rear poly bushings on outboard end of CA

[blueovalz]

Interesting observation on the thickness of the steel in this area. It validates the importance of designed strength in this area of the car. What I was refering to on the saddle thickness was to effectively increase the gauge of the material. I thought the saddle caps were about .060 material, and that by cutting some pices that mimicked the side view profile of these caps, you could then weld these thicker pieces on either side of the caps, and even some along the top curved part of the caps ("top" means on the top curve of the caps while mounted to the upsidedown car).

 

An issue is that you will need to address is any fore and aft movement of these housings inside the saddles (provided you are not welding these in). The OEM bushings had lips extending out and around the edges of the saddles, but your steel housings do not, and should not, until you know that the spacing of the bearings, in a fully assembled piece, are in their correct location relative to each other and to the body. The disadvange of welding is that to remove the CA, you will need to unfasten the upright for that CA so that the CA can be pulled rearward far enough drop it out of the front housing.

 

Thinking out loud here; You could slot (just slightly, and if you do your homework right, very little) the holes of the upper portion of the uprights so that once the "close" assembly is fully fastened together, you could then bolt the uprights into position, and if this process is done carefully, would allow the slotted holes to compensate for any minor (but extremely critical) errors in the exact spacing of the monoball bearings relative to each other, thus eliminating any side preloading of the balls.

[bjhines]

Ohhhhhh.... Ahhhhhhh.... nice work JM!!! I just have to do something like that too...

 

Could you post some pics of what you did to the inner part of the control arm...???

[JMortensen]

I'll post more detailed pics of the arms when they're all done John, don't worry.

 

The disadvange of welding is that to remove the CA, you will need to unfasten the upright for that CA so that the CA can be pulled rearward far enough drop it out of the front housing.

Not so. When you pull the bolt out the spacers stick out farther than the housing, so you can just pull the inside of the control arm straight down and it comes out. So two bolts, one in front and one in back and the inside of the control arm pulls straight down and out.

 

I'm not too worried about that critical placement of the holders. The way I mocked it up the first time was just by clamping the front down tight and leaving the rear loose. I set the control arm the proper distance from front to rear (marked the center of the control arm) and then just tapped the rear housing with a hammer to make sure it was solidly hitting the control arm then tightened the bearing cap down. It seemed to work pretty good on the mockup trial. If all else fails, my version of the toe adjuster is "less than rigid" in that plane so it will fairly easily take up a couple thou slack and not really preload the bearings much at all.

 

I was thinking about the frame rails more though Terry, and I'm starting to think I should do what bjhines did with his cage and a lot of drag racers do, and run diagonal bars from the cage down to the floor there. I already have the frame stitch welded to the floor, but maybe about 10 or so plug welds through to a plate that then connected into the cage might be in order...

[JMortensen]

Didn't get a chance to do anything to the car today, but I did run out and take a couple pictures and a measurement. That part of the frame that holds the bushings in came out at .108" on my caliper. It was kind of a weird angle to measure at but that should be accurate within a few thousandths.

 

John, I took a couple pictures of the control arm for you. I cut the end of the arm off with my bandsaw. I just cut enough so that the welds that hold the large washers on were gone. Then I used some 5/8" threaded tube ends from Coleman Racing. These are made to fit a 1" ID tube, so they're too damn big for the control arms. Ron Tyler offered to turn them down for me (THANK YOU RON!) and so he turned them down to .745" with a 1" head that almost matches the tube on the control arm perfectly. This worked out pretty good. On one control arm they are just a little teeny bit loose, on the other one I had to spend about 30 minutes with a Dremel and a drum sander to get the inside hogged out enough to slide the tube ends in. I was a bit impatient and really had to hammer the end in on one side, that was pretty dumb because it took me about an hour to get it out later on...

 

Anyway I drilled a couple holes in the control arm and plug welded the tube end in, then beveled the end and welded it there as well. I used a heat setting of 7 and a wire speed of 5, so I don't think there will be any lack of penetration on the welds, but I think welding on these tube ends is one of those places where a tig would come in handy.

 

[blueovalz]

Jon, What size are your monoballs (yes, I here the snickering already).

[JMortensen]

Com-12 3/4" monoballs. http://www.stockcarproducts.com/susp3.htm

 

I think I'm going to put better quality monoballs in before I actually run the car.

[LLave]

Com-12 3/4" monoballs. http://www.stockcarproducts.com/susp3.htm

 

I think I'm going to put better quality monoballs in before I actually run the car.

 

 

Better quality? What seems to be lesser about the stock car products monoballs? What brand do you think you will go with in the end?

[blueovalz]

I finished my jig, and the other rear CA modification. I built the jig around an OEM CA, and then used it to ensure the modified CA was exactly like the OEM CA in regards to placement of the critical components. One thing to note here is the difference in rigidity of the OEM arm verses the modified arm. Without actual measurement of deflection angle, I compared how much deflection (in angle) between the inner and outer axis' of the CA using a 3 foot long torque arm. I found that the modified arm was over twice as stiff, and less likely to permanently deform than the OEM arm. I attribute this to the solid plate at the end of the two main structural members of the arm. The OEM arm allowed the two members to move in relationship to each other. Now, with that said, the spindle pin would prevent this movement in an OEM arm, so the advantage I see here is that this plate is reducing any attempt to twist at the Heim joints, thus reducing the shear loading on the joints themselves. It was quite a difference between the two arms.

 

The jig by itself (very simple and took about 2 hours to build):

 

The cut CA partially mounted in the jig awaiting the end plate with Heim fittings:

 

The final pieces fitted together in the jig, but not yet welded together:

 

 

 

[JMortensen]

Very nice Terry!

 

I was thinking that adding the bit between the two rod ends would significantly stiffen the arm. Good to have some verification of that.

[JMortensen]

Here's what I got done today. I welded all the bearing holders in place. In the rear I welded the caps to the monoball holders and to the uppers as well. In the front I welded the monoball holders to the frame rail, and I left the crossmember loose. I welded all the way down the sides of both holders to the frame rail, then found that my weld interfered with the crossmember and had to grind it all down. It's still there and providing some support though. In the front of the front monoball holders it was really hard to move the welding gun, so those welds aren't very pretty, but I'm sure they'll hold. The welds in the back look a lot better. I also positioned the bearing holders so that the ridge inside faced outward on both the front and the back. This way that steel rim inside takes any load instead of the snap ring.

 

First some control arm shots for John. End of control arm cut, cleaned and beveled. Then the modified tube ends (THANKS AGAIN RON!), then the tube end in the control arm ready to weld, and the holes drilled in the control arm to plug weld.

 

 

 

 

 

Then the rear bearing holders from various angles:

 

 

 

 

Then the front bearing holders:

 

 

 

 

 

Now all I have to do is reassemble one last time and make sure nothing moved, then it's on to the next project... Driving the car is still a long ways off, but I can say this; DAMN that is a HUGE reduction in friction!!!

[blueovalz]

Jon, earlier in this string you mentioned that the monoballs themselves were not a "tight" fit in the housings. This brings up two things:

1) have you noticed any difference in this since the welding is finished

2) If they are still not tight, consider locktight on the outside race. I talked to a builder that had done this very successfully, and simply uses a heatgun to remove them when necessary.

[JMortensen]

I kinda figured the idea was for them to be a bit loose so that when the housings got welded the balls still slipped in. I didn't try to minimize the warpage, I just welded all the way across and all the way around all at once. If I need to buy a brake hone to get the balls back in so be it. I'll have to check it all out tomorrow though, already took the shop clothes off and took a shower...

 

Llave, I missed your question before. I don't really know how to determine if a monoball is good or bad other than by price. Last time I needed some for my sway bar project I just got a recommendation here and went with it. I do know that Teflon linings help, and with a teflon lined monoball you don't need to lube it. So that will definitely be a priority for me when I replace them. If anyone has any suggestions on a good quality monoball to use, I'm all ears...

[bjhines]

You can look up the brands with google... then look at the specifications on the manufacturer's website...

 

I think Stock Car Products uses Aurora bearings...

 

Their COM12 monoball is a middle weight ratings wise... another consideration is the material the bearing outers are constructed of... You dont have to worry about stainless and hard chrome rusting... another consideration is teflon lined bearing races... this usually comes with a higher price... good teflon lined balls will last a long time with zero lubrication... steel on steel balls can be stronger... but not always... some of the cheaper lined bearings can "beat out" their teflon liners...

 

When using spherical bearings.. you should always ensure that failure of the bearing cannot allow a piece to fall off or come loose... backup washers and good design can eliminate this possibility...

 

It seems to me that the rear suspension arm bearings are captive even if they fail....

[JMortensen]

I was going to put washers on the outer ends of the spindle pin, but I think the inside is OK, like you said. My understanding is com-12 is just a size designation, I'm pretty sure the 5/8" monoballs like those used in my camber plates are com-10.

 

I don't think that these are going to fail and cause a crash or anything, I just think that they need to be lubed to move smoothly, and since I don't have an easy lubing mechanism installed and don't want to have to install one and then constantly lube these, I'm going to try and finds some good quality teflon lined monoballs.

 

I still have a really hard time picking them out though. I could spend $80 each on these things if I wanted to. I know the ones I'm using on the front control arms are still very tight after years of service, and they are these here: http://www.stockcarproducts.com/rodend3.htm

 

On the other hand the monoballs in my camber plates haven't held up for ♥♥♥♥, even though I bought the most expensive ones the bearing supply place could get there hands on. Maybe they just sold me crap, I don't know. If it was crap, it was very expensive crap...

[tube80z]

I have had good luck with the XM series QA-1 rod ends. Before that I used mostly aurora. They have similar monoballs. If you're camber plates put all the load on the bearing then you won't see them last too long. It's not loading the bearing in a way it was intended and short life is the result. While not really built for our cars the larger com-12 would probably last longer.

 

Cary

[JMortensen]

I use GC camber plates, so the load goes to the needle bearing underneath. Probably just crappy bearings that beat the liner out like John said. Thanks for the recommendation, I'll take a look at those XM rod ends. I'm going to need 10 rod ends and 8 monoballs, so a little bit cheaper per unit makes a big difference in the end...

[tube80z]

Try searching ebay. I've seen a few sellers selling lots of ten at really good prices.

 

Cary

[JMortensen]

I did search ebay as you suggested and emailed one guy to get a quote on everything I need. I'll let everyone know what the deal is when he responds. Also found the XM's at this website: http://www.racetechmotorsports.com/index.php?cPath=23_132 and it looks like they are $14.50 each, which is less than half the cost of the JMX10 that I was using up front. So right there that's $150 savings. Hopefully these guys will give me a break since I'm buying so many.

 

So I reassembled everything, it all looks peachy. I think this is pretty much done, just needs paint. I'm going to have a LOT of little parts to paint one of these days...

 

I looked at the tunnel again and there is a plate that goes up the sides of the tunnel right where a Ron Tyler diff mount would go. So what I'm going to do is weld in a plate on the floor and have it curve up the side to the second plate. I figure this will be the the most rigid way I can attach the roll bar. In the inside I had patched a couple of holes and cut a couple little brackets out poorly, so I'll have to do some grinding to get this area flat enough to weld a plate in there. You can see the 7 holes where I'll plug weld the plate to the floor before welding around the perimeter. This will ensure that the parts underneath will be securely attached to the plate inside.

 

 

Thanks for all the help guys! I'm really happy with how this one turned out.

[blueovalz]

It's good to see this project coming to an end successfully Jon, and I think there has been more advancements in sperical bearing assembly for the Z rear control arms on this single string than from any other source. In regards to the monoball source, I bought 8 of these 3/4" bearings, with teflon liners, from a guy on Ebay, and they were in such good shape (description said "slightly used"), I ordered 8 more from him. Anyway, these are the bearings (3/4" though) I'm using.

 

Today (funny how both our projects, on the same subject, are coming together at the same time) the machinist called me and told me my bearing holders were ready. These holders are very similar to the ones you purchased, only with a slightly different direction toward installation. I only had one side done, but he has the numbers in the CNC machine now, and can do more at a cheaper price. Anyway, on the the specifics.

 

My goal was to bolt the monoball assembly into the existing Z saddles and caps, thus requiring only modifications to the CA as far as fabrication at home goes. The bearing retainers I recieved today take a few taps with the hammer to push them into the saddles and for the caps to be set in place. The machinist turned the outer diameter (saddle portion) about 2 thousanths big and I told him to leave it that way until I test fit it. As it currently sits, I have about .070" gap between the two saddle pieces (saddle and cap) that hold this retainer. I figure I'll simply stick a shim between the two, and tighten them down instead of risking a loose fit with the OD turned down any smaller.

 

First photo is the assembly thrown together. I need spacers made for both sides of the monoball, and this will come next week, but until then, this is roughly what the retainer assembly, on the arm, looks like inside the transverse link and cap:

 

This shows the other side of the same assembly with the front retainer and sperical bearing. The front one is longer than the rear one. To retain these bearings I had a groove cut for a clip, but I was concerned that the material around the bearing was too thin for a groove to be cut, so I extended the lip to be about 1/2" deep, and then simply had the groove cut into this part, eliminating any weakening of the retainer with the groove cut inside next to the bearing. With this, I will thus need a spacer between the clip and the bearing.

 

Below is the transverse link and cap from the end view. Notice the .070" gap between the two pieces. The retainer has a perfect fit.

 

Lastly is the CA showing the 3/4" stud extending out of the pivot tube (this work was done 3 years ago. So this is an indication of how long I've been thinking about this. It took Jon to get me of my a$$ to finish it though. Thanks Jon!!!

[JMortensen]

You must be using 5/8" balls then instead of 3/4... I like your version a lot better from an installation perspective. Very nicely done!

 

I did forget to mention how the loose bearing issue turned out. 3 of 4 holders were snug but not tight. One monoball needed a bit of sanding with a dremel and a flap wheel, and still takes a couple taps with a socket to the outer race to drive it in. I think I'll use a bit of loctite on the other 3 like you suggested.