I see alot of replacement bushings made out of urethane. Looking for some pros and cons experienced fro. Switching to urethane bushings. Looking to change swaybar and dogbone bushings.

 

I was just doing a bit of research on this. It appears that for the dog bones (rear upper and lower control arms) and for the rear lower strut rod (rear camber arm) that those bushings ought to be rubber or the Super Pro brand bushings which have the requisite flexibility and relative lack of hardness so as to not unduly bind up the suspension during travel.

Prothane and presumably Energy Suspension polyurethane bushings as well are too hard and rigid for those particular locations, and should be avoided unless the car isn't being driven very hard or aggressively.

The harder less pliable polyurethane bushings in those locations can cause rising rate non-linear resistance to suspension travel which can cause the "snap" part of snap oversteer.

Energy Suspension and similar basic polyurethane bushings are good to go in most other locations, all of the front for example and in the rear the shock mounts, spring mounts, and sway bar bushings for example can be simple hard polyurethane.


But a full set of Super Pro bushings is competitive in price with a full set of Energy Suspension, so you might as well go with the Super Pro in my opinion.

I am waiting on a Super Pro set myself right now.

On that topic, is it easy to remove the dog bone control arms and the lower strut camber rod arm WITHOUT disassembling much else of the rear suspension?

I have most of my rear suspension apart right now to do rear half shaft U joints and replace studs in the rear wheel bearing hubs, but my Super Pro kit might not arrive for another week or so.

Can I put everything back together to get the car out of the garage, then swap the dog bone and lower camber strut rod bushings later without too much fuss?

Thanks!

 

I redid my 88 with poly bushings fully. The front and rear. This was mostly done between 2005 to 2010ish. Everything. I only just replaced my rear camber rod bushings as they were falling apart. Cant blame them..zero issues or complaints otherwise. Some say they squeak, never had that issue either. Just my .02.

 

I'd wait!!! But, you could definitely do what you are purposeing! If you do put it back together and do the bushings in a week, I would just do one dog bone at a time...take it out, replace bushings, put it back in....same with the lower rods. I feel this will help keep everything kinda in place...but it can be done both ways. One other thing is (at least on my '84...e-brake setup with shoes) if you have your knuckle on the bench with wheel bearing and everything else still apart....make sure you put your knuckle-side dog bone bolts in there holes before reassembly (threads go towards center of the car). If you don't, you can can't get them in after the fact!!!! And I personally would not run them with the threads facing out. On the lower camber rods, don't forget to only loosen or tighten on the nut side where it connects to the differential brackets👍

 

Yak said everything in Post #2 that I would tell you. In any other location I can think of, the only downside to poly is that they sometimes squeak, but you can add lube to them any time to fix that. Energy Suspension sells a little tub of their lube, and it will last a few people's lifetimes. It's super sticky, which is good for this application, and works well. When you have a full tub of it, you will use more in the installation, and that's good! My 96 had EG bushings in almost every location and it didn't squeak.

For the tailing arms (dog bones) and camber rods in back, I would avoid hard poly for the reason Yak said: the ends move in multiple axes and hard poly only wants to allow movement around its single axis. Ergo the bind. Super Pro is a great option for most C4s here. For any C4 driven on track or autocross, another option is to replacing these parts with rod ended links (heim joints). If you only pick one set of links to use rod ends, do the camber rods: replacing them also allows you to ditch the factory eccentric adjuster for rear camber and use the threaded rod ends to set camber instead. This is easier, give you more range of camber settings, and stays put a lot better than the factory eccentric. After Dark Speed makes a nice set that also allows three settings of inner mount height, so you can change the roll centers around if you want.

 

Dang I am a bone head. I tried loosening the lower strut camber arm bolts by wrenching the bolt heads facing rearwards, and I put a bend in the metal tabs of the brackets and interface with the eccentric washer thing.

Here is a pic. Did I trash these brackets or can an alignment shop still get me aligned?

 

Pic isn't showing up, but if you can't bend the bracket back then I bet you can find replacements from a salvage yard cheap. Or on eBay. Or use this as the perfect excuse to get rod-ended camber links from After Dark Speed!

 

I just replaced the camber rod bushings with the poly knowing dam well what Miller has to say! Kick myself in the *** now!

Just looked at their site...only see 3 sets of bushings? Dog bones and camber rods the same? Or am i missing something?

 

Yeah it is confusing. For individual bushing kits from their website, they don't appear to list as many bushings as there are presumably in the full kit.
Not sure what is up with that.

 

find a set of stockers or as Matthew said venture over to ADS and get a set of his brackets.

 

Is this camber bracket salvageable or did I goof it?
can I bend it back over?

I have a spare set of camber brackets from a 88+ car, but I assume I can't use them?

 

I'd take it off and give it a squeeze in the old vise, that should straighten right out!!! Should be fine, IMHO👍

 

So I'm changing out some easy bushings for my daughter's car. The car has more rattles in back end going over bumps and sounds to me like there is some looseness/play that needs dealt with. To put this car in perspective it was a $1,500 barn find. I plan to go thru rear hubs and u-joints just because it's fricken old and i want very dependable. Starting with low hanging fruit like stabilizer bushings ( totally find with hard urathane) and dog bones (quite honestly need to see suspension diagram) and want as close to stock bushings for dog bones and everything similar for soundness and feel. Looks to me like only option for those bushings are the Super Pro. Does that sound right? Are they the only ones that are close to factory rubber?

Car is for my daughter and she will never push the suspension of this car. She got out of dirt bikes when she found d fear and everything change. She just need a reliable sound driver for good weather.

 

sounds right to me! I hope not to repeat that error! I would say you torgued in that pretty hard.

 

I just ordered a complete set of Super Pro bushings from C&S Corvette. Reasonable price, friendly customer service, fast shipping!

Half shaft U Joints I have been using Spicer 5-3615X that are coated for aluminum drive shafts.

I just did my third set of half shaft U joints and on the last two cars I did them on, they were pretty toasted.

Wheel bearing hubs I would not do unless you can feel play in the wheel bearing hub itself via the "3 and 9 o'clock" test. Car in the air, wheel and tire assembly mounted, grab the wheel and tire assembly at 3 and 9 o'clock or 12 and 6 and try to wobble the wheel and tire out of its plane. Make sure that nothing else in the suspension is allowing the movement and only if it has play there would I replace. The issue is that there are simply no good high quality wheel bearing hub replacements available. The ones from parts stores and eBay and rockauto while serviceable, are not great.

That being said IMO it sorta depends on miles and how much hard cornering the car has done.

 

Yak, your camber bracket doesn't look too bad to me. I agree with trying to straighten it in a vice, if possible; but after that I'd probably send it.

There are of course multiple sources for hard poly bushings for the trailing arms, but Super Pro are the only ones I know of that approximate factory rubber, yes.

 

I do not regret for a single second doing everything on my 84 with the super pro bushings. The car still tends to snap and move around under harder cornering but it seems more like an issue of the staggered offset used in 84 on Z51 cars than anything... I'd describe it as twitchy where before I touched anything it was... well... scary. Oddly for as bad as some of the bushings were, my alignment after the work was pretty close. (Marked everything when it came apart) I also did the rack at the same time and my front/rear hubs were toast. So every suspension component is brand spanking new.

 

I believe that's probably more an effect of the higher rear roll center on 84-87 C4s. GM lowered it a bit on the later cars to help with that, although you probably lose some camber gain in roll in the later cars. You could consider different shocks. In my limited experience, Bilsteins tend to have a lot of compression rate and that may unsettle the car in transitions (including entering/exiting corners). Good late-model shocks with adjustable rebound (at least) damping might help that a lot (I recommend Ridetech HQ quite a bit, or Vikings if you can get them plain instead of coilover). Additionally, an 84 Z51 has a 23mm rear swaybar (only year and option package that size ever came on), but you could try a 22mm rear bar which is easier to find. All C4 rear bars from any year will interchange.

 

I miss spoke. I have the 84 Z51 staggered offset wheels but the base suspension with the smaller roll bars. I do have the bilsteins. The car feels fine and behaves like you describe. I have a twisty road by my house I bomb up every day in both that car and pickup... the pickup cruises along at the same speed where you feel like the vette is on the ragged edge even though I really don't think it actually is. Car stays razor flat by comparison between anything else "sporty" I've driven outside of newer sports cars... and even then I think it's more you're much less isolated from what the car is doing than anything. I want to go to a track and actually test where the limits are to really understand the car... I don't feel comfortable pushing it like that on the street. I just cruise and have a spirited drive every now and then.

 

One thing about C4s in particular: you sit almost over the rear axle line and every time the rear starts to feel light, you really feel the yaw compared to most other cars. When I was autocrossing mine, it took a bit of getting used to because I would be convinced I was going to spin and yet the car was still very "savable." Part of what you're feeling might just be that. Speaking of which, track days are fine but I would strongly recommend autocross competition to develop feel for the limits (and beyond) and car control skills. It's a much safer venue and you actually get lots more practice at these things in a few runs than in a whole track day.