Not sure which section to post this in, so will let the bigwigs move it if necessary.

A few days ago I decided that it was time to pull the Dynatrac hubs off my truck for inspection and regreasing. Each hub is held on with two 6 point nuts. I know them as spanner nuts, but some of you may call them something else. Discovered on one side that one nut had a piece of just over 1" long broken right out of it and had hairline cracks in other places. On close inspection of the other 3 nuts I discovered hairline cracks in every one. One nut was just about to break in two. Don't want to think about what could have happened had I not discovered these problems. Could have been even worse towing the fiver. Preventive maintenance pays off!

I found the cause of the cracks and want to alert anybody using these nuts of a potential safety problem. I had the hub mod done up in the states by supposedly experts with this kind of thing. This is one of the very few times I have allowed anybody to touch my truck. At every crack I can see evidence of punch marks at the bottom of the socket slot. This tells me that that shop did not posses the correct socket spanner and used a punch to tighten the nuts to some unknown torque. This kind of nut MUST be tightened using the correct wrench. Impact damage to this hardness of steel (resulting in stress raisers) is guaranteed to cause fatigue cracks. DO NOT re-use any nut that has evidence of damage, particularly in a highly critical area such as the hubs.

I have replaced all the nuts with new nuts and tightened them using the correct size of wrench to the factory recommended torque.

 

Gracias for the great head's up Amigo.

 

Years back we used to do that all the time on the class 8's. Once in a while I will still have a truck come in with every side of the nut hacked up by a chisel. Funny thing is the sockets to do the job are not that expensive.

 

Tim,

Funny you mention that. Trouble I see up here, is someone is in a pinch, a couple hundred miles from the nearest store that " doesn't have that socket, but they can order it".

Lots of chiseled spindle nuts up this way yet.

 

I used a punch to tighten mine after the socket I had bought did not work......resulted in me having a spanner nut overnighted to me from Dynatrac as I could not find one locally. One nut had broken in two.

 

Stan,

You wouldn't happen to have a pic of that would ya?

It would be great for a maintenance/Inspection/good catch update during daily pre-tour meetings on location.

I promise I won't GPS your locale and ship the remnants of furballs Ph00 t00 y0u!!!

 

Just on my way out, but will see what I can do later. Not sure if I can focus my camera down close enough to show the punch damage, but can do the nuts for sure.

 

Oh yeah I agree completely, and for the record I would still do it with a chisel if need be in a pinch.

Stan, thanks for the write up and looking out for the members here.

 

Recently repaired truck from another shop which did $1500 damage to truck. They didn't tighten lug nuts to spec and wheels came off. They attempted to replace damage studs and used wrong size studs. Removed rotor from hub and broke off bolts. Reinstalled hub bearing with no lubrication on wheel bearing or grease and over tighten nut. I love it when other shops destroy things makes my day. $$$


Tool Number 8954
Your Price (USD) $96.32
Tool Name HUB NUT SOCKET
Description Use this special tool to remove and install the Hub Nut on the new 10 1/2" and 11 1/2" American Axles. To Current

 

castelated nut I think, spelling may be wrong.

 

This is not a castellated nut. A castellated nut is made for cotter pins or lockwire. This nut uses a tabbed lockwasher.

 

Stan,

Dynatrac has now converted their pn#'s to Timken #'s now.........it is easier to find spares now. Just in case you hadn't been told.

 

Posted a couple of pics in my gallery and they are now waiting for approval. Sorry, but with this camera, could not focus any closer without the pics getting fuzzy and then for sure someone will pick on me for having fuzzy nuts.

Let me know if they work for you.

 

Tim, I suspect that the class 8 nuts may have a bit more meat on them and therefore be more forgiving to abuse.

These nuts below the slot for the wrench only have 2 - 2.5 threads. Also the material is quite brittle and cannot accept any deformation such as from a punch. Looking at the way they cracked, I am going to take a wild guess that the material is in the 190K to 220K tensile range.

 

Thanks. Just to clarify for everybody. As far as I can ascertain, these nuts are not made by Dynatrac, but are industry standard manufactured by 2 or 3 different companies such as Spicer and National.