1970 Sportster Clutch M/S Nut Torque ?

[whittiger650]

I am in the process of reinstalling the clutch components and the manual says 150 ft/lbs for the mainshaft nut. That is a lot, is this correct ? Am I reading it right ?

So far I have torqued it to 130 ft/lbs but that seemed like I was really pushing it !

TIA

[JAWS]

I am almost 100% that it is correct. I know the nut on the crank is way more than that, I think 250 if memory serves.

When all else fails follow the manual. If something gives and shit breaks, it was in bad shape and a ticking time bomb and you just saved yourself a possible fiasco.

[CookieMonster]

Yep, 150 on the clutch hub nut. Made a tool to do this as there is a concern the wedge type tool will damage the oil tight rivet seal on the clutch drum. The best way would be with an impact and torque bar, but that’s quite fancy. If you have a good enough ‘feel’ of your impact gun you can do it that way. Caution, too much will mushroom the kicker spacer and cause it to stick.

I think the crank nut actually less, perhaps 100? But no worries here if you overdo it, you can put a lot on before doing any damage.

I’ll look up facts and figures later if you haven’t sorted it, but there are no torque values in the FSM.

[whittiger650]

150 it is. Thanks for the help.

[CookieMonster]

Here’s how I held it to torque, foot peg rest stops everything turning. If you have a kicker and are fitting a new spacer you’ll want to torque up then remove to measure to work out clearance as per the manual, tightening compresses the spacer slightly.

[whittiger650]

Originally Posted by CookieMonster

I’ll look up facts and figures later if you haven’t sorted it, but there are no torque values in the FSM.

I got it torqued to 150 ft-lbs. The factory service manual does give the 150 ft-lbs setting on page 143. It actually says at least 150 ft-lbs !

[CookieMonster]

Originally Posted by whittiger650

I got it torqued to 150 ft-lbs. The factory service manual does give the 150 ft-lbs setting on page 143. It actually says at least 150 ft-lbs !

Apologies if I misinformed anyone then, but I’m fairly sure my manual (‘59-70?) doesn’t but later copies do, a member here advised the value. Out of curiosity do you have a dry clutch and a kicker? The ‘at least’ part seems odd, as you can definitely do damage with too much. Glad you got it together.

[whittiger650]

Originally Posted by CookieMonster

Apologies if I misinformed anyone then, but I’m fairly sure my manual (‘59-70?) doesn’t but later copies do, a member here advised the value. Out of curiosity do you have a dry clutch and a kicker? The ‘at least’ part seems odd, as you can definitely do damage with too much. Glad you got it together.

No worries. I will have to scan that and post it as I chuckled that it said "at least" for a torque setting !

I do have the dry clutch and the reason I had it apart was to install a kicker.

[whittiger650]

Looks like my manual covers from 1970 - 1975, revised 1-75.

[whittiger650]

Originally Posted by CookieMonster

Here’s how I held it to torque, foot peg rest stops everything turning. If you have a kicker and are fitting a new spacer you’ll want to torque up then remove to measure to work out clearance as per the manual, tightening compresses the spacer slightly.

I found a seller on eBay who makes service tools for a decent price and here they are. Easy peasy !

[CookieMonster]

Originally Posted by whittiger650

I found a seller on eBay who makes service tools for a decent price and here they are. Easy peasy !

I made something similar to that tool to tighten the crank nut as I could find no other way to lock it (hindsight I should have just impacted the shit out of it), but I didn’t want to use it for the higher torque on the clutch drum in case of damaging the drum or upsetting the integrity of all the rivets I’d just sealed. I know that tool is pictured in the manual but there are lots of ways the clutch can let oil in and through those rivets is one. It didn’t take much to drill a few holes in a piece of flat bar, if it avoids taking it apart again.