jjgkdg

OK got a new problem. The car gets loose when I get in or out of the throttle. I'm not getting in or hard. Just normal driving. It's always been bad to track but NOTHING like this...I also noticed the rear tires are crooked and the entire rearend it 1/2 inch to the left. I don't think this is normal.lol

jhammons01

From that description it will be hard to make a recommendation.

Maybe get the wheels off the ground and start looking for worn or loose components.

jjgkdg

I thought of that, but afer i realized the rearend had moved, thought my bumb *** might seek some advice..What would cause the rearend to shift ?

jhammons01

There are only two real mount points.....the Batwing on the D36/D44 has two mounts on the extreme ends (you can't miss them) and the C-beam mounts

Then there are four Dogbones (Two uppers and two lowers) that attach to the forward side of the rear wheel. (Can't miss them either)

The Sway bar is a connection but It does not have much support, its just supposed to keep the wheels level..

The Shocks are attached but the just handle up and down movement.

while sitting still, You take Sway bar and shocks off and nothing will happen.

So three points to inspect on the independent rear suspension.

The Batwing, The dogbones and the C-Beam bolts.

If your rear end is actually flopping around that is where I would begin to look.

Both of your wheel bearings could be shot. While the rear end is up, Grab that wheel and wriggle it and see if it is sloppy.

383vett

Check your rear alignment. Camber, toe or thrust angle might be off which would affect traction.

jjgkdg

Rear hub is shot along with u joints on right side. left side it tight and smooth.

jjgkdg

hub may not be bad ...How replace u joints on tha half shaft

jhammons01

Tell me how you inspected the half shafts?

You can't roll the wheels to inspect the driveline unless you place jacks under the suspension.

You shouldn't roll the wheels with them hanging.......let the weight down on the suspension and then roll the wheels

of course if your u-joints are flopping then all I said is of no use.

removing the half shaft is easy

glass slipper

The portion in bold above is not true. There's no reason why you can't roll/turn the wheels with the suspension at full jounce. And you definitely don't want to jack on the suspension.

jjgkdg

Common sense i have, experience i dont. Pick up th car on both sodes at the same time...One wheel feels tight through the joints w no play.....The other one has two inches of play while i'm looking nat the rearend thats not moving...I think that would be a u joint....Now do I have to take the rearend suspension apart to do this?

glass slipper

If you mean your tires are spinning, welcome to winter. The very cold temperatures you have in TN mean the engine is making more HP while at the same time the cold tires/road give much less traction...you could pull four spark plug wires and still spin the tires easily. You can't drive performance tires in the winter and expect to get traction, even the tire manufacturers say that. If you want to get traction in the winter, get snow tires that are compounded to stay soft at low temperatures.

The "rearend" being ½" to the left isn't unusual for C4s either although it isn't the differential/rearend that's to the left, more like the body which is no big deal. As far as the rear tires being crooked, you might want to take it to an alignment shop to get that checked out.

aboatguy

The portion quoted above is untrue....

Lower shock mounts are a good place to lift, under the rear spring bolts is another.
Mike

aboatguy

Two inches of play????

The wheel rotates two inches, or does it have two inches top to bottom movement, side to side movement????


U-joint replacement is not difficult, just a little time consuming.

There used to be a good write up in the tech tips (check there)
Link to tech tips seems to be dead
Here's a link to a working article

A search of u joint replacement will give you dozens of threads....
There used to be a thread with lot of pics but I'm having trouble searching CF tonight

I usually remove the camber rod from the bottom of the knuckle vice from the adjustment cam (different than shown in link)


Good luck.

Mike

glass slipper

The shock mounts and the spring bolts are not part of the "suspension" and they are meant to take vertical loads. However, lifting under the spring bolt will only compress the spring, it won't raise the tire when the car is jacked up. The trailing links, toe control rod, and lateral links which are the suspension members are not meant to be used as jacking points. The FSM also doesn't have the shock mounts or the spring bolts as jacking points. It's a moot point though as you don't have to jack the suspension up to roll/turn the tire when the wheels are off the ground.

jhammons01

Oh, you CAN do it that way....and I have done it that way as well...only to find that the diagnoses I arrived at was incorrect due to the wheels hanging well below ANY usable range they would ever find themselves in during use.

I think if you check your FSM you'll find the truth.

Not only that, just look at the angles you are placing your half shafts in when they are hanging....then you put rotation to that.....

OP, jack the car up, place jackstands under the suspension and let it down so the weight is on the suspension, then you can start the car, put it in 1-4th and let the clutch out.....climb under there and see what is wobbling if anything.

glass slipper

Your misdiagnosis was not due to the wheels being at full jounce, there is no reason why you can't rotate the wheels at full jounce. If anything, it helps find a problem quicker. FYI, it is possible for the wheels to go to full jounce during use...I have a video of it.

I've been through this before with another forum member and there is nothing in the FSM saying not to rotate the wheels at full jounce...what's the danger??? Are the u-joints going to destroy themselves? I can't imagine there being a warning in the FSM to not rotate the tires at full jounce due to possible damage to the suspension. You do realize the u-joint is part of the suspension...the halfshaft is one of the locating members of the rear knuckle and forms one of the five links in the rear suspension. Can you imagine GM selling a car that could possibly go airborne due to something in the road, have the rear suspension taken out at full jounce, land perfectly straight only to crash because the car lost its rear suspension. Do you really think they would leave themselves open to a lawsuit like that? The jounce and rebound stops are there to limit the suspension travel, any place in between the two is fair game for the wheels to turn regardless of whether you think the angle is too extreme.

OP, DO NOT PUT THAT CAR ON JACKSTANDS UNDER THE SUSPENSION.

In accordance with the FSM, that is not the proper way to support the car.
The spring bolt will not do anything, but if you try to place a jackstand under the shock mount, you run the risk of having the jackstand tip over hopefully as you lower it and not while you're under it. As you let the jack down and the suspension contacts the jackstand, the car continues to come down causing the suspension to go through its travel. As the suspension goes through its travel, it has a camber curve it follows which moves the suspension laterally causing the jackstand to tip.

jjgkdg

Bearings may not be bad...u joints on right shot just need instructions.Soon. need instructions may need to buy tools.....Car must be road ready by noon tomorrow.... I will have to go buy the wrench fo the axlenut...only one place in town....HELP!!!!!

jjgkdg

Got under the car...Its dirty so its east to see if anything has moved. Gonna start w u joints first...1/2 half an inch of play...Just need somegood detailed instructions.... thanks

rodj

Did you check out the link in post #13?
How too /with pictures

aboatguy

I agree that one should lift up on the half shafts, trailing arms, camber arms, etc since they may bend.



Lifting on the spring bolts will lift the car I've done it numerous times in order to remove the spring tension from the suspension parts when I'm working on the suspension and or driveline and once you lift the spring up enough to raise the car, the tires finally raise off of the ground. As for lifting by the shock mounts, since they are strong enough to become the spring mount when converting to coilovers, they are strong enough to hold the car up.

I post what I've experienced not what I read on the internet and jhammons' post IMO was trying to get the OP to check his components with suspension at ride hieght.

I use my FSM however, I've learned that the FSM does not have all of the answers.

I'm sorry that the OP's thread is becoming a pissing match and it was not my intent. My intent was to share some of my experience. I have changed/swapped replaced or removed every suspension component on the car. I have operated my car at driving speed on jack stands IOT find a vibration that all of the experts said was tires or driveshaft.....it was a failing torque converter (and my original diagnosis)

To operate car at driving speed without tires....to isolate a highspeed vibration the vette's rear was supported by jack stands under shock mounts.

IOT efficiently replace trailing arms with rod end trailing arms I lifted the springends by the spring bolts.




Have a great day.