Front Upper Control Arm Questions
#16
Driver
iTrader: (3)
I've got the same problem gtsfire. I recently replaced the lower control arms with supra arms and replaced the upper control arms with Dormans. It sounds and feels like I am running over a board when I run over reflectors making a lane change. I attributed it to the stiffer bushings on the upper control arm which will transmit the suspension impact much more directly to the cabin. Now I am starting to wonder when you have the same problem just replacing the lowers. I also replaced the transmission mount but the problem started after replacing the uca's and lca's. Any one else have any ideas here or had similar experiences?
#20
Well today I was FINALLY able to put my new upper control arms on. I've only driven the car about 6 miles but the vibrations I had been feeling were not there. The true test will be out on the interstate. The car is still a little harsh going over bumps but I figure as long as I have 18 inch wheels on it, it always will be. I need to get another alignment done and will do so on Monday. My (new) rack has a little slack in it so so that could explain some of the squirlyness. Here are some pics of the bushings.
They've seen better days. The ball joints are still good and I've got some upper control arm poly bushings laying around in my garage somewhere. I might experiment and try to put them in or maybe just hang them on the wall with my LCA'S.
#22
Not yet. I don't want to even go out side today. It's 30 degrees with a 30 mph north wind haha.
I bought the Dorman brand from RockAuto.com UCA's from Lexus are crazy expensive and the MKIV Supra one's aren't really any cheaper. The little bit I did drive it yesterday I was pleased.
I'm thinking I may put those Daizen poly's I've got on the used arms and sell them.
#23
While I can feel some changes and my front left tire no longer rubs the fender well when I back up, my car still has a tremor at highway speeds. Last night I had the cruise control on 90 mph out on the tollway that bypasses Austin and it felt smooth but when you get down to between 55 and 75 you can feel it. I'm about ready to scream Uncle!
#25
Driver School Candidate
Join Date: May 2008
Location: maryland
Posts: 36
Likes: 0
Received 0 Likes
on
0 Posts
just a thought but did you tighten all the bushing bolts with the weight of the car on the suspension or still jacked up in the air. cause if you tightened them while still jacked up the bushings are working against the suspension traveling up.
#26
The upper ones I know for sure yes. I had the jackstands under the lower control arms with the suspension level. The lowers ones I can't say 100% for sure as I did not do them. I helped with most of the big work that day but had to step out when my friend, (who's an older guy and Ford mechanic) put the lower control arms on. The car takes the bumps the exact same as it did before we changed the LCA's and that is harsh, so no way I can tell how they were tightened. What do you suggest in case they were tightened with the suspension hanging?
#27
Just a little update. I still have an intermittent tremor feel in the car but after doing some thinking about when I put the upper control arms on, I remembered that I just tightened the bolts down hard as I could by hand. I looked up the torque specs and pulled the wheels off, jacked up the arms level with the car and got the torque wrench out. All I can say is there was a lot more tightening that needed to be done and the test drive afterward was tremendously different. The car rolled over the bumps a lot smoother and drove so much better, straighter with almost no tramlining. I did all this the same day I put the rear TT's on the car ( another story detailed in another thread ). So in summary, my bad on forgetting to torque to upper control arms bolts. Cranking them down as hard as you can with a 19mm box end wrench is not going to cut it. As for the tremor, I'll update again when I have that figured out.
Last edited by gtsfire; 01-27-14 at 11:07 PM.
#28
Driver School Candidate
Join Date: Aug 2012
Location: FL
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
welcome to the club
I recently replaced my lower control arms with supra one's. Also replace the rack with new tie rods. Motor and tranny mounts. Four brand new tires. Also put supra shocks/springs with new mounts on the front. 97 SC400, 125k miles, with 18x8 wheels.
The problem is the car is very harsh over bumps and after 3k miles has developed a "tremor" again. The front end also feels loose going over potholes and such. Alignment is good, wheels have been rebalanced again. Yesterday I put yet another new tranny mount on since the other one looks squished again. It only had 6k miles on it ( I replaced it a few months prior to everything else) . Didn't seem to help the car much and actually feels more clunky in the driveline.
The only thing I have not replaced are the front upper control arms. I will probably replace those now but if that don't fix the tremor and harshness, what else should I be looking for??
Thnx
The problem is the car is very harsh over bumps and after 3k miles has developed a "tremor" again. The front end also feels loose going over potholes and such. Alignment is good, wheels have been rebalanced again. Yesterday I put yet another new tranny mount on since the other one looks squished again. It only had 6k miles on it ( I replaced it a few months prior to everything else) . Didn't seem to help the car much and actually feels more clunky in the driveline.
The only thing I have not replaced are the front upper control arms. I will probably replace those now but if that don't fix the tremor and harshness, what else should I be looking for??
Thnx
#29
I've replaced both front upper control arms since and the ride is a little better. The 18" wheels are a factor and I have a complete MKIV suspension. I believe my tremor, that is intermittent, is due to the rack and pinion having some slack in it sometimes. I need to check that filter on the sensor but that's going to entail dropping the rack and I don't have time for that right now. Most of the time it drives pretty straight.
#30
Lexus Champion
iTrader: (6)
I've replaced both front upper control arms since and the ride is a little better. The 18" wheels are a factor and I have a complete MKIV suspension. I believe my tremor, that is intermittent, is due to the rack and pinion having some slack in it sometimes. I need to check that filter on the sensor but that's going to entail dropping the rack and I don't have time for that right now. Most of the time it drives pretty straight.
You were really going through it for a minute. Thanks for posting as it helps us all big time.
I just ordered upper control arms (Doorman as well). Do you have any tips/advise for me to give my mechanic for installation so we can get it right the first time?
I was also hoping to also have my Daizen poly bushings pressed in to the new UCA's before installation if that is advisable.
Hope you are all sorted out!
Thank You!