Maintaining monoballs

Brotok · 03-02-2010, 11:18 PM

I am curious what people do to maintain monoball joints.

I have had monoball joints in my trailing arms on my '79 SC and haven't really thought about them for the two to four years they've been there - unfortunately I think they are Weltmeisters. So, should I be lubricating/checking or doing anything else to them at any point?

Thanks in advance.

Flieger · Flieger's Garage

I just got mine. Every time I asked, I heard that they are just wear items. No maintainance is really practical. The weather-sealed ones should last a good, long time.

175K911 · 03-03-2010, 04:00 AM

I've had mine in for 2 seasons. Since the engine and trans are out of the car, and I've got most of the rear suspension off I thought I'd pull one and check it. Still plenty tight. But I'm debating replacing the guts as long as I have easy access. Better now than after everything's back in and one fails mid-season. Kind of like ball joints- replace as maintenance before they fail.

GaryR · GaryR's Garage

Unfortunately it's one of those items that you really won't know it's bad unless you remove them or they fail. In my race only car the bearings in my originals (about 4-5 years ago) were Chinese and when I inspected them after two years they were on their way out and needed replacement. I was able to replace them (bearing only) with a better bearing. My current ones (different car) are not Chinese and will be two years old after this season and I will check them next winter. It's "possible" to pop them out without disconnecting the trailing arm from the spring plate but I doubt it will be easy.. They are easy to replace once you can get to them though..

I would ask Chuck Moreland for the final word on all this.

Brotok · 03-03-2010, 08:16 AM

Great, thanks for the replies. That cleared things up a lot. Any idea of what happens once they wear out? Does the suspension make noise or start to wonder?

I actually have a mysterious creak coming from the rear - so far I isolated the spring plate bushings, sway bar, and torsion bars so was beginning to think it may be the monoballs, but I have a hard time believing they can make a creaking sound.

Thanks

175K911 · 03-03-2010, 09:02 AM

What kind of spring plate and spring plate bushings do you have? If you have Weltmeister plastic bushings, they'll make noise. And frankly they're far inferior to Chuck's Polybronze parts. But if you still have the original rubber bushings in the spring plates, they're probably collapsed and that's your noise. And at the extreme, the bushing can deform enough to allow moisture into the torsion tube at the bottom of the bushing, not a good thing.

KTL · 03-03-2010, 09:28 AM

Here's some work I did on my trailing arm monoballs before installing them.

GruppeB • View topic - Bearing Question for G2

And the front strut mount monoballs are wear/replacement items too. Both Ed and I can attest to that with our use of the Tarett strut mounts.

The sway bar drop link rod ends with spherical bearings are also replacement items. My TRG/Tarett copy rear sway bar was squeaking pretty good, so I replaced the sloppy drop link spherical bearing ends with some bronze race rod ends. I suspect the bronze will wear out as fast or faster than the plain steel races. I didn't care since the rod ends are not terribly expensive and it would be a good test. There's also Teflon-lined bearings that can be used. Those wear out too.....

Brotok · 03-03-2010, 03:09 PM

Great information.

Currently, the car has ER polybronze bushings - just rebuilt. I just took out 28 mm torsion bars and am running a 600 lb coilover conversion on the stock bilstein sport struts. The sway bar is currently out of the car. From that, you can probably see why I suspected the monoballs, but again, I don't image a "creaking" sound, like metal binding, coming from them. Also, I can replicate the sound by just pushing up and down on the rear bumper, it is quite loud. The sound was just the same with the torsion bars.

I appreciate all of your input.