axle nut - tight or loose?

geordie_kuz · Post by **geordie_kuz** » Tue Jan 19, 2010 6:25 pm

just did my rear drum shoes and wheel cylinders, put the drum back on and did up the nut (36 or 37 mm, big nut). I put it just more than finger tight and chucked the split pin back in. Now i've got a thrumming noise in the rear wheel and some old guy telling me you're sposed to do the big nut up real real tight. Anyone know the correct torque for the rear drum nuts? it's not in my manual.

Geordie

subybrumby · Post by **subybrumby** » Tue Jan 19, 2010 7:42 pm

Mate, not sure what car you're talking about but the subaru axle is not a tapered shaft like a trailer axle. With a tapered trailer axle, the more you load the nut, the more pressure on the bearings. Those bearings are tapered rollers. That's why most trailer bearings preload at about 14footlb. The subaru shaft is stepped.

With the subaru, there is no loading on the bearings so the nut just does up tight. With these castle nuts, they have to be super tight. I don't have the specs here but there has been a lot of discussion about this.

In my case, I bought the proper socket for the job, put a breaker bar on it and push down my 130klg weight till I feel that the nut is tight without being overstressed. Put the car on the ground with the brakes on. Use a piece of pipe over the breaker bar if you must to get the torque and feel. Also, ensure that the cone washer is in good order and the flat washer is right way round with the flat side against the wheel. Some have a spec of white paint on them. This goes to the outside. When you feel it coming tight, take it to the next pin hole, don't back it off. Use a new split pin every time. If the cone washer and flat washer look dodgy, go to subaru and buy new ones. They are not that expensive. If this nut is not done up real tight, you will get all sorts of noises coming from the wheel, as the cone washer moves about.

Hope this helps.

Venom · Post by **Venom** » Tue Jan 19, 2010 7:47 pm

I assume you're talking about the castellan nut? Then yes it is torque'd to a ridiculous amount (over 170nm). Someone can probably confirm exactly how much, but my torque wrench doesn't even go as high what subaru recommends! I used a breaker bar and then slid a full length jack handle over that to tighten mine up. I also had a thrumming noise after a mechanic did my rear brakes and failed to tighten the castellan nuts up to spec.

Cheers,
Rhys

YouTube · Post by **El_Freddo** » Tue Jan 19, 2010 8:43 pm

subybrumby wrote:With a tapered trailer axle, the more you load the nut, the more pressure on the bearings. Those bearings are tapered rollers.

With the subaru, there is no loading on the bearings so the nut just does up tight. With these castle nuts, they have to be super tight.

Ummm... Hate to tell you but the rear bearings are tapered rollers and are loaded by the axle shaft. I don't know how they survive with that sort of loading but if you have a look at your hub you will see where the hub contacts the inside of the bearing - pushing it into the tapered "casing" in the bearing hub. I thought I had a photo of them but can't find one

Those castle nuts need about 196nm of torque - same as the front. I've got a 3/4 inch drive 36mm socket and very strong breaker bar. Basically I jump on this thing until I can just get the pin in a new hole. I feel like I'm going to strip a nut but that hasn't happened yet. My torque wrench won't go that high, I think it claps out at 140nm and is only 1/2 inch drive. I broke one of my dad's very good breaker bars, I couldn't get a new one or a replacement "drive" part, the square bit that plugs into the socket.

Any creaking while rolling will be the castle nut that needs torquing again.

Cheers

Bennie

geordie_kuz · Post by **geordie_kuz** » Tue Jan 19, 2010 8:59 pm

great thanks for your help, off i go to the truck version of autobarn to get a 36mm socket and a bar.

ive done around 30k since i got it (91 l series) and those nuts were loose as gooses' when i replaced the shoes. Been to lake eyre and all around with no noises! i guess i'm pretty lucky.

The drum on the passenger side was difficult to remove, and the tyre wore with a flat spot on the outer edge. I had the rim checked and its round, tyrepower reckons its a bad smash repair affecting the alignment (it has been repaired at some point, good job though) or the axle is bent. I wonder if the loose castellan nut had anything to do with it...hmm.

oh well, thanks again y'all, i'm learning slowly

Geordie

YouTube · Post by **El_Freddo** » Tue Jan 19, 2010 9:07 pm

geordie_kuz wrote:The drum on the passenger side was difficult to remove, and the tyre wore with a flat spot on the outer edge. I had the rim checked and its round, tyrepower reckons its a bad smash repair affecting the alignment (it has been repaired at some point, good job though) or the axle is bent. I wonder if the loose castellan nut had anything to do with it...hmm.

That seems to be an L series trait at this age. A mate's L does it but I haven't noticed mine do it with the last set of tyres. I've replaced my rear suspension bushes just over a year ago. This helps but may not solve the problem. You'd have to go to a place that can make your swing arms adjustable at the bush end where it swings.

Cheers

Bennie

T'subaru · Post by **T'subaru** » Tue Jan 19, 2010 10:50 pm

I bent a lesser quality breaker bar once, 145 ft lbs 196M-m 2okg-m

tony · Post by **tony** » Wed Jan 20, 2010 3:00 am

36 mm socket is a handy size fits lots of cars, like VW flywheel nut, mini minor clutch nut, and some others. also subi front axle nuts.
bit pricey though for a good brand, like around $35 or so, suggest you hit the hock shops and see if you can get one there, not as if they are likely to be worn out.
for the square for the bar they are available from most toolshops.
I undid mine by putting the carjack under the bar and jacked it up till it came loose.
oh it's a castellated nut

subybrumby · Post by **subybrumby** » Wed Jan 20, 2010 6:23 pm

No worries el freddo. What I was trying to say is that with a trailer stub axle, the axle is tapered and so are the bearings. If you do them up too tight, (preload) you'll stress the bearings and hardly be able to turn the wheel. I think about 14foot lb holds them. I think this is the mistake that Geordie Kuz was making as do some mechanics and not tightening the subarus up enough.

With the subarus, and I have changed both the front and back bearings on my brumby, what I was trying to say was that the bearings sit on a shaft and the castle nut does not as I see preload the bearings.

However, I will retreat to the lounge....(thanx mate)

holden26 · Post by **holden26** » Wed Feb 03, 2010 10:27 pm

i just keep going till the rattle gun stops turning haven't had a problem yet

YouTube · Post by **El_Freddo** » Wed Feb 03, 2010 10:38 pm

holden26 wrote:i just keep going till the rattle gun stops turning haven't had a problem yet

Hope its a bloody good rattle gun! I literally jump on my breaker bar...

Cheers

Bennie

Barry1956 · Post by **Barry1956** » Thu Feb 04, 2010 8:22 pm

El_Freddo wrote:... I literally jump on my breaker bar...

Cheers

Bennie

In the best tradition of the line drawings in John Muir's "How to keep your VW alive ..."

I love the immutable laws of physics.

holden26 · Post by **holden26** » Thu Feb 04, 2010 8:56 pm

El_Freddo wrote:Hope its a bloody good rattle gun! I literally jump on my breaker bar...

Cheers

Bennie

i think its 650tlb

arc413 · Post by **arc413** » Tue Apr 05, 2016 10:40 am

Yo.
Thread revival, sure... but I think I've stripped my front passenger nut (hopefully) or the axle (oh sh!t!)

Any ideas on where to grab a new castellated nut? Getting the rat off without doing more damage? Easier replacement than the whole driveaxle?

I noticed a rubbing noise coming from the front left brakes, hopped out to check, saw the castellated nut was less than finger tight so tightened it up... without jacking the wheel (oops!)
whilst tightening with the ol breaker bar, I noticed it suddenly became much easier to tighten. Cue bad feelings. That it now spins either way quite happily with just a T-bar and socket, I think something's stripped.

halp?

Silverbullet · Post by **Silverbullet** » Tue Apr 05, 2016 10:58 am

Most likely the nut has gone, I've had one strip it was a nut that came on a cheap pair of drive shafts. You would hope they make the nut softer than the axle so it strips before the axle does.

Just jack it up, remove the nut and you will see.

arc413 · Post by **arc413** » Tue Apr 05, 2016 1:35 pm

Fingers crossed it's just the nut

heading to Imlachs today to see what I can dig up.

Thank you for the response, I'll keep you posted with how it goes

-Bishop

sublime · Post by **sublime** » Wed Apr 06, 2016 4:59 pm

I have had the nut strip the axle/cv threads before so it can be done. I used correct torque specs too... Was not fecking happy! Cheap CV I guess.

Post by **TOONGA** » Wed Apr 06, 2016 5:28 pm

I had an axle strip was brand new and wasn't covered by warranty. cheap as outer CV no heat treating.

TOONGA

arc413 · Post by **arc413** » Wed Apr 06, 2016 10:02 pm

Hey, so it ended up being the nut

(mostly, there was some axle damage, but nothing too bad)

Had a bit of difficulty getting the nut off, as it was just spinning in place. Solution?
Lower the affected axle, pour over some fresh engine oil, wriggle nut a bit to work it all in, then let be for 5-10 mins. Then, using a flathead screwdriver as a chisel/spacer, crank the nut off. Screwdriver might need some "persuasion" to get it into place.

Hope this helps someone!

-Bishop