Dan Wendling

Looking for feedback on the plus and minus of installing T1 control arms with their stiffer bushings or simply go to a set of Poly bushings.

Also, anyone make a Poly upgrade kit that includes grease zerks so I can lube them often to prevent squeaks?

My application is HPDE/TT 8-10 time per year, otherwise a daily driver.

sperkins

I know Robert @ SpeedSouth does zerks, but I'm not exactly sure how that works. Just last week I installed Pfadt's poly bushing kit and I can't see how a grease fitting will get the lube all the way through the bushing to the pin. The way I understand it, the pin is designed to rotate in the bushing and the bushing does not rotate in the arm. The instructions were very specific about NOT lubing the outside of the bushing where it contacts the arm. Seems to me that a zerk would only allow the lube to get to the arm where it's not supposed to be.

I plan on pulling the pins every year to re-lube. Shouldn't be that big of a deal IMO.

Dan Wendling

You are pointing out my original concern over adding zerks.

Lubing the fittings once a year is clearly not a problem. Once a month would be a pain.

What is the experience that others have regards how often to re-lube the Poly?

Also how do Poly and T1 arms compare?

drivinhard

the bushing material may be stiffer, but the upper fronts are still probably going to start to leave the building. maybe the T1 guys can chime in on their experience. at least with the Pfadt (or even VBP) you are keeping the bushing halves in place with a snap ring/washer.

running the Pfadt poly (about our only option in the small TTA sandbox we have, bearings need not apply) has been a nice upgrade, so far everything still moves freely and no noise issues. my rears have been in the longest (since march)

you can pull the arms loose at the cradle and re-lube the pins once a year. just do it during a yearly safety check.

or stick with the stock rubber and just keep your eye on the upper fronts. the lower fronts also can creep out.

RX-Ben

Has anyone ever made a brace to keep the bushings captive?

Also, in terms of "lubing the pins" - you are referring to pressing out the pins from the bushings and lubing, and then pressing in?

Also - I would think some of the squeaking would come from the outer part of the poly pushing rotating slightly in the arm, hence the lube application.

Solofast

The problem isn't that the bushing is coming out, it is the arm that is bending and pulling away from the upper rear bushing...

If you try to put a brace across the upper arm you will run into the front shock, the old C4 had a piece between the upper arm legs, but that went away when the C5 came along... Ooops...

I posted a pic of an upper control arm with the rear bushing "flipped" so that it had something to hold the rear leg of the arm and prevent the arm from bending in the first place. Do a search on front bushings in the RR and autocross forum and take a look. If you flip the bushing on a new arm you won't have a problem with them coming out. The reason is that it will share the load between the two legs of the upper arm and it won't bend. If you just have one bushing (the front one) trying to stop the arm from moving, it will eventually bend and pull away from the rear bushing...

davidfarmer

T1 is still torsion bushings, but stiffer than OEM. I'd go with VBP Poly myself. Those OEM-style T1 bushings have constant friction, and the arms can't move smoothly. Unless rules restricted, Poly is my choice.

argonaut

I installed the Pfadt poly bushings last winter and installed Zerk fittings on my own. The bushings come in two varieties: split bushings where there are two halves to the bushing and one-piece. I don't remember specifically which control arms use the split and which use the one-piece but suffice it to say the kit has several of each type. For the split bushings - what I did was shorten each half slightly so that, when pressed into the arms, there will be a small gap between the two halves. Then I installed the Zerk right at that gap, so that grease will go into the gap and hit the pin/bolt. For the single bushings I first cut a small groove around the circumferance of the middle of the bushing and then drilled several holes into the bushing, within this groove. Installed the Zerk so it points at the groove. The grease flows into the groove and moves along it until it encounters a hole and then down to the pin/bolt. I have done 8 events on them thus far and they seem to be working perfectly. No sqeaks or binding noises yet. I have not tried to re-grease them thus far however. Time will tell if it works.

dvandentop

i like my vbp and no noise after a full year

cottoneg

Have you considered Spherical Metal Joints & Sleeves? Ride quality remains the same. They come with grease fittings and do not squeak. They are the best for eliminating rear trailing arm movement and seemed to have helped with the trailing throttle oversteer.

Guldstrand has them.

varkwso

Unless running T1 use poly - I like the VBP ones.


Sway bar end links make more noise...

AU N EGL

VBP with some silicon grease.