anyone know the taper on C6 Vette ball joints?

[mfain]

Originally Posted by The GMR

It is a little different, I actually had a custom reamer made for the fabricated uprights we make.



lower BJ on C6 upright.

Nice piece! Do you ream the uppers too, or just the lowers? Edit: Jason, after looking at your website, I see you have provision for a press-in upper ball joint -- do you stay with the C6 piece, or are you set up for a different upper ball joint? Thanks

Pappy

[byndbad914]

thanks GMR and Pappy - further confirmation the angle is off from "normal" racer stuff. If I were doing a bunch I can certainly see the value in a custom reamer. Since I am doing one car, 4 spindles, I will go down the path of picking a "standard" and just getting that reamer.

Pappy - furthermore, imagine if you didn't really know what you are doing and just bought that ball joint on their recommendation and bolted it in! You wouldn't make it far before wallowing out the spindle and bending the castle nut threads and then just having it tear apart. Maybe they should read their own tech guide about misfit at the taper BTW, you are right, I went out and yanked the boot off of one of the joints so I could really get a good measurement and it looks to be about 9.9 degrees (I got .155" of total taper over a length of about .900"). 2"/ft = 9.6 deg. Doesn't seem like a lot but there is a difference, enough that you can see the slop of course once you tried to fit it in the spindle.

So far I am still thinking I will go down the ~7deg 1.5"/ft taper route but seeing now how close to 2"/ft it is I am going to go back and look at some stuff. After my post above I realized that Coleman offers a lower control arm with the smaller, upper ball joint thread and that Howe has a hybrid lower joint with the smaller, upper body but large diam lower stud so that will buy me a little more clearance to rotors. Another option v. the monoball item that has a Coleman pin in it, but that only comes in 1.5 taper from what I can tell, not 2. I can easily go to 1.5" without opening the bottom up (that is always the case as long as I am less angle than what is in the spindle now) and clearly going to the 2" reamer will be of little consequence if I choose to go that route as the angle change is slight. Howe offers a quite a few "hybrid" joints so I suspect they have the Chrysler housing with the 10 deg stud in some form that I could use.

[Ron in SoCal]

Originally Posted by byndbad914

Pappy - furthermore, imagine if you didn't really know what you are doing and just bought that ball joint on their recommendation and bolted it in! You wouldn't make it far before wallowing out the spindle and bending the castle nut threads and then just having it tear apart. Maybe they should read their own tech guide about misfit at the taper .

For whatever reason, this has happened before within our little community. BJ taper documented as different than spec and ripped the BJ's out. Could have been disasterous! Matter of fact a whole batch.

Make sure you check this every time...

[mfain]

Tim,

Howe offers a quite a few "hybrid" joints so I suspect they have the Chrysler housing with the 10 deg stud in some form that I could use.

I don't think the Chrysler housing is available with the 224240 stud (2 in./ft. taper), but Howe fixed me up with a heavy duty, screw in housing -P/N 22329X - that screws into a 22340 weld-in ring. I talked to a Howe technician this morning and he said he would investigate the C6 lower taper issue.

Pappy

[byndbad914]

thanks for the info. I spoke to Coleman today about their lower control arms with the monoballs and I believe this is my best bet. I can get either 10deg or 7deg pins - I think I am just going to go Chrysler and 7 deg. I can ream the bottom to fit the 7 deg pin, it is fully adjustable for roll center height, and if I need more I can swap the pins in the uppers as well for roll center variance. Then the angle matches the upper so I only have one ream to keep track of and a standard K772 upper will work.

On a good note, I got my Forgelines today built to fit my 2011 Z06 with the 395mm rotors and these are what I am using on the Nova (295 fronts/335 rears). I had already built the suspension up from my custom stuff I had in the Porsche then ended up finding a buyer for the roller so took it all back out of the Nova - turns out I could literally have reused everything from the Porsche with the Vette spindles and stock Vette wheel offsets. I had designed that suspension for the Porsche without much info on a Vette and decent info on a modern Porsche... but just having an idea of how suspension works... turns out the A arm ratios match the Vette, caster within a degree, kingpin inclination the same as a C6 Vette. Guess that explains why the car picked up nearly 10 seconds on the track when I put the new suspension in! Good news is this means the Nova should be impressive for cornering This time I am hoping to make inboard shock mounting work out as well, already designed the rockers.

also good to hear the Howe is going to reconsider the taper on the BJs they are selling for Vettes - they will have a problem some day if they keep up with what they have now. They just need to carefully measure the taper and make their pin match - just not that big of a deal for a mfr IMO.

[mfain]

Originally Posted by mfain

Tim,

Howe offers a quite a few "hybrid" joints so I suspect they have the Chrysler housing with the 10 deg stud in some form that I could use.

I don't think the Chrysler housing is available with the 224240 stud (2 in./ft. taper), but Howe fixed me up with a heavy duty, screw in housing -P/N 22329X - that screws into a 22340 weld-in ring. I talked to a Howe technician this morning and he said he would investigate the C6 lower taper issue.

Pappy

For those still following this issue, I completed my "fixes" and here is what worked for me. I used a quality 2 in./ft. taper reamer on the lower tapered hole in the C6 spindle. I had to remove only a slight amount of material, after which the Howe 224240 stud fit perfectly. I then used the 22329X screw-in ball joint housing to capture the stud. For the upper ball joint, I used the 2 in./ft. reamer to enlarge the 1/2 in. hole in a heavy duty (3/4 in. threaded shank) solid rod end. The factory upper ball joint in the C6 spindle fit the now-tapered rod end hole perfectly. The rod end then screws into a threaded insert welded into 1 1/4 in., .095 wall chrome-moly tude that is part of my upper suspension link. Taper problem solved -- moving on.

Pappy

[byndbad914]

Interesting that the taper reamed in the bottom of the Vette spindle didn't work with a 10 deg tapered Howe ball joint but the upper BJ works with a 10 deg ream... you sure about that? The stock upper and lower BJ seem to have the same taper to me.

I bought a 1.5"/ft (7 deg) reamer and got the lower spindle eyes reamed to that and put the Coleman lowers pins in and those fit pretty well. I now need to get the upper BJs out which is a PITA at this point - I have a press but the KPI of the spindle and so forth make it so I can't get lined up on the BJ to press it out (the lower end of the spindle hits the fricken press) so I may look into borrowing a puller tool at the FLAPS and see if I can get something setup to work. Nonetheless, I need to get them out and make a plug pressed back in with the taper reamed into it for my uppers.

I will have to get some pics in the future - been really busy lately and have a vacation planned next weekend so hope to be back on it in a couple weeks.

[mfain]

Originally Posted by byndbad914

Interesting that the taper reamed in the bottom of the Vette spindle didn't work with a 10 deg tapered Howe ball joint but the upper BJ works with a 10 deg ream... you sure about that? The stock upper and lower BJ seem to have the same taper to me.

I bought a 1.5"/ft (7 deg) reamer and got the lower spindle eyes reamed to that and put the Coleman lowers pins in and those fit pretty well. I now need to get the upper BJs out which is a PITA at this point - I have a press but the KPI of the spindle and so forth make it so I can't get lined up on the BJ to press it out (the lower end of the spindle hits the fricken press) so I may look into borrowing a puller tool at the FLAPS and see if I can get something setup to work. Nonetheless, I need to get them out and make a plug pressed back in with the taper reamed into it for my uppers.

I will have to get some pics in the future - been really busy lately and have a vacation planned next weekend so hope to be back on it in a couple weeks.

I measured the upper taper with a micrometer -- got 2.02 in./ft.. After I ran the taper reamer through the rod end, and inserted the upper ball joint, it appeared to fit perfectly. I painted the ball joint tapered shaft with a Sharpie, inserted it tightly, and rotated it. It scraped the Sharpie mark from top to bottom. By the way, I talked to the guys at Pfadt a while back, and they told me they had never had failure issues with the upper C6 ball joint -- not as much strain on it as the lower.

Pappy

[preston]

Just from reading, I definitely prefer MFain's solution to the UBJ problem. I'd be very nervous about the overall affect on the upright after pressing that UBJ out -
From what I understand they are not designed to be replaceable - if the UBJ wears out you are supposed to get a new upright. You may put a lot of stress on it trying to push it out and then monkeying up a further solution.

No one else mentioned how the GMR had that caliper mounted - that looks very interesting and very stiff.

(Actually on 2nd glance, you are not really improving the mounting stiffness so much as just providing another solution to custom mounting and I guess it might be stiffer than cast in lug ears) .

[byndbad914]

Pappy - there is indeed less load on the uppers normally so you are probably fine as you note.

Preston - I will need to see what the upper looks like with the BJ out - I want to use a serviceable item and that is the point actually of why I want to get the stockers out of there and use a Howe piece with the upper As. It went in so it should be able to come out just need to make sure I get adequate support so I don't bend the upper "arm" of the spindle.