Speedtoys

I have not had to RE tighten mine, since removing the inner bolt on the plate.

It all moves freely now..as opposed as to not.

IcemanG17

I recently installed these on the Estate..which is track driven only....they quickly got loose and continued to get loose.. It is quite annoying... However it did make for some "interesting" handling dynamics..... Right pull-movement on decel (brakes) when left rear is loose....then it also would move left under acceleration....I only noticed it since we were on our warm up lap and I was constantly accel-brake to warm up the tires (I don't believe in swerving all over the place just to pick up junk in your tires)

I will have to take a more serious look at this part.....

Lizard928

Brian,

Same thing I experienced. I removed them and problem solved.

IcemanG17

I just printed out the installation manual...will take a look at it next time I am at the track..... Luckily I have a set of adjustable drop links that will work with the stock location to increase stiffness in the rear......

76FJ55

I think the solution for those who want to continue running them might be a slight modification. By boring out the hole the pin goes through you could install a hat bushing that would allow you to tighten the pin against the inner LCA bushing sleeve as designed. This would also allow for relative rotation of the pin and bracket, and the flange of the hat would take the load of strapping the car down. I made a quick sketch but can't seem to figure out how to attach a pic of it from my phone. I'll post it later when I get home.

blown 87

I have seen them very loose after taking them off, I always replace them.
On the last car I did they were so loose I could screw them past the lock part by hand.

It just makes god sense to replace any nut that is called for in the WSM, because not only of the chance of them coming loose, it will change the compression value at the stated amount of torque.

Another thing is that you can not hold one nut and torque the other end and think that they are both torqued to the same value, due to the friction and drag of the pin turning in the control arm and shock.

Speedtoys

The WMW calls or double-nutting to remove or torque them.

I didnt replace mine..but they still require wrenching to remove and add..still quite tight.

TheoJ

I think at this Point 928 motorsports would be needing to chime in and comment on the issues. They loose credibility if they don't.

It is not about return policy, it is about customer support.

76FJ55

So anyway here's a pic of the quick sketch I tried to post yesterday. Essentially the design change would incorporate a hat bushing in the tie down Bracket (TDB). Basically the hole for the pin would need to be enlarged so that it is just bigger than the OD of the inner sleeve of the aft LCA bushing. Then a Hat bushing could be made to slip into the TDB. The addition of the hat bushing would allow for the correct torqueing of the pin, and would eliminate the relative rotation of the compressed stack on the pin. My interpretation of the compressed stack of components is as follow: starting at the aft end working forward,
Nut, aft washer (or TDB if installed), inner sleeve of LCA aft bushing, washer, inner sleeve of shock, aft cone washer, upright, forward cone washer, inner sleeve of forward LCA bushing, forward washer and forward nut.

From this stack up it can be seen that the pin should be locked rotationally with the hub upright through the cone washer assembly, and all the inner bushing sleeves, washers and TDB if installed, will also be rotationally locked to the upright.

The LCA and shock will both have some rotational movement to the pin allowed by the compliance of the rubber bushings.

With the TDB installed with the bolt attached to the LCA the rear suspension is essentially locked in place as the LCA angle is locked to the upright, until enough force is generated to overcome friction in the stack up and force rotation either at the TDB to pin or at the pin to upright.

By installing the hat bushing it would allow free rotation of the bin relative to the TDB in turn eliminating the bind cased by the TDB installation. And at the same time allow for the compressed stack to be torqued to the correct value without adding friction to the suspension movement.

There are however still a few issues with this modification. 1 due to the rubber bushing compliance the pin will have some radial movement and the hat bushing will most likely rub on the ID of the TDB hole, which may still generate some noise. 2 is there room for the installation of a hat bushing with the placement of the alternate sway bar link mount locations? 3 is it even worth the effort. 4...

Carl Fausett

I just became aware of this thread. Guys, you may think the Rennlist is the 928 Motorsports Tech Support Forum, but it is not. We dont even watch it. We cannot watch Renn and expect to get anything ever built, shipped, or in boxes.

PLEASE contact us first when you have questions, or at the very least throw me an email to carl@928motorsports.com if there is a thread that you want me to weigh in on.

Carl Fausett

Again. I do not have ESP. I am not normally at my desk. I am happy to respond if I know that there is a thread that wants my input. TELL ME and I will join the thread.

Carl Fausett

Now to the creaking problem:

I think Bill Ball's post at #17 is right.

I also think Simon's over-view at #54 is right.

I think the creaking you are hearing is the rubber bushing grabbing and breaking traction on the back of our plate.
The washer that used to be there could spin freely, the plate cannot.

I am thinking of a product improvement here: a shim or thrust washer behind our plate and before the rubber bushing. The goal of which is to allow greater ease of movement of the pin.

Simple test: remove our plate and grease the back of it where it contacts the rubber bushing, which will prevent the rubber from getting "traction" on the plate. My guess the reason that Bill Ball's and mine do not make noise is that we lubed our pin and threads with anti-seize during assembly and some got onto the plate or bushing and is doing this job.

If this turns out to be an accurate diagnosis, I can come up with fender washers (large diameter and thin) to install before the plate and send them 'round to everybody.

Lizard928

When looking at the design of the stock components you see that bolt pinches all parts together so that as the suspension moves up and down the rubber bushings in the control arm and shock twist with the movement of the hub.
By locking the rear end down with this plate that twisting action is taken away. But the weight of the car allows it to still rotate.

If you increase the hole diameter where the pin goes through and install a bushing to go between this plate and the threads with making this bushing around 3-5 thou longer than the plate is thick then back this with the original washer. I would recommend anti-sieze to be placed between this sleeve and washer to reduce friction. But this would allow it to still rotate and thus prevent it from backing off the nut. Yet due to small clearances it would still do it's job without giving additional clearance to cause a clank from the swaybar.

Does that make sense Carl?

Ducman82

hummm.... thats not a bad idea. i start my machining class up again next week. sounds like a good lathe project.

Bill Ball

Carl: Don't misunderstand - I don't have this installed, and If I did I think it would creak as well as reduce suspension travel. If the big washer and end nut and the pin need to ROTATE with the shock, rather than the LCA, as I think they do, putting this plate on as tight as it needs to be locks the washer to the plate instead of the pin and its bushings, so the suspension is locked down too. Something like Simon's hat bushing MAY solve the problem as long as it is not locked to the plate too by the pressure of the washer and nut on the pin. Parenthetically, I'm not sure it needs to be a hat as I think the full face of the washer is not involved in the normal setup - just the center against the center tube of the LCA bushing. So, it may just need to be a tube like the stock bushing center, very slightly taller than the plate thickness.

When we removed the bolt on the other end of the plate, in that case allowing the plate to move with with the pin, suddenly we had no creaking and full suspension movement. I didn't contact you because I still wasn't sure I fully understood the problem enough to convey it correctly. There is a question as to whether Jeff has it installed correctly as there is disagreement about the space behind the plate. I wanted to look at Jeff's situation one more time first. Anyway, if it is as we currently think, this plate is problematic. This plate is a godsend for dyno strapdown, so it would be good if this issue could be resolved one way or another.