huh! "click-click" in the A-arm wasn't the bushing!

[a.d._510_n_ok]

Ripped my 1980's front end apart today to put in new struts, tie rod ends and A-arm bushings. Everything came apart pretty easily. I grabbed the now unattached passenger side A-arm, wriggled it back and forth and heard a very metallic sounding "click-click" and thought, "Yeah, that bushing is pretty bad".

 

When I took the bolt out of the center of the first A-arm bushing I noticed that the bolt had a groove worn in both ends from where it had been seated in the stamped "crossmember".

 

Just for the hell of it, I found a bolt the same shaft size, jammed it through the crossmember and bushing and the "click-click" disappeared! The bushing looks mint - I may just leave it.

[a.d._510_n_ok]

Also, on my '80 510 the original A arm bolts were 10mm shafts, grade 8.9 and were pretty loose in the A-arm bushings. I replaced them with 1996 Pontiac Grand Prix engine mounting bolts that were 3/8 shaft (took up the slack in the bushing but still moved very freely) that were grade 10.9. I have no clue what size they are on other Datsuns but if they are a 10mm upgrades are as close as the top engine brackets/mounts on a GM 3.1 V6.

[1Low620]

Also, on my '80 510 the original A arm bolts were 10mm shafts, grade 8.9 and were pretty loose in the A-arm bushings. I replaced them with 1996 Pontiac Grand Prix engine mounting bolts that were 3/8 shaft (took up the slack in the bushing but still moved very freely) that were grade 10.9. I have no clue what size they are on other Datsuns but if they are a 10mm upgrades are as close as the top engine brackets/mounts on a GM 3.1 V6.

 

I'd be really careful what type of bolts you start throwing in holes, a 3/8 dia NC bolt is almost the same as a 10mm however the grading system is a LOT different. 3/8-16 NC you're either looking at grade2, grade2 zinc, grade 5, grade 5 zinc, grade 8, grade 8 zinc, grade 8 zinc yellow.

 

3 hash marks on the top of the sae bolts signify it's a GRADE 5

 

6 hash marks on top of the sae bolts signify that it is a GRADE 8

 

Metric bolts are stamped 8.8,8.9,10.9, 11's and some 12's that I've come across.

 

I wouldn't be caught dead sticking anything less than a grade 8 in an a-arm or anything else that gets serious vibration.... it will bend and break over time.

 

I sell nuts and bolts for a living :D, get these types of questions all day long.

Edited September 15, 2009 by 1Low620

[MikeRL411]

Just remember! SAE Grade 8 and the various Metris 8.whatever are NOT the same!

[Skib]

Just remember! SAE Grade 8 and the various Metris 8.whatever are NOT the same!

 

 

ya thats an important one to not over look, dont quote me on it but I think a metric 8 is = to an SAE 5?

[1Low620]

ya thats an important one to not over look, dont quote me on it but I think a metric 8 is = to an SAE 5?

 

**ninja edit** let me rephrase that.

 

You can look at several metric thread charts and they will state 8.8,.9,.10 are close to grade 8 sae, if you look at the charts they will show material and tensil strengths, if you use a hardened steel, it is close to an sae grd 8, mild steel and low alloys reduce it down to = some where close to sae grade 5

Edited September 15, 2009 by 1Low620

[a.d._510_n_ok]

so is this chart wrong :confused:?

 

Approximately Equivalent Grades

 

10.9 SAE J429 = grade 8

 

http://www.sizes.com/tools/bolts_metric_standards.htm

[1Low620]

so is this chart wrong :confused:?

 

Approximately Equivalent Grades

 

10.9 SAE J429 = grade 8

 

http://www.sizes.com/tools/bolts_metric_standards.htm

 

It all depends on the material, metric bolts can be made from several materials that have different tensil strengths.

 

Out of curiosity I looked in my system today and and I'll use an example of what I found on a M10 x 40mm Hex head bolt.

 

I've got them listed as this.

 

M10 x 40 Hex Head 10.9 Plain ( this is just a plain black oxide look )

M10 X 40 Hex Head 10.9 Zinc ( blueish coloring )

M10 X 40 Hex Head 10.9 Zinc Yellow ( same as the second, just a yellow color )

M10 X 40 Hex Head 10.9 A2 ( This is stainless, tensil strength is lower than any of the above )

 

M10 X 40 Hex Head A307/304 ( again, the material is stainless and tensil strength is lower )

 

As you can see, even with the stainless stamped with a 10.9, it's not equal to the plain, zinc or zinc yellow bolts.

 

Hope I didn't confuse you, even with all this great information on the internet, stuff can be very misleading.

 

In short, grab a 10.9 grade metric bolt that isn't of stainless material and you will be golden.

[1Low620]

Also, I see you're in Oklahoma, where about's are you? I know blackwell has a Fastenal company there, not sure about OK city,ponca,enid,stillwater ect. That company is like weeds, they're every where. Their prices should be a lot lower than a local true value or what ever they call them back there :)

[a.d._510_n_ok]

1Low, I ain't sure what it was made of it but it was black (with a rough finish) and not stainless.

 

Yeah, got a fastenal about 16 miles from me - those people think nothing of spending fifteen minutes helping you find one specific nut or bolt - nice folks!