I am at the stage of re-assembling the rear axle on my 1929 RK Saloon.I have the differential carrier back together. I have the offside case and the banjo housing bolted back together again.

Following the instructions in Doug Woodrow's Austin Seven Manual I have put the diff assembly and half shafts back in the nearside axle case (this picture is a test run I haven't put in the felt housing and washer plate yet)

Can I ask for some pointers as I can see myself getting in the most horrible mess with this?

1) It seems that the Journal bearing is a very tight fit in the axle case. Is this right? I was thinking of applying some heat to the case with a blowtorch then a few gentle blows with a soft faced mallet to the end of the opposite half shaft. I'm going to have to take it to bits again even if it comes out right first go as there are no oil seals fitted yet and I can envisage the journal bearings coming apart.

2) Woodrow talks of a pre-load of 2-4 thou to the halfshaft differential assembly in the housing. I don't understand this does he mean endfloat on the halfshafts?

3) The axle originally had one shim in the nearside case. I've not changed the crownwheel or pinion although the pinion bearings and thrust bearings are new. I can't seem to get new shims. If I just put it back together again the same way it came apart what's the worst that could happen?

This is as far as I have gotten

Location: Northumberland

As the pictures have not come up its hard to answer.Do you have the screw in torque tube axle?
Someone must stock the shims to shim the bearings up,although it is possible to make them yourself from shimstock from a local engineering bearing/seals supplier.
I've only had experience of axles with adjusters in the side tubes which make adjustment much easier.
The halfshafts only "float" within the diff their position being fixed by the outer hub/bearing.
I think now you have changed the bearings you will have to set it up from scratch.

The preload means that there is a negative clearance, not end float.
It depends on which axle you have.
If it is a screw-in torque tube axle (late 1929 & 30) it is done using the adjusters. Basically they need to be done up firmly so that the diff does not move from side to side. I think Jack French's article in The Companion describes the technique. I believe they are done up tight and then backed off one or two notches, but preserving the correct free play in the CWP.
If it is the earlier axle, the one that is adjusted by shims, it is a bit of a fiddle to set up. It is done by measuring the end-float of the diff assembly and then adding shims that are 2-4 thou thicker than the measured end-foat. Thereafter, if adjustment is needed it is done by moving shims from one side to the other so that the total thickness of shims on both sides remains the same.

Location: Melrose, Roxburghshire

Hello

Sorry about the pictures I followed the bb code examples but it doesn't seem to work.

https://goo.gl/photos/CnFpmDCJmuwhtfwD8

https://goo.gl/photos/JeiZktuscbjpZz5i9

https://goo.gl/photos/Tieo8u35WQogDFkt5

Try that for size.

Location: Northumberland

Thank you Jim that explains the pre-load question.

The whole job looks awful.

I can get everything together by the application of a little heat and the odd bash with a hammer. I've already wrecked one felt seal housing because the outer part of the thrust bearing got jammed in the axle housing see here and getting it out again with a long drift down the axle tube mangled the felt seal housing.

Location: Northumberland

Thrust Bearing Outer Part Jammed in Axle case

Location: Northumberland

Location: Northumberland

Alan,

The two ball bearings on either side of the crown wheel carrier should be a sliding fit in the housing. The two ball thrust bearings have to be carefully placed in so they seat together.
If you haven't changed anything but the bearings, then the early differential with shims is probably easier to assemble than the later screw assembly. if it ran well before disassembly and the crown wheel and pinion are the originals, keep all the original shims in the original order.
It should all 'slide' together without hammering.
Careful with new felt seals - usually quite tight making assembly tricky. Check them first.

Tony.

Alan,

i hate to undo all your hard work but...you have the crown wheel bolts in the wrong way around and I am not sure if there is enough clearance in the casing to leave them as is. It's also good practice (and piece of mind) to use tab washers under the nuts if you haven't already.

Nick

Alan,

Something was nagging me about your pictures- if this is a shim diff then it shouldn't have a split carrier, which was fitted to the later screw adjustment diff.
The comment about the bolts made me check - the earlier one piece carrier has bolts and studs with nuts on the crown wheel side, the later split carrier has all bolts with the heads on the crown wheel side.
The split carrier had a different bearing assembly with angular contact bearings- without checking I an not sure if it assembles easily in the earlier housing using ball bearings and ball thrust bearings- or was there an intermediate 1929? differential assembly with split carrier and ball/thrust bearings?

Confused of Malvern.

Yes Tony, the split carrier was introduced in early 1929 (or maybe late 28), screw-in tube late 29.

Location: Melrose, Roxburghshire

Jim,

Wyatt- diff case in two halves (I assume he means split carrier) 21st June 1928, torque tube socket- (I assume he means screw in torque tube) 30th May 1929.

I should have remembered anyway- the Sports has a shim adjusted differential with split carrier - that is what happens when you get old !!

And if you assemble it with the crown wheel on the wrong side the bolts don't clear (called are sup I believe)

Tony.

Location: Northumberland

Location: Northumberland

As I understand it, all the advice about retaining original shims only applies if the exact same compressed gasket thickness is reproduced.

Bob Culver

Location: Auckland, NZ

Alan,

Can you try a new bearing? Given the axle assembly is an unknown quantity then you will probably need the ball bearings to slide in their housings so you can set up the adjustment. The one in the picture looks slightly cocked which will jam in the housing.
You will need to assemble the carrier with a few shims either side of the thrust bearings and try to adjust the carrier to get no sideways movement in the crown wheel by adding or removing shims. Check with the torque tube off.
When testing, assemble the side tubes without paper gaskets and then use a good gasket cement for the final assembly.
Then you need a few of the shaped shims for the torque tube mounting and you have the next fun job of assembling the pinion, trying for a slight backlash between the pinion and wheel by adding or removing shims.
You could try bluing the teeth but with a worn CW&P set it is going to be difficult to get a meaningful result.
No guarantees that it will be quiet - I haven't tried but they say running the car briefly with lapping paste in the diff can help!

Tony.

Location: Northumberland

No - they are identical!

Tony.