Upper control arm bolts

[FG Jeep]

I'm in the midst of upgrading some of the hardware in my suspension. Initially it started with a hardware upgrade and flex joint into the track bar. But I'm not a fan of the dinky m10 hardware for the upper control arms. I would like to step up to a M12 bolt for the uppers. It sounds as if m12 isn't to tough to do as there are just some shoulders in the Xj bushing to center the m10 bolt in the 12mm hole that need to be drilled out.

What I was wondering has anyone gone larger then a m12 in the uppers like a m14 to match the lowers. If so what did you do for the bushings on the axle end? Where you able to locate a bushing with a 14mm sleeve or did you drill the existing one out?

I already have adjustable tubular control arms with flex joints for both upper and lower control arms in the front. I'm content with running 12mm but if it is easy enough to step up to a 14mm at this time I rather just do that.

 

[Johnnie Walker]

Lots of people go to 1/2" hardware on uppers. Pending the joints/busing repalcements you buy they offer 1/2". WOuld ahve to drill out existing UCA holes.

 

[FG Jeep]

1/2" and 12mm are nearly the same size. I was more wondering if anybody has gone to a 14mm hardware which would be nearly the same as 9/16".

 

[Boostwerks.com]

http://www.prothanesuspensionparts.com/88216

Easy peasy.

 

[FG Jeep]

Link doesn't work. Upon going to page on my own it doesn't say anywhere in the description of it that these bushings allows for a larger bolt. From what is listed I would expect it to be a stock replacement keeping the 10mm bolt.

More than likely I will go with 12mm or 1/2". But I'm curious if there is a bushing out there that would allow for a 14mm or 9/16" hardware.

 

[Boostwerks.com]

Link doesn't work. Upon going to page on my own it doesn't say anywhere in the description of it that these bushings allows for a larger bolt. From what is listed I would expect it to be a stock replacement keeping the 10mm bolt.

More than likely I will go with 12mm or 1/2". But I'm curious if there is a bushing out there that would allow for a 14mm or 9/16" hardware.

Hrm works for me? :dunno:

I'm using that kit actually with a 1/2" bolt. Works Great. A 9/16" upper wouldn't really be worth it IMO. You might be able to bore out the provided sleeves however if your heart is set on 9/16"





Can't seem a find an installed pic unfortunately

 

[FG Jeep]

I already have the 12mm stuff I was just curious if anybody had run 14mm on the upper.

 

[Devilfrog]

I don't think anyone makes a 14mm or 9/16" spec'd upper bushing.
If you use a carbide burr to remove the nubs inside a Moog upper bushing, the hole is 1/2" ... Which by the way is actually 12.7mm.
The bushing sleeves are hardened steel and difficult to bore. A machine shop might help but ups the cost with little benefit. Going to 1/2" bolts is easy, and most cartridge joint makers (RE, Currie, etc) offer a bushing with a 1/2" hole. So again the easy way about it without going into expensive custom modified parts. And 1/2" gr8 is more than up to any stresses the upper links will see, far better than the stock M10 is. I've actually snapped an M10 torquing the uppers when my torque wrench locked up, never done that with a 1/2" bolt.

 

[rockclimber]

Most people will never shear a 10mm bolt in a UCA. properly maintained, the combined strength of both sides is more than capable of doing the job.

however, if you have your heart set on "upgrading"

the easiest/best thing is to run 7/16" bolts in f-9/11. there is no modification required and they are a significant strength upgrade.

in all honestly grade 8 7/16"s are fine. but the f-9/11 is just a little more comfort zone.

 

[cdn_xj]

You should be using a Class 10.9 Metric bolt in suspension applications. Strength-wise it's about equivalent to a Grade 8 bolt.

Class 8.8 metric is on par with Grade 5 SAE.

 

[cal]

Most people will never shear a 10mm bolt in a UCA. properly maintained, the combined strength of both sides is more than capable of doing the job.

however, if you have your heart set on "upgrading"

the easiest/best thing is to run 7/16" bolts in f-9/11. there is no modification required and they are a significant strength upgrade.

in all honestly grade 8 7/16"s are fine. but the f-9/11 is just a little more comfort zone.

I have broken more than a dozen 10mm upper control arm bolts, before I gave up on them and went bigger?

Maybe I was doing something wrong.

 

[rockclimber]

I have broken more than a dozen 10mm upper control arm bolts, before I gave up on them and went bigger?



Maybe I was doing something wrong.

Notice how I said "most people"

You are not "most people".

You are a special kind of idiot.

So yes, you were most likely doing something wrong.