Wheel Lug Bolt Torque

[workinghorse 0]

I have a 414-8 (31-14k803) that I just put new tires on. I am trying to find what the torque should be on the lug bolts. Thanks in advanced!!!!

Edited August 4, 2013 by workinghorse

[KC9KAS 4,741]

Sorry, I don't have an answer for you, BUT....

[Wheel-N-It 2,968]

Don't overthink it. Just use a standard 1/2" drive ratchet, and steat the wheel bolts nice and snug. Dont try to take the bolt any further into the hub. There is no need to tighten them any further than that.

[Jeff-C175 7,199]

In general, proper torque spec is a function of the bolt size and thread pitch, the MATERIAL of the bolt AND the material it is threaded into.  There is a 'standard' that has been set by the SAE and is available all over the internet.  Search for something like " torque spec chart ".

 

Here's one:

 

http://www.portlandbolt.com/technicalinformation/bolt-torque-chart.html

 

Too much torque on a fastener and it becomes stressed (elongated) and can of course break.  It will also damage the threads.

 

Too little torque and the fastener can loosen.

 

There is a lot more to the 'science' of torque specs... for example, a wheel lug is designed with a tapered seat, and the wheel itself has a 'raised' portion around it.  This raised portion is in fact a 'spring' of sorts.  If you over-torque this type of fastener, you are defeating the purpose of the design by 'flattening' the spring and not allowing it to do the job it was designed for.

 

An experienced mechanic soon gets a 'feel' for how tight fasteners need to be and probably doesn't need to use a torque wrench for every single bolt they tighten. 

 

That said...  I'm kinda with Wheel-N-it and say to just tighten them snug... and EVENLY, the same snugness on each one... it's not 'rocket surgery'... but understand that a 1/2" drive wrench would make it very possible to easily exceed the torque spec of the lugs.  Unlike Wheel-N-It, I can't help but overthink stuff... just my nature and my engineering background.

 

I use around 25-30 lb-ft on my machine.  In 30 years I've never had one loosen up.  25-30 lb-ft is not that much.  You can easily exceed this with even a 3/8" ratchet.  Get out your torque wrench and tighten a few to 30... then with your 3/8" drive ratchet, try and tighten and loosen a few without the torque wrench and get a feel for how tight (or loose) that actually is.  I think you will be surprised that it isn't NEARLY as tight as you think it should be.

 

Tighten them to 30 lb-ft with a torque wrench and go out and mow the grass.  When you come back, check them again...  just to give yourself a sense of security that they haven't loosened up.

Edited August 4, 2013 by Jeffpicks

[gwest_ca-(File Mod) 11,031]

From page 2-2 of the 1978-79 B, C and D-Series service manual

http://www.wheelhorseforum.com/files/file/1930-tractor-1978-1979-b-c-and-d-series-sm-section1-4-810063r1pdf/

 

C AND D-SERIES
Mount a rear wheel and tire assembly on each axle hub
so the tire valve stem faces inside on the C-Series and out-
side on the D-Series. Secure each wheel and tire assembly
with the lug bolts provided. On C-Series tractors, starting
at the top, tighten every other lug bolt until all are tight.
On D-Series tractors, alternately tighten lug bolts on
opposite sides of the wheel until all are tight. Torque the
lug bolts to 75 to 80 ft. Ibs. (105 to 112 Nm).
Lower the tractor and remove the jack or hoist.

 

Are the bolts in the C hub the same size as the D hub?

7/16-24 Grade 5 bolt torque spec is 59 ft. lbs. in my chart.

(Correcting this - should be 7/16-20)

 

 

Garry

[Jeff-C175 7,199]

 

Are the bolts in the C hub the same size as the D hub?

7/16-24 Grade 5 bolt torque spec is 59 ft. lbs. in my chart.

 

I don't know if they're the same size, but I seem to recall that they were 3/8 ?   Now ya got me going to check!    OK, I was mistooken, they are indeed 7/16.

 

Maybe I'm lucky I've not lost a wheel at 30 lb-ft all these years? 

 

Wouldn't 7/16 fine thread be 20 ?

 

Here's another chart with both coarse and fine thread listed... easier to read than the other:

 

http://www.boltdepot.com/fastener-information/Bolts/US-Recommended-Torque.aspx

 

I think WH recommendation of 75-80 is a quite high for 7/16-20.

Edited August 4, 2013 by Jeffpicks

[Martin 2,131]

the thread size is 7/16-20 in most if not all 5 bolt hubs, c series included.

[Trouty56 565]

D's are 9/16-18 (I think) so maybe WH was trying to cover both lug bolts in one article.....

[Jake Kuhn 1,554]

[Tankman 3,518]

 
Where 'bouts in Pennsy? I'm just south of Allentown.

 

Air pressure both front and rear is 12 psi. Torque is (like duh), I don't know. Never bothered to torque the lug nuts bolts, just tight.

 

One of my favorite "upgrades" is to ditch the lug bolts.

From the back of the hub, 7/16-20 x 1-1/2" bolts. I use a small washer and Blue Threadlocker® installing the bolts. From the auto supply 7/16-20 open end acorn lug nuts. Done.

 

Sure makes life easy mounting heavy tires. Just hang 'em on the bolts, spin on and tighten lug nuts. Done.

 

Edited August 6, 2013 by Tankman

[gwest_ca-(File Mod) 11,031]

D's are 9/16-18 (I think) so maybe WH was trying to cover both lug bolts in one article.....

The parts lists all show 7/16"-20 for the D-Series Auto rear wheel lug bolts.

 

Wheel nuts very common because GM used them for years for those that want to switch to studs and nuts.

 

Garry

[BPjunk 184]

From page 2-2 of the 1978-79 B, C and D-Series service manual

http://www.wheelhorseforum.com/files/file/1930-tractor-1978-1979-b-c-and-d-series-sm-section1-4-810063r1pdf/

 

C AND D-SERIES

Mount a rear wheel and tire assembly on each axle hub

so the tire valve stem faces inside on the C-Series and out-

side on the D-Series. Secure each wheel and tire assembly

with the lug bolts provided. On C-Series tractors, starting

at the top, tighten every other lug bolt until all are tight.

On D-Series tractors, alternately tighten lug bolts on

opposite sides of the wheel until all are tight. Torque the

lug bolts to 75 to 80 ft. Ibs. (105 to 112 Nm).

Lower the tractor and remove the jack or hoist.

 

Are the bolts in the C hub the same size as the D hub?

7/16-24 Grade 5 bolt torque spec is 59 ft. lbs. in my chart.

(Correcting this - should be 7/16-20)

 

 

Garry

To add on to Garry's information ..... the little guys AKA Lawn Ranger lug bolts get torqued to 35 foot pounds and early blank 7/16 x 20 (i.e. RJ series) get torqued to just 50 foot pounds. What I mean by "blank" is the bolt heads have no markings on the head.

 

All threads should be cleaned when using a torque wrench.

 

Wild Bill

Richmond, VA

[Kelly 1,029]

The D and the C-195 have 9/16 lug bolts, all the 5 bolt wheels used on WH is 7/16, the ranger is 3/8