Jump to content

Photo

Upper Control Arms Out of Spec

- - - - -

  • Please log in to reply
30 replies to this topic

#21
Bench Racer

Bench Racer

    Different strokes for different folks : )

  • Members
  • PipPipPipPipPip
  • 5,451 posts
  • Location:Wauwatosa, WI
  • Region:Milwaukee
  • Car Year:1990
  • Car Number:14

Tighten at ride height?  How do you do that?

Have the car with all weight (driver, driver equipment, cool suite water, 1 gallon of usable gas) included with the car at ride height high enough off the garage floor so that one may reach under the car to tighten the suspension bolts. My weight scale stands were fabricated to a height which I could lay on garage floor and tighten said bolts.  


Broken record - You are starting to sound like a broken record. Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#22
TylerQuance

TylerQuance

    Member

  • Members
  • PipPipPip
  • 92 posts
  • Location:Houston
  • Region:Texas
  • Car Year:1999
  • Car Number:70
Put a floor jack under the LBJ or rear knuckle while the car is in the air and lift until it's near where ride height would be. I have found it doesn't need to be exact, just get it in the range.

Think of all your rubber bushings as torsion springs. When you tighten the bolts with the arms in droop, the torsion spring is "wound up" when you set the car back down. Then they can slip a little on-track and your setup is perpetually awful.
  • DrDomm likes this

#23
Tom Sager

Tom Sager

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 1,653 posts
  • Location:Chicago Suburbs
  • Region:Central
  • Car Year:1998
  • Car Number:94

Put a floor jack under the LBJ or rear knuckle while the car is in the air and lift until it's near where ride height would be. I have found it doesn't need to be exact, just get it in the range.

Think of all your rubber bushings as torsion springs. When you tighten the bolts with the arms in droop, the torsion spring is "wound up" when you set the car back down. Then they can slip a little on-track and your setup is perpetually awful.

Yep, the car is at about ride height when the jack lifts the car off the jackstand. 


Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver We have a Winnah! - Won their 1st race... Congratulations! Make it Rain - Made Paypal donation of $100+

#24
DrDomm

DrDomm

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 882 posts
  • Location:Binghamton, NY
  • Region:NER
  • Car Year:2000
  • Car Number:46

Put a floor jack under the LBJ or rear knuckle while the car is in the air and lift until it's near where ride height would be. I have found it doesn't need to be exact, just get it in the range.

Think of all your rubber bushings as torsion springs. When you tighten the bolts with the arms in droop, the torsion spring is "wound up" when you set the car back down. Then they can slip a little on-track and your setup is perpetually awful.

 

That is very interesting, and makes sense.  Thanks.  

 

If anyone wants to know how to do a C-Section or something else, I can trade some medical knowledge for basic mechanical or racing knowledge.   :laughing:  :noidea:


  • Tom Sager likes this
Domm Leuci
--because someone commented that we should all post our names, and not be anonymous. I agree.
Make it Rain - Made Paypal donation of $100+ Bona fide - A bonafide Spec Miata driver

#25
Brandon

Brandon

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 750 posts
  • Location:North Jersey
  • Region:NNJR
  • Car Year:1996
  • Car Number:48SM

That is very interesting, and makes sense.  Thanks.  

 

If anyone wants to know how to do a C-Section or something else, I can trade some medical knowledge for basic mechanical or racing knowledge.   :laughing:  :noidea:

 

The zombie apocalypse hasn't quite arrived yet to require knowing how to birth a child but I'm always more than happy to provide guidance in the ways of the mechanic.

 

Tyler - these look pretty slick. They don't require pinning to retain bushing positioning?


Bona fide - A bonafide Spec Miata driver

#26
FTodaro

FTodaro

    Veteran Member

  • SMembers
  • PipPipPipPipPip
  • 3,062 posts
  • Location:Columbus Ohio
  • Region:Great Lakes
  • Car Year:2001
  • Car Number:35

Tighten at ride height?  How do you do that?

 

BTW, my curiosity was really about whether everyone was moving to the extended LCA ball joint.

quick story, At the NASA championships at Mid-O like 6 years ago, as a part of tech before the big race they pulled in a select group of racers to check parts. Rather than have me mark the shock and pull it after the race, they had me pull the left rear shock to dyno it. Well that went OK but when i reinstalled the shock, I did not put a jack under the axle to compress the suspension when I tightened it back up. The next session was the race, I went out on track and could hardly keep the car from spinning out. Lesson learned always preload the suspension in that situation before you tighten the parts and lobby tech to mark the parts and pull off after the race. How stupid is it to mess with your stuff before the big race.


Frank
TnT Racing
SCCA Ohio Valley Region
Chairman, SCCA Great Lakes Divisional Series Committee.

Make it Rain - Made Paypal donation of $100+ We have a Winnah! - Won their 1st race... Congratulations! Bona fide - A bonafide Spec Miata driver Donor - Made PayPal donation

#27
TylerQuance

TylerQuance

    Member

  • Members
  • PipPipPip
  • 92 posts
  • Location:Houston
  • Region:Texas
  • Car Year:1999
  • Car Number:70

The zombie apocalypse hasn't quite arrived yet to require knowing how to birth a child but I'm always more than happy to provide guidance in the ways of the mechanic.

Tyler - these look pretty slick. They don't require pinning to retain bushing positioning?

I used to pin them but found there's no way they are moving. It's a hard press to get them in, 8 tons or so.

#28
Steve Scheifler

Steve Scheifler

    member

  • Members
  • PipPipPipPipPip
  • 2,666 posts
  • Location:St. Louis

I used to pin them but found there's no way they are moving. It's a hard press to get them in, 8 tons or so.


My concern with that is the amount the receiving sleeve in the arm stretches when pressing that hard. This became very obvious when doing Whiteline bushings the first time and I pressed one back out so I could realign it slightly. Very little force was required to press it in the second time. I pushed it back out and tried a new bushing and it too went in easily, so the arm had stretched. It’s quite possible that if properly aligned the first time and left in that would never be a problem, but I decided to pin them all anyway.

This reminds me, at the same time I discovered that even brand new long-bolts for the upper arms are not always perfectly straight, making perfect alignment of solid bushings a bit trickier. Has anyone else encountered that?
Bona fide - A bonafide Spec Miata driver

#29
TylerQuance

TylerQuance

    Member

  • Members
  • PipPipPip
  • 92 posts
  • Location:Houston
  • Region:Texas
  • Car Year:1999
  • Car Number:70
Most of the press force I have encountered is to make the sockets in the arm circular again. Only one half of the socket is welded to the arm so it's an oval due to weld cooling stresses. I have screwed up and had to remove several, never seen the arm socket stretch. I have never pressed in whitelines myself however so what you are saying could be true for those.

#30
Steve Scheifler

Steve Scheifler

    member

  • Members
  • PipPipPipPipPip
  • 2,666 posts
  • Location:St. Louis
It is absolutely true for the whitelines, BUT they have a steel outer sleeve. The ISC version (made of white Delrin) had no outer sleeve so rather than stretch the arm they deformed which slightly collapses the center causing the inner sleeve to be tight, requiring a crude hone job unless the installer had advanced tools to rebore/true the hole. Neither were acceptable IMO.
Bona fide - A bonafide Spec Miata driver

#31
Brandon

Brandon

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 750 posts
  • Location:North Jersey
  • Region:NNJR
  • Car Year:1996
  • Car Number:48SM

Where do you source your front UCA's? I've bought 2 pairs of Moogs that are 5/8" longer than stock (total length from subframe to balljoint). Measurements are taken while installed in the Advanced Autosport's jig. 

 

Has anyone else seen this? Can you recommend a source with consistent dimensions?

 

What exactly do you mean when you say "from the subframe"? From the flat area that mates with the frame horn or the approximate centerline of the bolt hole?

Trying to visualize the measurement you're taking and whether the set of replacement UCAs I have on-hand are in the same boat as yours since I didn't pay all that close attention with the control arm jig measurements.


Bona fide - A bonafide Spec Miata driver




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users