U-joints done

[rhipsher]

All six U-joint replaced. All spicer. I finished that project last night. There is no more low humming at 120mph do to two of the ujoints freezing up. Also no more stick shift moving around anymore. But upon taking it out for a short high speed run, while accelerating my rear end wanted to go to the right and I practically had to counter steer just to keep going sraight. My right rear tire was low on air 10 psi while the left rear tire was 35psi. That could have something to do with it. But the rear end still feels unstable. I also noticed my right rear tire has rubbed against the wheel well. My rear end looks like it has always sat lower than all you other guys ZR-1's do. It could be time for new shocks to. Anyway chew on that and see what you think.

[Paul Workman]

Originally Posted by rhipsher

All six U-joint replaced. All spicer. I finished that project last night. There is no more low humming at 120mph do to two of the ujoints freezing up. Also no more stick shift moving around anymore.

Two joints frozen up? Those would be the ones on the drive shaft, no?

Just curious, cuz I suspect mine are "due" and I'll be doing mine too, after hearing a faint "squeek-squeek-squeek - in (I guess) sync with drive shaft rotation velocity. and you mentioned a Hmmmm...

P.

[tomtom72]

I don't believe that shocks affect the ride height; maybe a bit, but I can't see a bad shock(s) affecting it enough that you would see it. Usually the only way to make the back lower is longer spring bolts. I don't know enough about how to do wheel alignments to say if lowering the rear changes any of the alignment settings.

rear feels loose? Was obviously when the tire psi's were way off, right? What about after you adjusted the psi? No change? Little change? It was loose before the U-joint work, or just after the work, or both? I'd start looking at all the bushings, jez there's plenty of'em too. Maybe the batwing mounts? Sway-bar end links loose? Or anything that could be not T/Q'ed down to spec that came apart when the joint work was done. The C-beam is up to T/Q?

Sorry, I'm just tossing out stuff that I'd look at. I really don't have an answer.


Tom

[ZR1Vette]

Well.. 10 psi would certainly do the trick in making it pull... but me thinks you need to look at cumulative issues:
-worn out shocks+alignment+tire pressures+ possible bad suspension components (lower and/or upper wheel spindle control rods/spindle rod/axel tie rod/axel tie rod knuckle/spring insulators/cracked spring/compressed spring insulators) Also, while looking at the spring might check to see if all the spring spacers are accounted for and in equal amounts on both sides (mean looking at both spring anchor plates). Not knowing the history to your ZR-1 (like prior owner modifications) I do know you do not drive like a grandma going to confession so all these items come under a lot of stress in more 'aggressive' driving.

[rhipsher]

I think I found the issues. One bad passenger side rear wheel bearing. And two bad rear shocks. When I jacked up the rear end and sit it back down it sat 2" higher. Then drove around the block it sat 2" lower again. And when it sits that low it causes the half shafts to be at a steeper angle which is not good. And I already know I need new front tires and probably a good alignment.

[tomtom72]

Hi Mr. R,

I gonna say something & I just want to be sure that you're aware of this before you go chasing bad expensive shocks. I don't mean nothing smart a$$ by it.

On T-verse leaf spring cars, if you suspend them and then compress them it it is normal to measure differing ride heights before and after the suspension resettles or has become loaded again because you drove the car. I hope I'm expressing this right.

Our shocks normally leak as a result of the method of lubrication for the shaft. So oil build up over time is normal. Now I'll hasten to add that it is a minute quantity of oil, but unless you wash your shocks everytime you wash the car it could look like a bad leak if you are really noticing it for the first time. I'm sure you know if it is porposing. That's how I figured out that I needed to spend $725.00 for new shocks. They were pretty oiled up, to me, but not by the book.

I don't have my FSM handy and I know somewhere in there is the ride height table.


Tom

[rhipsher]

Originally Posted by tomtom72

Hi Mr. R,

I gonna say something & I just want to be sure that you're aware of this before you go chasing bad expensive shocks. I don't mean nothing smart a$$ by it.

On T-verse leaf spring cars, if you suspend them and then compress them it it is normal to measure differing ride heights before and after the suspension resettles or has become loaded again because you drove the car. I hope I'm expressing this right.

Our shocks normally leak as a result of the method of lubrication for the shaft. So oil build up over time is normal. Now I'll hasten to add that it is a minute quantity of oil, but unless you wash your shocks everytime you wash the car it could look like a bad leak if you are really noticing it for the first time. I'm sure you know if it is porposing. That's how I figured out that I needed to spend $725.00 for new shocks. They were pretty oiled up, to me, but not by the book.

I don't have my FSM handy and I know somewhere in there is the ride height table.


Tom

Even when Bradley Taylor was visiting he said dude your car is sitting way to low in the rear. It sits alot lower than the front by a good 2". Thats when we discoverd the bad wheel bearing in the passenger side rear which caused the tire to sit at more of a tow out angle and you could see where it has rubbed the wheel well. He showed me how to adjust the ride hight and said that has to come up another 2". I could also see it in the video of me drag racing. The rear end just sunk down big time. And the other two ZR-1s that came with me hardly budged. That leads me to believe its shocks. Nothing else looks broke under there.

[A26B]

If you're going to go the coil over route, then spend the bucks in that direction. You'll be losing the leaf springs, F&R and all the bushings. Your shocks should be sent in to Bilstein for re-valving, grooving & repairs if needed.

Then, you can adjust the height independently at all 4 corners. The tow (toe) out you are referring to is more than likely camber. Toe doesn't change with squat, but camber does.

Now, when you finish with the coilovers, replace the camber struts with heavy duty spherical heim-end assys. When you do that, you eliminate the rubber & that goofy eccentric camber adjuster and end up with some really good camber control. And then there's the heim-end rear toe rod assy...... and the rear links that can use some poly bushings...... oh yes, don't forget the sway bar poly bushings. You know, it just goes on & on.

BTW, you guys were there when I talked to Corey this afternoon. He said Brad was there!

Take care,
Jerry

[Paul Workman]

I waited till now to mention the transverse spring. I believe you may more likely have an issue there as the shocks do not lift the rear that much. Run you hand (carefully - gingerly) over the top of the rear spring and see if it is splintering - a problem I had with my 95 LT1 Vette. The shocks may well need attention too, but that would be more of a dynamic problem - and wouldn't affect the static problem you're dealing with.

So, my money is on the spring or the adjustment thereof, but NOT the shocks. But, you can have the shocks rebuilt for a fraction of the cost of new ones, and that would be my route too.

Let us know what you find.

P.

[rhipsher]

I'll get under there tonight and check it out. Its not something that gradually got worse. It happened over night. I guess those components can break instantly if pushed hard enough.