live axle rear wheel bearings

[shaunsl]

I have worn off-side rear wheel bearing which I need to replace, can anyone please tell me what sort of bearing do I need (for 1996 live axle) and also are there any workshop manuals available which will tell me how to do this?

[R2D2]

Which axle do you have ? Ital or Ford.

 

I have Workshop Manauls for both and can scan the relevant pages and e-mail them to you.

 

I haven't changed the bearings on my Ital axle as yet but for the Ford axle you will need a slide hammer to pull the half shaft and access to a press to fit the bearing retaining collar back onto the shaft.

 

 

[allen]

Bet you're the other end of the country, but I'm in Somerset & have a slide hammer if required.

 

Regards,

 

allen

[Graham Sewell]

Have a chat to Classic Carriage as they have a mod to the usual fitting instructions that include shims to prevent bearing movement.

 

My understanding is that the bearing has to be pressed onto the axle which is a task that the average amateur cannot do. So you may need professional assistance. Again, CC use small spots of weld to prevent the axle moving relative to the bearing.

 

Good luck

 

Graham

[R2D2]

I think that it is a bearing retaining collar that has to pressed. Putting a force onto a bearing could cause some damage.

 

I would worry about welding on a half shaft. Most half shafts are manufactured from steels that are not particularly weldable and even small local welds can introduce small surface cracks into the parent material. These cracks would be very good fatigue initiation sites and could easily cause failure fter a relatively short time.

 

The use of welding in this area may be convenient but it is not very "christian" and there must be a better solution.

[Graham Sewell]

From my understanding, unlike the Escort or Manta, the Ital axle does not use a bearing retaining collar on the half shaft! This leads to migrating half shafts if you ever hit a bad pothole on the apex of a corner as the car acts like a massive slide hammer. The shims that I refered to are purely to lock the bearing in firmly against the axle tube so as to minimise the effect of the slide hammer - no play gives a lower hammer effect. Whilst the half shaft cannot come out, it is very disturbing to hear it knock in and out of the axle casing and smashing the diff! So far, I have had to replace 2 half shafts, 3 bearings and a diff to get back to a state where the axle is 'as good as new'.

 

Cheers,

 

Graham

[R2D2]

It is interesting that the Ital doesn't use a bearing retaining collar and that must mean that the only thing holding the wheel in place is the interference between the bearing inner track and the shaft.

 

There are a couple of details about the bearings that might be important.

 

If the bearings that are being used now are a different tolerance grade to the OE bearings that Leyland used, the interference may be reduced as the tolerance could be greater. The lower grade bearings should be cheaper but may contribute to the problem of loose shafts.

 

The clearance of the bearing between the tracks and the rolling elements is also quite important and bearings can normally be purchased in different clearance grades. I would think that the ideal interference between the bearing and the half shaft must be quite high and this would need a bearing with a relatively large clearance. If a bearing with a small clearance is used the interference could close up the operating gap and cause the bearing to overheat. Bearings with small clearances are normally relatively expensive.

 

This really means that cheap bearings may cause one type of failure and that expensive grades may cause a different problem. The only answer is to use the identical bearing to the OE set up.

 

I would imagine it would be difficult to find the detailed specification of the original equipmnet bearings but the information must exist.

 

The lack of a retaining collar is also quite worrying and if there is enough space to fit a collar I would be prepared to machine a batch and see if this helps solve the problem.

 

I think that the tack welding is also a bit risky because bearing tracks are made from though hardening steels which are not suitable for welding. It is quite likely that any welding process does cause small cracks in the bearing track. This will almost certainly lead to fatigue failures in the track and a fairly catastrophic failure will result.

 

Seems like a interesting set of problems to try to resolve.

[Graham Sewell]

I forgot to mention that the half shaft has a 25thou ridge to prevent the bearing moving toward the diff end. But if you hit a pothole mid-corner with the outside rear wheel, there is nothing stopping the haft shaft moving toward the diff other than the interference fit of the bearing - hence the need for them to be pressed on with significant force!

 

The bearings supplied by Ratrace, when they repaired my rear axle, apparently head enough clearance of the bearing between the tracks and the rolling elements that they initially rejected them as being faulty!

 

Cheers,

 

Graham