Tires Kubota M5700 4WD Front Wheel Lug Nut Torque Value

[ccbrd]

While installing new front tires (9.5 x 22) I discovered several stretched wheel studs.

This is the first time the wheels/tires have been removed.

I installed three (3) new front wheel studs/lugnuts (Kubota OEM) M14 x 1.5 thread.

My owners manual calls for 124-145 foot pounds torque value.

I'm getting excessive stud/thread stretching at 135-140 foot pounds.

I set the torque at 125 foot pounds.

I use a good quality "click-style" torque wrench and "do-not" use an impact wrench to install the lug nuts.

Has anyone had this problem?

What torque value do you use for this application?

Thanks for the help/info.

CB

 

[Recoveryhill]

L3700 specifications call for 160 ft. lbs rear and 100 ft. lbs front. This is also on a 4WD unit. 135-145 sounds high to me. I don't however argue with the manual? How are you checking to discover stud stretching? Are you saying the threads are actually being deformed? Something doesn't sound right....

 

[oosik]

My OP manual - for front/rear wheels on 4WD. 192-224 ft. lbs for the inner ring of nuts & 180 ft. lbs for the outer ring of nuts. This is the spec for both front/rear wheels. I, also, wonder how you are determining that the studs are stretched. If they are truly stretched - I'd be contacting my Kubota dealer with this concern. Agreed - something isn't sounding just right................

Another thought - you say this is the first time the wheels have been removed - - I guess it is possible that they were overtightened when it came from the factory - never heard of this, but its possible.

 

[ccbrd]

I inspected the studs/threads before reinstalling the wheels/new tires.

I ran a thread chaser on the studs.

I was surprised to find thread stretching (about 3 threads +/-) at the base of the stud (nearest to the axle hub) on several.

Yes, the threads are deformed/stretched.

I replaced three (3) of twelve (12) studs.

When installing/torquing the lugnuts the newly installed studs (3) stretched the threads similar to the original studs.

The factory/dealer may have overtightened the lugs originally.

I removed and replaced the three (3) newly installed studs and torqued to 125# with no problem.

After resetting all lugs to 125# they have remained tight after working the tractor.

The local Kubota dealer replaced the three (3) studs and is submitting them for warranty.

I thought the specified torque (124-145 foot pounds) sounded high but went with the manual.

There are "no markings" on the studs regarding "grade" which makes it difficult to consult a torque chart for guidance...

Thanks for your help/info.

CB

 

[newbury]

Another data point -
My M4700/M5400 manual specs 191 to 224.2 ft lbs for front inner and 123.9 to 144.6 for front outer nuts.

 

[ccbrd]

Interesting, my manual specifies front inner & outer at 124-145 foot pounds.

When I torqued the lugs I "worked-up" starting at 120#.

At 135-140# I noticed stretching.

I should've stopped at 125# (the low end of the spec)!

What torque value have you used for your M4700?

Thanks for your help.

CB