Jump to content

Reproduction Herald Driveshafts


JumpingFrog
 Share

Recommended Posts

We had a reproduction drive shaft fail (8,000 miles old) 2 days ago on the Pamir Highway, Tajikistan. Bad roads (gravel, potholes, washboard, the lot) yet it failed on a relatively smooth tarmac section dodging a pothole. Skidded to a halt with nasty noises. Fitted a spare (1 of 2) with the car beached in the middle of the road about 70km from anywhere.

Failed at the yoke, roll pin snapped and splines popped out.

We had it repaired today in Osh, Kyrgyzstan (as a future spare), pin replaced with a tightish fitting bolt and welded into the yoke. We thought welding shaft to yoke would help strengthen it but the Kyrgyz mechanic insisted it would weaken the shaft.

Any ideas?

IMG_3634.JPG

IMG_20180810_115821.jpg

IMG_3693.JPG

Link to comment
Share on other sites

You've found the weak point (or one of them) on the repro shafts then...... Never seen an OE shaft fail like that, though I did once manage to dismantle one at that point after a lengthy and bloody battle.

Actually I agree with your Kyrgyz mechanic re the welding, assuming you meant welding around the exposed side? Though it is a bit of a case of what is the greater weakness!

I would be happy to weld around the inside, where the extreme end of the shaft sits inside the UJ trunnion, though you'll probably need to split the UJ to get access.

Was it really a roll pin that failed? Absolutely NOT fit for purpose in that application - it takes the cornering loads ffs! OE ones are solid and something tough.

Love the middle of the road fix pic........ presumably traffic was quite light?

May the force be with you!

Nick

Link to comment
Share on other sites

3 hours ago, Nick Jones said:

You've found the weak point (or one of them) on the repro shafts then...... Never seen an OE shaft fail like that, though I did once manage to dismantle one at that point after a lengthy and bloody battle.

Actually I agree with your Kyrgyz mechanic re the welding, assuming you meant welding around the exposed side? Though it is a bit of a case of what is the greater weakness!

I would be happy to weld around the inside, where the extreme end of the shaft sits inside the UJ trunnion, though you'll probably need to split the UJ to get access.

Was it really a roll pin that failed? Absolutely NOT fit for purpose in that application - it takes the cornering loads ffs! OE ones are solid and something tough.

Love the middle of the road fix pic........ presumably traffic was quite light?

May the force be with you!

Nick

Definitely a roll pin... Will think about splitting the UJ to get the internal welded if we break another. I assume welding the outside could make the driveshaft brittle?

OE shafts probably have an advantage in that they are well rusted together at this point in their life.

The mechanic definitely knew his stuff but only spoke Russian. He didn't charge for the repair either as it only took 10 minutes!

Quite light traffic in those parts, mostly Chinese lorries crawling along. Would've preferred to not be in the middle, but was a bit immovable once we skidded to a halt ;)

Link to comment
Share on other sites

27 minutes ago, JumpingFrog said:

Definitely a roll pin... Will think about splitting the UJ to get the internal welded if we break another. I assume welding the outside could make the driveshaft brittle?

OE shafts probably have an advantage in that they are well rusted together at this point in their life.

The mechanic definitely knew his stuff but only spoke Russian. He didn't charge for the repair either as it only took 10 minutes!

Quite light traffic in those parts, mostly Chinese lorries crawling along. Would've preferred to not be in the middle, but was a bit immovable once we skidded to a halt ;)

Roll pin....... Jeez.......! Do the people selling these realise what they are selling?  Would be less of a hazard if the splines were properly tight (that's 20 ton press tight) but I can see from the polish on yours that it had been fretting for a while.

Yes, the welding worry would be creating a brittle zone and possibly a stress-raiser at the weld edge.  However, given the roll pin and sloppy splines I think the weld is probably the safer option - though you are already better off by using a cut down bolt!

See what you mean about repairing where it came to rest...... 

Just seen your river crossing vid....... bit of a sudden stop on the first attempt!  Sump guard earning it's keep!

Make sure you charge Pete enough for the film rights ?

Nick

Link to comment
Share on other sites

Worrying, as I need a new halfshaft for the GT6 following last Saturday's mishap... and the roads round where I live are much worse than that...

Please don't tell me, as with many other parts, that they all come from one supplier....

Oh - and yes, welding the shaft will weaken it, so the mechanic is spot on.

Link to comment
Share on other sites

Doubt there is more than one manufacturing source. Not a massive market. I suppose that at price of around £75 and low production volumes it's unsurprising there are quality issues. However, they do need to be good enough not to try to kill you after less than 10,000 miles ( and heard of issues occurring well below that)

Nick

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...