I just purchase a 68 coupe. It was smooth driving at first, now it feels like something is binding. When I take my foot off the gas, the car will slow itself down. When I first purchased the car, I jacked it up, and the wheels spun fine. Now the fronts are good, but the rear wheels are hard to spin. The brakes are all new, and the parking brake is not hung up. The rear does not hum, so I think the gear oil level is fine. It is just hard to spin. Any info would be great. Thanks, NICK
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Re: 68 Rear Problem
The rear wheels are never going to spin like the fronts if the drive train is intact.
Rear wheel bearings check out the archives.
Collapsed rubber brake lines can maintain braking pressure. -
Re: 68 Rear Problem
Nick----
The rear wheels are normally a lot harder to rotate by hand than the fronts. This is because there is a "lot more connected to them". If you are expecting the rear wheels to rotate as easily as the fronts, that's an unrealistic expectation. If you are saying that when you previously did this rotating test, the rear wheels were as easy to rotate as the fronts, then I'd say something was wrong then or your recollection of it is faulty.In Appreciation of John HinckleyComment
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Re: 68 Rear Problem
I know the rear wheels are harder to spin then the fronts, but they are really hard to spin. I have to grab hold of the rear wheel with both arms to spin, and still it is hard. Again when I'm driving the car, and take my foot off the gas. The car will almost come to a stop, with out me touching the brakes. I replaced all brakes, lines, hoses, rotors, and parking brake. All seem to be working fine. This problem just recently happened. Thanks, NICKComment
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Re: 68 Rear Problem
Did you replace or overhaul the master cylinder? If so, there could be an obstruction preventing complete release of fluid pressure.Comment
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Re: 68 Rear Problem
I didn't replace the master cylinder, but even when I removed the rear calipers, the wheels were still hard to spin. Could it be the U joints?Comment
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Re: 68 Rear Problem
Nicholas-----
Assuming there actually is a problem, I don't think it's going to be possible to do further "remote" diagnosis. If you're convinced there is a problem, I think you should take the car to a competent shop specializing in Corvette repair. If there's no problem, their work is not going to cost you all that much. If there is a problem, you're probably going to have to take it there, anyway.In Appreciation of John HinckleyComment
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Re: 68 Rear Problem
If your wheels are still hard to turn with the calipers removed, this eliminates the brakes. Is the transmission in neutral when you attempt this? What does the opposite wheel do while spinning the near side?Comment
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Re: 68 Rear Problem
I wouldn't evaluate the force needed to turn the wheels unless the trailing arms were supported a close-to-normal ride height. The extreme angles on the half-shaft universal joints while the wheels are hanging free will induce all sorts of strange forces into the rotating (if they move at all) assemblies.
One also has to have both rear wheels in the air or you may be assessing the force needed to actuate the limited-slip unit. See the description of this "test" in the FSM (Factory Service Manual) for more information.TerryComment
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Re: 68 Rear Problem
Nick:
Here's a couple of old school tests that might help you determine if there is a problem and diagnose it.
Drive the car (or roll it) slowly, about 2-3 mph close to a brick wall with your window down. Listen for either a fast, repetetive squeak, squeak, squeak (U-joint), or a slower crunch, crunch, crunch (wheel or axle bearing). Repeat for the other side. You can also have a knowlegable assistant kneel close to the car or walk along with it and listen.
This test works best when the bearings are beginning to fail. If they are too far gone you will either hear a rumble or nothing at all.
The test is just a guess, but it's always worth a try.
PaulComment
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Re: 68 Rear Problem
Yup what Terry says.
rest both trailing arms on jack stands as close to ride height as possible so that the geometry of the half shafts is as straight as possible.
If you still experience the "bind", then I'd pop the drive shaft to isolate the rear end/half shaft assemblies from the tranny all together
Usually, if a u-joint was heading south, there would be audible or visual clues.
Was any work performed on the pinion?
ChuckComment
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Re: 68 Rear Problem
You say that you "KNOW" its not the parking brakes but I would suspect them as the likely problem. The parking break setup on these cars is famous for being an issue and are a real pain in the butt to get right. So before you go to all kids of grief make extra sure that the parking break didn't come apart or is out of adjustment.Comment
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