How to: Front Lower Control Arm Replacement
Here's my take on how to replace the front lower control arms (LCA):
These instructions are provided for information purposes only. Attempt at your own risk.
SRX trim - 2004 3.6L V6 AWD
Problem presentation - squeaky/scrunchy bushing noises at slower speeds over bumps and coming to a stop; clunk from ball joint typically present when creeping forward/reversing with wheel hard over and slight bump; improper caster/camber alignment numbers and inability to bring it within spec
- Lower Control Arm Assembly (w/ new bushings and ball joint pre-installed) - AC Delco 25862781 (driver's side) & 25862782 (passenger side) - roughly $190 per at local dealer (pricematched to GMpartsdirect.com)
- When done you will need an alignment
Dealer quote - ~$380 plus labor
- jack & jack stands (or lift )
- wheel chocks
- flathead screwdriver (for lug nut cover & clamp removal)
- breaker bar
- impact gun & air compressor
- 1/2" drive ratchet
- 3/4" socket (for wheel lug nuts)
- 18mm standard & deep socket (for end link, yoke to shock nut)
- 24mm deep socket (for yoke to LCA nut)
- 21mm standard & deep socket (for cradle to LCA bolts/nuts)
- 18mm combination wrench (for steering rack bolts and back wrench)
- 21mm combination wrench (for back wrench)
- 5mm & 6mm allen wrench (using a impact gun may preclude the need)
- torque wrench
- 2-arm gear puller, large C-clamp, or wedge & hammer (for separating yoke to LCA)
- 3lb hammer
- Marking tool
- Thread-locker (blue)
- PB Blaster or equivalent
- Shop rags
- Note, LCA stands for Lower Control Arm
- Note, procedure is same for driver and passenger side and pictures may be used interchageably
- Put transmission in Park, chock the rear wheels, and set the parking brake
- Jack up front tire to be worked on; Note: it will be easier if you can get both front wheels in the air at the same time; that way you'll have easier access to the steering rack bolts
- Lower vehicle onto jack stands
- Remove the lug nut cover with the flathead screwdriver
- Remove the six lug nuts with 3/4" socket & your choice of tool (impact gun, breaker bar, ratchet) - from now on I'll omit this tool list unless I have a specific recommendation (air tools are always preferred IMO)
- Set tire aside
- May be a good idea to hit the bolts/nuts with PB Blaster at this time
- Using the 18mm socket & 18mm back wrench remove the shock to yoke retaining nut
- Remove the shock to yoke retaining bolt by pulling up slightly on the LCA to remove pressure on the bolt
- Using the 24mm deep socket remove the yoke to LCA retaining nut
- The yoke is effectively pressed onto the LCA tapered stud, you need to break the pressed fit; this step gave me some trouble as I didn't have a good 2-arm gear puller. Take care of the yoke as you'll be reusing it. I tried a 3-arm gear puller, but was worried about damaging the yoke machined surface. I found I could take a large C-clamp and draw in the yoke to flush against the control arm, and then take a hammer and whack the stud a couple times. This didn't noticeably free it up, but once I tried to remove the control arm and twisted the yoke on the stud it came right off. I never actually removed the yoke from the shock. A pic of the gear puller:
- Using the 18mm socket & 18mm combination back wrench remove the stabilizer shaft end link lower retaining nut (Moog FTW!); if you have stock end links you'll need to use an 18mm combination wrench and a 5mm or 6mm allen wrench (can't remember which size) - this is a great time to replace those old end links with serviceable Moogs!
- Remove the stabilizer shaft link from the LCA
- Remove the ABS wire harness from the LCA
- Using the 21mm socket and impact gun remove the LCA to steering knuckle nut (ball joint nut); if you don't have an impact gun you'll most likely need a 21mm combination wrench and 5mm or 6mm allen wrench
- Take your hammer and whack the LCA to steering knuckle stud (ball joint stud); this is a tapered fit they you need to break free; we don't care about the condition of the bolt because we are installing a new LCA
- We now need to raise the power steering gear to have clearance when removing the rear LCA to frame retaining bolts
- Using a 18mm combination wrench, remove the two power steering gear retaining bolts
- Take a marking tool and try to mark where the LCA to frame nuts and bolts sit - you'll need to try and match the position when installing the new LCA to ensure a decent alignment
- You may have to drop the lower splash shield to access the front bolts/nuts
- Using the 21mm socket & a 21mm back wrench, remove the LCA to cradle nuts and bolts; both bolts should be pointing forward and the steering rack will need to be raised out of the way to remove the rear one
- Remove the LCA by lowering it at the frame and moving the ball stud upwards
- Install the new LCA by inserting the ball stud into the steering knuckle and then rotating the LCA up into the frame
- At this point I actually inserted all bolts and put nuts on a couple threads
- Install the LCA to frame bolts (they should ALL point forwards towards the front of the vehicle); try to match the bolt/nut locations with the marks you made earlier during removal
- Using the 21mm socket and 21mm back wrench tighten the LCA to frame nuts/bolts; torque to 96 ft/lbs
- Add blue thread-locker to the steering gear retaining bolts and use the 18mm combination wrench to tighten the steering gear retaining bolts; torque to 89 ft/lbs (couldn't actually get my torque wrench on them)
- Using a 21mm socket install the LCA to steering knuckle nut; torque to 15 ft/lbs and then tighten nut an additional 210 degrees
- Install the ABS wire harness to the new LCA
- Using the 18mm socket and 18mm back wrench install the stabilizer shaft end link to the LCA; torque to 81 ft/lbs
- Install the yoke to LCA retaining nut with blue thread-locker (if you haven't already) but don't tighten at this time
- Install the yoke to the shock and install the retaining bolt with blue thread-locker and nut using an 18mm socket and 18mm back wrench; torque to 81 ft/lbs
- Torque the yoke to LCA retaining nut to 133 ft/lbs
- Install the wheel & tire using a 3/4" socket. Torque to 100 ft/lbs (may need to do this with tires touching the ground). Make sure you tighten in proper sequence (if studs are numbered sequentially - 1, 4, 6, 3, 5, 2).
- Install the lug nut cover.
- Jack up the front of the vehicle to remove the jack stands. Lower the vehicle.
- Remove the wheel chocks and carefully drive to the nearest alignment center!!! A special tool is required to adjust the caster & camber - ensure your shop is capable of aligning the SRX before you spend any money.
Final thoughts - All in all this project wasn't so bad. I'd say the trickiest part was figuring out exactly how to remove the yoke from the LCA. As always, the lift and air tools are a big help. The front end is much quieter now and my wife is back to enjoying her ride...
I hope this information is useful to someone.
My 'how-to' posts:
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- 10-11-13 04:46 PM #2Cadillac Owners Member
- Automobile(s): 2005 sts4 1SG v8 perf pakge
- Join Date
- Dec 2009
Re: How to: Front Lower Control Arm Replacement
it is a very good presentation but you forgot something.
before thightening the lca bolts you must lift it so i has to be like the wheel is resting on the ground otherwise it will put too much stress on the bushings when you hit a bump and the wheel is lifted at maximum because you have thightened it at its most lower position
- 01-04-14 05:11 PM #3
Re: How to: Front Lower Control Arm Replacement
I've attached a PDF of the how-to to this post as I'm deleting the photos from my server. Moderators, please feel free to contact me for the originals if you'd like to host.