Hello Guys,
When taking off this morning I heard a HUGE snap on the left rear fender, really strong, it actually hurt my ear. The handling hasnt got badly affected, but once I parked at work I could feel the car was lower on the rear left side.
Measuring by the tire distace to the body the left side is a inch lower, or the right a inch higher.

Looking at the leaf springs, bushings, shocks they all look ok, or at least even...
Was it just a rock thrown by the rear tire and the car was always uneven?
What am I missing here?



Thanks,
Fábio.
Edit: What am I risking by driving it this way?

 

It could be anything so look at everything. Spring mounts, or a crack in the diff cover, shock mounts , diff crossmember, or just a stone tossed up like you said. I would check everything I could before driving. A good visual examination won't take too long, up on ramps and on jackstands with the suspension at full droop.
Also look for a nick in the paint that wasn't there before.

 

if your sagging on one side, you might have broken a leaf spring, inspect all leaves very well. find out why it is sagging ...69VETT

 

Ok gathered some more info and pics on this: Click for pics Let me know if you find anything unusual.

I inspected everything couldn't find any signs of trouble on the leaf springs, there is a thin layer of rust all around, the bushings are beaten up, the rear dif is leaking and it seems that the right camber strut rod is lightly bent, you can see that on the pics, can it be the cause of my left sagging?

The leafspring and the shocks don't look old, I assume they were replaced sometime in the last 3 years.

Also I can see some shiny metal where the left semi axe joins with the dif when the car is raised, the right side looks ok. What does it mean?

While I had the rear on jack stands I checked the car height on the front and found out the front left to be 1" higher then the front right.

With the front jacked found the oposite side, the rear right to be about .75" higher.

With all 4 weels on the ground front left is 0.5" higher and rear right is 1" higher.

What does it mean? I need a full suspension work? can be bushings only? the dukes of hazzard owned my car and twisted the chassis by jumping over road blocks?


Anyways I'm pretty bought into the idea of upgrading to a 330 monoleaf composite spring from VBP since they have 20% off now. But I fear that it wouldn't really solve my problem. By the way, should I get rubber or poly cushions?
Should I order the struts too? replace all the rear bushing with poly?

Let me remind you that this is a daily driver which does 50miles a week.

Thanks guys!
Fábio.

 

You need struts- that right one is bent like a horseshoe. The left axle should NOT come out that far- good sign the snap ring groove on the end of the axle is worn off. Looks like the left spring bolt is bent too. For your application rubber bushing will be fine. Calipers look like they might be a little wet too.

 

Your passenger side strut rod is bent, that will put the rear tire at the wrong angle and would lower one side. That being said most C3's are off on one side or the other 1/2 on. or so for one reason or another.

 

[QUOTE=TimAT;1568275274The left axle should NOT come out that far- good sign the snap ring groove on the end of the axle is worn off.[/QUOTE]

if hes lucky, itll be like mine. my yoke just slid right out of the diff. all that happened was the snap ring broke off. was a pita to get the diff out, but it was a 50 cent fix.

 

The bent strut rod is a sign of something not right. That is the classic Bubba alignment practice. If Bubba could not get it aligned then he bent the struts. Check your t-arm bolts and shimms. Also check the front Diff mount. Looks as if you need a rear suspension/diff rebuild.

 

You can't tell from the pics, but I would check the differential mount. When I bought my '76 there was an ear broken. If it clunks when you shift, it's the front differential mount bushing. I heavy duty differential mount is around $120 in Ecklers + 40 or so for the gasket and fill kit. Maybe you heard the snap ring on the stub shaft break?

I don't envy you, I have redone the back suspension on my '76 over the last few years and it adds up quick. Really piecing things together doesn't work well. Unless you find something obvious, it could be a combination of things. Until I fixed everything, I couldn't get my car to sit level. If you go that route, below is what I did.

T arms rebuilt: Have to take them to a specialist to do it right and may end up buying new spindles and rotors like I did. I bought the heavy duty offset T arms and cryo spindles while I was at it. $600-$1200 on this depending on what you do. Get the stainless steel emergency break kit while your at it to prevent future rust. Have fun getting the old ones off. Go with Vansteel on all of this.

Rear composite spring: $300 + long spring bolt kit for $30. VBP is who you want to call.

Probably need stainless sleeved calipers, but check, because they may have already been sleeved, if so you just need a $10 seal kit. A sleeved caliper set is $300 or so. Also probably need new caliper lines while you are at it.

New strut rods: Don't get stock, get some jam nut/adjustable rods with urethane bushings from Vansteel, $120.

Shocks if you go with a composite spring as you need the right shock.

Your stub shafts might be in trouble, but at least check them when you have the cover off the differential. I'll assume your diffential and posi unit are ok since you didn't say you had problems with it.

Half shaft Ujoints, get the spicer joints without the zirks. Also, don't put them on with a vise, have them pressed in so you don't dent your halfshafts (don't ask).

Of course with everything apart, your not going to like the way your exhaust looks/sounds either...

So, if you do all of this, you are looking at $1,500+.

 

i had problems with my rear suspension. My daily snapping was of course the ujoints, but then the trailing arms were rusted and had signs of being welded. everything else was shot. half-shafts and flanges beat up bad.

SO, i read here that peicing it together was a mistake that would give poor results, so i replaced it all. Used trailing arm assemblies from Duntov, plus all other parts needed for a complete rebuild. Shocks, struts, halfshafts, spring, all of it. Cost: about $3000 for parts. Labor was about another $600 or so.

Was it worth it? the car drives like a dream. it is now a daily driver (i need a new car, but in this economy, i will drive what is paid for).

 

The left yoke is pulling out of the differential. c clip must have broke. This normally pushes into the rear so there is more to this than can be seen in the pic's. The bent rod on the right is not the problem aliment guys bend the crap out of theme when the can't get the aliment right .

 

I've seen them bent for other reasons, some have tried to jack the car up using them. Also his rear might not have been level before he heard any noise.

 

Looks like your problem is inside your rear diff.

The fun begins with the while your at it -itis.

Your local corvette shop may be able to help you out with getting the diff repaired-replaced if there is any collateral damage.

Your spring looks in decent shape and your shocks look newer.

Spin the trailing arms once the half-shafts are removed and feel the bearings for any roughness. Id replace your U-joints since your taking it apart. you might be able to get out of this without taking a big hit.

Id replace the strut rods and get a new alignment.

If your brakes need work, look at doing just an O-ring conversion kit ($140) from VBP to do all 4 calipers good as new. Replace your brake flex hoses.

Good luck...Brent

 

Yeah, this is looking deeper than I first thought.

I already replaced the front calipers by SS O-ring ones, and the rear ones are on the line to get replaced too.

I love the idea that someone tried to jack the car by the strut rods, but I think is more likely to be a bubba alignment work wich might mean that my trailing arms are in need of some investment How can I diagnose that?

About the yoke, I hope its a 50 cent C clip fix. But I know once I open that cover other stuff will jump at me. What should I look for in terms of other broken stuff?

To finish it all what I need the least is the new spring I was hoping to buy for xmas at 20% off

Now the trick will be to split all this rear end work into small projects that I can execute on a weekend and keep on my monthly vette budget.

Hey Dave thanks for sharing your rear end tale, I will definetlly follow your footsteps on some of that.

Fábio.
Ps: I'll check for the TA bushings and dif mount bolts and post back.

 

The bent strut has nothing to do with the trailing arms or bushings- most likely the worn yoke(s) left the alignment mechanic no choice but to bend it to get proper camber. Bad trailing arms or bushings will affect toe-in, not camber.

This will not be a 50 cent fix, don't kid yourself. Most likely the diff will need a full rebuild, you're looking at at least $500+ plus labour.

Bubba has been under your car at least once, witnessed by the incorrect installation of the shock hardware..

There's nothing wrong with your spring, spend the money on what's broken or about to break and not 'upgrades'.

 

Yeah Mike you are probably right
Since we are shooting for the diff let me give you some more facts:
When cruising at 35-40mph on 3rd gear I can hear the rear end roaring on a wavy pattern like RRRRrrrrRRRRrrrrRRRRrrrrRRRRrrrrRRRRrrr can also feel that vibration on the shifter.

When I come to a full stop and do a sharp tun as a corner I hear the rear end "creeking" like an unoiled door.

Are those signs of anything ?

By the way, I bought this crappy old car just to work on it, driving it on my 3 mile comute is just a way to justify the investment to the wife Therefore I dont do "local shop" or pay for labour. Unless the tools I need for the job are expensivier than hiring it someone every time I'll need that done in my lifetime. ie: alignment, exaust work, etc.

Fábio.

 

If your diff fluid hasn't been changed it can make some really bad noises. This is especially true on turns.

cc

 

Possibly u joints. You'll find out when you pull the diff off.

 

Yeah, I would wait on the spring and shocks as those look ok and can easily be replaced later. I bet you have a lot of expense otherwise anyway. Problem is if you use the car as a daily driver you can't get all that done in a weekend without replacement parts and that is way more expensive than rebuilds. I think Vansteel has most of what you need and they will reimburse a lot of stuff if your core pieces are good, that might be one possibility. You could pull everything out in a weekend...

The problem is just having someone inspect the differential could cost you quite a bit of money as it needs pulled apart etc. to look at the bearings I think. A guy took me for $390 inspecting two differentials I had. Fortunately one was fine and still is, otherwise that is half the cost of a rebilt diff and nothing was replaced but the crush sleeve. It sounds like you might have bad bearings from what you posted later on with the groaning sound. I think Ujoints usually click when they are bad.

I would never take my vette to the local GM dealer for anything as they charge ridiculous labor fees and parts will probably be double as well (if they even agree to or know how to work on it).

 

I would be suspect of the left yoke moving out. It appears the ring has fallen out. If so, the ring may have gotten lodged between something as the ring and pinion or got into the case. This may have caused your snap noise. I would start by pulling the differential.