Drive Shaft couplings

[Fanfaniracing]

Hi guys!

Have a mk1 Cooper S here wich has the rubber type couplings on the driveshafts/diffoutputs...

Two years ago someone changed to the Minispares plastic QH-Type couplings and now they've broken again.

I suspect that the mecanic who changed them just tighten the U-Bolts & Nuts to much so they broke.

On the side they don't broke they are more Oval than round...

Is this a common problem?

Till now i never saw one broken...

Best regards

[Supersonic]

I’ve seen the plastic drive couplings broken a number of times in competition Minis. For me the rule of thumb is any engine putting out more than 80 BHP it is Hardy Spicer couplings without a second thought.

Alan

[woodypup59]

Those U bolts are stupidly tight.

They should be tightened so that 1/16" of thread protrudes beyond the lock nut.

[mk1]

As above. An avoidable failure caused by not following the fitting instructions.

TAKEN FROM MINISPARES SITE:
The rubber coupling alternative made by Mini Spares has superior nylon cups with needle bearings. U bolts should be tightened to 8-10lbf.ft-do not over tighten.

[Fanfaniracing]

What i suspected was now confirmed by you guys!

Thanks for the help!

[roymck]

The first time these came on to the market I bought a pair straight away and they had a Steel adaptor cups instead of Nylon , never seen another pair since .
Too harsh or too expensive wouldn’t know but they were boxed Hardy Spicer .

[smithyrc30]

Not sure if it is an illusion carried by the picture but in the last picture with the complete coupling, the flange on the gearbox looks bent

[swindrum]

The first time these came on to the market I bought a pair straight away and they had a Steel adaptor cups instead of Nylon , never seen another pair since .
Too harsh or too expensive wouldn’t know but they were boxed Hardy Spicer .

I have part of a set of those in a box in the shed! Never seen another set either

[iain1967s]

Some discussion about the metal type here: viewtopic.php?f=3&t=21194

Available [at a price...] from Heritage Garage in the USA.
http://www.heritagegarage.com/parts_hg5 ... g_set.html

[gr4h4m]

I have tried both the rubber and plastic joints. The rubber seem much more reliable and study. They saw over 90bhp ATW.

[360gts]

The first time these came on to the market I bought a pair straight away and they had a Steel adaptor cups instead of Nylon , never seen another pair since .
Too harsh or too expensive wouldn’t know but they were boxed Hardy Spicer .

I have part of a set of those in a box in the shed! Never seen another set either

Interesting! I have a few sets of the steel versions here.....used them back in the day on my 1071 race car....were very reliable....
Glad I held onto them.....

[Fanfaniracing]

A8F4FB08-828B-4468-9650-25A5C887B928.jpeg

C5BC014D-17BF-4B2E-8E22-AFB405808E1F.jpeg

After some issues with the Carb and Corvid19 pause. I could go for a 10 km testdrive and after that i found this:

[Fanfaniracing]

This time the couplings where by sure not overtighted!
I tightened them with 10 lbf.ft as described on the Minispares site.

Any ideas?

9113B519-C0C8-4D39-AD02-74649384C2B7.jpeg

[roymck]

The ones on my car are white plastic , wonder if they have altered the plastic specification?

[dodge44]

Don't think it tells us anything we don't already know but stumbled across the original fitting instructions for QL5000 couplings (From 1991) earlier when looking for something else in a pile of paperwork....

[mnicoop63]

If it is the same side that broke again I would immediately guess that one of your yokes is bent. Depending on where you are at I have a box of parts from those. If you cover shipping I'll send you another cap. I also have some yokes if one of yours turns out to be bent.I am in California.

Brian

[Polarsilver]

Just a thought .. i am fortunate to have a 4 post lift & with the front of car jacked up i spun the wheels while looking upward & was very surprised to see one drive shaft was "Bent" this slight but actual bend along the length of the shaft was very apparent when the drive shaft was removed & changed. How it became bent i have no idea probably from past Rally Days .. suggest to just check your drive shafts>

[SMOKE GREY]

When I built the Orangebox to go rallying I used MiniSpares QL5000 but had trouble with them breaking up, went through two sets in very little time, unusual for their stuff is usually pretty good. I then used a set of original ' white ' QH ones and they did three years rallying with 1293cc with no issues at all.

A few years back I found a new set of steel QH QL5000 at Bingley Minifair and now have theses fitted, brilliant things.

[Fanfaniracing]

I allready checked the driveshafts on a late.

The coupling on the right side was bent and changed. Now the left side has gone, but the couplings and shafts are straight.

Hope its good now or i change to rubber couplings...

[dodge44]

Rather than buy MS repros don't forget you can refurb the old white QH couplings with new GU102 Triumph Stag UJ's - see:-

viewtopic.php?f=3&t=24206&p=207415&hili ... ag#p207415