MS3 mount bolt recall.... what is Mazda REALLY replacing the stock bolt with?

bast525

Member
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'07 Mazdaspeed 3 GT
I was back at the dealer today to look at a squeak I've been having from the engine bay, and got to talking to the same tech who did the recall service on my MS last week.

He told me straight out that he saw NO difference between the bolt he removed and the bolt he replaced it with.

No length difference, no different kind of washer, nothing.

he questioned his supervisor as to why they were replacing a bolt with the same bolt, and was basically told to just do whatever the recall said.

WTF is up with this??? Does anyone know for a FACT that the are replacing the bolt with a different bolt? b
 
The old bolt was a grade 8 (english) / 10.9 (metric)

I'm not sure of the exact figures, but i think the tightening torque spec on the bolt went up to 104 lb-ft. That's up from about 70 lb-ft.

Unless the engineers at mazda skipped school the day they taught engineering there is no way they would pre torque that diameter bolt to 104 lb-ft if it were still a grade 8 / 10.9

The new bolt is a grade 9 (english) / 12.9 (metric)

It don't git no stronger thin that!!!!!

(cheers)
 
The old bolt was a grade 8 (english) / 10.9 (metric)

I'm not sure of the exact figures, but i think the tightening torque spec on the bolt went up to 104 lb-ft. That's up from about 70 lb-ft.

Unless the engineers at mazda skipped school the day they taught engineering there is no way they would pre torque that diameter bolt to 104 lb-ft if it were still a grade 8 / 10.9

The new bolt is a grade 9 (english) / 12.9 (metric)

It don't git no stronger thin that!!!!!

(cheers)

I thought the new bolt was grade 10? I was also told by my Tech that once the bolt is removed, it gets tossed for a new bolt. Per Mazda's specs, the bolt gets replaced if removed.
 
The old bolt was a grade 8 (english) / 10.9 (metric)

I'm not sure of the exact figures, but i think the tightening torque spec on the bolt went up to 104 lb-ft. That's up from about 70 lb-ft.

Unless the engineers at mazda skipped school the day they taught engineering there is no way they would pre torque that diameter bolt to 104 lb-ft if it were still a grade 8 / 10.9

The new bolt is a grade 9 (english) / 12.9 (metric)

It don't git no stronger thin that!!!!!

(cheers)
no
the bolt was originally CLASS 8 *metric*, the new bolt is CLASS 10 *metric*
ALL bolts except for seat belt anchorage bolts in the car are METRIC
 
no
the bolt was originally CLASS 8 *metric*, the new bolt is CLASS 10 *metric*
ALL bolts except for seat belt anchorage bolts in the car are METRIC

I realize that all the bolts in the car are metric size.

From a strength perspective an english grade 8 is the exact same thing as a metric grade 10.9

From a strength perspective an englich grade 9 is the exact same thing as a metric grade 12.9

I personally conducted a test on the mount bolt at work a while back. THE OLD BOLT WAS AN ENGLISH GRADE 8/METRIC GRADE 10.9.

metric grade 8.8s are equivalent to english grade 5s. Those might be good enough to hold a headlight assembly in place, but not an engine. Just becasue the bolt was stamped with an "8" and was a metric thread doesn't mean it was a metric grade 8.8
 
if it was english grade, they should've used the hash marks instead of a number stamped on the bolt head
 
I realize that all the bolts in the car are metric size.

From a strength perspective an english grade 8 is the exact same thing as a metric grade 10.9

From a strength perspective an englich grade 9 is the exact same thing as a metric grade 12.9

I personally conducted a test on the mount bolt at work a while back. THE OLD BOLT WAS AN ENGLISH GRADE 8/METRIC GRADE 10.9.

metric grade 8.8s are equivalent to english grade 5s. Those might be good enough to hold a headlight assembly in place, but not an engine. Just becasue the bolt was stamped with an "8" and was a metric thread doesn't mean it was a metric grade 8.8



maybe that was the original problem the supplier of the bolt sent what was thought to be metric grade 8 but was english grade 8 and hence the problem???
 
ok... totally different than what i originally read here.

Well the tech didn't mention anything about torqueing it down more or anything like that. But whatever... i'm going to assume, as long as he followed the instructions for the recall, and he did say he replaced the bolt... as long as he torqued it down to the new spec, I assume I should be okay.

We shall see
 
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