Rearend troubles, everyone take note!

[bittentoo]

Well I've broken everything on the Orange 1 except the rearend. Can't say that anymore. This past weekend I was idleing down a gravel road to a field to take group photos for the Texas Cobra Meet and noticed that I was dragging bottom. Thought that I had a rear flat. No such luck. Looked under the car and the lower control arms are dragging the ground. I had sheared all 4 bolts that hold the control arms to the diff.

I called Butch Capps Monday morning explaining the situation and he said that he has seen this happen before on cars that are "driven" or have some horsepower. The bolts are in a high shear load and don't be fooled by the safety wire as it will stretch and allow the bolt to loosen and then shear. Exactly what happened to me. Butch said these bolts should be checked several times a year if the car is driven very much.

The rear two bolts look like they had been broke for a while and the front two just failed. I'm lucky they failed when they did.

[TurnpikeBoy]

Wow.......not good at all. Truly sorry for your troubles, but I am also truly thankful to you for your posting.

Had no idea these bolts were given to simple failure.

Glad you are OK and that this is just causing you heartburn.


-Roger

[pgermond]

Thanks for the heads-up.... someone asked a while back what components to to check periodically. The answer is obvious - anything that can come loose! Hope you get it back together quickly :)

[eliminator]

You can check to see if they are broken but you can't tighten all of these, 2 are nearly hidden by the pivot shaft. Besides these didn't back out they broke.

Kelly "too many burn outs"!!! Plus if you had waxed your frame you would have found this a long time ago.
Have you had this car on a chassis dyno? If so where did they tie down the rear of the car?? Think about it!

Well on the positive side if you wanted to change rear end gearing, now is the time.

When you go back with everything there is one more item to check and adjust, will post some pictures as it will be easier to explain with a photo on rear suspension set up.

[will butterworth]

that old loud orange paint causes stuff to break like that too.Now, fishing out the broken bolts, I never could do that good, always messed up a bunch of other stuff.Will-alabama

[Brent]

"This past weekend I was idleing down a gravel road to a field to take group photos for the Texas Cobra Meet and noticed that I was dragging bottom. Thought that I had a rear flat."

Nothing like a bunch of cattle and dusty cars for a quality photo shoot in Kentuc..........I mean Texas.

Glad you did not find this creature at 7K rpm and 100mph at homecoming. O-:

Very lucky!!

[weaver]

We make a plate that ties the lower control arm brackets together, this should eliminate bolts shearing or pulling out. You can do a search on REAR END PLATES to see more.

Alan

[eliminator]

Alan,

He has a rear end plate on the car, that helps but will not totaly eliminate the problem.

If he had not had the plate on the car there would have been some serious problems. Thats all that held it together.

[weaver]

Sorry, I looked at a pic that didn't have a plate.

Alan

[spd4me]

There use to be a place called "Concourse West" that sells jag rear ends and newer independent custom rear ends that sell extra hard bolts to go on rear end parts especialy for cars with high hp (400 and up). If I can remember, I'll check my file folder and get address Monday.
Bob

[pgermond]

Could it be C.W.I. (concours west industries) http://www.cwiinc.com/ ?

[bittentoo]

Got the rearend assembly on the ground today. What a pain in the A$$!!!!!!!

If I lived closer to Alan or Maurice I'd probably have kick them in the .....! The rearend is bolted to the frame and then the body is set on the car. No problem except that where they bolted the diff. to the upper mount they used those big a$$ allen head bolts and this is just below the floor of the trunk. I played Houdini and was able to get two of them, but had to drill holes in the floor of the trunk and access from the top down. If they were typical hex head I think that I could have gotten them all from underneath.

And thanks for the link. They have the bolts I need and will call them first thing Monday and get them headed my way.

[weaver]

I think you should kick Maurice when you get to Homecoming next month, oh yea, we use hex head bolts now.

Alan

[Russ Dickey]

Yikes! Thanks for the heads up on this one.

My car is up in the air right now as I complete some other minor maintenance. I drive my car a lot, and quite hard at times, and while I for sure don't have the HP that most of you guys do, I sure would feel better replacing these bolts now verus after catostrophic failure.

But it looks like to get to them, I'll have to remove wheels, outer hubs, and lower control arms. Is that right?

Thanks,
Russ

[eliminator]

Thats correct, all that you have stated.
On most cars you have to drop the rear-end to do all of the above.

So just when are you going to replace these bolts???

You need to think about the problem he had then just why he had the problem. If it applies to you then go for it.

I think I am hearing a lot of knee jerk reactions on this thread that don't apply. These bolts just don't break every once in awhile, and they don't need replaced on every car out there. It would be like me replacing a rod bolt because one broke on someone's car.

[Russ Dickey]

Thats correct, all that you have stated.
On most cars you have to drop the rear-end to do all of the above.

So just when are you going to replace these bolts???.

Depending on the level of difficulty, as soon as possible.



You need to think about the problem he had then just why he had the problem. If it applies to you then go for it.

I think I am hearing a lot of knee jerk reactions on this thread that don't apply. These bolts just don't break every once in awhile, and they don't need replaced on every car out there. It would be like me replacing a rod bolt because one broke on someone's car.

I see your point, but I guess what concerned me is that he said Butch Capps had seen this problem before on cars that are "driven". Obviously, that term is defined differently by everyone, but I put roughly 2500 miles a year on my car, with some of those miles being at an autocross, dragstrip, or open track event. I guess I assumed that I may be a likely candidate for this type of failure, so why not practice some prevention?

[bittentoo]

A little follow up as to what I have seen and learned from my last post.

In order to get to these bolts, you have to drop the rearend down which requires unbolting everything. the reason you have to drop the rearend is because the long bolts that the lower control arm pivots on will not slide all the way out. It hits the frame in the front and the trunk in the back.

I though that my bolts loosened up some allowing them to shear. That wasn't the situation. The threaded portion of the bolts that were in the diff housing were tight and not going anywhere. I used a reverse drill bit to drill the ez-out hole hping the bolt would spin out. No such luck. I then tried the ez-out putting as much force on it as possible without breaking it. No such luck. I resorted to the Butch Capps method of heating the area around each bolt melting the lock tight and the bolts came out.

The only way that I can think of to check/inspect these bolts without disassemly of the complete rearend is to get the car off the ground and use needle nose pliers, getting a good hold of the safety wire next to each bolt and wiggle it, looking for any give or slack. If the bolt head moves, it's broke.

So the bolts were tight. What surprised me was how soft the bolts were. I didn't have any problem at all drilling the holes in the bolts. If these had been grade 8 bolts I think that it would have been more difficult.

I ordered new bolts from CWI and they are grade 8. They should cure the problem.

[eliminator]

In talking with Butch on this subject he has seen this on only one other car over the past 11-12 years.

And guess what, the guy admitted that it happened right after a Chassis Dyno Run in which they strapped the car down using the lower IRS control arms. They did numerous pulls on the dyno. Butch told me that in his opinion the chassis dyno tie down procedure was the culprit.

[bittentoo]

All I know is when I called CWI and told Mark I needed some bolts, he said, "the ones that bolt the lower control arm to the diff?"

[Russ Dickey]

In talking with Butch on this subject he has seen this on only one other car over the past 11-12 years.

And guess what, the guy admitted that it happened right after a Chassis Dyno Run in which they strapped the car down using the lower IRS control arms. They did numerous pulls on the dyno. Butch told me that in his opinion the chassis dyno tie down procedure was the culprit.

More good info. Did Butch suggest an alternative strapping point on the chassis dyno? I usually have my car on one at least once a year, and the lower control arms are where the straps have gone.