Stephen Irons

So, I've noticed that our '78 has a tendency to pull a little to the left under acceleration and then returns to straight when I lift off. Am I right in thinking that this may be a sign of worn trailing arm bushes?

If so, just how hard are they to change? I've no lift here (its Europe after all!) so it'd be on the ground on jack stands if the job needs doing.

Ta!

Jartanyon

My '78 had the same issue - rear end would walk out from behind me when accelerating and then return. TAB were shot. One of the top 5 worst jobs I did on my car. I did not have a lift which wasnt really a problem. The problem is if you need to saw the bolts off if they are rusted solid. It took me weeks of soaking the bolt and shims in ATF/acetone and then I cut the bolts off. MAKE SURE you buy good blades - I wasted a lot of time and money until I bought Milwaukee blades. Good luck!

resdoggie

The bolts are not worth saving so why bother with penetrating oils. Sawzall and a good blade or two. I cut right through the shims down to the bolt. Took about 10 minutes per side and some patience.

Stephen Irons

Thanks for that - I think! Sounds like as much fun as I had expected.

Although, I have to say that the bolts actually don't look too bad from what I can see. Nicely undersealed form a long time ago, but of course, can't see how they look in the actual trailing arms.

Did you guys dis-assemble the TAs, callipers obviously, but spindles etc?

But, assuming I do get them out, what's the story on getting bushes out and new ones in. And, are there poly bushes available for them? I put poly bushes on the track bars many years ago and have been very happy, not to mention they were a whole lot easier to fit!

leadfoot4

I last replaced the TABs on a C-3, about 20 years ago, so here's what I remember......


I did this while the car was off the road for the winter, so I didn't have to rush the job. I didn't have a lift, so the car was SECURLEY on jack stands.

Yes, I seem to recall that I had to cut the "through bolts" that secure the TAs to the frame. There are two potential "issues" with these bolts. Either the hex nuts rust themselves solidly to the bolts, or the bolts rust themselves solidly to the steel "sleeves" that are on the ID of the bushings. While brute force usually can overcome the hex nut issue, there's no practical way to bust the bolts loose from the bushings, if they've indeed rusted in place, so you'll wind up cutting through the shims and bolts. Might as well just cut them and get it over with. Replacement shims and bolts, in stainless steel, are available, so it's no big deal.

The other issues are related to the removal of the TAs, which is necessary. You need to remove the halfshafts, disconnect the camber adjustment rods and the lower shock mounts. The shock mounts, especially, need to be removed with care, as they have to be reused. There was a tool called a "shock knocker" that I bought for this step. Then you have to remove the brake calipers and disconnect the e-brake cables. At this point the TA can be removed from the car, but it's heavy and bulky to handle.


The bushings themselves, also present a few "quirks". When I did this job, I used polyurethane bushings, but from what I've seen lately HERE, some of the suppliers are having quality/durability issues with the material. While I liked the poly, I'd make sure that I bought them from either Energy Suspension or Prothane, the well-know suppliers.

As I recall, the bushings are actually a 2-piece affair, with half the bushing going in from each side of the TA, then the inner sleeve is "flared" at one end, to keep both halves in place on the TA. The bushings that I bought (in the mid 90s) weren't either of the above bushings that I mentioned, I got mine from VB&P, and they included a small "flaring tool" with the bushings.


That's pretty much all I can remember......Good luck!!

Tampa Jerry

Before cutting the bolt off, try soaking the bolt, bott inside and outside of the pocket for a few days with Liquid Wrench or ATF mixed with acetone. The bolt and shims may come out easily. My 66 from sunny Calif. took about 10 hours to remove because it was so rusted. My 68 out of New York City took about 10 minutes to remove even with some rust present. Try soaking first. Whatever you do, do not replace with poly bushings. I went down that road and they literally turned to glass after 3 years and fell out. The good news is that the bolts were very easy to remove the second time around. Lastly, replace your shims etc. with stainless steel for future work. Good luck. Jerry

resdoggie

So you had a bad experience with poly. Most folks don't. If poly was such an inferior product, no one would make them anymore.

To the op, as suggested above, buy poly from a well known company. Btw, my adjustable strut rod bushings are still working after 20+ years and no signs of crumbling. Highly recommend poly for longevity and ease of installation.

leadfoot4

I started using poly bushings back in the late 70s, and never had one "crumble". HOWEVER, I haven't used any in about 12-14 years, and maybe "Chinese copies", with poor chemical formulations are filtering into the market, giving them a bad reputation.

DUB

For whatever this is worth.

I do not use polyurethane bushings for the trailing arms any longer. AS a mater of fact..I do not use them anywhere any longer. (My choice) I use greaseable heim joint strut rods or the Global West front control arm bushings that are re-greaseable Delrin bushings.

With the XYZ motion of the trialing arm..I prefer to use the rubber. Most of my Corvette customers are not racing them. If I want a really good bushing I would use Global West trailing arms.

Even though I like a lot of products from Vette Brakes and products. There trailing arm bushings (in the past) have burnt me really good when I installed them when a customer requested them. They are WIDER than the stock bushing...THUS...this CAN effect you getting your trailing arms aligned because with it being wider...you might not be able to put the trailing arm where it needs because the bushing is now hitting the inside frame pocket and not allowing you to get your toe setting correct. This burnt me SEVERAL times....so I do not use them ...nor never will again.

AND YES...in the past...I did use them in some Corvettes and they were fine...so it depends on the condition of the trailing arm. Sometimes it is hard to see with the naked eye and get you when you go to the alignment shop....and then have to pull it all apart and 'tweak' the trailing arm.

YES..there HAS been documented proof that the urethane has failed.

DUB

Stephen Irons

Thanks for all the above guys. Some things t think about there clearly.

I'm hoping not to have issues removing the things like drive shafts, strut rods etc, as they have all been off recently for various jobs

So re the bushings - do they need to be pressed out, and back in again, or do they (in theory!) just pull out from each side?

As leadfoot4, this would be a winter job, so hoping not to have to rush it. My biggest issue really is getting the parts - shipping and the extortionate duty that goes on the cost of the parts PLUS the shipping charges makes things pretty pricey over here. But, at least they are all available!

resdoggie

Are the trailing arms still on the car and have they ever been removed? If not, you're in for a challenge. The bushings, once the TA is removed, can be pressed out or hammered out using a hammer/chisel or an air chisel which works great. If your car is not a daily driver and mostly driven in nicer weather, then I would go poly from Energy Suspensions. They don't need to be pressed in and are very simple to install by yourself.

DUB

The trailing arm bushing can NOT be pressed out or hammer out. The staked sleeve and special washer that it is staked to prevents this. Because they are staked together. And due to the integrity of the trailing arm itself....I would not be doing any severe hammering or pressing on it and possible damage it.

When I get the trailing arms out. I take my Porta-Band saw and cut the inner sleeve. I cut right through any rubber and through the sleeve. This then allows me to get the inner sleeve assembly out....then pull out any remaining rubber....and then pull out the sleeves of the bushing itself.

The new bushing will get pressed together...and then staked to hold that compressed value.. It all depends on which design you choose to use.

If using rubber factory style...there is a special'staking fixture tool' I have that allows me to compress the bushing and stake the inner sleeve. You might be able to make one if you want.... instead of buying one.

DUB

resdoggie

I guess your set in your ways and thats the way you do it but there are other effective ways to get the bushings out with much less effort and no more risk of damage to the trailing arm than your method. It's also been documented on you tube and confirmed by others, myself included. Poly bushing replacements of good quality are also a good idea mainly for the ease of installation and no loss of performance compared to rubber.

htown81vette

Once you get the trailing arm out you should take them to (or send them off to) someone who really knows how to remove and install the new bushings. Don't take them to just any mechanic, chances are they won't really know how to do it (but probably will tell you that they can). Take it to a Corvette specialist such as DUB.

Oh yeah, and good luck getting the trailing arm back in. Have you ever built a "ship in a bottle"?

htown81vette

I've bought poly stuff for all my cars everything from motor mounts to suspension bushings. I love that stuff, way better than rubber. But the only thing I've heard is if you let your car sit for awhile, especially over a cold winter, they can get brittle. I've never had that problem, I drive my cars often so it's not an issue.

DUB

OK...I guess this is true. You did it..so it can be done..I do not dispute that at all....and YES...I guess I have found a method that works for me. Hard to change doing something when something works and does not cause for added work or problems.

There is no risk of damage to the trailing arm with my method. Absolutely NO CHANCE. Mainly because I am watching what I am doing and the saw blade from my Porta-band can not cut the trailing arm....there just is no way...unless a person is using it and are BLIND.

I do not know how much less effort you ahve mentioned is...but it does not take a lot to hold a Porta-band and allow it to cut. That seems to be pretty effortless. Because I allow the weight of my Porta-band to do the cutting...I just basically guide it.

Post a link to this YouTube video you mentioned. ( If you have it handy) I need to see it. The reason is this. I have done so many trialing arm bushings that were so badly seized up...that the thought of pressing out out the inner sleeve and not bending the trailing arm and trying to take the inner collar by it... with it....it seems (to me) to be a waste of my time setting up my press. Especially when I can have it cut off in under a minute with my Porta-band. Getting the sleeves that are pressed into the trailing arm out is a snap with my air hammer. A few taps and they are out.

I guess they are just forcing everything out with the press.

SO..I guess it also depends on the tools at hand for the person doing it.

I look at the video but I know I will stay with my method ...it works for me.

Others can do as they wish.

AS for the aftermarket poly trailing arm bushing. I wrote what can happen..so those who choose to use them...GO FOR IT! I am not telling you what to use on your own car. BUT...if you have an issue when it goes in for an alignment and setting the toe-in...do not 'say' that you were not warned.

And as for the 'performance' of these poly bushings that a person can install themselves. All I can say is hopefully the person spends some time making sure they achiever the gap required...which I believe is .010". The reason I 'say' this is becasue I have ripped out incorrectly installed poly bushings and put rubber back in.

DUB

resdoggie

Dub, your experience and how to do repairs is appreciated but most in here do not own repair shops and related equipment. So, to try and save a few bucks and have the enjoyment of working on our cars ourselves, we look for alternative methods/products to carry out repairs. I wish I had a 4-post lift but I don't so I use 16" high jack stands and work on my back. I'm ok with that but sure wish I had a suite of tools like yourself. Anyway, just sayin' that there are other ways to do repairs and save a few bucks by doing it ourselves and still accomplish the same end result. Yes, poly can have its faults but so does fiberglass, rubber and metal. Nothing in this world is perfect as you know.

DUB

I GET THAT...I just hoped you could point me in the direction of the YouTube video you mentioned...and stated was documented.

I understand that many people LOVE to tinker and work on their own cars and HAVE TO find ways to get repairs done. I AM NOT passing judgement if a person only has ONLY a pair of Channellocks and does not have dedicated wrenches to do a repair. Because I WAS THERE a long time ago. Whatever I could find to fix my car....I used.

And I reply/comment/advise on 'things' BECAUSE I see a lot of it. Way more than the average person with one Corvette. SO...I thought I would do the right thing and pass along that information.

If that 'ruffle peoples feathers'....keep in mind I an NOT directing and harsh comments towards anyone. If people take it that I am...then that is them. I did not doubt that you did it as you wrote. All I asked for was the link to that YouTube video you mentioned.

DUB

resdoggie

I stand corrected. The you tube was for hammering out the control arm bushings. Air chisel worked quite well. For the TA, I used a cut off wheel to cut the end of the flared sleeve in order to remove the washer. With the washer out of the way, the bushing was pushed out easily by hand. The outer sleeve was re-used with the new poly bushing which didn't require any special installation tool.

leadfoot4

Along that line.....

I believe that when I replaced the TABs on my wife's former '79 C-3, I used a somewhat large diameter drill, to cut the "flared end" of the sleeve. Same result, different route to get there.

Also, thinking back, when you use rubber bushings, the factory shop manual calls out a specific amount of "crush" to be applied to the bushings, before flaring the sleeve. The poly bushings don't call this out, as obviously, they won't crush.....