Ah well...

Ultimately, a good day - the RAC took 2.5hrs to arrive (mostly due to inaccurate instructions to the driver), but sent a recovery truck first off so there was no mucking about with 'I can't fix that mate, I'll have to call recovery' which meant we were back home by 12.30.  Into the Mustang, off up to Stamford to join the field for lunch, pick up our paperwork etc. and do the afternoon sections.  Nice and sunny and home by 5.

Just left with a very disgraced Cobra sitting in the garage, having been told to think very carefully about what it has just done.

Hi Roger,

Glad to hear it all turned out well in the end and the RAC did not do the usual shenanigans with the middle man episode.

Can't help but feel that photo really does lend itself to a caption competition, "What is Morag thinking..." 

Oh dear Roger, I’m sorry to hear about your woes.

It will be interesting to see what the issue is with the diff. Given that most Kirkham diffs go into much more powerful 427 Cobras, I’m rather surprised that your 289 has managed to eat one.

Paul

Oh Roger; bless you - I feel your pain.

It can happen to even the best prepared car.

I sincerely hope that the rest of your day passed without incident.

Bloody old (and not so old) cars...

Lee

Thanks for your kind thoughts, chaps.  The genuinely old car was fine - it always is, touch wood - that Mustang owes us absolutely nothing.  It's the new bits that fail!

Who knows?  I need to look at it, but I have a (much cheaper) plan B.  However, I also need to replace the Land Rover's rear brakes and finish fabricating new door hinge frame panels for the Jag and heaven knows what else.  The Cobra might end up sitting there until spring!

Posted by: @webmaster

Hi Roger,

Glad to hear it all turned out well in the end and the RAC did not do the usual shenanigans with the middle man episode.

Can't help but feel that photo really does lend itself to a caption competition, "What is Morag thinking..." 

 

She's reading a book, Dave.  She knows better than to come out on a car trip without a book.

I have photos of her sitting in cars reading books all over Europe.  She does get a bit annoyed when I turf her out because I need to jack it up, though.

...or playing Candy Crush. 😉

Sorted, hopefully...

I think the problem is the NS hub bearings.  Again.  The retaining bolt for the driveshaft flange on the inside of the stub axle has backed off half a turn, allowing the bearing inner races to turn on the stub axle.  I'm pretty sure this is what the noise was, not the diff.

Had good support from David Kirkham who did not hesitate to offer a warrantied repair even after 3 years which I think is pretty good.  Apparently the lateral movement is normal in this design, although shouldn't be excessive.  Back together now and road test is favourable, so far.  You're right Paul, diff is not eaten.

This sounds like a problem I had, it's always the same side!!! I think it something to do with left hand thread on right hand side of the car etc. etc. Do you not have the tab washers for the big bolt? I found that was the only thing that stopped mine coming undone. AC mk4's are torqued to 210 ft lb torque!!!!!!

@289-baz

Yes, Barry - the correct thickness ones are Jag parts.  The problem I was having was primarily with the locktab washer.  I bend the two 'ears' carefully with a little positive angle on them to allow for movement when tightening the bolt.  I use a long breaker bar to tighten the bolt, but if I really go for it the bolt head picks up the washer and pulls it round with it, bending the ears the other way and sometimes out of the locating holes.

This time I very carefully smoothed and polished the fit surface of the nut (there's a land to keep the washer clear of the hex points to help avoid this problem), and the washer itself, and used a very fine smear of grease on the contact surfaces.  Then Red Loctite on the threads and do up the bolt.  This time I got pretty much as far as I could go with a 2' breaker bar, which I'd estimate at somewhere north of 150/160ftlbs, then locked off.  That's a lot more than it had before, and the lockwasher has barely moved.  AC never published any torque figures for the leafspring car, which will be different from the Mk4 anyway, but hopefully this should be OK.

It's all in the preparation, just like decorating the bathroom.  The XJ40 rear drive shaft nut is the highest I've had to tighten - strictly single-use only (it's a pre-helicoiled nut), and it must be at 228ftlbs torque, or your wheel will come loose and only be held on by the brake caliper.  This happens primarily on Italian autostrada, just north of Rome, the day after encountering some very aggressive rumble strip under heavy braking on the Autodromo dell'Umbria .  Ask me how I know.  So, those of you with the XJ40 outboard disc conversion should avoid this bit of motorway at all costs.*

Omnino accersita!

*or buy a big torque wrench. 

That really is belt and braces, Mk4's only go that tight because they don't have the tab washer.

@289-baz

I hope so!  I don't want to go any higher on the torque figure as I don't know the limits of the fastener material or thread configuration, and a stripped thread would be a bit... annoying.

I torque mine to 140 ft lb, for the same reasons. If you need it I have a big torque wrench, up to 220 ft lb you could borrow.

@289-baz

Thanks for the very kind offer Baz, but my biggest Techwrench goes up to 250.  I didn't use it because I don't have a figure to work to.