Heim Joints for 4000 series

Cobra75 · #1 (**permalink**) 09-10-2004, 09:35 AM

Last week while doing some hot laps at VIR, I noticed an unusual amount of (fore-aft) movement in the rear suspension. It was particularly noticable when transitioning from acceleration to deceleration/braking or down shifting.

Upon inspection, it appears to be coming from the heim joints. There is an excessive amount of movement (1/16" +/-) in the heim joint on the upper arm and the lower control arm heim joints. When I disassembled it, it looks as if the "ball" component has worn out the material between it and the "socket" component. (Is that understandable?) The bolts, bushings and washers are not worn or loose, only the actual joint. The rubber seals on the outside are also dried and cracked, so perhaps dirt has created the wear.

Has anyone had similar experience? The car (although built in '98) only has about 8000 miles on it.

More importantly, where can I get replacements for these pieces? I'd like to replace all the heim joints and the rubber seals. Are these something I can get from SAI or Kirkham?

Thanks for you advice.

Tom Wells · #2 (**permalink**) 09-10-2004, 11:06 AM

Yo Elder,

Most Heim joints are not made for passenger car use - i.e., wear life is low number of cycles, no provision to grease them. OK for racing but not for extended usage.

See

Breeze Automotive

to see some "greasable" Heim joints that can survive street usage. They may have/be a source for some for your installation

And now back to preparing for ivan

mickmate · #3 (**permalink**) 09-10-2004, 02:09 PM

Tom is right with the limits on road car use. A grease fitting can hurt you if it's sticking the road dirt in there. A heim can be a $7 or a $37 item in the same size and type, you definetely get what you pay for with them. Teflon is available in some also. QA1 are pretty good. Jegs, Summit, Pegasus or any good race car supplier will have what you need. They are specified by the material (you want steel) thread size, thread direction right or left, thread male or female, and the hole size.

CSX 4027 · #4 (**permalink**) 09-10-2004, 02:31 PM

Been There. Done That.

Don't use grease fittings. That is old world. The new high strength stuff from Aurora will do just fine. Call Brian at Hoerr Racing to help you with the application 866-851-race

BTW .. That is not your only problem...
The rod ends for the toe link need to be replaced too and most importantly..
The bushings for the toe link under the seat need to be either steel or bronze. Not urethane or delron.

Cobra75 · #5 (**permalink**) 09-10-2004, 07:20 PM

This is very helpful info, but how does one order the correct sizes etc.? Are the only variables the material, thread size, thread direction right or left, thread male or female, and the hole size?

Steve,
There's no part number or specs from SAI on these. Does Hoerr racing know what sizes are required if I tell him the application?
Why do the rod ends have to be replaced? Are the original bushings from SAI the correct material?

Thanks again for the info.

CSX 4027 · #6 (**permalink**) 09-10-2004, 08:57 PM

I don't know what bushings are in your car. You would have to tell be what they look like. As for the rod ends, take them out to measure. I have no idea what was used on your car and I don't remember the sizes or direction off hand. If you are not mechanical, which is the vibe I am getting, have someone look who is. Owning a Cobra is one of the best ways to develop your mechanical skills. You too will be able to build one on your own after this one. I rebuilt mine. I mean really. And it was an invaluable experience. If all would get to know their cars in and out, there would be many less mishaps reported on CC

Rick Parker · #7 (**permalink**) 09-10-2004, 10:59 PM

Here is a source with some good information:

Baker Racing

Typical sizing is for the hole to be the same size as the shank, although there are exceptions. Use the High strength Chrome- olly with the teflon liner. This is one item you don't want to compromise on. You get what you pay for in this product. The original CSX 3XXX cars would occasionally break the upper rear pivot and the suspension would collapse allowing the wheel to tilt inward with a huge camber change causing a dangerous situation. This was due primarily to materials, poor access and infrequent maintenance of the joint.

Rick

CSX 4027 · #8 (**permalink**) 09-11-2004, 07:05 AM

One of the most important things to remember with rod ends is that you MUST HAVE AT LEAST A MINIMUM 1.5 TIMES THE DIAMETER OF THE THREAED SIZE ACTUALLY THREAED INTO THE A-ARM OR TURN BUCKLE NOT INCLUDING THE LOCK NUT.

I HAVE SEEN A LOT OF GUYS RUN THEM OUT TOO FAR. THIS IS A DISASTER WAITING TO HAPPEN AND THEY WILL BREAK.

Cobra75 · #9 (**permalink**) 09-12-2004, 07:14 AM

Thanks guys for all the info.
I'm not totally ignorant about mechanical things...I just have zero experience with heim joints and their sizes/dimensions. I was hoping to find out how & where to order the correct ones. I don't like dealing over the phone or internet without knowing what I'm talking about. If I don't have all the correct info, I end up getting the wrong parts and the only winners are the UPS drivers. Sounds like I'm better off getting racing components than replacements from SAI.

This helps alot. Thanks.

BTW, the bushings are steel.