12 replies to this topic

[callumhay]

First off I'd like to say I have learned a ton reading the information on these forums and everyone who I have communicated with on here has been great.

 

This is my second car that I have installed the Whiteline offset bushings on. Both times the install went fine and my questions really are based on how to know that the control arms are moving freely enough and then how frequently to check them.

 

I guess the premise of my question comes from the fact that I do not know if inertia in moving the upper control arms will play into the handling of the car...meaning is there going to be an optimum amount of move-ability to the control arms with these bushings for our purposes??...or is this just overthinking on my part??.  Clearly the metal bushings are meant to rotate within the urethane and need to be greased on install to work properly and would be a problem if they were not. That being said, where the urethane contacts the subframe and the washers are friction points which needs to be overcome by the movement of the car. Can that movement be modified to be optimal by the level of torque to the bolt?..or greasing the contact points? Even if it can, is it irrelevant given how much force is going through the suspension?

 

It seems to me that the torque of the long bolt through the bushings would have some effect on how much the arm moves. Too much might cause the urethane part of the bushing to bind on the subframe and too loose might lead to the arm moving fore and aft. 

 

Also in terms of monitoring the control arm movement and re greasing the bushings, I wonder if some have done this. If I recall correctly, the urethane bushings should not need to be re-greased...but I wonder if that is really the case. I figure some of these questions also probably factor in to how Delrin bushings might perform differently... 

 

If anyone has an opinion on this, I'd be interested in what they think.

 

Cal

 

Tampa 

 

(Ain't won squat, but I podium for fun every time)

[Armando Ramirez]

Nice, great way to be!

 

 

"(Ain't won squat, but I podium for fun every time)"

[callumhay]

Appreciate that !

[luvin_the_rings]

We use the bushings sourced straight from Mazda Motorsports.  Not sure if they are also manufactured by whiteline, but here is what we experienced.  Just did this job last month so I'd be glad to help since its still fresh in my head.  

 

The metal sleeves that go through the delrin bushings are slightly longer than the bushing, so tightening the bolt clamps these sleeves in the clevis in the cross member.  The shoulders on the delrin bushing are responsible for taking the fore-aft load on the a-arm, but since the a-arm is long from the pivot axis, this creates a moment that reacts into the bushings as a radial load, not fore or aft "axially" on the bushing.  The steel sleeve inside the bushing does not compress much when tightening the bolt, so whatever friction is generated at the shoulder of the bushing is relatively constant, no matter how much you tighten.  Once the bolt is tightened, yes, the shoulders of the bushing are responsible for reacting whatever fore and aft force is at that bushing. However based on some calculations I did for Formula SAE during school, and some good ole blue sky estimating.  I'd estimate that the axial (not radial) load on these bushings is minimal in braking, and almost non-existent in other scenarios.  You have the braking torque applied clockwise to the suspension, pushing the bushings forward, and you have the Inertia force applied in a backwards direction pushing the bushings back, so the forces there kind of cancel each other out.  Being the upper a-arm, the forces in it are a fraction of what they are in the lower a-arm, I'd estimate only like 75-100 lbs per bushing, so any wear on the shoulders of the Delrin bushings will be minimal.  Also, the coefficient of friction for Delrin on the steel is very low, so low, i'd be surprised if the best drivers can notice it.  

 

In short, put em in, tighten them to factory spec, or above, grease them, and inspect them for pay before every weekend.  People have been seeing very good durability with these parts, and I think your headaches can be better spent trying to gain time elsewhere.  

 

Good luck, and make sure you use hardened washers to get old bushings out.  We used the pipe and bolt method over the press.  Worked great.  

 

-Z

[Parity]

Do you think grease fittings are beneficial? Does cross drilling the bushing for grease possibly compromise it? I pinned mine to prevent rotation so need to have spare a arms pre-assembled to change out at track in necessary.

[davew]

This is only slightly confusing. The white bushings are not manufactured by Whiteline motorsports. The black ones are made by Whiteline. I have never dealt with the white bushings. But I have sold and installed a lot of the Whiteline (black) version.

 

This only represents the Whiteline bushings:

 

The "plastic" is bonded to the outer sleeve and can not rotate. The only potential rotation would be between the outer metal sleeve of the bushing and the control arm sleeve. A metal to metal contact. With as tight as these go in, I do not see any way for it to rotate. I have not seen any of the whiteline bushing rotate.

 

dave

[Jim Drago]

 The only potential rotation would be between the outer metal sleeve of the bushing and the control arm sleeve. A metal to metal contact. With as tight as these go in, I do not see any way for it to rotate. I have not seen any of the whiteline bushing rotate.

 

dave

 

I would agree with that. We did pin ours, but they are very tight and doubt they would move either. 

[Marc Cefalo]

for those that use the Whiteline brand, we have 1/2 of a set avail for those that want to build up a spare arm to have on hand with the offset bushings.

 

can be found/bought here:

 

http://www.planet-mi...ch-item&idn=951

 

we prefer the delrin ones made by ISC but i know many others including shops like Advanced Autosports prefer the Whiteline brand.  to each is own, both versions accomplish the end result of negative camber gain.

[luvin_the_rings]

I bought the white nylon pieces directly from Mazda Motorsports. we drilled them all the way through so the grease could reach the steel sleeve.  We put the zerk fittings on the direct opposite side of the a-arm so we can access them from the engine bay to grease.  Also, I don't feel that particular area sees much contact stress so we were ok with drilling all the way through to the steel.  

 

Time will tell if this was correct, but that is what was directed by MM.  

[Adax]

I think Callum is asking where it is supposed to move (rotate) and does the clamping effect of the mounting tabs prevent that movement to some degree. I have the same question.

[Bench Racer]

As has been stated the WhiteLine outer steel sleeve is not going to rotate because of the assembly press fit and there is no real load to rotate the bushing/outer steel sleeve. The inner steel sleeve is not going to rotate because during assembly it's squeezed between the sub-frame tabs/ears. The normal rotation is between the white plastic rotating on the inner steel sleeve.
A potential process to obtain any tab/ear radial load created by tab/ear clamping force would be to before the long bolt is tight and before the spindle is connected to the control arm use a tension fish scale and with the fish scale lift the control arm from the outer end. Then tighten the long bolt to specification and lift the fish scale for a second reading. You now have your potential radial load.

[Steve Scheifler]

I don't know that anyone has really answered the original questions.

Callumhay, it sounds like you are in fact using the Whiteline (as opposed to white ISC) bushings and experiencing rotational friction when installed. Unfortunately you aren't alone. Originally we installed the ISC kits because the Whitelines had been discontinued and it was months before they became available again. I had some concerns about those and still do, but nobody else seemed to have a problem. I later installed a set of Whitelines on a backup car and do not recall any serious issues other than the same concern about the thin-walled sleeve cutting into the subframe and washer. More on that later.

More recently I purchased a couple more sets of the Whitelines and this time had the issues you have described. The problem, as I see it, is that for either version, by design the center sleeve MUST be slightly longer than the poly/delrin bushing. That allows the inner sleeve to be pinched between subframe and outer washer and therefore remain stationary while the bushing is free to rotate on it. The gap should be minimal to prevent fore-aft movement but sufficient to minimize friction between bushing and outer washers in particular (inner sides pinch to a tube so less surface there for friction, but more than zero).

Does this matter? Well, it would require a fairly big fish scale to measure the force required to move some of the ones I got where the inner sleeve was if anything a bit shorter than the bushing material. For a street car that would likely go unnoticed. For a race car I think it might be an issue. For starters it slows and/or reduces the rate and amount of movement of the suspension particularly on the unloaded side. Perhaps in the real world that's completely irrelevant, I don't really know, but where it might really screw with you is on the scales. Have you ever been trying to get a particular cross weight but every time you try to jounce and settle the car it comes up with a different value? Something similar can happen if the eccentric adjustment bolts are a bit loose allowing the arms to slip then stop in different positions as they pivot on the bolts. The friction/resistance I got after installing the arms would have been more than enough to cause similar problems with measuring cross weight. Slip-bind, slip-bind, each time taking a different set and therefore changing the weight on that corner.

I don't recall that being an issue with the set I bought last year but at some point I will re-check that car. I've spoken to others who were certain they had no such issues and the arms moved freely when fully torqued. It's possible that later runs of either the sleeves or the bushing are slightly different, or that filling the bushing mold is not tightly controlled. I don't know, but I think there is a problem. Actually, I know there is a problem with the sets I purchased this year.

Back to the thin-walled sleeves. Having to take the first of this new set back apart a couple times I also had problems with the inner sleeve again. It is intentionally thin to maximize the available offset but that makes it only very slightly larger than the diameter of the hole in the large washers, which is a bit larger than it really needs to be for the long bolt. During assembly that hole and sleeve are unlikely to be perfectly concentric so part of the sleeve overlaps the hole and gets pressed into it when torqued, damaging the end of the sleeve. That exacerbates the friction problem but can also damage the sleeve enough that it drags on the bolt and makes disassembly very difficult.

Something I've noticed is that the stock bushings which come out of new NB arms for our 2002 have an even thicker-walled center sleeve than those from the NAs. There is no "strength" issue with them so why has Mazda added more steel? Meanwhile we are greatly decreasing the thickness on ours. Others say they haven't seen it, but a few thousandths at a time they are digging into the subframe tube and big end washers. I haven't decided yet whether to make new bushings or come up with hardened steel washers with the correct size hole to supplement or replace what's there. The aftermarket offset ball joints are looking better every day.

[Bench Racer]

If you caught larger fish, you'd have the correct size fish scale.