The hub nut specs is around 200NM so it definetely doesnt use the hub nut to set the preload like I would on the morry minor.
The nut is a set torque so the spacer in between the bearings is used to set the preload by holding them the appropriate distance apart. I have all the information in the mazda workshop manual with regards to doing it the textbook way
owene,
Dec 26, 8:44am
The original OP is a piss-take. Surely that's obvious!
morrisman1,
Dec 28, 5:24am
Why do you say that owene!
unbeatabull,
Dec 28, 5:51am
Could be a twin taper like what the Rear Falcon Bearings on IRS systems, in that the hub presses into thebearings and the driveshaft comes through the centre of the hub. The nut would be torqued up tight as a normal bearing would be. Wouldn't be able to tell without Photos of the bearing/assembly in question though.
aragorn2003,
Dec 28, 5:57am
what does OP stand for!
unbeatabull,
Dec 28, 6:01am
Original Poster, or in this case, the Original Original Poster
male_timaru,
Dec 28, 6:03am
knowing morriman as i do it is probably 100% legit and been done on a road car
He's been quite inventive over the past few years haven't you morrie!
morrisman1,
Dec 28, 6:03am
Aragorn, it stands for Original Poster
Unbeatable, that is how it works but the preload is set by a spacer holding the bearings at the correct distance apart and then the nut is tightened real tight (200NM).
It is all together so photos are not available but i have a workshop manual exploded diagram that I will post shortly. Edit, here it is: http://i43.tinypic.com/rthm4p.png
aragorn2003,
Dec 28, 6:09am
yeah i know it was just weird he put original infront of it.
Dont listen to the naysayers mate , your only considered crazy if it fails.
skin1235,
Dec 28, 6:50am
get it right MM, that spacer does not set the preload at all, it fits between the cages, not the cones, is a cheap engineering trick to do away with machining a register on both sides of the hub, puts double the thrust load on one side and no thrust limit on the other ( your axle can actually "float' both bearing cages out to the front of the hub) I'd also be checking those figures again, your 200nm is cranking direct into the cones, are you sure thats correct, even heavy truck diffs don't crank that onto cone retainers - cos they'd break the cones if you did
unbeatabull,
Dec 28, 7:15am
If its how I think it is (going from that picture), the Hub presses into the bearing cones and the inner race runs on the bearing, the hub then has the shaft go through the middle and the nut holds the shaft to the hub, the bearings won't be over tightened as the hub will hit the dust shield/rotor/whatever it mates up against.
pay attention to page 29 MM, I'm not the enemy you've already had one bearing set failure It is definitely a different setup to what I am used to, so follow the book, all the steps for future ref, I'd suggest if you have another set blow, look for a front with more distance between the bearings, the wider the better ( less leverage and better capacity to carry lateral loadings - but hey, I'm old school, stub axles should be as lang as the tire tread is wide)
unbeatabull,
Dec 28, 9:42am
There a bit different when they have a halfshaft running through them, unlike the older style front bearings that are just running on a stub axle.
skin1235,
Dec 28, 9:56am
lol, I think I see what has happened here, we're talking about two different parts
the bearings fit into the suspension member or bearing carrier ( can't think of the technical name for it - ) the hub which carries the disc brake and your wheel then slides (tightly) right through the bearings on the splines of the halfshaft stub, the great nut on the end is then tightened to ( your 200nm) which holds the hub on the halfshaft stub - it is not loading the bearings to 200nm - it is merely holding the hub on the spline - the hub bottoms on register on the halfshaft stub the bearing preload is set by the distance you have between the outer races, it creates the desired amount of pinch to the inner cone and outer race, and must be checked and adjusted if need be tightening the nut beyond 200nm ( or whatever it should be) will not produce more pinch - that can only be done by changing the spacer I have probably come across this many times but never actually bothered to pay too much attention to it - replace the bearings, check preload, adjust if needed, carry on don't get bent out of shape over my comments MM, i have followed a lot of your exploits so far and wish you well cheers
skin1235,
Dec 28, 10:02am
I'd also be interested if you have changed the original setup re rims the center of the wheel tread should be directly over the center of the bearings in a vertical line, to have it inside or outside the center line would load one bearing more than the other with a twisting force used to be a common problem in days of old with the good old 'jolly' widened rims - add 3 inches to one side only and be forever replacing bearings
morrisman1,
Dec 28, 10:11am
I have the ford laser hubs on there, and matching ford laser rims at the moment but Ill change to the RVR rims once i get the tyres swapped over.
need better tyres because with these ones first gear is basically unusable if you want to drive fast. they are skidding up to about 80km/h. With these new hubs I have noticed a lot more grip and that is going to nasty tyres too so must be something about the geometry which is helping with grip. Cannot wait to get some silverstone FTZ for it, then I should be able to go properly fast.
skin1235,
Dec 28, 10:20am
are you not limited by the class to tyre sizes or patterns!
skin1235,
Dec 28, 10:23am
thought rvr has 5 studs, or is that only the 4wd ones, the rvr I have sitting here definitely has 5 stud, but too deep to fit my old falcon setup on the tandem trailer - tyres rub on inside against main chassis
edit, and they're 15 inch, did laser run 15's!
morrisman1,
Dec 28, 10:29am
The tyres we put on must be dot rated (road legal) and not mud tyres or have offset blocks on the outside. The Silverstone FTZ are perfectly fine to use and they have proved to be a great tyre. I have yokohama A008 tyres currently but they are a bit old and have lost their edge.
I got the rims off an RVR and they are 4x114.3mm, thats all I know, there could well be different stud patterns available.
morrisman1,
Dec 28, 10:37am
the RVR rims I have are 14", the laser rims are 13" and the 121 originally had 12" so I'm 'moving up in the world' haha.
skin1235,
Dec 28, 10:38am
how do they compare for offset! any limits on width of tyre/rims
skin1235,
Dec 28, 10:40am
you'll have the poor 121 ( fiat!) on such long legs you'll need double rotors in front to get it stopped
morrisman1,
Dec 28, 10:43am
Offset seems alright but I havnt looked at the numbers yet. the biggest tyre I can get in there is a 185/60r14. The silverstones will be 185/55r14 which should be fine.
I have the laser brakes on there which are ventilated discs the same size as the 323 astina discs. They have plenty of stopping power. The stock 121 discs are rather lame, small and solid rotors which look like they would soak up the heat like a black car in the sun
skin1235,
Dec 28, 10:46am
ceramic pads! or copper
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