I keep breaking lokka pins help! :) (1 Viewer)

[Blomie]

Hey everyone

I've had a lokka installed in my front diff for a few years now with no problems and I've given it a fair bit of punishment.

I recently installed another lokka in the rear of my hj61 in a good diff centre.

while installing it I replaced my wheel bearings on both sides and checked all the clearances on my lokka.
the clearances were on the tighter end of the scale.

since installing the lokka in the rear I've gone through two sets of pins and around 20 hub studs!

I'm running full floating axles with 31's and I don't drive that crazy haha

can anyone think of any reason why this is happening any help will be greatly appreciated! this is driving me crazy haha

 

[hj 60]

Tolerances must be wrong somehow, make sure you measure with the axle pushed outward because I measured when the axle was a bit inward and that messed up the mess.

Must use same tire size and inflation pressure.
Do you drive a lot 4x4 on paved road? because I was driving 4x4 low on a tiny bit of concrete and the wheels left a black stripe just from a small turn parking.

LOKKA - Automatic Differential Locker
I dont see a different product# for semi/full floating.

Mail to iorders@lokka.com they are very nice with troubleshooting.

I have more info and PDF in the link below, just to much and I don't know if full floater makes a difference.
hj60.freeforums.org • View topic - LOKKA rear diff lock TOY-RO-404 30 spline reardiff

LOKKA mailed me when I was struggeling with measuring the right gap:

The Spacer is LESS IMPORTANT.
I agree it would be better to have less gap than 0.165".
0.165" may lead to failure of the little pin dowles and springs.

One question, I have abused the LOKKA in uphill steep rocky slopes and what happens if the pins break, instant loss of the drive?
A lot of grinding sounds? and must you stop and remove something or can you drive home with front axle locked?
And how is the front LOKKA because I am thinking about getting on in front too.

Where do you order new pins because I need some spare pins I think.

 

[Output Shaft]

20 broken hub studs....
Something isn't right there.
I have FF rears on my petrol 2F (USA) with locking diffs and have used it pretty hard fully loaded down. 31" tires. Never torqued it with hard core binding boulder crawling though. Mostly steep rocky trails, but not boulders.

If you're breaking that many hub studs, I don't think the problem is the locker. It's either cheap China replacement studs you're using and/or using the lockers incorrectly.

I've heard of guys breaking axles, but not all the wheel studs.

Toyota supplied some cruisers with factory lockers and breaking stuff is very rare.

 

[lcwizard]

You're not the only one who's broken hub studs. I've run a few factory full floaters in my 55 and a couple 60's. I never had the 8mm studs last long. Eventually all the hubs and axles got redrilled to be fitted with 3/8 studs. On our competition 40 we ran in 1999 we used the larger studs and added 4 dowel pins. Later, Marlin Crawler and Bobby Long offered driveplate and dowel kits to do the same.
When ever I'd add a full float to the rear I'd carry an 18v drill, the correct bit, tap and hardware , for the upgrade on the trail if needed.
It paid off on a Colorado trip through Holy Cross Trail. I heard the familiar popped and said "looks like we camp here".

 

[Output Shaft]

Wow. I guess I've been easy on my gear. Good to know.

 

[Blomie]

I've found two possible causes so far.

on my hub there seems to be a slight burr where the dowels have broken and slightly elongated the hole which would cause less friction between the axle flange and the hub causing the studs to take alot more stress than usual.

on inspection of my lokka inside the diff it seems like one set of the plates aren't sitting together properly.

ill post a few pics later of these

 

[Blomie]

These are the burrs I was talking about. I replaced the wheel bearings in the hub right before this happened so I'm not too keen on replacing the hub, I'll have a go at grinding/filing/sanding them flat first

 

[hj 60]

I think the only repair is go bigger and drill, there is no sideways (wheel rotation) support anymore (?)
Or replace, I ordered front lokka!
Do you have a picture of the lokka plates?
This is my rear diff after 5000 km, replacing gasket from paper to cork :

 

[Blomie]

here are the pics of my lokka install, after a little playing aroud with the thrust washers I got the tolerances pretty much perfect

 

[Blomie]

and more pics

 

[Blomie]

hey guys

I'm still having trouble with this lokka.
As you know I've been breaking pins and axle studs.

To fix the problem I have removed the lokka replaced the springs and pins, checked and ensured all clearances are within tolerance(I have photos of all the clearances)
replaced all my axle studs with chromoly ones, replaced my axles with chromoly ones, and replaced all the rear wheel bearings.

Ive driven it for about a week now with everything installed and everything has seemed to be going good (no broken studs etc)

I'm now having the same problem as before one side is unlocking alot easier than the other and making a louder noise than it should be.

I put it up on stands and did the unlock test again where you rotate one wheel forwards a bit then rotate the opposite wheel backwards.

it passed in all 4 situations so i started it and put it in gear on the stands both wheels turn at the same speed and i tried to stop one wheel at a time with my foot which I could not.

I put the side that unlocks the easiest onto to ground and kept the other in the air. started it and released the clutch the side in the air spun while the side on the ground did not move instead it just made a loud clunking/clacking noise. I found a video on youtube that seems to be exactly what I'm experiencing ( )

from all the testing/ fault finding I've done it seems like one side is getting no drive it could possibly be a fault with the lokka itself? any ideas?

 

[cruiserpilot]

I have to keep an eye on my FF studs on the back. A friend who is a heavy mechanic told me to always check them
as they tend to loosen. No surprise they do, so it's part of regular walk around.
I'm wondering if anyone has come up with a hardened stud of factory dimensions?

 

[Blomie]

Arp do a chromoly stud upgrade, that's what I've got and they seem pretty good so far

you can get them from Locktup Fabrication, Hardcore Offroad Parts & Accessories

these are the ones I have ARP Hub Stud Upgrade [TOY-ARPHS-KIT] - $69.00 : Locktup Fabrication, Hardcore Offroad Parts & Accessories

that along side with some permanent strength thread locker has solved the stud problem

still have a problem with the lokka though

 

[cruiserpilot]

^^Thnx, sure wish I'd heard of Locktup before, could have saved a bunch of money and time.
Better late than never. J

 

[hj 60]

Sounds like it is in a turn (slipping as it should in a turn because inside turn is slower rotating)

So when this happens straight I can only say: while straight the lokka thinks one side is going faster and therefore unlocking
Or: one side gap tolerance is different than the other, or the &*^$(@ LOKKA is out of tolerance from factory?
Or one axle is 27 spline and other 30 slap: (just stupid ideas)

Or one wheel is other size OR same size on label but worn OR looks right but is wrong.

How is the pinion shaft? can you feel a worn out bit with your nail? does it have play in the carrier?

If driving reverse does it move to the other side? !

The set of feeler gauges looks familiar, to be exact please add the numbers and check with manual.
I think you are on end of scale (like mine) but maybe just over the end to much?

What did you change on the thrust washers? I have a guy in my village that machined them (in official machine, micro stuff)
But I asked and got 1.68 (they were 2.00) but it did not fit
so used original 1.75, (also bought 1.60) then bought new 2.00 for second time but at this moment I don't know what to ask as right size maybe 1.72 but I will have to measure again!

LOKKA is a PAIN if odds and knowledge unite against you
Measuring while lying under the car with the feeler gauges is a pain literally. Make sure the axles are pushed outwards!

The video is strange: they must have removed the rear driveshaft to do that, very good test but a lot of extra work.

My advice is: fill in the nasty many questions form on the lokka site to get support: Contact - LOKKA

Just to show how this is nagging me I made this to look at and try to understand what is happening in mine:

Maybe it is an optical illusion but below it seems very different left and right off pinion/cross shaft and tolerance is about a hair thickness (micro s***)
AND your tabs look more worn then mine, yours are smooth (worn) cornered?, mine are square (_ to \_

 

[Blomie]

I actually had the diff centre entirely out of my cruiser and on my shed floor when i installed it

my spacer clearance was 0.006 on both sides of the cross shaft pin which is dead on what the manufacturer recommends

and my cam gap was 0.156 which is right in the middle of the clearances apparently its the optimal gap.


I was driving my cruiser for a week with no problems then it started making more noise than it should.

while checking everything out i simulated a wheel being lifted off the ground by jacking up under the axle.

I tried to drive forwards like this and I couldn't as the lifted wheel just spun and the wheel on the ground did not move but instead just made a loud clacking noise similar to when the lokka dissengages around corners but much louder.

since its a locked diff while power is applied i should be able to drive even if a wheel is off the ground, both wheels should be turning at the same speed unless going around a corner when the lokka is designed to unlock.

so far ive contacted 4wdsystems here in aus as they has the distribution rights here and still no reply, ive also contacted lokka using there site aswell, hopefully someone can come up with some type of explanation haha

i just cant figure out whats causing one wheel to unlock so easily when all the clearances are correct

 

[rob5182]

I've read several posts lately about broken hub studs and the cause were all due to improper seating and torquing of the hub bearings and locking nut. Most guys didnt have the 3 prong wrench to properly set the torque.

 

[hj 60]

Landcruiser rearwheel bearing adjust:
read chassis/body pdf page RA-13 and RA-14 for procedure
Purple three holes are to turn loose with special tool,
green lines lineup with one of the metal pins in the stubaxle and then insert yellow bolts left and right to block.

toyota rearwheel bearing tool 09509-25011

 

[Blomie]

I've got that exact tool the bearings are all good, ive set them properly and even made sure it was all in spec with the correct wheel weight preload,

 

[hj 60]

I am now installing my second lokka in the front diff and I have found some casting sand before and now one spacer is not spinning freely on the axlegear:
I have asked the sheep but they looked funny so there must be something wrong.

I dont know if this sticking can break the pins but I can turn one half and then it just locks up, impossible to turn one full turn.

one side does not fit nice, it needs a hit/tap to seat and then it will not move:

After some negotiation with inner self decided to grind a little bit off and now it spins freely:

I have no time to mail lokka and in locker measure style this was a very small amount, I dont think I can even measure what came of: