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Front lower control arm pinch bolt?

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Old Jun 19, 2017 | 03:33 PM
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Front lower control arm pinch bolt?

Hi,

I bent the front lower control arm and trailing arm on my car when I hit a tire wall at Pitt Race. I had hoped to go through all the suspension hardware over the winter, to make sure everything was easy to work on, but I didn't get around to it. So now I'm in this predicament.

The pinch bolt for the ball joint on the outer end of the front lower control arm has a nut in it. So that suggests to me that it isn't threaded into the knuckle. But no amount of cranking on that bolt or hitting it with a hammer will budge it. The bolt is not threaded into the knuckle, is it?

Thanks!
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Old Jun 19, 2017 | 03:54 PM
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Originally Posted by Mr. Pockets
Hi,

I bent the front lower control arm and trailing arm on my car when I hit a tire wall at Pitt Race. I had hoped to go through all the suspension hardware over the winter, to make sure everything was easy to work on, but I didn't get around to it. So now I'm in this predicament.

The pinch bolt for the ball joint on the outer end of the front lower control arm has a nut in it. So that suggests to me that it isn't threaded into the knuckle. But no amount of cranking on that bolt or hitting it with a hammer will budge it. The bolt is not threaded into the knuckle, is it?

Thanks!
Nope...its a normal tapered attachment.

Since you are replacing the control arm you don't have to worry about screwing up the end of the ball joint...so give it a whack....

Usually if you hit the knuckle right where the taper is it will pop out....or you can use a puller on it if you can get it in there...it is kinda tight. A bit of heat likely will help as well
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Old Jun 19, 2017 | 04:16 PM
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Thanks, but what I'm actually having trouble getting out is the pinch bolt itself. It's not like a outer tie rod, where it attaches with a nut right on the ball joint's spindle. The ball joint fits into a socket on the knuckle and then gets squeezed with a pinch bolt. That bolt is stuck in my knuckle.
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Old Jun 19, 2017 | 04:17 PM
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Your terminology is very confusing. Are you saying that you took the nut off, but cant get the ball joint end to release from the knuckle? If so you need a tool like this or variation of same

Great deal on OTC Tools 7315A at ToolTopia.com


If you're saying you can't get the nut to budge then you need an impact gun. Hard for me to understand what you really mean.
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Old Jun 19, 2017 | 04:30 PM
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Here's where I think the confusion lies: this is the front lower control arm on the rear suspension. On the end that attaches to the knuckle, there is a ball joint. It is held into the rear knuckle with a pinch bolt. I have gotten the nut off that bolt, but can't budget the bolt, either by trying to turn it or hammering on it.

https://www.promazdaparts.com/auto-p...uspension-scat

See item #6 in the above diagram.
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Old Jun 19, 2017 | 04:41 PM
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That's the rear tie-rod end, was wondering if he meant that. The bolt head end has knurled splines. You have to take the nut off to the end and then tap it back with a hammer to get the bolt head end out
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Old Jun 19, 2017 | 04:44 PM
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Hey, I just went by the name in the diagram. Mazdaspeed refers to it as the 'toe control link,' which is also similar to 'rear tie rod.'

Thank you for your help. Knurled? Great. That sucker is going to be difficult to get out.
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Old Jun 19, 2017 | 05:53 PM
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Toe control = tie rod

Just to be clear, the tie rod end has a round groove machined in it the matches the bolt diameter. So the bolt has to come out to get the tie-rod end to drop out. The bolt will tap out fairly easy. It's just a double safety so that if the nut ever came off the bolt won't fall out and let the tie rod end come loose to send you on a magic carpet ride ...
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Old Jun 20, 2017 | 11:32 AM
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Yeah, I think we're all on the same page, here. But just in case here's the bolt I can't get out.

Last night I even tried cutting the bolt carefully through the split in the knuckle, hoping I could at least free one side. No dice so far. At this point I plan on trying to remove every other link, and the axle, so I can work on this bolt out of the the car.
Attached Thumbnails Front lower control arm pinch bolt?-file_000-2-.jpeg  
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Old Jun 20, 2017 | 07:42 PM
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I might be completely off base here. But if it were me, I'd be heating the knuckle itself. Heating the bolt is just going to cause it to expand more. I have no idea if that's detrimental to the control arm for some reason though.
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Old Jun 20, 2017 | 08:23 PM
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The knuckle is part of the forged aluminum upright. Heating it is going to anneal and weaken it . This should only be the absolute last recourse. I would pull the upright off with toe link attached and support it such that with the nut screwed onto the end of the bolt and the knuckle around it supported on something solid like a vise etc. that a 3 or 5 lb hammer could be used to bang it out. It likely has some corrosion in the splined area, but it should still be possible to pound it out.

Edit: you need to heat the bolt head end where the splines are. Heating the bolt head end is for the purpose of breaking/weakening thecorroded surface interface. The expansion will make it tighter, but that's not really what is causing it to be stuck that tightly. And sorry, I forget that due to limited street use/miles that things on my car may not have corrosion issues etc. The bolts on mine popped right out with some light hammer taps.



.

Last edited by TeamRX8; Jun 20, 2017 at 08:28 PM.
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Old Jun 21, 2017 | 08:20 AM
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Yeah, that's my plan right now. Get the knuckle and (what's left of the) toe rod out and work on a vise. I think that the broken links are allowing the whole assembly to move, absorbing the impacts from the hammer.

Also, it's worth noting that I tried cutting the bolt and the ball joint through the crack in the knuckle. My hope there was to free up the friction of the bolt against the ball joint (which worked, that spins a little now) and only work on one half of the bolt at once. Time (and money) will tell whether that was a bad idea. At least used knuckles are cheap on eBay, and I have a parts car.

Last edited by Mr. Pockets; Jun 21, 2017 at 08:24 AM.
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Old Jun 30, 2017 | 05:01 PM
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The bolt eventually came out. I had to remove the knuckle with that end of the toe control rod (it broke in half when I hit the tire wall) and the axle attached to it. The rest of the ball joints came out, though one did take the sleeve with it. I didn't remove the axle from the knuckle because it seemed happy enough where it was.
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