CB/CL/SL 350 Torque Specifications

LongDistanceRider

LongDistanceRider

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Front Fork
Ass’y/Part ................................Bolt/Nut Size

Front Brake Stay Bolts....................8mm ......................................180-250 kg. cm.........13-18 ft. lbs.
Fork Tube Top Bolt .......................16mm.......................................700-800 kg. cm.........50-58 ft. lbs.
Upper Bridge/Triple Pinch Bolt .........8mm.......................................180-250 kg. cm.........13-18 ft. lbs.
Front Wheel Axle..........................12mm.......................................550-650 kg. cm ........40-47 ft. lbs.
Steering Stem .............................24mm ....................................800-1200 kg. cm ........58-87 ft. lbs.
Bottom Bridge/Triple ......................8mm ......................................180-250 kg. cm ........13-18 ft. lbs.
Headlight Case ............................10mm ......................................300-400 kg. cm ........22-29 ft. lbs.

Handlebars
Handlebar Clamp Bolt .....................8mm ......................................180-250 kg. cm ........13-18 ft. lbs.

Frame
Front Engine Mount Nuts ...............10mm ......................................350-450 kg. cm ........25-32 ft. lbs.
Rear Engine Mount Nuts ................10mm ......................................350-450 kg. cm ........25-32 ft. lbs.
Engine Upper Hanger Plate ..............8mm ......................................180-250 kg. cm ........13-18 ft. lbs.
CL Muffler Hanger Upper ................10mm ......................................350-400 kg. cm ........25-29 ft. lbs.
CL Muffler Hanger Lower ..................8mm ......................................200-250 kg. cm ........14-18 ft. lbs.
Dual Sheet Mounting Nut?? ..............8mm ......................................180-250 kg. cm .........13-18 ft. lbs.
Rear Fender ...................................8mm ......................................200-300 kg. cm .........14-22 ft. lbs.
Rear Brake Pedal Pivot Bolt ............12mm .......................................350-450 kg. cm ........25-32 ft. lbs.
Swing Arm Pivot Bolt/Nut ...............14mm ......................................550-700 kg. cm .........40-50 ft. lbs.
Rear Shock Upper Acorn Nut ..........10mm .......................................350-450 kg. cm .........25-32 ft. lbs.
Rear Shock Lower Bolt ...................10mm ......................................350-450 kg. cm .........25-32 ft. lbs.
Rear Wheel Axle ...........................16mm .....................................800-1000 kg. cm .........58-72 ft. lbs.
Rear Brake Stay .............................8mm .......................................180-250 kg. cm .........13-18 ft. lbs.

I haven't figured out what the "Dual Sheet Mounting" is in English.

General Nut Bolt Screw Torque

5mm bolt and nut,,,,,,,,,,,,,,,,,,,.46-.60 kg. m ,,,,,,,,,,,3-4 ft. lbs.
6mm bolt and nut ,,,,,,,,,,,,,,,,,,.80-1.2 kg. m ,,,,,,,,,,,6-9 ft. lbs.
8mm bolt and nut ,,,,,,,,,,,,,,,,,,1.8-2.5 kg. m ,,,,,,,,13-18 ft. lbs.
10mm bolt and nut ,,,,,,,,,,,,,,,,3.0-4.0 kg. m ,,,,,,,,22-29 ft. lbs.
12mm bolt and nut ,,,,,,,,,,,,,,,,5.0-6.0 kg. m ,,,,,,,,36-43 ft. lbs.
5mm screw ,,,,,,,,,,,,,,,,,,,,,,,,,,,.35-.50 kg. m ,,,,,,,,,,,3-4 ft. lbs.
6mm screw ,,,,,,,,,,,,,,,,,,,,,,,,,,,.70-1.1 kg. m ,,,,,,,,,,,5-8 ft. lbs.
6mm flange bolt and nut ,,,,,,,,,1.0-1.4 kg. m ,,,,,,,,,7-10 ft. lbs.
8mm flange bolt and nut ,,,,,,,,,2.0-3.0 kg. m ,,,,,,,14-22 ft. lbs.
10mm flange bolt and nut ,,,,,,,3.0-4.0 kg. m ,,,,,,,22-29 ft. lbs.
 
Last edited:
The engine torque specs are not included in his post. He did that to cover the other parts of the bike that are not covered by the engine torque specs found in the FSM. If you need the FSM, get it from our library
 
Last edited:
Gorankh said:
I can’t find cylinder head bots in your post.
180 kg-cm
Click to expand...
Page 39 of the later FSM says 180-200 kg. cm or 13-14.5 ft. lbs. following the specified pattern.
No I didn't include any of the actual engine torque specs because I expect people to read and follow the directions in the FSM. The majority of the posted numbers are only found in the early FSM, not in the later version. And the General section is actually from another models FSM but applies to any bike.
 
Anyone have a torque specification for the cylinder head bolt studs? #12 in the image below:

cylinder-head-stud-bolts-01.jpg

I had to replace all four; two got totally shredded on the way out, one broke and was successfully removed with a bolt extractor, the last was already broken off inside the head when I got the bike and had to be machined out and now has a Heli-Coil installed (thanks, TOOLS1!). The bolts appear to be made of unobtanium so I picked up these from Grainger, which I had to cut down just a bit to make them as close to the original as possible. Not sure what the originals were made of, but the Grainger bolts are made of steel with a black oxide finish. Picture taken a few hour hours ago:

cylinder-head-stud-bolts-02.jpg

I'm not seeing any mention of these bolts in the shop manual. I've been dutifully using the standard torque specs as listed above and dropping by 25% when applying anti-seize, so in my head for an M8-1.25mm with anti-seize this should be in the neighborhood of 10 to 13 foot pounds.

You know that feeling you're torquing nice and slow and it just feels off and you break out in a sweat? I've got mine torqued up to 4 foot pounds with a liberal application of anti-seize and that I am extremely hesitant to go any higher... just doesn't feel right. Anyone who has broken bolts before knows what I'm talking about.

Thoughts?
 
#1...Black Oxide will be rusty in a week......
#2...IF it doesn't "feel" right, stop and undo....Chase stud threads and start over using anti-seize sparingly.....
Too much can fill the hole and hydraulically lock the stud from proper entrance depth......
 
Great info here. I (1972 CB350K) have a few quick questions re torque specifications:
- what's the difference between "8mm bolt and nut and 8mm flange bolt and nut" as described above?
- is the torque specification the same for bolts of the same length?
- I'm not seeing a description anywhere (eg on VHT or the FSM or the Detholz Twin Shop Manual) of the torque specifications for the lower and upper crank case or for tightening sequence. Can someone point me to a source?

Thanks
 
Flange bolts and nuts have a slightly higher torque because the flange changes the load
Yes, the torque numbers are a constant regardless of length.
There is no pattern for tightening the case bolts. I just get them all snug then use a sort of star pattern using front center as a starting point.
 
Good. This makes sense. Relieves some of the stress of worrying about stripping bolts. I've read horror stories about others putting a bit too much strain when torquing. Dont want to be among them.
 
66Sprint said:
#1...Black Oxide will be rusty in a week......
#2...IF it doesn't "feel" right, stop and undo....Chase stud threads and start over using anti-seize sparingly.....
Too much can fill the hole and hydraulically lock the stud from proper entrance depth......
Click to expand...

LongDistanceRider said:
Here's a selection of studs https://www.belmetric.com/m8x125-coarse-thread-c-9_71_1840/
As for torque spec you'll use the 8mm bolt/nut spec of 13-18 ft. lbs.
Click to expand...

Finally circled back on this today. I wound up taking the bolts out, and, for the most part, starting over. The application of anti-seize was considerably less and things started acting closer to what I expect. Torqued to 10 foot pounds and called it good.

I'm nearing the end of this build, so I'm getting very, very paranoid of ruining ANYTHING at this point. :)

Thanks, gents!
 
Hi, can anyone help me with torque specs for alternator cover? I had an oil leak and replaced the gasket (3). Is it enough to hand tight the screws?
alternator cover.PNG
 
Yep. The screws squish down against the o-rings, I usually check that they’re still tight every couple of rides.

I’ve never used anything but a regular old (JIS) screwdriver.


-Ed
1972 CL350
 
But only the 3 small cover screws have o-rings, he meant the large gasket (#3). Make them as tight as you can with your hand screwdriver, don't use an impact driver on them. This is where a t-handle screwdriver really helps
 
My Swing Arm Pivot bolt/nut is definitely not 14mm. Mine is 23mm on the left, and 21mm on the right. There is a 14mm on that triangular piece of frame mount, along with two other 10mm.
 
teebo said:
My Swing Arm Pivot bolt/nut is definitely not 14mm. Mine is 23mm on the left, and 21mm on the right. There is a 14mm on that triangular piece of frame mount, along with two other 10mm.
Click to expand...

But remember that torque values are based on the size of the bolt or nut threaded area, not the outer size of the bolt head or nut. A 10mm size bolt or nut on our bikes is actually a 6mm thread, so if you need to torque it to a specific number you use the 6mm torque value. Think SAE nuts and bolts like a 1/4" bolt typically has a 7/16" head size, but you torque it to specs for a 1/4" bolt
 
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