Upper control arm replacement
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Joined: Jan 2015
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gl450
Upper control arm replacement
I replaced my front driver side upper control arm yesterday, so thought I'd share my experience.
- You can use 11mm wrench instead of E14 socket on the two bolts securing the arm. It's easier because there isn't much room between the bolts and the strut. If you have a ratcheting 11mm wrench - even better
- The nuts on these bolts are 16mm, the rear one is a REAL pain to get to. If you have someone turn the bolt while you are trying to blindly catch the nut with an open end wrench, it would help a lot. Once loosened, you can kinda reach with your hand and take the nut off by hand. Same with installing - start by hand and then use the open end wrench to feel/catch the nut and tighten the bolt. Since I didn't have a helper, I had to petty much lie on the fender with one hand in the engine bay and another in the wheel well. That's where a long ratcheting 11mm wrench really helps.
- the rear bolt can come out with the air strut in place, but the front one can't. Take out the strut bolt at the lower control arm and loosen the top three strut bolts - it will allow you to move the strut outward so the front upper control arm bolt can come out
- lift both sides of the vehicle, so the sway bar doesn't push the suspension up
- remember to tighten the control arm and lower strut bolts with the car on the ground, or, as I did - measure the wheel center to fender distance before lifting the car and then use a jack to lift the hub to that distance when tightening the bolts.
Hope this helps someone.
- You can use 11mm wrench instead of E14 socket on the two bolts securing the arm. It's easier because there isn't much room between the bolts and the strut. If you have a ratcheting 11mm wrench - even better
- The nuts on these bolts are 16mm, the rear one is a REAL pain to get to. If you have someone turn the bolt while you are trying to blindly catch the nut with an open end wrench, it would help a lot. Once loosened, you can kinda reach with your hand and take the nut off by hand. Same with installing - start by hand and then use the open end wrench to feel/catch the nut and tighten the bolt. Since I didn't have a helper, I had to petty much lie on the fender with one hand in the engine bay and another in the wheel well. That's where a long ratcheting 11mm wrench really helps.
- the rear bolt can come out with the air strut in place, but the front one can't. Take out the strut bolt at the lower control arm and loosen the top three strut bolts - it will allow you to move the strut outward so the front upper control arm bolt can come out
- lift both sides of the vehicle, so the sway bar doesn't push the suspension up
- remember to tighten the control arm and lower strut bolts with the car on the ground, or, as I did - measure the wheel center to fender distance before lifting the car and then use a jack to lift the hub to that distance when tightening the bolts.
Hope this helps someone.
Last edited by mtm; Oct 9, 2024 at 09:20 AM.
Thread Starter
Senior Member
Joined: Jan 2015
Posts: 306
Likes: 78
gl450
Forgot to mention - the reason I replaced the upper control arm was that there was creaking sound and knocking when going over bumps. It was caused by the rubber bushing on one side that was completely torn, so whenever the arm articulated the two parts of the bushing were rubbing against each other.
Here's the video of the creaking part - hopefully it can help someone identify their suspension noise:
Here's the video of the creaking part - hopefully it can help someone identify their suspension noise:
Last edited by mtm; Oct 9, 2024 at 05:05 PM.
Thread Starter
Senior Member
Joined: Jan 2015
Posts: 306
Likes: 78
gl450
