Twice now, last Spring in Toronto, and now yesterday near Amarallo, Texas, the castle nut on the axle spindle has come off while going down the highway, with subsequent extensive damage to the bearings and brake drum, i.e. all have to be replaced on the roadside. This is a dangerous situation.
The castle nut is held onto the spindle thread by means of a flange washer with a tab in it, which gets bent down into one of the gaps in the castle nut, i.e. NOT a cotter pin through the spindle. IMHO, this latter method is better, but it seems I'm stuck with what I've got. It appears the tab must weaken with time or conditions, and allow the castle nut to revolve. Oh, for a left hand thread on the LHS !
Obviously, this tab method is not a strong enough method. This time the mechanic also used red thread glue, but I am concerned this problem could occur again.
Has anyone any permanent solutions to this problem, or even ways of monitoring the strength of the tab ? For example, maybe I should replace the flange washer every 1,000 miles or whatever.
I'm just hoping we'll make it back to Ontario OK ! Thanks.
1) R-Vision Trail-Lite TT, 19'. TV = 2007 Chevy Trailblazer, 3.42 axle. 4.0L 2) Heartland North Country, on a permanent site in Arizona.
Got enough threads left to add a second nut and tighten it down against the castle nut? ...Just as a temporary repair to get you home. I would see a drill motor and bit in my near future to add a cotter pin.
2005 2500 Cummins/48RE/3.73, QCLB, 4wd, BigHorn, Edge Juice w/ CTS + Turbo Timer, ISSPro Oil and LP pressure gauges in cubby hole, GDP 20/2 filters on frame rail, Custom Diesel Steering Box Brace
'10 Forest River Shockwave Toy Hauler 21'
Honda EU3000I Genny
I'd like to point out, that while I agree the tinfoil tab locks are pretty cheezy, if you drill a spindle which utilizes one of the axle lubing systems which are becoming popular these days (Easy Lube, SuperLube, etc.), the cotter pin may pass directly through the grease passage. This will render this lubing system less effective because it will impede the flow of grease to the rear bearing and possibly allow grease to exit at the cotter pin hole. Not to mention the possibility of passing metal chips through the passage into the bearing.
Drill and size carefuly and clean out the hole before reinstalling the bearings. I would think you'd want to use a smaller pin than than the grease passage and size the hole to fit the pin snugly. If you lube by hand packing, obviously it won't effect you. Happy drilling.
"It`s not important that you know all the answers, it`s only important to know where to get all the answers" Arone Kleamyck
"...An unarmed man can only flee from evil, and evil is not overcome by fleeing from it." Col. Jeff Cooper
Sunset Creek 298 BH
I wouldn't be drilling any holes in the axle. I have seen three different styles of holding the axle nut in place. The bend over tab, the spring tab that goes over the nut, and the cotter pin type. Instead of the bend over tab you might look at the spring tab style since I assume your RV has a flat portion on the axle. The spring tab snaps right over the nut, actually encapsulates the nut as it snaps on.
You probably should be talking to the people that designed and built the axle and ask about their solution first. The solution may be as simple as using a quality name brand bend over tab instead of a generic.
They have been using those bend over tabs for years. Ford used them on their 3/4 ton rear axles without problems.
If you (the mechanic) does not get the pre-load on the bearing correct your going to get what you have.
The hub will pound on the nut and try the shear the tab. Lots of force on that little part. If you get it correct there should be no problem. Bearings that grab can cause this also.
If it came to me I would check all the parts out and more than likely replace the bearings. Then pack the new bearing real well and set them to correct pre-load.
I pitty the poor guy that has to take that hub off with red Loctite on the threads.
~ Too many freaks & not enough circuses ~
"Life is not tried ~ it is merely survived ~ if you're standing
outside the fire"
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I've never had a tab system FAIL but I've never trusted them either.
