T500 - bolt torque

[Fritz500]

I have always used my Suzuki Service Manual T500-II (that I purchased in about 1972) when doing odd jobs on the bike. It wasn't till recently I noticed the engine cases shown have less bolts holding the crankcases together than my T500J and K. I also have noticed the torque figures quoted for the crankcase bolts are different to what I found in the service bulletins.

Workshop manual:
6mm bolt 7 lb-ft (9.5 Nm)
8mm bolt 14 lb-ft (19 Nm)

Service Bulletin:
6mm bolt 4.3 to 7.2 lb-ft (5.8 to 9.8 Nm)
8mm bolt 9.5 to 17.0 lb-ft (12.9 to 23 Nm)

What do you folks torque your engine case bolts up to?

Cheers

Geoff

[celt_rock]

I noticed also that my engine had more bolts in it than the pictures in the manual. I had gone through and labeled all of them according to the diagram and noticed there were two others that didn't appear in the book. With nothing else to label them I
called them Thing 1 and Thing 2 (T1, T2). As far as torquing them... I'll have to get a torque wrench, I just sort of put it back
together till it felt right. I look forward to someone knowledgeable coming through on this one

[GT750Battleship]

Hi,I'd go with the Service Bulletin figures...purely & simply that they were written after the Manual...if you know what I mean ? I don't have a Torque Wrench,but I think it would be a good idea to have one..I think I can be a little heavy handed at times
Cheers,
Roger

Four Wheels Move The Body
Two Wheels Move The Soul

[Pete O'Dell]

always amuses me when peeps waffle about the 8 & 6mm bolts yet no one mentions the most important ones ....... the 10 mm ones

[Fritz500]

I looked at the 10mm head nuts and they were quoted as 25 ft.lbs (Service Manual) and 21.7 to 26.8 ft-lbs (Service Bulletin) which is the same sort of variance to the case bolts. I torqued them to 25 ft-lbs. (34 Nm).

My query was more about what figures folks use as the mechanic or previous owner of the 500J I'm restoring over-tightened and under-tightened just about every critical bolt and nut.

I don't use a torque wrench for clutch or sprockets nuts (my arm is calibrated...) but where studs or bolts go into alloy I like to adopt best practice.

[ConnerVT]

Mechanical engineers standardize torque specifications based on the fastener (size, thread pitch, material), the material the fastener is threaded into, and any locking and/or flat washers used. The specs are for the first time these items are fastened, as reused fasteners may be distorted or damaged after first use.

As we are not building nuclear reactors or space exploration vehicles, the biggest concerns are even distribution of force, and that fasteners are sufficiently tight to hold, and not to distort or break anything.

Given that very few of us even know when/if our wrenches have ever been calibrated, the good rule of thumb is, if given a single value, to get close to that. If given a range, shoot for a consistent value in the middle of the range.

[casperdog]

always amuses me when peeps waffle about the 8 & 6mm bolts yet no one mentions the most important ones ....... the 10 mm ones

Resurrecting old post....Anyone able to advise on the correct torque setting for the 10mm crankcase bolts please.

6mm 7 ftlb
8mm 14 ftlb
10mm ?????

Many thanks
Phil