Proper rear diff bolt torque spec?

[chicknwaffles]

So I installed a rough country rear diff skid plate on my 23 JLU rubicon today.

Two things.

I guess one of the 4 bolts they included was 1 inch long instead of 1.25 inches long, so need to get more.
Was like that for both the front and rear skid. thought that was odd.

But my crackishness is showing

The torque spec for a 10.9 13mm bolt is like 90+ ft lbs, at least least on the instruction they provided.

no damn way these bolts should be torqued that high.

I know the ones that are stock are much less at like 20 something ft lbs.

saw on youtuber put his rancho rear diff at 20 ftlbs. pretty much hand tight if that.

I torqued the new bolts down to 30 ft lbs.

it seemed like quite a bit even at that.

So figured i'd get on here and ask what ya'll have used. the rear diff isn't anyplace to just say screw it, whatever.

Sponsored

 

[entropy]

I think you are fine. Don't overthink it.

 

[Vinman]

Is that a 13mm bolt measure at thread diameter or does it take a 13mm socket/wrench to install?

 

[Chocolate Thunder]

DO NOT torque the bolts to 90 fr/lbs. 25-27 ft/lbs. is what’s needed.

 

[chicknwaffles]

8mm-1.25x25mm Bolt

yeah i agree 90ft lbs would be bad. not sure why rough country shows torque specs at over 75ft lbs for this size/class 10.9 bolt. it's not a damn lug nut.

Their specs on the instructions show the capability of the bolt. Not the proper torque for this application. wow

 

[chicknwaffles]

Is that a 13mm bolt measure at thread diameter or does it take a 13mm socket/wrench to install?

that is a good observation. It should be torque for thread diameter, not socket size

this bolt head is 13, BUT the one that is stock is 10mm.

The 10mm torque spec makes more sense at 32ft lbs

I went to 30 ft lbs and am considering buying 4 more and going lighter

 

[ChuckQue]

I remember when I did the diff covers on my XJ and everything I could find indicated a high torque setting, though it wasn’t THAT high.

I torqued to FSM specs and snapped the LAST bolt left on the cover, which also happened to be a lower bolt. I was so pissed. I said fuck it and RTV’d it, it held until I took it back in for a regear a few thousand miles later ?

From then on I did like 25ft lbs with lube lockers and they were fine despite multiple hits.

 

[DGT]

The spec for an M220 Dana 44 (rear JL Rubicon) is 25-30 ft lbs.
The M210 front spec is 28-33 ft lbs.

This is the Dana Spicer spec from the spec sheet on their website. I've heard this is different than the Mopar spec but it's what I use.

 

[chicknwaffles]

The spec for an M220 Dana 44 (rear Rubicon) is 25-30 ft lbs.
The M210 front spec is 28-33 ft lbs.

This is the Dana Spicer spec from the spec sheet on their website. I've heard this is different than the Mopar spec but it's what I use.

Nice. I think I'll be doing 28 for the front tomorrow.

I'd be so god damn pissed if I snap a bolt

 

[Kleiss1]

Inch-Pounds maybe?

 

[chicknwaffles]

Inch-Pounds maybe?

no ft lbs

 

[Vinman]

Without looking it up that 90 ft/lbs sounds about right for a grade eight bolt with a thread diameter of 13mm.

 

[Chocolate Thunder]

I repeat, DO NOT attempt to torque those bolts to 90 ft/lbs. You will regret it. And it is not at all necessary.

 

[chicknwaffles]

90 is ridiculous and doesn't apply to this application at all. Anyone that does that should not be doing their own work in the first place.


My question was really about what number most use, in between a common sense range of 20-35 ft lbs.

I'll probably be putting the front to 25-27 tomorrow, with blue loctite.

 

[NewJLU2019]

My Rancho Rock gear glide plates front and rear call for 25 lb-ft torque

Sponsored