Ital - Live Axle - Rear Wheel Bearing

[andysteele]

got the car back following MOT and check over, mechanic says we need to replace rear wheel bearing on one side.

 

I had hoped this would be a relatively simple task, but just been reading the Haynes Manual for Ital's and found old post on BC here. Haynes says "take axle shaft to your dealer and have him remove bearing and fit new one", this is after we have pulled the hub off with BL special tool.

 

Sounds like quite a job!

 

Numpty question, I`ve heard people go on about shims before, what are they? Haynes manual doesnt use that term, is it the axleshaft key.

 

I see the bearing kit is available from CC for £28, anything else i need to be aware of, or just get the kit and let the garage sort it out?

 

Cheers, Andy

 

1999 VX1600 Classic - andysteele.net - picasa albums - driving in marigolds

[bstark]

First thing to say is that if it needs replacing don't use the car (or at least don't put any significant cornering load on it).

 

7 Indulgence don't recommend shims and have used new parts and engineering adhesive to stop the shaft moving on the bearings ( so far with A021R's and soft R888's). I know from Blatchat that others swear by the shims.

 

Do a Search on the subject - plenty of info over the past 2 years.

 

 

Bob Stark

Supersprinter

[James_Russell]

I've just shimmed my half shaft, there have been a number of debates about shimming vs tack welding (as caterham originally did). My knowledge doesn't extend to engineering adhesives suitable for this purpose, but the majority of owners have solved the problem one of the two ways I mentioned.

First of all, removing the shaft should be possible without "BL special tools", But a hydraulic press will be required to get the hub off the shaft.

Strip is as follows:

-Put the rear of the car on axle stands (under the axle itself) handbrake off

-Reduce the diff oil level to an inch or so below the level plug (optinal, might avoid some mess if its overfilled (as it should be!)

-Remove roadwheel on the affected side

-Remove brake drum

-Remove brake backplate (very easy I assure you, but you will need to bleed brakes afterwards)

-Unbolt the two keeper plates sandwiched together by 4 bolts into the axle tube (probably sealed in)

-Use a slide hammer, hooked behind the hub, to pull the hub/shaft assembly out

(the shock of the hammer is neccessary as you are dislodging the bearing outer race from the inside of the axle tube and also the splines from the differential)

-This'll leave you with a half shaft, hub assembly with the keeper plates dangling off it.

 

This is about as far as you can go without a press!

 

Basically your Bearing inner race is loose on the half shaft (this is usually the problem, bearing might just be worn out!)

Its loose because the press-fit onto the shaft has given up because of the side-to-side forces the assembly is subjected to. Caterham tack weld the inner race to the shaft on the inboard side to stop the bearing jumping off the taper entirely (causing the shaft to part from the axle!) however there is nothing on the other side (to stop the shaft moving inboard in the axle), hence the play. Options are to:

 

-Fit shims (manufactured on a lathe or found somewhere !?) on the shaft between the bearing and the hub

or

-get the welds re-done and hope it sticks together longer than last time.

 

Shimming is invariably better but either way you'll need a new bearing for the affected side of the car, a press to put it on (if its tight, I didn't need one because mine was loose) and probably a machine shop/someone who can weld (good welding skill required)

 

Famously, refitting is the reverse of removal (but with sealant and new parts)

 

If you need any more info, just ask! I'm sure others will come along to contribute too!

-James

 

 

 

 

 

 

1999 VX 8v (Q41 ACF)

[Gun Bunny]

Ive got the special Churhill tool to remove the hub but you still need a bit heat before it will let go. The following posting from the Marina/Ital owners club might be of interest to you. I have not tried it myself so dont know if it works.

 

Olly

 

Re: Puller for Marina car halfshafts .

Over the years the hub/halfshaft/woodruff key seize together, my last but one wheel bearing replacement needed a 50 ton press to release the hub.

However since then I have learnt that if you slacken the hub nut off by one complete turn and then drive slowly round in circles for a few minutes, the torque of the engine and the grip of the tyre on the surface will loosen the hub from the halfshaft. I have tried it and it works. You probably wont even need a slide hammer. With the car supported securely on axle stands. Remove the four back plate bolts and disconnect the hydraulic and hand brakes. Then replace the wheel with a couple of nuts on only a couple of turns loosely. Then use the wheel as a slide hammer to pull the bearing out of the axle.

[James_Russell]

Q187RFB: what does the 'churchill' tool look like? I presume its a plate you bolt onto the wheel studs with a threaded boss in the middle, which acts as a puller?

 

Andy- It looks like the method you use to get the hub off the shaft depends on what equipment you have at your disposal! One thing I will say is I used a 20 ton press to do mine (still didn't give up 'easy'!), so I'm sceptical simply driving the car with a loose hub nut will free the hub from its taper/keyway. If you do it, obvioulsy only back the nut off a little! Perhaps the inventor of this method was removing the bearing again shortly after removing it for the first time (making it easier, less corroded, maybe not torqued up enough?)

At least on a caterham this is easy to do, with the hub nut exposed in the center of the wheel.

[Revin Kevin]

Hi all.

I have done a fair bit of research and built a number of Ital axles now, from basic shimming to axles that should take 180lbs of torque and 200bhp. I've somewhere on the computer got a document I wrote outlining how to build and modify an Ital axle the later not being cheap. If you want a copy I'll dig it out.

Two main things mentioned above, Tack welding should be avoided, It's dangerous!! it causes a stress raiser on the shaft which can cause a shaft failure at the outer end resulting in you loosing the wheel!

As for not shimming and glueing the bearing in place, I would question this. there is no good reason not to shim the bearing and under heavy loading I would be suprised the glue will stand up to the loading leaving you back at square one.

This is all assuming that your car failed it's MOT because the bearing is moving on the shaft allowing the wheel to move in and out usually by about 1/4".

 

Cheers

Chris

[andysteele]

thanks all, I think I`m getting the whole shimming thing!

 

Kevin - if you can did out that document it would be good.

 

If the current bearing is tacked on to the half shaft, will it need a new half shaft as well, or is it ok to re-use with new bearing and shims?

 

Cheers, Andy

 

1999 VX1600 Classic - andysteele.net - picasa albums - driving in marigolds

[James_Russell]

I re-used my tack welded half shaft, and its been fine so far. The welds are tiny and although the process would have affected the adjacent material metallurgically, and this causes an undesirable change in the metals properties, I'd stop short of calling it 'dangerous'! In the grads club, pretty much all the actual shaft failures we see are at the base of the hub taper keyway, at least 75mm from the welds. The latest theory is the weakness is caused by poor machining on the keyway, its a very rough finish and the sharp edges in the keyway cause a stress raiser.

I would shim them though. Shims (from memory) are 1" internal 1.5" exernal. you'll need several of various widths (I used 25 thou to 50 thou).

[elie boone]

I never had a problem to get the hub off with a 2 leg pulley, i do have to say that this pulley has a ring to prevent the jaws from opening under load, 1 or 2 whacks with a hammer is all there is needed.

 

James, i use the shim between hub and bearing, the Ital manual only gives a distance to the bearing from the end of the shaft. So i fit the bearing right up to the stop ( in theory that is a bit to far ) and use about 5mm of shim. No problems in 3 years of track day on 048's but with only 110bhp.

[Gun Bunny]

Hi James

 

The hub puller looks just like this

here

 

Link failed type MOGWOG PART S356C in to google

 

Its marked churchill S356c. Its fits over the 4 wheel studs & is then held by fitting the wheel nuts. On the end of the threaded bolt it has a ball bearing that fits into the concave dimple on the end of the half shaft.

 

 

Olly

 

Edited by - Q187RFB on 3 Feb 2010 17:47:12

[andysteele]

jacked her up this evening, there is about 2mm of play, latterally. Bearing kit on order.

 

is it safe to use (gentle road use) or should I deem it off the road until fixed?

 

 

Cheers, Andy

 

1999 VX1600 Classic - andysteele.net - picasa albums - driving in marigolds

[PAC]

I've done this job, which has been a bit of a saga, but I am a tad confused

 

I was given the distance to press the bearing on the shaft, but then advised that it is imaterial, because when it is all fitted, and the hub wound on, it will push the bearing further home.

If this is correct (advise from Redline) then the hub butts up against the bearing.

Does the Ital manual specify a gap? *confused*

P

[James_Russell]

The Bearing butts up against a shoulder on the shaft (and the additional tack welds if still original caterham shaft). The bearing is supposed to be a press fit, so (in a 60bhp morris ital) needs no further retention!

The hub is pressed on to a taper with a keyway, the when assembled the nut is hightly torqued up. There will be a gap between the hub and the bearin inner race, if there is no gap at all the bearing is being forced over its shoulder (which is a bad thing!)

Shims are used to take up most of this gap, a certain amount of play is necessary because otherwise the hub will be trying to force the bearing over the shoulder in the shaft when its fully torqued onto the shaft.

I turned an assortment of 1" I.D. 1.5" O.D. shims in various thicknesses. When the shaft was out of the axle, I removed the hub (with a press, but in other cases a puller will do it), took out the keeper plates, fitted the new bearing up to the welds on the shaft, then I re-fitted the hub and torqued it up to the correct torque with the assembly held in a vice. Then you can see what combination of shims will take up nearly all the play (as the hub is fully torqued onto its taper) I think I used about 75thou (2mm).

This is somewhat long-winded but I'm an engineer by nature and enjoy a good tinker! Sadly enough, I quite look forward to using my left-over shims to do the other side

-James

[PAC]

Thanks James,

 

Makes sense

P

[Revin Kevin]

Andy,

YHM

 

Cheers

Chris

[Revin Kevin]

Olly

Did you recieve my mail, I had a mail failure message. Try mailing me again with your address in the text.

 

Cheers

Chris

[Gun Bunny]

Chris

 

☹️ not recieved

YHM

 

Olly

[Revin Kevin]

Andy and Olly,

You should both have mail.

 

Cheers

Chris

[Gun Bunny]

Cheers Chris message recieved.

 

Olly