Confused about rear axle nut torque.

[IdahoMtnSpyder]

166 ft/lbs is insane for this application. I'm sorry, but I have to wonder if they put such a high torque value as to discourage home mechanics rather than a mechanical necessity.

Keep in mind the torque required to get the desired axial force on the shaft or bolt is proportional to the diameter. I don't know the numbers but think of it in terms of 166 ft-lbs on a 1" bolt giving the same axial tightness as 20 ft-lbs on a 3/8" diameter bolt. But I agree, 166 does seem to an awfully high number. What we need is a torque value for lubricated threads. That would far less than for dry threads and easier to achieve. And with the fine threads I don't believe there would be any concern about the nut working loose.

 

[Firefly]

I've always gone with 120, thought that was the apex from way back. Never had a problem at 120 on my GS or RT. One scary thing is on the F3's they don't have a hole for a cotter pin.

 

[PMK]

Keep in mind the torque required to get the desired axial force on the shaft or bolt is proportional to the diameter. I don't know the numbers but think of it in terms of 166 ft-lbs on a 1" bolt giving the same axial tightness as 20 ft-lbs on a 3/8" diameter bolt. But I agree, 166 does seem to an awfully high number. What we need is a torque value for lubricated threads. That would far less than for dry threads and easier to achieve. And with the fine threads I don't believe there would be any concern about the nut working loose.

I always wet torque the rear axle and have since early 2014. Since I do not want to debate the value or have someone try it and fail, I will not share the value or process I use.

As for 166lbft, my opinion is the BS cheap cast axle adjuster that will crush over time. A very poor design on their own and possibly the worst adjusters I have ever worked with.

 

[papanorm]

There's definitely a cotter pin on my F3 rear axle

 

[PMK]

There's definitely a cotter pin on my F3 rear axle

Probably like an RT, cotter key but no castle nut.

The entire setup can come loose, just not start dropping parts to the pavement.

 

[Warlock]

I always wet torque the rear axle and have since early 2014. Since I do not want to debate the value or have someone try it and fail, I will not share the value or process I use.

As for 166lbft, my opinion is the BS cheap cast axle adjuster that will crush over time. A very poor design on their own and possibly the worst adjusters I have ever worked with.

Working offshore as a chief mechanic it is important to make sure on the torque value. If the Spyder calls for 166 ft of torque dry and you add lub you need to take away 25% of the torque value. All our equipment states whether it is a dry or wet torque. So for good practice take away 25% if you are using lub on a axle nut that is valued at dry torque.
David

 

[PapaHotel]

I have a BRP trailer hitch. It doesn't change the chances of loosening, but it will sure keep the parts from ever falling off.....lol

 

[papasmurf1958]

2015 F3S Rear Axle nut torque

I have a shop manual which shows the rear axle nut torque specification on my 2015 F3S to be 177lb/ft.

 

[Warlock]

Ahhhhhhh. Gotcha David......sorry, I'm a bit slow

.....better buy a set of dumbbells to go with your breaker bar though. I used a 3/4" torque wrench with a 2' arm and still had trouble getting past 150ftlbs. Luckily, that's enough with the +/- 10%... :thumbup:

Pete

One thing it doesn't say about the torque limit. Is it a dry or wet torque. If it is a dry torque and you add lub you need to subtract 25% off the torque value or you will be over torquing it. Being a chief mechanic offshore for 30 years it is very important to make sure of this. I dealt with equipment that could cost someone their life so I made sure when tightening up bolts, nuts etc that it was correctly done. All our manuals on equipment would state if it was a dry or wet torque. I don't have a service manual but would be nice if it stated it or not.
David

 

[Peteoz]

I have a shop manual which shows the rear axle nut torque specification on my 2015 F3S to be 177lb/ft.

The official figure, in writing, from BRP, is 161 +/- 10% for 2013 and later, papa.......so 177 is at the high end. As for Warlock’s wet or dry question, that wasn’t stated, but I believe it’s dry based on earlier conversations with BRP.:dontknow:

Pete