How weird..Rear hub loose due to oil seal?

[Donnie]

Very odd this one. I thought I noticed something a couple of weeks ago on the rear hub, ie a little play so double checked the torque setting on the rear hub nut and it was ok, still better safe than sorry.

However on the way back from the Luton Lambretta Clubs 60th anniversary yesterday thought there was something odd again, ie my rear brakes felt like they were occasionally sticking on. Here we go I thought, it's been a while since Ive done the rear brakes (I do favour the disc at the front a lot to be fair) so have just put her on the bench and found the rear locking ring has dissappeared and quite a wobble on the rear hub! Not massive but certainly not the normal amount! So hub off to find the following.




So, basically the rear hub seals obviously gone, bit of a pain but at least when I checked the layshaft it's all well, so that's a bonus, however I just need to sort out getting the hub cone out of the hub as it's stuck fast at the moment So I think what's been happening is that a small amount of oils been mixing with the show dust and has welded it into the hub therefore not really doing it's job

[hullygully]

aren't you missing the oil seal retaining plate?? behind the brg retaining plate??

[Donnie]

Nope, it's there, not the best picture but you made me doubt myself and ive just checked in the shed, it's definitely there.

[weeks]

aren't you missing the oil seal retaining plate??

Id agree Mick ............. First picture appears to be missing the retaining plate which is shown in situ in pic below.



Personally out of all the oil seals to go id rather this one every time ............ Lambrettas, don't just love em

[steveg]

Donnie when you say the layshaft is ok have you checked the case hardening at the gearbox end for ware? Mine was worn which caused the shaft to run out of true and in the process it knackered the rear hub bearing and seal.it might explain why your hub nut came loose?

[hullygully]

have you had your crankcase side off too to check if your gearbox studs aren't loose?
the dust could be from the hub not running true & rubbing out of concentricity on the shoes.

[Donnie]

Can i just reassure everyone, the plate was there, here's the bits removed

]

[Digger]

It's in that pile but it doesn't look like it's in your first picture?

[johnnyXS]

Hi Donnie
all your images seem to have dissappeared which is a shame as the thread now lacks a visual element. oops they are now back again
Strange things happening on the net today it seems.

Did you get the problem solved ? its worrying that the hub lockring screw came undone . Perhaps it would benefit from some locktite on the threads

[Wack]

I never loctite the screw as they're too easy to round off , if anything I fit a 6mm stainless spring ring.

[Captain Pugwash]

I don't loctite the locking screw, but the official workshop manual says that you should. Maybe there is a need to do somthing more than just tighten the screw so maybe You have the right idea in fitting a spring washer.

[johnnyXS]

there are many different types of thread locker from weak to strong strength setting and non setting etc
You just need to select the correct one for the job like Locktite 243 or similar which is medium strength and easy to undo with normal handtools.
Most problems arise through reusing a screw that has a damaged head rather than replacing with new

[Donnie]

It's in that pile but it doesn't look like it's in your first picture?

Maybe so, but it was on there, not sure how many times I can assure that it was to be honest.

As for getting anywhere, not really, new seals fitted but also needed a new rear hub spacer as the old one was knackered and of course the one ordered from a "dealer" on ebay is crap. instead of being a standard 1mm it's only 0.2mm thick, literally feels like its made from a coke can!

[johnnyXS]

I've seen a selection of shims somewhere recently. I'm sure it was on ebay .
Should be possible to buy some shims from an engineering supliers I should have thought .?
What thickness do you need ? you could always put 2-3 together to make up the correct thickness .

[Donnie]

Jaysus, Im sure you just spoke a bit of Vietnamese there!!!!!!!!

[MK Monty]

Donnie im out of the box on this one are you sure you have a problem with the oil seal, when mine have gone i know coz it wont stop. Looks more like grease used in the rebuild. Have you had a look at the gearbox end plate (loose) and bearing, when they collapse its unridable unless you hold on with your but cheeks

[johnnyXS]

Jaysus, Im sure you just spoke a bit of Vietnamese there!!!!!!!!

its ok to stack shims to make up a thickness, they are specially hardened steel unless of course they come from India.. Vietnam.. Taiwan..... China...Malaysia . .........

[Donnie]

Donnie im out of the box on this one are you sure you have a problem with the oil seal, when mine have gone i know coz it wont stop. Looks more like grease used in the rebuild. Have you had a look at the gearbox end plate (loose) and bearing, when they collapse its unridable unless you hold on with your but cheeks

Definitely oil seal gone, the spacer washer between the cone and inner race of the bearing was worn and ovalled slightly, i suspect it was then catching the seal, seal was deffo gone, just though so there wasn't a lot of oil in the hub but definitely a bit.

Not looked at the gear end plate, nor will I be as rocking the layshaft from this side theres no wiggle etc or any indication to show theres anything wrong. Im quite sure its a worn spacer causing the issue, not allowing the hub to tighten fully on the cone.

If it's still not right when the parts all arrive and are on, them i may consider other causes.

[Donnie]

Jaysus, Im sure you just spoke a bit of Vietnamese there!!!!!!!!

its ok to stack shims to make up a thickness, they are specially hardened steel unless of course they come from India.. Vietnam.. Taiwan..... China...Malaysia . .........

Indeed, though im surprised at an indian (supposed dealer) using such crap. Im used to most of the indian stuff being reasonable but this guy seems to have taken a leaf out of the vietnamese coke can shim philosophy.

[Ivor the engine]

Hi,
When you look at what actually holds the whole rear hub on, it appears to be between 5 - 7/8 mm of M7 thread or in some cases, M6 threaded screw, which isn't a lot.

Without doubt, I always take the rear hub off any scooter i'm working on, to have a look and check all's well as this area tells a multitude of tails....
It's always good to consider obtaining the best lock pin, hub nut / crinkle washer and hub cone washer that you can due to the force placed in this area.
Check your inner hub splines for wear.

As for thread locking the pin, it's favorable. If you have a deep hex nut, you won't have a problem loosening this is you purchase the best possible screw you can get and have a good allen key to match.

Cheers n' regards,

Ivor.