rear axle clean up - how far to go?

[JonE]

I've got an entire rear axle and torque tube that I'm bringing back to life for a new lego build. It is Feb 1927 from the case.
It has two coats of paint which I'm cleaning back around the edges of castings, and i've removed all the set screws on the casing to renew the lock washers (they were all bent over the casing edge!) and get the bolts back to clean metal for a thin coat of black paint. The halfshaft ends are all clean/threads ok so I suspect its just been stored for 60 years.

I'm in mind of something Ruairidh said to me when I got my first Seven about not disassembling too far when you just initially want to get it running (I still think about this practically daily) but exactly how far is common sense with getting an axle back into service? Everything moves ok. But of course it's all accessible now. I'm just wondering whether I should check shims or anything... or get it rolling in a chassis first and and then await noises before doing anything?

[Tony Betts]

hi jonE,

R is right to a point, you dont have to total strip down.

but if you dont, how do you know the condition of whats inside.

my 1925 boulogne has come to a standstill at the moment because of the back axle. 

previous owner done the usual thing, it was checked? and when they found the halfshafts splayed open on the keyways. so they bolted it back together and painted it.

so if you dont open it, and dont check. you dont know whats in there.

check what usually goes wrong. keyways. chipped crownwheel and pinion gears, bearing wear, and if it has the pinion nut prone to coming loose.

to do this, you dont have to touch any adjusters, or disterb the bearings. just gaskets and tabs.

the main thing is, when you find something wrong. replace it, DONT just leave it.

tony

tony

[JonE]

ok thankyou - so split the case, remove it all from N/S for visual check? After presumably removing the torque tube stuff which will stop it coming out. And then check for basic soundness.

But as you say, if it's shims, then as long as they go in as taken out, all stays the same... and an opportunity to clean down insides with spray can oil or diesel etc?

[Parazine]

With my 1926 Top Hat axle, the original lubricant was still inside, a foul smelling mixture of grease and oil. I felt compelled to get this out as 90+ years of deterioration would not have improved the lubricants efficacy at all!

I ended up with an almost completely dismantled axle (it's documented in the thread) to get the wretched stuff out but I didn't adjust it on reassembly as nothing had been changed.

I subsequently found the torque tube was bent and the axle is likely to be demoted to a shed ornament when I eventually get the car on the road.

Beware these early axles as they are set up with shims and it's a real palaver to get them adjusted correctly. As with any A7 axle the real killer is pinion end float, any sign of this must be acted on otherwise the result is likely to be terminal in short order.

[JonE]

here is the linking post for others... hmm... photos not there yet: https://www.austinsevenfriends.co.uk/for...063&page=6

presumably the issue with the early smaller-halfshafted axles are that the (old) oil/grease mix retains impurities and metal fragments. And that removing/cleaning down entirely may enhance the looseness of what is left?
From reading Parazine's thread, I've summarised advice-of-others there as:
split the axle but dont disturb shims. Replace felt seals
diesel or brake clutch cleaner good for grease
blow torch heat helps remove
use oil after - but not designed for it so will be more leaky

(I note I have holes drilled on the underside of my axle side cases already... so I'm hoping the change to oil may have happened and it all be nice and clean and restored inside!! ha...)

[Bob Culver]

I am not familair with the early ones, but splitting with a different gasket can alter cw position and side bearing settings so is best avoided. The cw teeth can presumably be inspected thru plug hole as on later cars, but the pinion wears more.. If the pinion can be fished out without losing track of settings the cw and pinion can be examined for deep wear, serious pitting etc and, as Tony mentions, the pinion shaft nut checked for tightness. A close study of the cross section diags likely to be useful. To simplify any subsequent attempts to alter adjustment, the wear step on pinion should be ground off, but difficult with the bearing in place. Metal detritus in the oil or casing is an ominous sign. It is diffiult to judge bearings if the tracks and ball surfaces cannot all be viewed.
It should not be possible to move the cw laterally.

[JonE]

ok, well I may have a course directed already. No real end float movement on O/S half shaft and pinion, but oddly, despite all being very smooth and easy elsewhere (no oil in), the N/S half shaft has a simply enormous amount of movement 1/4 inch or more. Hmm. Rebuilt with a wrong item perhaps?
Whatever happens, it will have to come apart...

Bob's point about checking inside... all squeaky clean, although can only see through the holes of the carrier every so often. Outside of carrier clean.

[Rogerfrench]

When you say the half-shaft ends are clean, I take it you have removed the hubs? Well, with a 3/4 floating axle like the A7, you don't have lateral location and should be able to slide the half-shafts in and out at will!

---

Well, not all the way out.....

[JonE]

Roger - no, the outer hub seal has not yet been broken on either.
Rear carriers flapping around - but one side moves in/out... and the other doesn't.
So that might be normal?

[Rogerfrench]

The hub bearing locates the half-shaft, so if they haven't been disturbed I'm puzzled. How did you I inspect the half-shaft ends without taking off the hubs? What's flapping around?
Have you just removed the outer halves of the hubs, leaving the inners still on the casing? I f that's the case, the bearings are no longer locating the shaft laterally, except by stiction. You may have no problem. Look carefully at what moves with the shaft when it moves. Maybe the shaft moves in and out of the bearing, or the bearing in and out of the inner part of the hub.