Difference in GS/Skylark rear upper control arms?

Hm, I will have to check my Olds assembly to see if part #s are the same.

 

It sure is nice to know that I am not the only "nutcase" here.:laugh:
Duane

 

Re: Nut cases
When I refurbed the back half of my Olds chassis, I found the "NZ" application code stamped with red/orange paint still in good condition on one lower control arm, thanks to protection from the sway bar. I took measurements and had a rubber stamp made, then re-stamped both control arms after powder coating. I figured I was just being faithful to the car, not being a nut case.

The first Olds show I attended after completing that work, I hadn't even finished parking the car before some guy was crawling underneath. He has somehow spotted a flash of red on a control arm and had to know what it was. He continued to pester me until I promised to ship him the rubber stamp so he could stamp his control arms. He never did say anything else about the rest of my car -- but, boy, he sure did like those red/orange letters! Nut case. :grin:

 

Duane..I guess I could be considered a nut case too. You'll know what I mean when you see the three posts I sent you earlier today! ou: Wheelz, Tampa Bay

 

If you do put that bar on the front 1 1/4" would have been better you MUST install a factory or better bar on the rear as well or your handeling will be seriously hurt and may even develope an understeer

just my .02

Ken

 

Both Walt and Duane are correct, as I now feel comfortable stating that it is the bushings that were different between the NK and NL/PX stamped upper rear control arms and not the control arms themselves.

I just pulled the NL uppers from my Flint-built '69 GS 400 and compared them to a pair of NKs that I pulled from a Skylark. Except for the stampings, they appeared identical in every way. I then removed the bushings and weighed the arms and sure enough, they weighed the same (26 ounces).

The bushings in the NL uppers were labeled "INLAND" and "N-11-17", with a red and green stripe on them. The lower control arms from my '69 GS 400 also had "INLAND" bushings with "M-9-60" and "M-17-25" . The bushings in the NK uppers were "Harris" and "62538". I do live in Denver where these cars were in daily use for many decades, so I can't guarantee that any of these bushings were original.

As many of us realize now, the assembly manual does in fact call out different bushings for these two different control arms.

 

Curtis - Not sure if this is fact or urban legend and I'm not a suspension engineer but a I have always heard that fat front bar needs a bar in the back to balance the suspension and weight transfer. Check it out. For example from the MG folks:
"If you go too stiff up front you reduce front grip to the point of inducing high speed understeer. This is not terribly bad for a street car. If you do something stupid at speed the front end will drift to the outside of the turn. If/when you then (instinctively) lift off the throttle, the deceleration will transfer a small amount of weight forward giving better grip up front at the same time as the car slows down, and it will turn in and stay on the road (very civil, nothing dramatic)."

 

Wow you dug out this oldie. Considering we are pretty limited in bushing availability now none of this has much relevance unless you find NOS.

 

Apparently (especially after Ralph Nader’s little book) GM was very much afraid of oversteer. The ‘78-87 El Caminos couldn’t be had with a rear sway bar even with F41. I have heard people say adding one can make them tail happy.
Patrick

 

Wow Dave - didn't even notice the date!!!

 

Yeah,
The 68-72 El Caminos didn't come with rear sway bars, not even the SS models................but I put one on the X-Camino.

However, it does get a little interesting if you get caught in the rain.
Duane

PS. Some questions keep bugging people and need to be answered. I feel exactly the same as Mike S. about some things.

 

Nearly all vehicles are designed with understeer for this reason. It's measured IIRC with what's called a steering gradient test (don't recall the SAE test #). Basically, the vehicle is driven in a constant radius circle faster and faster until either the front end ploughs or the rear end comes around.

 

I had an Uncle that put his 396 El Camino through a building. Maybe he added a sway bar? I was pretty young so don’t remember the details. Maybe adult beverages involved?

 

Yeah,
I guess the idea of balancing out the rear wheels by using a sway bar is not a good thing when the vehicle has no weight in the a$$. The rear just wants to come around.

I know of a guy that did this with another "Truck". He welded some re-bar in the back bumper and filled it in with cement. At that time he had ZERO traction problems.
Duane

 

I would hate to rear end him.