cbartonbrown

my mechanic says that my rear control arm bushings in my 1967 Oldsmobile Cutlass supreme convertible are no longer functioning properly. For this reason he says the control arms must be replaced. viewed in place, the bushings are definitely cracked and look flattened. There is a squeak when the rear end moves up and down. I have some questions.

1. are these cracks evidence that these bushings need to be replaced?
2. if yes they must be replaced, do the control arms themselves have to be replaced or just the bushings? he said something about the bushings being pressed into the arms.
3. Summit racing sells tubular upper and lower control arms for $290.
4. my mechanic says the tubular arms improve the operation of the car. True?
5. if the cracking means the bushings need to be replaced and the control arms need to be replaced, is it wise to replace these control arms with these new tubular control arms? The great feature of my car is that it is completely stock. 208,000 miles, but it looks great inside and out – and stock. it is just a Supreme convertible so it is not a collector car but a fantastic surviving example with a great looking paint job. I do not see that tubular control arms will damage the value because it is a decent number two – three plus (I think).
6. he wants to charge $500 in labor which at his hourly rate is about four hours.

thank you so much for any ideas everybody. I really appreciate it.

Signed, Charlie Brown. Feel free to call or email me at 312.316.6054/charlie@corplaw.com

oldcutlass

Moog K5161 is the replacement bushing kit for upper and lower control arms. Each kit contains 2 bushings to replace for 1 control arm. You need 4 sets as there are 4 control arms. Rockauto sells them for $18.68 per kit. They are fairly simple to change.

70Post

Don't waste your money on any tubular arms......they won't change anything on the car and any effect on the value means nothing. The car is stock and nobody is going to care, one way or the other, if it has tubular arms on it.

A good set of shock absorbers would be a sensible change/addition if you have older shocks on it.

You can probably do a lot better on the cost if you can pull the rear arms and find someone to install the new bushings as Eric suggests above.

cbartonbrown

OK, so i don't have to replace the trailing arms, correct because they usually don't fail? My mechanic did not say they had failed. So, the bushings could be pressed into the old trailing arms? maybe the labor is the same to install bushings with or without replacing the arms so he thought, hey, why not replace the arms?

droldsmorland

If you were to do any type of "upgrade" install boxed 442 lower control arms with new OEM rubber bushings and matching OEM anti-sway bar(s). That would be a great bang for the money and would be stock appearing.
Kits are available to convert your non-boxed arms to boxed if your arms are in nice shape. The sway bar has to be installed to see any gains and make it worth the boxing process. None of this is big money. This stuff is available used.

Look at what new replacement arms cost with new bushings already installed(if avail for 67s). It could be economical from a labor time perspective. So long as the new stuff isn't chineasium garbage.

With 200K miles the front end likely needs bushings, brake flex lines, and BJs too. Of course, let the MAWs commence. You should refresh the front end and install a larger 442 front sway bar with Polly bushings. It will carve corners(at least from 1967 standards compared to a regular Cutlass chassis).

If your original control arms are not rusty just replace the bushings...all 8. If you're doing the lowers you should do the uppers as well. If the mechanic hasn't suggested that find another mechanic!
It all has to work in unison. Old bad uppers will only stress the new lowers and vise versa.
I'm sure the uppers are just as bad as the lowers....AND....MAW change the rear diff fluid and rubber brake line to the rear brakes....See how nicely I can spend your money! The rubber flex brake line is a safety thing.

Ask the technician if he will properly support the control arm during the bushing installation process to prevent the collapse of the arm. If he looks at you strangely...run and find another mechanic.

RandyS

I would say that your mechanic is wanting you to pay for his kids college education.

cbartonbrown

Thanks, guys. I appreciate the proactive repair ideas. I'm maintaining it to full spec's with annual inspections but I can still ask specific questions about important areas.

What is MAW?

And dare I say what are BJs?

OLDSter Ralph

MAW = Might As Well
BJ = Ball Joints

1967Supreeeme

1967Supreeeme

The rear arm upgrade was the first thing I did to practice my first TIG weld project. Super easy upgrade. Someone put the sway bar on my car without boxed arms. I did the weld ins and all the bushings at the same time. Well worth it!

Schurkey

1. Every rubber part that came on your car has failed. Suspension bushings, body-to-frame bushings, radiator retainers, hoses, belts, weather strips, EVERYTHING that was made of rubber is shot. This stuff was past it's expected service life decades ago. That's the nature of rubber parts.

2. You can replace the bonded-rubber OEM style bushings, but you have to use special tools to support the arm while the bushing shell is squeezed out of the control arm. OR you can buy new stock-appearing arms--generally low-budget Chinese junk. OR you can buy aftermarket control arms, which can be expensive, USA-made, quality pieces, or they can be Communist Knockoffs of the "good stuff".

3. Or you can do like I've done on a heap of vehicles. DON'T press out the bushing shell. Warm it up with a propane torch, the rubber bushing practically squeezes itself out. Clean up the inside of the shell with Scotchbrite pads or maybe some emery cloth. Install new Polyurethane bushing inserts in the original shells. There's not a thing wrong with the design of the OEM rear control arms, once you figure out that the rigid aftermarket arms advertised as "stronger" are generally engineered wrong--the OEM upper arms in particular are INTENDED TO FLEX. They're not "weak", they're doing double-duty. The rear suspension design of the "A" body results in binding due to the angles of the arms. If the upper arms can't flex, the suspension locks-up.

4. If you install bonded rubber OEM-style busings, the suspension MUST be at normal ride height before you torque the bolts. With Polyurethane bushings, the position of the suspension doesn't matter. Torque the bolts in any convenient position.

5. If you think $500 to replace rear control arms is high, just wait til you get his estimate for body bushings.
https://www.chevelles.com/techref/body_bushings.html

cbartonbrown

Schurkey and others- Thanks so much for this valuable input. It will help me immensely.

Cheers.

Charlie

VC455

Be careful if you decide to use polyurethane bushings for the rear control arms ...and not just for the harsher ride that could ensue.

Think about what happens when one of the rear wheels rises or falls below its mate (such as when going over bumps or crossing a swale at an angle).

The axle motion causes the bushings to twist. If the bushings are hard (polyurethane) they will resist the twist and cause the axle to bind. If the bushings are soft (rubber) they will accommodate the twist and there will be no binding.