Torque For 40 AMP Alternator - 3 bolts 12mm Head

[Uncle Phil]

I can't seem to find a torque setting for the 3 12mm headed bolts that secure the alternator to the engine in the Honda Service manual.
It gives a torque for the nut that holds the wire in place but I see nothing for the 3 mounting bolts.
Any ideas?

 

[Bush]

I'm not 100% certain, but if memory serves, as I no longer have the manual (maybe it was Clymer) where I found it, it was 45 ft/lb. John O. will know for sure. Hopefully he will be along shortly.

 

[SMSW]

Phil, @Bush's number seems awfully high to me. Torque goes by the bolt diameter - not its head size or style.

You said a "12mm headed bolt". Do you mean the bolt is 12mm or the head is 12 mm? I pulled out my 12mm wrench and a plastic box of assorted nuts and bolts. I had none that fit the wrench, but an 8mm bolt came close. An 8mm bolt takes 16 lb ft of torque. My HSM says a 12 mm bolt gets 40 lb ft. Note the page shot below is from my 1300 manual, '03-2011 edition.

 

[Larry Fine]

You said a "12mm headed bolt". Do you mean the bolt is 12mm or the head is 12 mm?

It's gotta be the head size. 12mm bolts are way too big for the alternator.

Plus, all bolts have heads.

 

[Uncle Phil]

12mm is the head size not the bolt size, as I said '12mm headed bolt'.
45 lbs would about right for a 12mm bolt but that is not this size - my ST1100 parts guide says it is an 8mm bolt.
The 'default' torque is 16 foot-pounds so I guess that's about as good as it's going to get.
The Honda service manual (AFAIK) is silent on the torque setting specifically for those bolts (number 4 in the diagram - that's the reason I'm asking) -

 

[tnbill]

I would believe 18-20 ftlb

 

[dbst1300]

FWIW, I just installed a brake disk on a Yamaha wheel and 17 Lb Ft was the spec for 8 mm bolts (thread size).

 

[Bush]

Obviously, my memory is not serving me well on this occasion!

 

[Josh_ST]

I believe the torque spec is "gudentight"

 

[Uncle Phil]

I settled on 18 and called it good.
Once again I find it strange that the Honda ST1100 Service Manual does not 'spec' a specific torque on that page for these bolts since they are kind of important!

 

[Larry Fine]

I settled on 18 and called it good.

You're making real progress if you're already putting the alternator back in.

 

[Sunday Rider]

You're making real progress if you're already putting the alternator back in.

All those surgeries, and cracked ribs and the UP keeps on going. Well done indeed!

 

[Larry Fine]

All those surgeries, and cracked ribs and the UP keeps on going. Well done indeed!

He's an animal!

 

[Uncle Phil]

Another question - any gasket sealer on the oil pan gasket?
Again it appears the Honda ST1100 Service manual is silent which would mean no to me.

 

[John OoSTerhuis]

Page 1-15, Honda Service Manual: 20 ft lbs. BTDTx8. Are you positive that flange bolt takes a 12mm socket (not 10mm)?
No sealant on the gasket, assuming new gasket/clean and flat surfaces.

John

 

[Uncle Phil]

Page 1-15, Honda Service Manual: 20 ft lbs. BTDTx8. Are you positive that flange bolt takes a 12mm socket (not 10mm)?
No sealant on the gasket, assuming new gasket/clean and flat surfaces.

John

John - Is that the 'general' Honda Service Manual or the ST1100 Service Manual?

Here's what my ST1100 manual (issued 1996) shows on 1-15



The 'torques' are few pages further along and it only gives the 'general' settings for the bolt size but not for the specific alternator bolts.
It does give the torques settings for three other alternator fasteners but not the mounting bolts which sort seems strange to me.

 

[John OoSTerhuis]

Honda ST1100 Service Manual, not the Honda Common Service Manual.

 

[Uncle Phil]

John - My guess is that the one I have is 'later' addition as those torques show up on 1-17.
I see specfic torques in mine for -

Alternator Terminal Nut (After 95)
Alternator Shaft Nut
Alternator Drive Gear Bolt

but nothing specifically for the alternator mounting bolts.
In the 'general' section I see 20 f/p for a 8mm flange bolt - is that what you are talking about?

 

[John OoSTerhuis]

In the 'general' section I see 20 f/p for a 8mm flange bolt - is that what you are talking about?

Yes

 

[Uncle Phil]

Yes

Thanks - just wanted to be sure.