Upper cont arm bushing

Moderator: Moderators

Re: Upper cont arm bushing

Postby cjbiagi » Sun Jan 03, 2016 5:53 pm

Art, the problem is every car is different and the lower control arm cams only give you so much adjustment. Once you max them out that is all you can do and if you can't reach the correct alignment setting then you have to look for other ways to correct it. The offset bushings are certainly the cheapest and are an effective way to do it. Otherwise you are looking at custom adjustable control arms (which allow you to move the upper balljoint in a similar manner that the offset bushings do) and those are obviously a lot more expensive. They do offer some additional advantages such as being to able to make more adjustments on the car. Without knowing what your camber is it's hard to say exactly what to do. Did your car exhibit a lot of negative camber? Generally you can just eyeball the car from the front and see if it looks like the tires are really tilted in at the top. A little tilt is good as you probably want about a 1/2 degree negative camber but if it really looks tilted in you probably have an issue and the offset bushings installed as mentioned should help or alleviate the problem.
Clyde.........75 Monza 2+2
User avatar
cjbiagi
 
Posts: 8323
Joined: Sun Jun 25, 2006 2:37 pm
Location: Glenwood, Illinois

1975 Chevrolet Monza


Re: Upper cont arm bushing

Postby v8vega383 » Sun Jan 03, 2016 6:13 pm

I definately need the upper offset bushings for my ride. After lowering the front suspension the angle of the tires really show. The car is extremely stable and drives straight at 122mph, so any minor adjustment to straighten the angle would be fine by me. Can some of the "offset" be adjusted by the lower control arms?
Attachments
image.jpg
Front tire angle is off after lowering suspension
image.jpg (180.75 KiB) Viewed 215 times
1976 Pontiac Astre, Pro Street, 383ci stroker, TH350 with 8 inch TCS convertor, 10 pt cage, back halved with 4 link and 9 inch rear. Best Et 10.85 in street trim ("all natural, no steroids"). Visit my Youtube page @ v8vega383.
User avatar
v8vega383
 
Posts: 16
Joined: Tue Nov 11, 2014 11:47 pm
Location: Edmonton, Alberta

Re: Upper cont arm bushing

Postby cjbiagi » Sun Jan 03, 2016 7:01 pm

Yes, the camber and caster alignment settings are done through the lower control arms. The problem is that you may run out of adjustment before you get the alignment set where you want it. That is very common with these cars. So, the only way at that point is to either get adjustable upper control arms or use the offset upper control arm bushings to get things back into alignment.
Clyde.........75 Monza 2+2
User avatar
cjbiagi
 
Posts: 8323
Joined: Sun Jun 25, 2006 2:37 pm
Location: Glenwood, Illinois

1975 Chevrolet Monza

Re: Upper cont arm bushing

Postby chevyart » Sun Jan 03, 2016 7:04 pm

thanks CJ. i am really going to school on this issue, and getting close to understanding the front end dilema on these nice cars, and i will hopefully know exactly what i want when it comes time to go to the alignment shop.. ill be watching how 383 solves his front end dilema. as fast as he is going, he needs a good front end setup when he goes a little faster in the near future. art
chevyart
 
Posts: 1866
Joined: Fri Oct 27, 2006 10:00 pm

Re: Upper cont arm bushing

Postby cjbiagi » Sun Jan 03, 2016 7:52 pm

For a street car I would shoot for between 1/4 to 1/2 degree negative camber, as much positive caster as you can get from the lower cams (lucky to get 2 to 3 degrees positive) and 1/8" toe in. This should provide good all around handling and tire wear.
Clyde.........75 Monza 2+2
User avatar
cjbiagi
 
Posts: 8323
Joined: Sun Jun 25, 2006 2:37 pm
Location: Glenwood, Illinois

1975 Chevrolet Monza

Re: Upper cont arm bushing

Postby v8vega383 » Sun Jan 03, 2016 10:34 pm

Thanks for all the info. This gives me a project for winter now.

Quick question,...How does one adjust the lower arms?

Cheers!
1976 Pontiac Astre, Pro Street, 383ci stroker, TH350 with 8 inch TCS convertor, 10 pt cage, back halved with 4 link and 9 inch rear. Best Et 10.85 in street trim ("all natural, no steroids"). Visit my Youtube page @ v8vega383.
User avatar
v8vega383
 
Posts: 16
Joined: Tue Nov 11, 2014 11:47 pm
Location: Edmonton, Alberta

Re: Upper cont arm bushing

Postby cjbiagi » Sun Jan 03, 2016 11:11 pm

The lower arms are adjusted by rotating the cam bolts that go through the control arm bushings. As you rotate them they move the lower control in and out as well as front to back. The front bolt is used to adjust the camber and the rear one for caster.
Clyde.........75 Monza 2+2
User avatar
cjbiagi
 
Posts: 8323
Joined: Sun Jun 25, 2006 2:37 pm
Location: Glenwood, Illinois

1975 Chevrolet Monza

Re: Upper cont arm bushing

Postby v8vega383 » Mon Jan 04, 2016 12:20 am

thanks CJ
1976 Pontiac Astre, Pro Street, 383ci stroker, TH350 with 8 inch TCS convertor, 10 pt cage, back halved with 4 link and 9 inch rear. Best Et 10.85 in street trim ("all natural, no steroids"). Visit my Youtube page @ v8vega383.
User avatar
v8vega383
 
Posts: 16
Joined: Tue Nov 11, 2014 11:47 pm
Location: Edmonton, Alberta

Re: Upper cont arm bushing

Postby Monza Harry » Mon Jan 04, 2016 9:16 am

Just to add a little to the soup. What has happened with these cars, started with the frame and frame plate situation, the factory V8 Monza plates are trying to twist the lower frame "Horns" and this is the cause of the long heard about frame spread issue, which then pushes the LCA outwards usually beyond the ability of the Cams ability to pull the LCA's back in line so the "FIX" that came about was the eccentric uppers. Tim McCabe has a post about how he used the steering box to pull his frame back in line and he added some beef to the "K" frame part to reduce the chance of reoccurrence of this problem. Oh 383 those lower Cam bolts are a Mother :cuss: :censored: ing Son of a :cuss: :censored: to get to turn if they haven't been turned in a while or if they weren't reinstalled with "Never Seize", the factory put them in dry and about 2>3 years later around here in the rust belt they wouldn't move without a torch and new ones. Harry
I'm not a hoarder I'm a preservationist 78 Monza Spyder (Soon To Be 2+2 with Spoilers)
User avatar
Monza Harry
 
Posts: 2368
Joined: Tue Oct 04, 2011 8:50 am
Location: Windsor ON Canada

1978 Chevrolet Monza 2+2

Re: Upper cont arm bushing

Postby cjbiagi » Mon Jan 04, 2016 11:07 am

Correct, the K member is designed to hold the frame horns from spreading so anything you can do there can help. I don't think it is that easy to bring the frame together without special fixtures or tools. Doing it with the steering box I guess has been done but I am not sure I would do that. Ideally you want to bring both sides in evenly and without knowing where they are or what you are doing could bring one side in more than the other and.......well you get the idea. There are frame dimension charts and holes in the chassis to measure by if you want to go that route but it is certainly more involved. It would be easier with the engine out as you could see more of what is going on and would not be also lifting the weight of the engine as the engine mounts also attach to the part that sags.
Clyde.........75 Monza 2+2
User avatar
cjbiagi
 
Posts: 8323
Joined: Sun Jun 25, 2006 2:37 pm
Location: Glenwood, Illinois

1975 Chevrolet Monza

Re: Upper cont arm bushing

Postby hammerdown7 » Mon Jan 04, 2016 1:15 pm

I think the biggest point here on frame spread is do not remove the k-member with the car sitting on the front tires.

Dick
User avatar
hammerdown7
 
Posts: 3650
Joined: Mon Jun 26, 2006 7:53 pm
Location: Clawson, MI

1976 Chevrolet Vega Cosworth

Re: Upper cont arm bushing

Postby v8vega383 » Mon Jan 04, 2016 1:56 pm

If the front Hooker/transdapt engine mounts still fit without any issues and the thicker front bumper plates, (behind the 74-77 model years bumpers), bolt back on without issue, do you still think there is any frame spread?
1976 Pontiac Astre, Pro Street, 383ci stroker, TH350 with 8 inch TCS convertor, 10 pt cage, back halved with 4 link and 9 inch rear. Best Et 10.85 in street trim ("all natural, no steroids"). Visit my Youtube page @ v8vega383.
User avatar
v8vega383
 
Posts: 16
Joined: Tue Nov 11, 2014 11:47 pm
Location: Edmonton, Alberta

Previous

Return to Suspension, Steering, & Brakes Tech

Who is online

Users browsing this forum: No registered users and 2 guests