Rod-ends

[wacko]

anyone tried using non-P.T.F.E lined rod-ends for their A-arms? trying to cut cost by using larger bore non-ptfe lined rod-ends which are much cheaper and more easily available locally instead of those expensive ptfe-lined ones...

any problems with stiction or accelerated wear & tear?

thanks in advance for your advice

[wacko]

anyone tried using non-P.T.F.E lined rod-ends for their A-arms? trying to cut cost by using larger bore non-ptfe lined rod-ends which are much cheaper and more easily available locally instead of those expensive ptfe-lined ones...

any problems with stiction or accelerated wear & tear?

thanks in advance for your advice

[Brent Howard]

Hey Wacko

We have used non-ptfe lined rod ends, yes we commit the rod end in bending sin purposly because it is easier and it still works, for the last two years. We used Ptfe rod ends in 2001 and all of them pretty much froze. They are all nearly unmovable now, so we switched to non-ptfe ones. They ahve worked quite well so far and I have no real complaints. When taking the suspension off of the 2002 car before Detroit we didn't find any that were really bad. A few were a bit sticky in the direction that they did not normally travel, but still better than teh ptfe ones.

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[wacko]

thanks brent howard

ptfe ones will cost us 200-300% more than non-ptfe ones even with large diameter bores.

[Alan]

Wacko,

Are you guys getting rod ends through Aurora? FYI, they offer a 50% discount to FSAE teams. We use a combination of their performance racing (PWB) spherical bearings and RAM series rod ends, all ptfe lined, with no problems. We have had some non-ptfe in the past and they started to show some freeplay after a while.

Kettering University FSAE

[Bob Gliege]

PTFE rod ends need to be broken in. Once broken in, they operate very smoothly. They cost $$$, but if they are broken in properly they should perform better than non-PTFE rod ends. I haven't seen a PTFE rod end stick in any direction of travel once it was broken in properly. An older car of ours didn't have the PTFE rod ends broken-in and the suspension didn't operate freely as a result. If you decide on PTFE rod ends, make sure you break them in prior to assembling the suspension. We break ours in using a drill press and fixturing. Best of luck,

Bob Gliege
UW FSAE 00'-03'

[Brent Howard]

Hey Bob

We did break them in for the 2001 car as I remember, but they seemed to jam up, resulting in a very stiff suspension. It is possible, indeed probable, that we did not break them in correctly. Could you please outline the breaking in procedure as I have never broken in a rod end, in 2001 I was just a junior member (aka useless).

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Denny Trimble]

One thing to watch out for, with non-PTFE rod-ends, is that you keep them lubricated. We had a bizarre failure in '99, a pushrod rodend (non-ptfe) failed in compression. It appears the rodend froze up and the bellcrank rotated and ripped the head off the rodend threads. The resulting loss of normal load on that tire was not a good thing.

So, if they're steel-on-brass (or whatever), keep them oiled! We found out the hard way.

University of Washington Formula SAE ('98, '99, '03)

[Bob Gliege]

Brent,
I don't know if there is a "correct" procedure, but this is what we did and we were told later on (after doing it the first time) that we did it correctly. The important thing is to make sure your set-up is safe and that you are happy with the end product.

Basically, run a bolt through the bearing in the rod end. Use a nut and washers to tighten down on the bearing so that the bearing and the bolt spin together. Be careful of course not to gall or scar the bearing. Next, you may want to thread the rod end into a shaft in order to avoid damaging the threads and to ease fixturing. Chuck the bolt into a drill press (or equivalent) and fix the rod end (clamp the shaft you threaded it into). Basically, you are going to spin the bearing in the rod end until the Teflon is broken-in. Make sure that your set-up is safe! You don't want a rod spinning around or anything. I recommend you start with a low spindle speed until you get it figured out. How long you do it will depend on your spindle speed and the rod end. Remember, you can always chuck it up and give it another spin if you didn't break it in enough. Do it until the bearing rotates easily. Be careful not to completely melt the Teflon. If I remember correctly, we did it until the Teflon just started to melt. Experiment until your set-up gets you the results you want (no slop, easy to rotate). The parts will be warm from friction, so be careful about that as well.

Maybe your PTFE rod ends weren't broken in enough? Dirt? We have had great results with them since we started to break them in a couple years ago. Balancing cost vs. performance is a struggle. We have ran our cars in the rain on many occasions (Seattle) and haven't had any problem with binding in our PTFE rod ends. I don't think anyone really cleans them after a drive either http://fsae.com/groupee_common/emoticons/icon_smile.gif. We abuse the PTFE rod ends and they still perform. As Denny T. said, we had issues with non-PTFE rod ends the last time we used them.

Hopefully I remembered the process correctly, but you should get the idea. If you have any questions let me know.

Bob Gliege
UW FSAE '00-'03

[wacko]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Alan:
Wacko,

Are you guys getting rod ends through Aurora? FYI, they offer a 50% discount to FSAE teams. We use a combination of their performance racing (PWB) spherical bearings and RAM series rod ends, all ptfe lined, with no problems. We have had some non-ptfe in the past and they started to show some freeplay after a while.

Kettering University FSAE<HR></BLOCKQUOTE>

Does the 50% discount apply to Unis out of North America? Thanks anyway would check up with them.

[wacko]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Denny Trimble:
One thing to watch out for, with non-PTFE rod-ends, is that you keep them lubricated. We had a bizarre failure in '99, a pushrod rodend (non-ptfe) failed in compression. It appears the rodend froze up and the bellcrank rotated and ripped the head off the rodend threads. The resulting loss of normal load on that tire was not a good thing.

So, if they're steel-on-brass (or whatever), keep them oiled! We found out the hard way.

University of Washington Formula SAE ('98, '99, '03)<HR></BLOCKQUOTE>

Thanks for sharing your experience, we were looking at THK bearings type NHS or NOS which are supposed to be lubrication-free and maybe get a bigger bore diameter for safety. they cost ard $10 Singapore dollars compared to NMB which cost ard 7-8 pounds before shipping. Just hoping the THK ones can work and it would save a huge chunk of our budget.