Okay guys...I have officially suffered my first breakdown in the 2 years I have owned my vette putting a very hard 13,000 miles on her. Anyway....I finally got her back together again yesterday and all shinned up for a vette cruise'n lunch. Well...sure enough as I am leaving the restaruant and honestly did not get up on here all that hard...no spinning tires, etc.....SNAP/BANK/CLUNK etc coming from uner the car about 20 feet down the road. I pull over and check everything....driveshaft, halfshafts, differential...nope all initially looks good. So I go back over it all and quickly discovered on my drivers side the spindle? has broke/snapped? (see pic below). The 4 bolts that mount the half shaft to the trailing arm assembly flange are still in place with nothing loose but the flange that it mounts to has broke onto a 30* angle away from the trailing arm bearing assembly. That made a ton of noise for the few short feet I went as I coasted back into the parking lot. Nothing more "cool" then telling all these other vette guys how great your car is and that you have been very lucky with no major probems...and then wham!!! just as you are pulling out. Ugghh!!! I am still new to all this stuff so exactly what did I break?



A little back ground info is that there are 100% new complete trailing arm assemblies from VB&P installed in December last year and have around 4,000 miles on them with my little whimpy 205rwhp rebuilt L46 powering my car so it is not like I got huge amounts of power to snap stuff. Also recently installed yesterday brand new 3" half shafts with spicer joints with the first time testing them out on the road. Also recently installed a Dragvette 6 link kit that I must say without a doubt the half shaft safety loops saved my battery box and rear shock as that safety loop got the crap beat out of it so the Dragvette kit has already in some respects paid off.

 

Dude, your photographic skills suck. Back off annother foor and try that again.

 

I have enough trouble seeing this 15" monitor as it is......

 

Take the c-clips out of the diff before you break something else!!!

 

OK, I'm not saying you are right or wrong, but how would a little c-clip cause a big spindle to break?

 

It won't let the yoke slide in and out, binding it in the housing and transfering that stress to the other suspension members

 

Hey SIXFOOTER - how about you open a fresh thread on this topic - that's the first I've heard of relieving stress on the diff housing. I've seen the effects of worn c-clips - you get scoring on the outside of the housing from the movement of the yolks. How about some additional info on how this would help?

 

I ain't the right guy to run that thread, But as I understand it, with a 6 link the upper and lower camber rods carry all the load and the half shaft should be left to float. That is because the 3 links on each side are not in the same plane or exactly the same length, so when the pivot thru their range, the hub will arc out in the canter of its range and back in again at the top and bottom. Meaning that the rear wheels will be farther apart in the center, than at the top and bottom of their travel.
Thats a guess, I never thought about any of that until Robs spindle broke.

 

So the 6-link is the key here - I think I overlooked that detail.

With the stock suspension, the rear halfshaft is actually part of the "link" stuff, holding the trailing arm in a plane, and the c-clip is required, right?

 

Just for the sake of argument, wouldn't the stress on the shaft pop the C-clip long before the spindle broke?

 

Yes, the halfshaft in a stock setup is a structural member just as the bottom smart strut is. The whole point of the 6 link is to remove the half shaft as a structural member and be allowed to flow freely and concentrate on only one purpose...to spin some tires.

Never thought this much indept about the 6 link but you have a good point here. The geometry would have to be absolutely perfect and arc up and down for all three links to stay the same length...but the TA is mounted to the frame kickup and therefore prevents the TA from that up and down arc. Unless you had one sloppy Johny-joint in there that gave the TA enough freedom to spin inwards and outwards to allow for that up/down arc you will have some binding...its just a matter of having as little as possible. And depending on how long the links are in relation to the half shaft the half shaft may actually have to move in and out of the diff housing more than the C clip allows. I would remove it, serves no purpose in a 6 links anyway. BUT this brings me to Glenns comment below...

When I opened my diff I found one and a half c clips from Bubba the previous owner. They seem to break very easily in my diff, the original drive side strut was way way out of wack and bent. I can't imagine a C clip would have more resistance and strength then a TA spindle/hub. I would put my money that the C clip would break first...but there is a chance the C clip may have broken and jammed the side yoke from sliding out or the side yoke was so tight the c clip had no room to break away. Then you have the strength of the diff case mounted to the frame of your car against the movement of the TA spindle/hub.

Regardless, better pics would be very helpful.

 

Maybe your Johnny's are sloppy but mine are just fine...

 

okay....I got some energy tonight and tore it apart. I snapped the spindle just after the big nut with the cotter pin. Ugghh!!!

I would post pics...but being my luch my camera that was working fine on Sunday decided to not work now. I hope its only a dead battery.

Anyway....I am now seriously on the hunt for a custom half shaft know as a "slip shaft" similar to Mark's (84rzv500r) that will be splinned and be adjustable in length that way I don't have to worry about this c-clip/binding stuff. I went to 4 driveline shops today all very old school truck shops and none of them had a clue of what I wanted. Mark got lucky I guess finding a good driveline shop where they knew what he needed. I show pics of Mark's setup and they all say...WOW!!! but can't help me any further as it seems all these guys are just interested in cranking on the usual truck stuff.

btw...believe it or not my c-clips are not broken as there is still less than 1/8" of side-to-side movement.

 

nice job mark on those johny joints.
What I meant was....using a 6 link without a johny joint you will most likely get binding as the wheel moves up and down b/c the wheel will still travel in a slight verticle arc but the TA bushing will only want the wheel to move up and down with no arc. A rubber bushing gives the TA some movement, poly less movement. A johny joint gives the TA a good amount of freedom to move how it wants, giving the TA the option of moving more in that vertical arc. The johny joint will help prevent binding throughout wheel travel however the whole point of the 6 link is to keep the tires level (full tire contact with ground) so there can be no vertical arc.
It would be ideal to have the telescoping half shafts that Mark has, i've only seen them on one other car and it was a wide body also. I've never seen a Dodge Viper's half shafts but I have been told they are somewhat similar in design.
Keep searching for someone to build those half shafts and get those TA's rebuilt in the mean time. If you have the cash and plan on running this car hard in the future now is the time to upgrade those TA spindles with Tom's Diff's 12 bolt style and upgrade the diff to the 12 bolt. Tom might sell you just the half shaft ends (12 bolt style) for you to put onto your telescoping half shafts when you get them.
If Toms setup is too expensive I'd replace with some heat treated heavy duty spindle parts.
Good luck

 

please see the 6 link thread for continuing information but I did find a shop to build me adjustable half shafts technically called a "slip shaft yoke".

 

No Issue... Just funnin ya a bit... even without the 6 link the rear will want to rotate about the trailing arm bushing notice the droop of a stocker on the jack.

Some here would say that this is NOT a place for a Poly bushing. I tend to agree.

I will say that with my setup the Ride quality is vastly improved and the suspension is far more compliant as in no binding and greased pivots in all directions. The buck board harsh ride is gone.

While I have not had the car under racing conditions I have a spot of road that I use to test suspension. we have a sweeper on the interstate with two bridges close together. That is 4 pavement transitions in a corner at double digit speeds 75-80...

Stock suspension with the same shocks and rear spring wheels tires tire pressure ect.. I have now would upset the car at 75 and each joint would cause the car to step sideways.

Only changes was 6 link and wilwoods at each corner and while I get a feel the transitions are there the car is not upset and tracks smoothly through.

I do have years of MC roadracing experience and have collected my share of 1099's doing it. I find that a setup that works well on most race tracks including bumpy ones like Neslon Ledges would be unbearable for any distance on the street. As the streets and interstates here in the northeast are far to rough. I think that experience would translate mostly. The quality and adjustability of the components I have on my MC FAR FAR exceeds anything I have seen used here on C3's.

Prior to the 6 link I would say my corvette would NOT out handle my 93 civic ex with sticky 17's Now I'm quite sure the honda would have some difficuly.

I'm gonna find out at an autoX a week from this coming Sunday

YES the 6 link is comprimise! NO i'm not going to race it at Watkins or Mosport or Calabogie or Pocono or VIR or NHIS or Limerock. I may do a track day and I will do some local autoX.

SEAT TIME makes you fast ALMOST independent of the equipment....



Hijack Over

 

haha good info.
Try to take some video of yourself on the track, I'd like to see your car in action. You got a buddy who can watch with a video camera or a rollbar mounted camera?
Can you take some pics of your setup on the car? I saw some brackets in one of your pics that I've only seen on a solid axle to adjust the ladder bars. Your pic at the bottom.

 

I don't think the binding actually comes from the C-clip. I would assume it is rather the yoke hitting the cross shaft in the posi, when suspension goes up. In a normal corvette this would somewhat push the wheel outward, but since you've got upper arms controlling that motion, the only way the axle can go is inward, thus the yoke hits the cross shaft, tension building up, and eventually something has got to break.

In order to get the combo to work right, you would have to have slip type half shafts.

 

We\'ll see about the video...

the brackets were my First Design for the upper outer brackets... They needed to be modified to fit the car...

 

The half shaft gets pushed in to the cross shaft when they are paralell to the ground, at top and bottom travel the yokes pull out of the diff against the clip, thats where the problem is. The 6 link keeps the wheel verticle, but since all 3 links are different lengths and the inner pivot points are not in line it causes the binding