I just got through replacing the front right wheel bearing/hub assembly on my lady's 91 olds cutlass and something happened while I did it.

I was puting a bolt back in to reconnect the ball joint and ended up stripping the hell out of it. I went to autozone to get a new one and while one guy was trying to find a replacment another guy started asking questions about said bolt and nut. He asked what is was for exactly and I told him suspension. He said, and i quote, "you're going to need a #10 bolt and nut, they're the strongest ones and suspension components require it."

Was this guy BS'ing me? Or is this true. The reason I ask is, when I stripped it...I wasn't tightning it down hard at all and BOTH the nut and bolt and completely rounded. Now, if these are susposed to be the strongest bolt and nuts (the guy also compared them to forged steel), why were they so easily stripped?

Needless to say...they didn't have the bolt buy itself and wanted to sell me a whole new balljoint replacment with the bolt for $20. Luckily I found a #9 bolt and a #10 nut and just used those.

Was this guy just talking sh*t, or is this true?

 

never heard of a #9 or #10 bolt. the more common american bolts are sold by grade, grade 3 is hardwear grade and not for any automotive application other than holding trim. grade 5 and grade 8 are for automotive applications. i only use grade 8 bolts, buy them at local tractor supply for 3.99 a pound. socket head cap screws ,and i'd suspect torx as well are grade 12 or so, very hard and strong. there is also some specialized amreican bolts and grades such as A325 which is for structural steel erection. not 100% sure how metric bolts are graded so it's just a guess from my understanding of them. the strength of metric bolts increases as the size goes up and is stamped on the head of the bolts, like 8.8. i just bought a box of metric bolts and nuts from a fastener supply and they told me metric bolts and nuts compare to our grade 8. take a look in your repair manual there's usually a section on bolts and their strength and how they're marked.

 

Ok, cuz the guy had me annoyed and wondering. We came across a few 8.8's, but I figured 9 would be stronger. And according to the guy at autozone, a #10 is the strongest (metric I'm guessing) that you could get.

Thanks for verifying what he said....cuz I was doubtful.

 

Metric bolts are measured with some other scale than the SAE scale. I see alot of them that are marked "10.8" or some such. I could be wrong, but I believe the 8.8 metrics are roughly equivalent to SAE grade 5, and the 10.whatever are similar to SAE Grade 8.

Aside from that, most suspension bolts are special, and single-purpose designed. They have shoulders of specific sizes, washer heads, etc. etc. Generic bolts wouldn't have all those features.

I'd suggest just going to the junkyard and horking the right thing off of a another car.

 

yeah i was going to say what rb did, most if not all of the suspension and stearing bolts anr specialized and you can't use common bolts to replace them with.

 

RB is right on with that. Here is some more info on bolts http://www.hioutput.com/tech/bolts.html

Gad, I need to change that color scheme...

Pete