Rear axle threads revisited

[carolinamudwalker]

As you may remember, I buggered up the threads on my rear axles ( yes both of them, I'm stubborn) using the cheap puller sold by all the venders. For those that suggested putting the nut back on, that wont work with this puller as the axle goes up inside the puller. I have chased the threads and now new castellated nuts will go on but I can feel about .001 inch looseness when I rock the nut back & forth. The nut in the photo is from automotive racing products (ARP) It has 4-5 more threads than the original nut. Jim Brierley (4-bangers! and me) uses a smaller version of these nuts on his connecting rods for the same reason, more threads. ( I hope he is reading this) My question is should I use a star washer or any type of lock washer with these nuts? The shoulder on this nut matches up to the hub washer very nicely. I am working on modifying the hub caps on the rear so they screw on/off so that I can monitor the torque until I gain confidence in the nuts. Someone mentioned that the axel threads were a special class, That's beyond my pay grade but maybe talking about thread angle or something. If that is the case then I have already screwed that up but may help someone else in the future. Any thoughts good or bad? Bob carolinamudwalker

[Mitch]

Does the flange on the nut rest on the metal face of the hub the same way a washer would? It's hard to tell the circumference size in the pic

[Mitch]

If so i would not use a washer, this way you have the nut on more of the threads

[Tom Wesenberg]

I too would skip the washer. I would use the white out pens from Dollar Tree to put a white dot on the nut, and a dot on the hub, to see if the nut moves.

Those pens are 2 for $1 and have a small ball bearing tip to dispense a very quick drying white paint.
These are ideal for marking wires, and a timing mark on the pulley edge, so you know when TDC is coming up.

[DaWizard]

Hey Bob, I feel your pain. One thing I am wondering is, do you have access to a mill or similar sturdy piece of machinery? The reason I ask is, that appears to be a Grade 8 nut, and what I would do is place the steel washer and nut on the axle, torque until you feel the threads begin to give, then mark where the cotter pin hole is on the nut and either machine a slot just past the mark so you have just a wee bit more turn to get it lined up, or perhaps drill a hole through the nut to do the same thing.

IF you can get a torque reading at that thread stretch, it would give you a base for reference when you check the next time. Since you are not removing any more thread from that nut, it should hold pretty good and installing the cotter pin should help insure it stays tight.

Just my 2¢ worth.

[plyfor]

Have used arp nuts mostly with good success, but many suggest only use them for 1 time application ,not re-use. Also, can you drill a small hole to place a cotter, for added insurance as in post 4? The steel washer helps with the gasket placement as stated.

[tbirdtbird]

ARP nuts and bolts are an even better alloy than grade 8, they told me equivalent to grade 13 if that even existed. I doubt you will be able to drill it. Even grade 8 is very tough to drill. As far as re-using, in this application that is not a worry. The ARP stuff is rugged as can be. The re-use issue is because racers usually prefer to not re-use rod nuts for obvious reasons. ARP does after all stand for Automotive Racing Products.

Tom Wesenberg had posted about a thread repair product here, made by Loctite. I couldn't find that one, but found an equivalent product made by Permatex, PN 765-1248, and got it off Amazon. Have not needed it yet. When I researched the product on-line at their website, it said it was good to 120 ft-lbs. I'd clean the daylights out of the male and female threads with lacquer thinner as a prep. Never paint thinner (mineral spirits) as it leave an oily residue. There is no mechanical operation on a car where paint thinner is appropriate.

Maybe Tom can chime in again here.

I like the idea of using more threads, Jim Brierley is pretty sharp, and is a racer himself as you know. If you are as close as .001, and are using more threads, and maybe try the thread repair epoxy, and use blue Loctite, and mark the torqued assembly with the white marking pen as suggested (we use those pens here like crazy) so you can monitor if it is loosening, then I think you have done all you can.

If all the vendors are selling this same puller, where you cannot put the nut on backwards, then that is a whole separate issue. They are very inadequate for the job, and a lot of people are gonna have the same problem. Some clubs have the correct puller that they loan out.

Some owners have turned the damaged threads down to 9/16. That is not easy to do at all, and I am not really fond of the idea, because these threads should have been 3/4" in the first place, which is the size used by competing cars of the era and beyond

Good luck

[carolinamudwalker]

Mitch, and Tom: Yes the nut face is the same diameter as the hub face and I am inclined not to use a washer. Dawizara and Plyfor: I will take a look at the possibility of notching the end of the nut for a roll pin. or a cotter pin. I wont know until I start putting things back together. right now all 8 shoes are off being relined, but that's another post. TbirdTbird, Dave always good to hear from you. I will look up the Permatex product. Do you think the original JB weld with steel in the threads as I tourq the nuts down would be overkill? I am with you 9/16 is going too small. Ill post a follow up as put things back together carolinamudwalker

[tbirdtbird]

Bob, is that you?
in this shop for whatever reason, JB weld never did anything it was supposed to, we gave up on it. If I used anything it would be the Loctite or Permatex high-grade epoxy that Tom W put us onto, it was made for the purpose. I would look up the instruction sheet on-line first before buying it. The kit I bought was only 20 bucks. You are not bonding the 2 threads together, you are filling in empty space. One side gets a release agent. I'd still use blue Loctite because you can never hurt anything with that product, you have nothing to lose. I have no personal use with these products, only going on what Tom W said a while back. Keep us posted, you are in uncharted waters....unfortunately

[Mitch]

Don't use the washer or anything on the threads
my 1/2 cent

[Tom Wesenberg]

Dave pretty well said what I would have posted. I seem to recall the product I used was a Loctite product made to repair stripped threads. The mirror on my 1960 BMW R-60 had stripped threads where it screwed into the aluminum housing for the hand clutch. It worked fine for my purpose, but the axle threads take a lot more torque. Other guys have said they did the 9/16" repair and it worked for them, so I'd give it a try, but I'd stop at 100 foot pounds torque. I'd most likely use a bit of liquid thread lock rather than drill the nut and loose some thread. I guess since the thread of a drilled nut would be over the hole already in the axle, it isn't adding to the grip anyway, so go with your choice. As Dave said, to drill a super hard nut could be a tough job.

[Tom Wesenberg]

I too would skip the washer. I would use the white out pens from Dollar Tree to put a white dot on the nut, and a dot on the hub, to see if the nut moves.

Those pens are 2 for $1 and have a small ball bearing tip to dispense a very quick drying white paint.
These are ideal for marking wires, and a timing mark on the pulley edge, so you know when TDC is coming up.

Update, I bought two white out pens for a dollar a month ago, and now they doubled the price, because you only get one on the card for a dollar.

[Beauford]

Update: My turned down axle @ 9/16 is still holding the wheel on at 600 miles so far.