Bus Lug Bolts

Busted Knuckle · March 01, 2010, 06:03:07 AM

Quote from: kyle4501 on February 28, 2010, 07:37:04 PM
My bet is they are better than grade 8. The nuts are grade 8, so I'd think if you followed the torque chart for grade 8, you'd be good. I may use loc-tite if there is one suitable for the temps that the hub will see from the brake drum . . .

Trust me Kyle, Gus (& anyone else) these nuts do NOT need Loc-tite! I have replaced many of them over the yrs and only once used Loc-tite.
And it was that once that I had to remove them again due to a tire shop screw up (not realizing they were left hand threads, and the driver didn't know any better!) using a torch on the nut (X3) and getting it red hot then stripping the threads completely out of the nuts before calling me and telling me they couldn't get the nuts off to change the tire!
I took the driver a different bus, helped the tire shop change change the tire. And limped it home to fix the damaged studs. (threads full & had been heated)

Once back at the shop we played heck getting the nuts back off the studs and ended up using an 8' cheater pipe on a 1" drive breaker bar to break them lose (after the 1" impact would not do the job!)

So if you tighten the nuts properly, or like Craig does (or like I do

) I can assure you they aren't coming off on their own!
FWIW JMHO YMMV

BK

kyle4501 · March 01, 2010, 09:29:29 AM

If you use the correct LocTite, it is easy to remove IF the joint is at the proper temperature.

Like I said, I'd have to look into what was available.

BTW, my bus has aluminium hubs that WILL crack if the wheels or studs are too tight. - That is why I choose to seek out the manufacturer's specifications & do my best to understand them before I follow or modify them.

Just Dallas · March 01, 2010, 09:51:53 AM

Removed

gus · March 01, 2010, 06:43:58 PM

I didn't know there was a bolt higher than grade 8??

I'm just getting ready to remove the nuts so don't know if they are high heat lock nuts.

I think these are 3/4 NF threads so 300 L-F may be about right.

I ordered five more bolts so I can replace all, should have thought of that long ago

The hardest part for me was removing the brake drum, that thing is a monster for an old guy like me.

I was surprised to find the hub lock nut on really tight and with no lock washer of any type! First time I ever had to stand on a 2' ratchet handle to remove a hub nut!

I was also surprised to find the hub full of oil and no grease in the bearings. Maybe the oil dissolved the grease because I'm sure these are not oil lubed bearings since they have two grease seals. I think the oil leaked through the key slot that holds the washer between the two lock nuts.

kyle4501 · March 01, 2010, 08:31:41 PM

Quote from: gus on March 01, 2010, 06:43:58 PM
I didn't know there was a bolt higher than grade 8??

Grade 8 is the highest 'standard', but there are higher strength bolts made from special alloys.

For bolt torque, here is a pretty good article explaining how the torque value is determined & what it does.

http://www.zerofast.com/torque.htm

Note the reduction of applied torque required to get the same clamping force with waxed vs. plain or zinc plated hardware.

gus · March 02, 2010, 03:14:29 PM

Based on that website it appears 400 - 500 l-f should do it. This makes sense since the lug nuts are supposed to be 400 - 450. The bolts are cad plated which, I presume, is equivalent to zinc.

There are sure a bunch of "ifs" concerning torque.

Never heard of waxed bolts before?

It does have a lock washer, it is just a type I never had seen before and the manual does call for a "firm" tightening of the lock nut. Mine was definitely firm!

DaveG · March 02, 2010, 04:02:07 PM

Almost all of Euclid's wheel end hardware is grade 8

kyle4501 · March 02, 2010, 09:00:10 PM

Gus,
My manual calls for 300 - 325 ft-lbs for the inner nuts
& 350 - 400 for the front & rear outer nuts.

Most hardware is oiled. If not left over from the manufacturing process - then added to prevent them from rusting before they are sold.
Waxed is a catch all term for lubricated. Different lubrication has different friction reducing factors - which is why the factory calls for dry threads - much more consistent results.

I'd think 400 ft lbs on the 3/4"-16 stud retaining nut would be best. You wouldn't want that one snapping off because it wasn't as dry as you thought . . .

This coming from someone who understands the problem of too tight - but still fights the urge to go "just a little bit more".
(Yes, I do have a rather large (& well used) assortment of thread repair taps & inserts)

DaveG · March 03, 2010, 06:45:56 AM

With regards to the nuts on the inside, they are refered to as 'back nuts' sometimes, and often are a locking type nut (crown/crimp head) so I do not believe that the torque is that critical.

gus · March 03, 2010, 06:38:08 PM

Kyle & Dave,

Thanks. I like 300 - 325 ft-lbs for the inner nuts. The back of the stud is 7/8" diameter, not 3/4" as I thought. The front side is smaller at 3/4". It is interesting that the lug bolt back diameter is larger than the front and the front takes more torque?? The front inner wheel nut does have a lot more threads engaged though.

The backs must be lock nuts because they resisted until the last thread. Two still won't come off, may have to use a little heat. I can't use my trusty 6' cheater pipe because the hub is off the bus and I have no way to hold it.

Busted Knuckle · March 03, 2010, 07:15:47 PM

Quote from: gus on March 03, 2010, 06:38:08 PM
Kyle & Dave,

Thanks. I like 300 - 325 ft-lbs for the inner nuts. The back of the stud is 7/8" diameter, not 3/4" as I thought. The front side is smaller at 3/4". It is interesting that the lug bolt back diameter is larger than the front and the front takes more torque?? The front inner wheel nut does have a lot more threads engaged though.

The backs must be lock nuts because they resisted until the last thread. Two still won't come off, may have to use a little heat. I can't use my trusty 6' cheater pipe because the hub is off the bus and I have no way to hold it.

We bolted it back on to a wheel and stood the up with it leaning against the shop wall with a wheel chock at the bottom and someone sitting on top of it while I used 300 + lbs. of my weight on an 8' cheater bar!

BK

kyle4501 · March 04, 2010, 06:47:41 AM

see:
http://www.busconversions.com/bbs/index.php?topic=15160.new

gus · March 04, 2010, 06:39:48 PM

I got the last two off today with my air wrench which supposedly goes up to 650 l-f.

Now my problem is getting the bolts out of the hub. I tried a few hits with a 3lb hammer with no effect except spreading the end of the bolt!!

Will a 12 ton shop press push them out?

I have a feeling I'm going to end up taking the hub to a heavy vehicle shop with a big press but first I'm going to try my little 12 ton.

I had to order the axle grease seals ($60 ea for the outside one) from the factory! The outside one is the biggest seal I've ever seen, it is more than just a seal, it also covers the end of the hub and the axle nuts and bearing. It is held on by the same studs that hold the axle to the hub.

johns4104s · March 05, 2010, 04:39:06 AM

Are you talking about the Stainless steel wiper seal thatslides over the axle?

John

kyle4501 · March 05, 2010, 06:33:13 AM

Gus,
If your 12 ton press won't push 'em out, try 'ringing' the stud/ hub with a small hammer while the full force of the press is on it. I have a pneumatic air chisel & a dewalt rotary hammer (that I can switch the rotation off & use as a chisel) that I have used in the past to help press things off/ on. The ringing vibration helps more that you'd imagine.

Thanks for keeping us posted & best of luck!