Lug nut torque specs.

[brdgbldr]

Anybody know the proper lug nut torques for a Bobcat A300 or 9/16" lugs? I have searched the forum and came up with anywhere from 105-160 ft-lbs. This is a huge discrepancy.
My Service manual actually has two different sets. In one section It says 105-115 ft-lbs (this is also what the Operation & Maintenance manual says) in another section it says to torque to 160 ft-lbs and check at 140 ft-lbs.
I'm leaning toward the higher numbers but I don't want to sheer any of them off.

 

[foton]

for what it is worth a chart listed grade 8, 9/16 max torque limit is 154 lbs. grade 9 is 180 lbs.

 

[brdgbldr]

Yeah, this should be the easiest thing to find, but not so much.
The Bobcat manuals call for 9/16" grade 8 bolts to be torqued to125-140 ft-lbs but this is for general bolts which does not take into consideration that the wheel steel is soft. My 2012 F-250 lugs call for 165 ft-lbs but those are M14x1.5 bolts which are close to 9/16".
I did find my old Bobcat Loader Technical Service Guide, updated to 2001, and for 90% of the loaders the torques are 105-115 ft-lbs. This includes all of the 800 series loaders. The exceptions only being that most of the smaller 400 and 500 series being less torque and the 900 series being a whopping 320-350 ft-lbs.
Until someone can come up with a definite answer for any of the larger Bobcats I guess I will go with 105-115 ft-lbs.

 

[Bobcatdan]

Normally I just send it with the impact wrench. If I was to check them, I'd set the wrench to 150.

 

[brdgbldr]

So here's an update to my torque problems.
This all started because the tires on my, new to me, A300 needed to be rotated. So today I decided to do just that. As I go to loosen the very first lug nut….I can't. It took a 6 foot long breaker bar to get it loose. I had to use that breaker bar on only 3 nuts but the rest obviously were not all torqued the same. As I go to put the lug nuts back on, I notice that some won't even start and others will only go on a few threads before locking up. I never force anything and upon further inspection of the lugs I found that the lug threads were clogged with the threads of the lug nuts that had failed. I found 9 of these. So someone had over torqued the nuts and the threads from the nuts had imbedded themselves in the lug threads. Luckily none of the lugs were stripped or broken. I had to take a pick and scrape out all of the nut thread material out of the lug threads. This was not an easy task, but several hours later and nine new lug nuts and I got the tires rotated. I went with 115 ft-lbs for torque for now. I'll keep checking them to see if they need more or not.

 

[dfb]

So here's an update to my torque problems.
This all started because the tires on my, new to me, A300 needed to be rotated. So today I decided to do just that. As I go to loosen the very first lug nut….I can't. It took a 6 foot long breaker bar to get it loose. I had to use that breaker bar on only 3 nuts but the rest obviously were not all torqued the same. As I go to put the lug nuts back on, I notice that some won't even start and others will only go on a few threads before locking up. I never force anything and upon further inspection of the lugs I found that the lug threads were clogged with the threads of the lug nuts that had failed. I found 9 of these. So someone had over torqued the nuts and the threads from the nuts had imbedded themselves in the lug threads. Luckily none of the lugs were stripped or broken. I had to take a pick and scrape out all of the nut thread material out of the lug threads. This was not an easy task, but several hours later and nine new lug nuts and I got the tires rotated. I went with 115 ft-lbs for torque for now. I'll keep checking them to see if they need more or not.

I do not have an answer to your torque spec question, though I will add that after decades of working in the automotive business and seeing the various outcomes of over and under torque fasteners{wheels in particular} I agree with getting it right the first time to avoid other problems down the road. Personally, I do torque every lug nut to spec.

 

[Phil314]

On my S650, I've always torqued them to 120 ft-lbs. I believe I read that somewhere in my manual.
That has always worked well with my snow tire, my solid tires and my regular tires.

I did forget to torque the nuts once on my 1845c a long time ago.
Yeah, the wheel came off, after breaking all my lugs.
Simple enough to fix, but I never forgot again.