Diff or halfshaft failure

Post by **Peetee** » Fri Jul 18, 2003 9:50 pm

Now I'm really confused

"A single clonk then no drive" is what my wife said.
Now the propshaft turns, the wheels don't and there is a faint rumbling noise.
Does that sound like halfshaft or diff failure?

Post by **Cam** » Fri Jul 18, 2003 10:01 pm

Halfshaft failure is a lot more common than a diff failure.

and that sounds like halfshaft failure.

Post by **Willie** » Sat Jul 19, 2003 7:07 pm

When my half shaft went it was just a simple clonk and that
was it. Try jacking both rear wheels off the ground and run
it in gear(chock the front wheels securely) if the diff is still
ok then one of the wheels will revolve. It doesn't
really matter though because you will have to remove the
half shafts anyway before you can remove the diff unit
and you will soon see if one is broken.

Post by **Peetee** » Sat Jul 19, 2003 9:14 pm

The passenger side half shaft has failed about 2/3 up the splies. Now I can't get that bit out and I will have to remove the diff.
Why the hell did they decide to use a 1/4 Witworth bolt for the propshaft????

It's a bit bigger than a 1/2" and a bit smaller than a 9/16".
And to make matters worse it doen't even match a metric spanner

Post by **Cam** » Sat Jul 19, 2003 11:26 pm

A 13mm is quite close, especially a worn one!! best to get some whitworth spanners and sockets if you can. If you are going to be working on British classics for some time then it's worth the investment.

1/2" is the smallest, then 13mm, then 1/4" Whitworth (if memory serves).

Post by **Willie** » Sun Jul 20, 2003 8:09 pm

You should visit a boot fair,they have loads of old size
spanners usually. Don't forget to buy a new diff unit to
axle gasket,sods law says it will tear if you don't(and
new half shaft gaskets while you are at it).

Post by **Willie** » Sun Jul 20, 2003 8:11 pm

I see it accepted 'sods law', though it might say 'I wear
silk stockings 'or something!

Post by **Cam** » Sun Jul 20, 2003 10:58 pm

You are saying you do what, Willie?

Post by **Peetee** » Sun Jul 20, 2003 11:07 pm

'I wear
silk stockings 'or something!

A standard moggie heater not good enough for you then - yer pansy?

Post by **Peetee** » Mon Jul 21, 2003 10:24 pm

Every thing is out now and although the halfshaft is well and truly B####ed the diff has survived. Now I'm just waiting for some new gaskets and a pair of toughened halfshafts.
"Nothing can stop me now...Nothing!"

BTW. I'm not suprised these half shafts fail. The splines appear to be rough cut. There are no radii to the spline edges and the failure has happened at a classic stress raiser - at the angle formed by the flat spline bottom and the 'ramp' of the spline taper

Post by **Gareth** » Tue Jul 22, 2003 9:27 am

It's a very common area of weakness on the Minor, along with the trunnions... A fair few people remember the adage that if a Minor is parked by the roadside with a wheel askew, the trunnions have failed. If the wheel's are all fine, then the halfshaft must've gone!

Post by **Willie** » Tue Jul 22, 2003 6:51 pm

Come on, the minimum age of the half shafts is thirty odd
years,and lord knows what mileage they have done. things
do wear out,even on a Minor!!

Post by **Peetee** » Tue Jul 22, 2003 8:04 pm

I see where you are coming from but my halfshaft wasn't worn, it failed. If you leave sharp angles on cast metal you run the risk of failure. Steel is flexible and, putting it simply, this flexibility is proportional to its guage. if there is an abrupt change in the guage then the metal flexes differently either side of that change and it runs the risk of failing.
I had a lightweight bike frame that did this. Even though the tube was well up to it's job it had a square gear boss brazed to it that created such a huge difference in the thickness of the tube at that point that it failed, creating a crack running away from the corner of the boss.

Post by **Kevin** » Wed Jul 23, 2003 12:46 pm

running away from the the boss

We all do that sometimes Pete

Post by **Peetee** » Wed Jul 23, 2003 1:52 pm

That would be a seriously bad idea - I'm married to her

Post by **Willie** » Wed Jul 23, 2003 8:56 pm

And you call ME a pansy!!

Post by **Peetee** » Thu Jul 24, 2003 9:08 am

Marriage is a MAN'S world.

Post by **Kevin** » Thu Jul 24, 2003 10:46 am

Pete did the broken bit come out easily or was it twisted and jammed in place as I have heard of it being a right so and so to remove at times.
And SORRY to disagree but my wife (she who must be obeyed) says that marriage is where men do as they are told at all times without exception, at least I dont have to call her the BOSS.

Post by **Peetee** » Thu Jul 24, 2003 6:22 pm

The bit did come out easily thank goodness. I removed the diff and tapped it out from the centre using a whopping big screwdriver.