12 replies to this topic

[BlueJay73]

I have a '99 with the Fat Cat bump stop kit on the Spec Bilstein shocks.

Looked in the trunk and found that the top "sleeve nut" that holds the top bushing in place had worked itself off.

I had assembled it correctly and used Loctite threadsealer on the threads at the top of the shock shaft, but the nut came off anyway.

When the nut came off, the shock shaft got out of position, buggered up the threads, tore up that plastic spring isolator and gouged up that red washer that comes with the Fat Cat kit.

I'm replacing it all, but now am worried that that sleeve nut can work itself off again.

It doesn't look too strong. The shaft threads only go maybe half way up inside of the sleeve nut.

Anybody have similar occurrence?

Does the MazdaMotosports bump stop kit have a  better, more locking nut design at the top of the shock?

 

As an aside, I read in one of the threads on this site where the Gorilla Glued plastic spring isolators were coming unglued. Sure enough, both my rear isolators had come unglued from the hat. I used the windshield urethane adhesive that some of you guys recommended, and it seems much stronger.

 

Thanks for the advice!

[chris haldeman]

Myself and others have seen the top fat cat but work loose. Our solution is too use a allen grub/set screw down from the top too jamb it

[Mark]

What Chris said. I don't know why the allen set screws are not part of the kit but we install them in all our cars. Checking the shoulder nuts is still part of the normal race prep process though. 

[BlueJay73]

Ok, I think I see what you're saying.

The top quarter inch or so inside the shoulder nut is empty; threaded, but empty.

You screw an Allen bolt down into the top of the shoulder nut, until it bottoms out tightly against the top of the shock shaft, inside the shoulder nut.

Do you know what size Allen bolt, or "grub" you use?

 

And Chris, congratulations on your dominant win at NOLA!   5+ seconds, I think it was!

[chris haldeman]

Thanks :-)
I will get the tread size for you tomorrow when I get too my shop

[Steve Scheifler]

We've been using a short regular bolt on the top rather than a Allen set screw. 10mm x 1.25 thread if I recall correctly. The allens are cleaner, I'll probably change at some point, but if you need a quick fix the bolts work fine.

[davew]

In my version of the kit, we supply a set screw specificly for locking the sleeve nut in place. Been doing it ever since these bushing became legal many years ago.

 

Don't feel bad, every body has done it.

 

If you need the screws, call me. I have them in stock

 

Dave

[LarryKing]

Another Hint from Heloise, err, I mean "hack" (isn't that what the hip kids call it?)

 

I apply a small paint drop that bridges the gap between the nut and the washer so I can instantly see if the nut has moved. I do the same with the alignment cams.

[Jamz14]

Walter, how often do you loosen your cam bolts? Mine would look like a 60's acid trip if I put a paint dot everytime I make an adjustment. I use a tape strip.

[Bench Racer]

Please allow me to correct my comment referencing Walter's comment. I only match mark the shock nuts. I have a secret marker I use on my cam bolt washers.

[Sean - MiataCage]

We bead blast the underside of the shock hat where the spring isolator goes as well as then rough up the contact side of the spring isolator on the sander prior to gluing them together.   Also make sure to follow the Gorilla glue instructions.

 

Sean

[Ron Alan]

If I'm not mistaken, the measurement that fat cat gives on the yellow washer compression insures that the nut has jammed down against the top of the shock shaft...it  can not tighten anymore. In the failure i have seen it was obvious this was not the case...because when the first nut was found to be loose...the others were checked(and not loose)but we were able to tighten them another 1/2 turn.

 

As Steve said the thread is common...I had bolts in my pile that worked(though yes, not that pretty!) 

[LarryKing]

 

Walter, how often do you loosen your cam bolts? Mine would look like a 60's acid trip if I put a paint dot everytime I make an adjustment.

 

A little acetone, or similar, removes old paint and a new dot is applied.