I'm new here and new to Corvette ownership. Have an '81 and I've got her running beautifully but she's downright scary to drive and hard to control because of how loose the suspension is. There doesn't seem to be play in the steering but anything other than driving in a straight line is just dangerous. Would simply getting a polyurethane super rebuild kit fix this (a-arm bushings, ball joints, pitman arm, tie rods, etc), or could there be a bigger problem? Any ideas on where I should start?

I simply want it to drive good right now for the least cost involved. I'll put what money I need to into it to do it right but I'm not ready for custom mods like rack and pinion, coilovers, tubular a-arms and the like (though that stuff will be coming eventually). Right now I just want a good driver that drives as good as stock, when it was new.

Any help or ideas would be appreciated. Be gentle though, it's my first time...

 

The steering is a pain to diagnose on these cars as there's so many parts involved.

IMHO to get a car that drives nice you need to check/replace everything and start afresh, if I were you i'd start with the suspension and leave the steering til last.

Concentrate on one section at a time. Perhaps start with the rear suspension? And when you've done that then move on to the front, this way you can do a weeks work then drive the car to see how it's improved, that's what I did. It also means the car is never off the road for long and you don't get into that 'i've changed a million things and now something isn't right' problem.

First, take pics of the rear suspension, all the bushes etc and post on here ( good quality with a flash, put them on photo bucket then link on here), other issues like diff play add to bad handling, it's not just worn bushings, we can sus this out for you.

This won't (shouldn't be expensive), more time consuming than anything, and you'll find other worn/broken/rust etc from 30 odd years of having the road thrown at it.

You'll be so glad you did it, and if you go through it systematically you'll be able to pin point problems easier as you'll be able to eliminate what you've done.

Once you've done the rear and aligned it yourself (near enough anyhow), then do the front, then do the steering.

Once all that is done then get it aligned....then you'll have a nice car to drive.

The reason I say to leave the steering til last is that the vette steering is a complex one with lots of components that with a little wear can multiply up to a lot of play at the wheel, add in the valve and it's a bit of a minefield, once the suspension is good then you can more accurately diagnose the steering, I got to pissed off with the steering that I replaced it with a Borgeson setup and it's amazing, not saying you should do that just be aware the steering can give you a headache.

Things I would recommend even for a stock rebuild -

Quality parts! Not cheap *****.

VBP smart struts on the rear, that's 4 bushings done in one hit without you having to fit them, and the adjustment on them is sooo much easier.

Quality Idler arm, the bearing version.

VBP adjustable steering arms.

Quality shocks - Bilstein etc.

Lower the car a little - Vette's are adjustable on the rear ( longer 10" bolts are available if necessary) but you'll need shorter coils on the front.

17 or 18" wheels, there's no real choice in performance 15" tyres, but you can always do this later.

Good luck

Aaron.

 

My wife used to own a '79, had it for about 18 years. At one point, I did a COMPLETE suspension overhaul, even though it didn't have a lot of miles.

I went with a full polyurethane bushing kit, new ball joints, new shocks, a composite rear spring, and a new rag joint on the steering column.

 

Just to give you an idea of what it takes to make a vette a REAL badass car, here's a list of what I have -

Rear -

VBP spring 1" shorter
VBP smart struts
VBP reinforcing discs
HD UJ's
Diff play checked
285/40/17's
Crossmember modified to raise the diff 3/4"
Spax adjustable shocks

Front -

VBP Monospring conversion
VBP offset top arms
VBP bump steer kit
HD idler arm
Borgeson steering conversion
Borgeson solid rag joint
245/45/17's
Strut brace
Bump stops cut down
Lowered approx 2.5"
Yellow Stuff EBC brake pads

Next stop is a '77-'82 steering column as they're 2" shorter than the '69-'75 and will make the car more comfortable to drive

 

I would try to do some troubleshooting to see where your issues are front, rear, etc. You may need to start off with rebuilding the front end. I would suggest getting Moog front end parts, poly preferred for the bushings.

 

Don't forget the trailing arm shims. Missing ones will cause the back to be 'swishy' for want of a better word. Hairy also comes to mind....

 

The first two things I would suspect are:
1) toe out in the rear suspension, or
2) really sloppy wheel bearing or bearings.
When the stock car is set up well, it will drive nicely. Before you drop a wheelbarrow full of money onto it, carefully check the front and rear suspension for worn out parts.
IMHO, a typically driven street car will do fine with just about all factory type stock components, set up correctly. You can "blueprint" the suspension, if you are willing.
The limiting factor on our beloved old cars is the willowy frame, what I like to call the "Flexible Flyer". The very stiff springs and bars that are sold by many of the aftermarket shops twist the frame as much as they load the wheels, and often increase the noise, vibration and harshness to the point where you end up with a "50 mile car." After 50 miles, you just have to get out of it because it is beating you up..

 

No.

Get a four wheel alignment. You need to establish a baseline before you start dickering with anything.

 

Thanks guys! And keep the ideas coming.

I guess I hadn't thought about the rear end being that big of an issue but then I've always had big cars with solid rear axles and leaf springs. Not a whole lot to worry about. But IRS is quite a bit different apparently. I do want to replace all the bushings, and soon. Anybody that has gone poly, please let me know what you think. Does it add to ride stiffness or is it barely noticeable.

Aaron, you mentioned lowering the car and changing to bigger wheels. I LOVE the stock wheels (aluminum sport rims) and don't want to change them. Not thinking like NCRS or anything but just really like the look. As for lowering, I'm kind of a biggish guy (6'2" 230 lbs), and it's already fun for bystanders to watch me getting into and out of this car. Not sure I want to be any lower but thanks for the idea. Who knows, I might end up doing it anyway.

Spinadog, you hit the nail on the head! Swishy, Hairy, just plain scary trying to navigate a tight bend or even a wide sweeping curve. Certainly gonna check the trailing arm shims (as soon as I research what they are, lol) and see if that helps.

I've got a lot of work to do this weekend then. Will try to post pics of the suspension, especially if something doesn't look right. I'm not at all new to cars but 'Vettes seem to be a slightly different animal. Thanks again guys!

 

As usual, I overlook one of the simplest possible solutions. I'm sure an alignment shop could tell me a lot and an alignment couldn't hurt at all.

 

I was a Po Boy when I did mine and a few guys on here helped me to get a good price.
Assuming your whole front suspension is well worn!
I picked up moog ball joints, tie rods , HD idler arm, ect...using amazon and rockauto.com
Most master bushing kits (contains everything and even bushings you wont use) are about $100-$150 in poly urethane and they don't squeak if you grease them well on install.
Rubber is cheaper but if your a hotrodder like me, you'll like the urethane
Wilcox has a great how too for the power steering rebuild. It's easy and cheap.
Your biggest expense will be ball joints but add everything up your looking a $300-$400 for a complete rebuild not including an alignment and labor if you're not doing it yourself.
Good Luck

 

This.

I just did a suspension rebuild on my '81 with stock rubber bushings with the kit from Wilcox. it's all over the place and is scary to drive now because the alignment is out of whack

 

Yah. Alignment first, drive it for a while after that, then determine what it may or may not need and which way to go with it.

 

four wheel alignment from a shop that knows Corvettes - the biggest offense other shops make is they have no idea about the trailing arm bushings. By experience I know that if those things are failed or failing, it'll drive so bad that you'll be pulling seat vinyl out your backside because you've puckered so hard.

I'm not sure I'd throw money at it until you know what's worn.

 

I will do all the mechanical work (besides the alignment). I've turned wrenches on everything from leaf blowers to C5 Cargo Jets, so I ain't skeered of a tired old sports car...well, okay, maybe a little skeered...

I might even try body work but not paint. I'm too much of a perfectionist to allow myself to screw that up. I just want to do things right with the right parts. I don't cut corners and though duct tape and bailing wire are great, they ain't gettin' near my car. I have the luxury of a company truck so the car can sit for days or weeks till I get what I need to do it right.

 

poly bushings do stiffen up the ride noticably. as do bilstiens

 

Then I cannot wait to get your take on doing trailing arm bushings. I've been doing cars for decades and those things about made me trade my Corvette for a Prius.

 

I don't necessarily agree. A 4 wheel algnment, done properly, will set you back at least $100. I'd rather spend that on parts for the car.

The OP is talking about a 32 year old car, A quick look at the bushings will tell you if they're dried out and crumbling...and therefore need replacing. Jacking the front wheel, and lifting at the bottom with a prybar, will show if the ball joints are loose...and need replacing.

Bottom line, if it was my 32 year old car, I'd replace pretty much everything, then get a 4 wheel alignment.


I've done them, they're not tHAT bad.....

 

I don't think a reputable shop will do an alignment on a car that has worn out parts. If the shop doesn't care, they'll charge you for the alignment and it will be just as bad or worse as it was before they touched it. If you aren't sure what needs to be replaced, take it to a place you trust and have them tell you what needs to be replaced.

And if you find a "reputable" place, let us know because they are disappearing fast.

 

Hence the reason I do my own stunts...I mean work. I quit a shop one time after working there a month when I realized that the owner was a bit unscrupulous. I got a glimpse of a brake job ticket I did and you would think I rebuilt the car from the ground up but all I did was turn the rotors and drums and replace pads and shoes and necessary bleeding. He had the nerve to charge for all new rotors and drums and even a caliper that I never even touched. I've been wary ever since.

Also, being that I'm in west Texas and the car sat in a garage for the last 11 years, replacing the old rubber bushings isn't even a question. It's more like a requirement.