FlyViper

My '71 has been sitting in the garage for about 3 months without being driven (drove with no large issues on the last drive prior). I start it up today without issue, runs well. When I go to back out of the garage, it definitely goes into gear, but I only get about 1/2 a wheel rotation before it felt like I was hitting wheel chocks, so I put it in 1st, drive forward. I checked, nothing behind the car physically blocking the wheels. I repeat this 4 times before something "breaks loose" and the car reverses fine. I get out and take a surface level look and don't see anything unusual. About 200 ft down the street I thought I heard a strange noise from the rear, stopped and reversed with no noise/issues, started forward again with no noise/issues (maybe the noise was just in my head initially). I then go drive for 20 min without any issues from idle to WOT, in 1-4 as well as reverse, highway cruise + stop/go traffic through town, etc. The car drives/sounds exactly as expected, tracks straight, brakes fine, handling in all phases of driving is normal. A quick glance over post-drive doesn't reveal anything. Is it possible the rear diff fluid is low and that would cause some sort of binding? U-joints? A squirrel crawled into my diff and it took a few tries to mash him up?

Thanks for the help as always!

billschroeder5842

No, you are good. Sounds like normal vehicle operations to me.

If I wash my car and then park it for a while, the brakes make all sorts of noises until they "brake free " (please give me a groan)

The fact that you had no issues after the initial back up leans me to believe that your brakes stuck to the calipers after 3 months.

The solution is to drive your Corvette more often!

CanadaGrant

Did you leave it stored with the park brake on?

FlyViper

I did not...parking brake has never functioned (it's on the list of things to do). I hope you're right Bill, makes me feel much better! I don't know why I didn't think about the brakes sticking, though I stored this car for 4.5 years once and never experienced this problem. We'll see how it drives tomorrow - if no issues, I'll let this one go and take Bill's advice of driving more often - just need to be at home more!

Stephen Irons

If I can jump in here......

If the brakes were stuck, surely you'd know that right away and the car wouldn't move 1/2 a wheel turn before hitting the invisible chocks? I get that sensation on my "other" car after I've washed it and put it away with wet brake discs (sorry, rotors!)

But, a year or so ago we were experiencing a strange "clonk" noise from the rear of our '78 if I put the car in reverse and turned hard, say into a parking space, or to turn around. I thought it must be the diff clutches, but a change of fluid did nothing. So eventually we pulled half shafts and found that one outer U/J was completely seized in the yoke. And I mean completely! The cap was stuck on the "cross" and in yoke and I needed both new U/J and yoke. But the amazing thing was that I had not felt any vibration while driving and no other sensation of impending doom other than the occasional clonk.

So, I'd suggest, to be on the safe side, get under and check the U/Js - I think now I'd rather spend a few hours removing shafts than having one come off at speed!

lionelhutz

The brakes rusting don't cause the wheels to turn 1/2 a rotation and then catch. You've got an issue, a dry u-joint is a likely suspect as Stephen pointed out.

FlyViper

It is weird I hear and feel nothing wrong in all parts of driving - forward, backwards, both in turns and straight...the initial problem has proven to be unrepeatable. That said, better safe than sorry - anyone have a few pictured to help me take this all apart/put it back together?

How can I tell if it's simply a lube problem vs. A replace-this-now problem?

lionelhutz

Once apart, the u-joints should rotate without any binding or drag. If a u-joint is sticking then it needs to be replaced. You can try forcing grease into one that is sticking but it never works out to be a good long term solution.

FlyViper

Maybe I'll take this as a sign from the car gods and replace the half shafts and u joints...they're old anyways and it's probably only a matter of time before the BB tears them apart. I'm not in a position to do a full rear end job, but those parts are reasonable.

Any recommendations for good/beefed up half shafts? Engine is a BB pushing 500/500 (at the shaft, dont know what at the wheels) attached to a 4 speed. It would be nice to have some pad built in for future power upgrades. Anything else I should look at/think about "while I'm at it" that won't destroy the bank account or weeks of my time? Should I replace yokes? We're getting ready to move/buy a house, so my wife's tolerance is low for this kind of stuff!

Stephen Irons

Can't help you with recommendations for Hi-Po parts, but removal is pretty straightforward really. Hopefully, you'll have a workshop manual? (Haynes is fine). Release the spring outer ends (some things to remember there, like fixing the jack on the outer end so it doesn't slide inwards). I remove the inner U-bolt nuts first, then the outer bolts attach shaft yoke to drive spline yoke. You should be able to slip the shafts out then, perhaps with a bit of "manoeuvring" of the trailing arm!. I'm afraid I always use new French Locks at the outer end and I'd check the inner u-bolts. Of course, Hi-Po ends may be different!

Now you've mentioned your hp, definitely change the shafts!

BKbroiler

Contact Fort Wayne Clutch & Driveline. I have their half shafts. They come with Spicer u joints and outer flanges installed. Good price.

FlyViper

Are these what you have?: http://fortwayneclutch.com/product/1963-1979-corvette-rear-axle-heavy-duty-steel-half-shaft-driveshaft-assemblies-3-x-083-sku-stlv1350_12sh3x83/

Any other parts/hardware I need to do this job? Always hate getting to the garage only to realize I can't finish the job because I neglected to order something.

BKbroiler

That looks like them. I bought mine a year ago and their website is changed now. Give them a call. Mine came with new outer flanges and U joints installed. That saves you the hassle of pressing U joints into the flange. Also, the shafts are clear coated.
No special tools but the bolts on the outer flanges (with the French locks) are tight. I did have to try a couple box wrenches before I found one thin enough to get on the bolts.

I just noticed your car is a 71. Mine is a 77 and the original half shaft diameters are different. I would check with them anyway and see what they have for your car.