Lotus Elan and Lotus Elan Plus 2 Forums

billwill wrote:Just had a thought. Is the construction such that if you take out the OTHER sub axle, can you poke a thin 1/4" rod right through the diff from the other side to tap the broken stub out if it is stiffly held?

The ones I have seen had a clean break so little chance of metal filings but I think you would have to look at them on an individual basis.I agree that it is unlikely the inner splines would be damaged and the output shafts are just a sliding fit.
The pin number 28 prevents passing a rod through from the other side, there is a slight gap but the rod would have to be flat and thin so I doubt it is an option.

I was thinking the same thing about using a drift through the center but looks like that's not happening. Of course I haven't gotten even one side out yet.

We'll be back at it sometime soon. Today is shot.

Thanks again for the company and advice. Looking more and more like we're going to take the unit out anyways for a good inspection and have an old pro look it over , and more than likely we'll be able to do whatever we need to with the unit out and on his workbench. This old fellow once wrenched for Peter Revson.

Please don't take anything the wrong way but the owner and I both have a hard time just yanking out an axle with twisted splines and believing there's not a bit of damage to its mated gear. We figure given the car's age it'd be wise to just replace as much as possible with seals and bearings - splitting it open - and complete inspection.

Yes depending on where the break is you may need to tap out the brocken spline section from the other side using a suitable rod.

Once you have the 2 bits you can put them together and see if any signficant bits still missing, generally it breaks cleanly and all you need do is drain and change the oil to remove any fine bits in the oil.

If the new shafts slide smoothly into the gear splines then the gear splines are ok which is normally the case.

cheers
Rohan

Slightly off topic here: yesterday I was at Donington Park where a Sunbeam Alpine broke a half-shaft and lost a wheel. I looked at the break and it was obvious that there had been a crack through around 2/3 of the shaft for some considerable time (it was black and oily). It was only driving on a slender "D" shape of good metal.

Almost all drive shaft failures including those in Elan diff output shafts are "fatigue failure" . These are caused by cyclic stresses in the shaft causing a crack starting from a small microspoic surface defect to slowly grow. Eventually the remaining good metal left is so small that you get a clean sudden break through the rest of the shaft and failure.

If you look closely at the oily two thirds you will see a ripple surface like ripples in a sand beach at a microsopic level it a smooth surface over the one third that had the final sudden failure.

cheers
Rohan

Broke half shaft

p-a

P-A

Now you can grind the end off,tap a suitable thread and use as an attachment for your slide-hammer.

John

john.p.clegg wrote:P-A

Now you can grind the end off,tap a suitable thread and use as an attachment for your slide-hammer.

John

He hasn't got one anymore.

You can use the shaft of an old damper to make one. and get a hefty chunk of lead pipe as the heavy slidy bit or cast your own by melting lead & pouring it into the space between two tin cans fitted inside each other (pop rivet or bolt together) of appropriate sizes. The inner one to be the 'hole' and the outer one the outer diameter of the 'hammer'. After casting cut off the bottom ends of the tins with a tin opener.

Well I would probably do that (your methods may vary) as I had lots of experience casting lead Scuba Diving weights back when I was a poor student. NB melt lead outdoors as the fumes are somewhat dangerous.

Lead pipe is not allowed under elf n safety rules, how dare you suggest such a thing?

Diff. is out ! My lack of patience was all that was wrong on the last prop. shaft nut/bolt. Marked the flanges - actually found they were already marked with better lighting.

Drained it out - surprised us both that there looked to be about a pint and a half from quick glance. No metal chips , filings , powder , etc....

Still haven't gotten those inner (stub) axles out yet. But now we can work with it and the owner is going for an entire seal and bearing job - bearings only if advised , I'm thinking. Everything spun really smooth on both sides and no play whatsoever so they can stay but given the age and not wanting to do repairs to the unit again I'm guessing they'll be swapped out anyways for the money.

Guinness just went out of season fo me so it's Harpoon IPA time. Looking forward to bringing this post back up in short time. For now the unit will be heading over to the old pro later in the week. Parts being ordered - axles ,etc ...

Hoping Chris the owner chimes in here with some pics ..... hint !

Paul, for removal, try a large magnet first. Failing that, it's back to the drift rod.

Greg z

Greg ,thanks but we haven't gotten much movement at all with penetrant and heat. A magnet was what I was thinking way back when before we broke open the toolbox. But I don't see that happening right now. We'll get them off now that its out. Didn't make any real effort on it once we removed the unit.

Man that thing is little !!! You guys had me scared about getting my little paws crushed or worse. That diff. is actually very managable to a Subaru guy. No jack needed , but I'm a little agressive sometimes. Gotta guess its right around 50-60 lbs. Funny how it looked much bigger in the car.

Don't forget - the "three legged monsters" are still inplace so I can't get that drift in through yet. Gotta sleep , check back soon. Cheers !!

Erm, don't forget that someone pointed out above that there is a whacking great big gear pin across the centre of the diff that prevents putting anything very substantial as a drift through from the other side.

~~##~

Talking of Diffs I was cleaning the muck off my spare one on Monday, preparing to photograph it to sell it.

I noticed that the play in the backlash on the output shafts is about 1 degree. Does anyone know if this is too much & hence that it definitely needs a major refurb inside. Personally I would expect that it could be used 'as-is' for road use for many miles yet; though It would not make sense to race it without careful inspection for cracks in the output shafts.


Is there any way from the outside of telling if it has been fitted with strengthened output shafts ? (Vegantune, Spalding, might have done that for me on a major refurb of the car back in 1983.)

I just popped down to my Garage to weigh it.

A Lotus Elan Diff complete with oil inside weighs approx 19 Kg. approx 42 pounds

The flange dia is approx 3 and 5 eighths inches.