Upper/lower Control Arm bushings questions

[Gary S.]

I am getting ready to replace the original (almost) 44 year old CA bushings on my 1972 LT-1 so I did some extensive reading after a search here. I will be placing an order for Carlisle pickup but wanted to see if I understand things correctly.

1. From what I read, no one produces a correct bushing although some are closer than others. I read that Moog is great but the usual vendors are good too. Is there any difference in quality between the vendors since judging points are out the window? How about NAPA rubber bushings?
2. There are some YouTube videos showing the removal of the bushings by various methods, including drilling multiple holes in the rubber and then tapping the bushings out. Here is one example that I watched. https://www.youtube.com/watch?v=1X9iOPpaBYA Is there anything wrong with this technique?
3. My neighbor has both a drill press and a hydraulic press so I plan on doing this myself. Is there any reason that a prudent and careful guy cannot do this alone?
4. In reading the DIY procedures for the safe removal of the spring, it was suggested that a 5/8" rod with the various nuts, washers and large plate on the bottom would work well. Of course, the usual warnings about the spring's stored energy were noted. Various sources said the plate should be 4, 5, or 6" square. Which one works the best? Also, it was suggested that the Home depot brand of steel rod wasn't sturdy enough. Do you have a source for a higher grade all thread rod?

I will evaluate the ball joints but, other than age, there doesn't appear to be anything wrong with them. The car only has 44000+ miles on it.

Thank you as always,

Gary
21316
grumpa72@gmail.com

[Mark E.]

Re: Upper/lower Control Arm bushings questions

Gary-

Disclaimer- I've never restored a suspension to NCRS Flight standards. But I have rebuilt suspensions on several GM cars over the years. With that said:

1. The reality is that most parts are manufactured overseas, and quality can be hit and miss. So I just stick with a major brand with a good warranty, then carefully inspect and compare to the original part. Last time I chose NAPA for the major components- they offered a "lifetime" warranty (although they couldn't answer the question whose lifetime- mine, theirs or the car's ), plus their local store offers an extra 30% off everything 7-9AM every second Saturday. So I would pre-order my stuff then wait to pick it up that morning. I was amazed that they actually have a lifetime warranty on their PS valve and cylinders. NAPA confirmed that if those leak next year (which I KNOW they will) I can exchange them for another. Net pricing was probably 50-60% less than the on-line Corvette parts houses which offer a very limited warranty and charge a fortune for cores and shipping. This last time, quality from a fit and performance perspective was good. My car won't do great during judging though- for example, the amount of exposed rubber on the UCA bushings is "incorrect". You might also shop AutoZone and RockAuto; many of their parts have lifetime warranties too.

2. I'm guilty of using an air chisel to remove UCA bushings. That was an attempt to do the job without removing the A-arm from the car. It saved time but there's the risk of damage to the A-arm or nearby components if the chisel slips. Since you have access to a press, I would just use that- much easier, safer and less risk of damage.

3. Go for it! Again, the job is straight forward using a press. Another option: Many parts houses will R/R bushings for free or little cost if you purchased the parts from them.

4. Safety first! I would use a spring compressor designed for the job. They're not expensive. Also, many auto parts stores loan or rent these.

Regarding ball joints and other parts: The time and labor to disassemble, clean, inspect, refinish/paint, assemble and align the suspension dwarfs the cost of parts. So I would err on the side of just replacing everything you can think of... ball joints, tie rods, center link, idler arm, bumper stops, brake hoses, calipers, rotors, bearings, PS components... maybe even consider rebuilding the steering gear and rag joint. This way when you're done, you're DONE.

Good luck with your '72 LT-1... nice car!

[Gary S.]

Re: Upper/lower Control Arm bushings questions

Well, good (ok, great) points. Spring compressor - I haven't called yet to see if the local places still have standard compressors. Ball joints - the biggest problem is that I want riveted ball joints and I don't have the means to do that. I read here of folks doing it themselves but again, that is probably beyond my abilities. Bairs is only 90 minutes away so I COULD go there for the ball joint install. Lifetime warranty? I am almost 65 - so what if I "only" get 10-15 years out of a part? No air chisel available but the YouTube looked simple enough, even if it was an old video on a Chevy not a Corvette.

[Mark E.]

Re: Upper/lower Control Arm bushings questions

I THINK NAPA offered riveted ball joints as an option. Check with local machine shops and parts houses about installing these; it shouldn't be difficult for them or expensive.

I wasn't recommending using a chisel; that was an example of what NOT to do. And I wouldn't recommend the gorilla approach of using a hammer to beat the bushings out like the video shows either. Again, since you have a press- use that. Much safer and easier.

[Mike E.]

Re: Upper/lower Control Arm bushings questions

I fabricated the J-7052 from dimensions that Joe Lucia supplied in this post and followed the Chevrolet SM. Using a 20 Ton low cost hydraulic press from Harbor Freight. The bushing I sourced from RockAuto. I bought one of the Kits from CC and when installing the bushing the metal was so soft it rolled when pressing in.

On a part like this I see no reason to buy from a Corvette suppler as mentioned no part is going to be 100% correct.

As for installing riveted ball joints it was somewhat involved and required some investment in tools. I followed Tracy Crisler's article that was in the Restorer a few years back.

Upper bushings

https://www.rockauto.com/catalog/raframecatalog.php?catalog=11&partnum=K5196

Lower bushings

https://www.rockauto.com/catalog/raframecatalog.php?catalog=11&partnum=K304

Mike

[Duke W.]

Re: Upper/lower Control Arm bushings questions

Why replace them? With only 44K miles they may be perfectly serviceable. Cranks on the rubber that protrudes from the ends is normal. It's the condition inside, which you can't see that counts.

Do you hear clunking or some other abnormal sound from the front suspension/steering when you drive? Does the car wander down the road? If not and the alignment is reasonable within spec, the bushings, ball joints and steering linkage joints are probably okay.

Test the bushings with a pry bar at various locations to see if they easily move. If not, they are okay. The lower bushings are more likely to deteriorate since the see most of the static and dynamic loading. Same with the lower ball joints.

Do the same with the ball joints. If there is no noticeable vertical movement, they are okay, too.

Duke

[Mike E.]

Re: Upper/lower Control Arm bushings questions

Why replace them? With only 44K miles they may be perfectly serviceable. Cranks on the rubber that protrudes from the ends is normal. It's the condition inside, which you can't see that counts.

Do you hear clunking or some other abnormal sound from the front suspension/steering when you drive? Does the car wander down the road? If not and the alignment is reasonable within spec, the bushings, ball joints and steering linkage joints are probably okay.

Test the bushings with a pry bar at various locations to see if they easily move. If not, they are okay. The lower bushings are more likely to deteriorate since the see most of the static and dynamic loading. Same with the lower ball joints.

Do the same with the ball joints. If there is no noticeable vertical movement, they are okay, too.

Duke

I missed the 44K miles...I agree they can only be original once. Unless you are lucky enough to find NOS GM ball joints they will be detectable. One of my lower ball joints was totally shot, saving it was not an option.


As far as tie rod ends, some of the vendors claim they are "Correct", I've found that is not really the case. For one thing the repop tie rod ends have grease zirks installed for decoration only they come with a tag that says they are sealed units.

Original


Reproduction









Mike

[Gary S.]

Re: Upper/lower Control Arm bushings questions

Duke and Mike,
Good points. The visual evidence was that they were shot because of the cracks on the exterior. I wjll use the pry bar method to test the CAs since there isn't any ride issues. Same thing with my sway bar bushings. Very ugly but I'll look closely at them.

Thank you all.

Gary

added: Nice photos btw.

[Mark E.]

Re: Upper/lower Control Arm bushings questions

Am I the only one who thinks it's bizarre to have sealed tie rod ends with fake zerk fittings?

What's the point?

[Mark E.]

Re: Upper/lower Control Arm bushings questions

Why replace them? With only 44K miles they may be perfectly serviceable.Duke

I guess it comes down to how the car will be enjoyed and the purpose of doing the repairs:
- If you want an original looking car for judging, then retain as many old, partially worn parts you can.
- If you want a well maintained car that handles and drives well, then replace all the wear related parts you can.

What's your intention with this car, Gary?

[Gary S.]

Re: Upper/lower Control Arm bushings questions

UCA1.jpgUCA2.jpg
Here are two quick cell phone shots showing the cracking that concerns me. I did put a pry bar in and got zero movement. In addition, as I stated, the car rides well with zero issues or noises. My purpose with this car has always been enjoyment first and judging/showing second. However, I have striven to keep the car as original as possible and had it judged 12+/- years ago at an Atlanta regional. Some day I will fix the very few extremely minor details and will have the car judged again. Fwiw, I even saved the original shocks that were still on it as well as all the underhood hoses. The shocks could be moved in and out easier that a kids accordion.

From what I have read today and what I learned, this car does not need new bushings in the control arms.

Gary

[Mark E.]

Re: Upper/lower Control Arm bushings questions

From what I have read today and what I learned, this car does not need new bushings in the control arms. Gary

Gary,

Are you talking about the bushings in your photos? Those are just about shot. Yes, they may (so far) hold their shape while the car isn't moving but bushings cracked that badly don't maintain geometry well.

This reminds me of high school days when my friends and I would debate how long we could avoid fixing our cars. The motivation then was saving money; today it's "originality". Is a Corvette really more valuable with a badly worn, albeit original, safety related part installed?

[Joe L.]

Re: Upper/lower Control Arm bushings questions

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Here are two quick cell phone shots showing the cracking that concerns me. I did put a pry bar in and got zero movement. In addition, as I stated, the car rides well with zero issues or noises. My purpose with this car has always been enjoyment first and judging/showing second. However, I have striven to keep the car as original as possible and had it judged 12+/- years ago at an Atlanta regional. Some day I will fix the very few extremely minor details and will have the car judged again. Fwiw, I even saved the original shocks that were still on it as well as all the underhood hoses. The shocks could be moved in and out easier that a kids accordion.

From what I have read today and what I learned, this car does not need new bushings in the control arms.

Gary

Gary-------


As Duke mentions, these may be OK. The portion of the bushing that is visible is not critical, at all, to the functioning of the bushing. Also, the portion that is visible is the part that suffers the most from environmental factors (ozone, heat, weather, etc.). However, the critical part of the bushing, the part that's functional, has done a lot of flexing over its life. Personally, I don't think it's feasible to assess the FUNCTIONAL condition of these bushings by using a pry bar or any other such means unless the bushings are in REALLY bad shape.

The original bushings, upper and lower, were embossed "Harris" on the rubber component. In about 1973 the uppers were changed slightly in configuration and re-sourced from Clevite. "Clevite" appears embossed on these bushings. The original "Harris" bushings had an exposed rubber "collar" on the inner end; the Clevite bushings do not and the steel shell extends all the way to the end of the rubber. If you find aftermarket bushings that are embossed "Clevite" on the uppers and "Harris" on the lowers, then these bushings will be identical to those sold by GM.

Most likely, bushings sourced under major brands like Moog will be the Clevite and Harris-sourced bushings. If they are embossed with Clevite and Harris I would not worry too much about what their country of origin is; many parts such as these are now manufactured off-shore.

If you wish, these bushings are still available from GM. The Clevite-manufactured uppers are GM #401267 and currently GM list for $14.71/each. The lowers are GM #3714368 and GM list for $29.68/each. The original Harris-style upper bushings are available in reproduction but I don't know anything about their quality or origin.

[Mark E.]

Re: Upper/lower Control Arm bushings questions

Joe,

Good to know that GM still sells original looking bushings.

We'll have to agree to disagree about their condition. Especially since Gary's priority is "enjoyment first and judging/showing second", assuming enjoyment means driving a car that handles properly. And now knowing original style bushings are available tilts the calculus even more towards replacing them...

[Gary S.]

Re: Upper/lower Control Arm bushings questions

Gary-------...


The original bushings, upper and lower, were embossed "Harris" on the rubber component. In about 1973 the uppers were changed slightly in configuration and re-sourced from Clevite. "Clevite" appears embossed on these bushings. The original "Harris" bushings had an exposed rubber "collar" on the inner end; the Clevite bushings do not and the steel shell extends all the way to the end of the rubber. If you find aftermarket bushings that are embossed "Clevite" on the uppers and "Harris" on the lowers, then these bushings will be identical to those sold by GM.

...

Joe,
Are you saying that the embossing is on the rubber bushing itself? Thank you for the GM part numbers, too.

Mark,
The car rides remarkably well and handles as well as I expect it would. My original assessment was based on the appearance of the outer portion of the bushing and not on ride, noise, or any other discernible quality. I will have to think about this for a while.

thank you all,


Gary