Snapping Axle Studs

[fweddy]

Today, I finally finished repairing my cruiser after I had snapped the axle studs on the full floating rear end months ago.

I ended up repairing my old hub and leaving out one due to ruined stud hole. I got a bit of work done on it at a workshop. They said it will be strong as. So I had five of the six studs in (and no dowels yet) and was down the river testing today and managed to snap all five new axle studs, on loose shingle!!

Any idea what is my cause?

I believe my locker is playing up again but would could that cause the studs to snap?

I was told that hitting the axle flange to remove cone washers damages the shape of the hole and allows the cone washers to not seat properly which in turn allows the nuts to come loose and this being loose snaps them. But I feel I've eliminated this as the cone mounts were all in good shape and well seated today.

The studs were all new so I'm counting out fatigue.

It takes a fair sheer force to snap five of these things!

I could perhaps understand it happening on seal, if my locker jammed on, but why on loose shingle? (I had been driving around or an hour or so on various surfaces before it gave up.)

[mudlva]

need to clarify what studs you are talking about. the wheel studs or the hub studs?

[Jafa]

bent axle?, bent flange?, bent housing?, studs torqued up too tight?

[Sadam_Husain]

The dowels are there to take the shear force instead of the studs, you auto locker could also be shock loading the axle flange if its not engaguing and releasing properly

[IcedJohnno]

Factory studs, or some an engineering company thought they were making from correct grade steel but actually from cheese?

[De-Ranged]

Can you post a close up pic of the end of a stud, if we can see the stress lines we may be able to tell whats done it

I've had a client who was doing this on his manual hub body studs... in the end to stop it we replaced all the studs with grade 12 caps

From what little you've given us I'd say its a safe call that you are going to need that sixth hole sorted

Cheers Reece

[fweddy]

need to clarify what studs you are talking about. the wheel studs or the hub studs?

Talking about the studs that hold the axle to the hub, right on the outer end of the hub.

bent axle?, bent flange?, bent housing?, studs torqued up too tight?

I've been wrong before but I don't believe any of those to be the problem.

The dowels are there to take the shear force instead of the studs

Yeah, the dowels are not yet fitted (was recommended 7mm roll pins), so that has weakened things a little, but still we are talking five new steel studs, what is the shear strength of that? On shingle? Last time it broke 4 studs (two had already broken) AND two dowels instantaneously.

Factory studs, or some an engineering company thought they were making from correct grade steel but actually from cheese?

Original studs from Just Cruisers. Engineering company considered various options and we decided to go with those.

Can you post a close up pic of the end of a stud, if we can see the stress lines we may be able to tell whats done it

I've had a client who was doing this on his manual hub body studs... in the end to stop it we replaced all the studs with grade 12 caps

From what little you've given us I'd say its a safe call that you are going to need that sixth hole sorted

Who knows where studs go when they go ping? I got half way home with one axle in the cab (it drives like a pig on road with one wheel drive - but the locker is great for keeping it going!) and then decided I should go see if I could find the bits, so I returned to the scene hoping to find cone washers and other bits but after a while crawling around on my knees in the open river bed I only managed to find one stud.



They all broke at about the start of the inner thread which is below the surface of the hub.

The sixth stud is naturally going to add more strength, but I don't think that is the problem, we are talking incredible strain to snap 5. Originally I only put three in to test because I thought it would be easier to get three snapped studs out rather than five — no problem even on seal.

I think that even if I strengthen this right up by welding, riveting, bolting, glueing etc the hub on I think some thing else will go bang! There is a cause and this is where it is being unleashed!

you auto locker could also be shock loading the axle flange if its not engaguing and releasing properly

I've been thinking and talking to others and I'm thinking that you are on the button there Marty. The locker IS playing up and it occurred when the locker re-engaged. Some times under acceleration the locker will go click click click and only one wheel spin and then if I power off and start again it often will engage. There are times when it will engage while still under power. There must be an incredible strain coming on instantly when the locker decides to re-engage and the instant shock can't be passed onto the wheel to make it spin even on very loose shingle so its spitting the studs on the side with the most torque (short axle).

So I'm going to chase this as the cause until I can prove it other wise as it makes the most sense to me.

Next question is why is the locker dis engaging? Technically it can't do that, it can only be overrun. We had it out and checked over recently and it was AOK, it worked fine shortly after it was put back in but after a river trip it started giving up again right when I was trying to climb out of a steep river exit.

Previous when I brought this up some one mentioned water getting in the diff causing it. Is there some reasoning behind this?

Both times it has given trouble, water was got in the diff, it also fits with it working ok after being refitted (new diff oil) and after a river trip giving up (drained about 4ltrs of excess oil/water mix between both diffs).

I'm working on pressurising the diffs to prevent water getting in but..

Has any one had any experience with water and lockrites, or any wisdom on if there might be a link between water and the locker releasing??

[IcedJohnno]

Was the Lock-right shimmed correctly? I know that when the clearances are too loose, things don't work right. You have had the springs fall out, so something is not right.
Talk to Dave at Falsgrave Auto. He spent a long time sorting out the optimum clearance. We used to work together as toolmakers so he does understand the significance of correct settings.

[fweddy]

Was the Lock-right shimmed correctly? I know that when the clearances are too loose, things don't work right. You have had the springs fall out, so something is not right.

Last time it was out we checked it all. It was all ok before but went through and reset it. Was check by two people who know lockrites. So locker SHOULD have been all ok in that regard.

Pretty sure now that the springs that fell out the sump drain was the axle seal spring bits. But did the spring cause the failure or did the failure damage the seal/spring?

[H2OLOVA]

Pretty sure now that the springs that fell out the sump drain was the axle seal spring bits. But did the spring cause the failure or did the failure damage the seal/spring?

You sure they aren't the springs from the locker?? Seems like a long way for the seal spring to travel.

[fweddy]

You sure they aren't the springs from the locker?? Seems like a long way for the seal spring to travel.[/quote]

I'm pretty sure - the diameter of the spring looks too small and its too long

[H2OLOVA]

You're right i'm guessing thats one long piece. Is it the spring from your pinion seal? or did you say axle seal?

[fweddy]

You're right i'm guessing thats one long piece. Is it the spring from your pinion seal? or did you say axle seal?

That is two long pieces. I'd say its axle seal, as that part of the seal was missing when I investigated so figured it went down there.

Does diff oil become thicker or thinner when water is added? Could the viscosity affect the locker to make it disengage?

[H2OLOVA]

Thicker, depending on how well "mixed" it gets, and depending on how long it sits. Over time the oil and water will seperate. Although the mud and oil doesn't. My guess is that its a locker failure. Having that bit of spring floating around in there wouldn't have helped things either. Sounds like it needs to come into the shop

[fweddy]

Looks like I've located the problem!

Took the locker out last night and had another set of eyes over it

I have yet to test it to prove the point but its pointing right at the locker or actually the way the locker was set up the last two times it was out.

Have had it readjusted by a different 'professional' so will trial it now and see if his set up is better.

If it proves that the last setup was incorrect, unfortunately it also caused damage to the locker and of course a couple of sets of axle studs.

Will put the locker back in and see how we go.

[Beer_Cruiser]

You got to have the dowels in the hub.The studs will just shear without the dowels.Ive done the left side 3 times and once on the right. The dowl holes were all flogged out. I would replace the studs and dowels then shear them all off as soon as I loaded them up with abit of right foot(5mins in to next trip)
In the end I moved the axel 1/4 of a turn redrilled new dowel holes in the hub and used the other end of the drill bit for the dowl.They have lasted a few trips now

[Kimbo]

I recently got home from a hardcore bush trip and was pleased that for the first time I did not have to do repairs to my truck untill I noticed the right rear axle missing alltogeather Having great hindsight I recalled thinking that the truck appeared to be struggling in places so now i know why. Both dowels and all studs sheared. Some other guys found the axle next day and so a new oil seal and new studs were put in along with my run away axle. I got some new dowels from the Toyota dealer and have now put 4 dowels in each axle so will see how this goes. Looking to the cause I drained the diff oil and found a mixure of oil and water so i am hoping this was the cause of the problem. I dont think the studs were loose but cant say for sure however I will see what happens next.

[Sadam_Husain]

I recently got home from a hardcore bush trip and was pleased that for the first time I did not have to do repairs to my truck untill I noticed the right rear axle missing alltogeather

Sorry mate I had to laugh at that one

[fweddy]

oh no! I figure you have a locker or a very good lsd to get all the way home without noticing? Didn't you feel it pulling right under acceleration and left in deceleration?

I spotted my escaping axle both times when it had just started drifting out - just as well you didn't collect a tree with it sticking out part way! - then you might have noticed it!

I seem to have solved my problem - the corrected locker gave no trouble last weekend when I put it through some riverbed action. Nothing snapped and no locker slipping.

But now, after a trip to town yesterday, I have to replace my front left wheel studs and a rim...

[mudlva]

But now, after a trip to town yesterday, I have to replace my front left wheel studs and a rim...


KRICKY YOU CANT LET THAT INFO OUT WITHOUT TELLING US THE STORY.

COME ON WHAT HAPPENED

[Heath]

Heard a rumor that a loose rear bearing can cause extra stress on the studs and dowels causing breakages also. Not sure of validity though.

[mudlva]

VCome on fweddy what happened i see you are after two wheels whats going on man

[Kimbo]

Looking back on it now it is farking funny . I run a lockrite in the rear and as we were on mud and clay tracks did not notice too much and I did use the front air locker more than usual. I guess for 3 wheel drive it did all right. Hopefully will get out this weekend and see if I have solved problem.

[fweddy]

VCome on fweddy what happened i see you are after two wheels whats going on man

Ok here's a deal - you supply or find me a wheel and I'll fess up

In the mean time I'll get out there and replace the studs.

[350cruiser]

if you go to toyota and get a full set of axle/hub studs and dowel pins for a 100 series cruiser (10mm not 8mm) and a bit of machining by someone that knows what they're doing and presto no more problems.

[fweddy]

Guess what I did yesterday!

Snapped the lot off again! Five axle studs and two dowels.

How? 2wd, loose shingle, light throttle.

Why? You tell me!

I had been driving in the open river bed and was starting to drive up a fairly steep shingle bank. The front wheels went up and at about the point that the rear ones started to climb, it went bang (that sickening type of bang). I rolled back to where the front wheels were just in front of where the back ones had got to and checked the situ.

The back wheels had dug small holes so they had obviously just started to lose traction trying to push the vehicle up the loose shingle (I wasn't expecting to get up the bank). I looked for the snapped off bits — I couldn't find one stud, nut, cone washer, spring washer or dowel in quite an area (these were new parts and the washers are all bling and goldy colour) so they must have fired out at some extreme pressure and may be orbiting the globe.

I turned the axle a small amount and it clicked in and couldn't turn any more. This tells me the locker was disengaged??

Any ideas, thoughts?

Obviously if it is breaking it could be strengthened. But this is some pretty extreme pressure to shear 7 pins off in one go under only light throttle. There needs to be some cause. Is making it tough at the axle studs going to shift the problem some where else?

Still seems like a locker issue to me but am considering that something may be out of true some where.

[meatc]

I have no actual experience with 70 seris but did read a couple of years back in an Aussie mag that this was common. The fix was as stated above go to the bigger diameter 100 series studs and dowels. Will see if I can find the artical and scan it for you.

[H2OLOVA]

Bring it down to the shop and we'll get it sorted

[Sadam_Husain]

All I can think is you must have a pretty powerfull 3b in that thing Damon, I've never sheared any studs or dowels with my 35" tyres, diff locks and 350?

[H2OLOVA]

I'd have to agree with that Sadam
Does it seem to be the same side each time they break? And the fact you recently had rear wheel/bearing issues makes you wonder