Can anyone advise me ?I’ve Lost drive to back wheels without any warning

[Gibbbo]

Hi al sorry for the delay on information on the car.Today after sourcing a mechanic to remove the engine and gearbox out of the car,the trouble has been diagnosed.

The input shaft has sheared off, its a ford type 9 gearbox fitted to a 1.6 Sigma 2009 roadsport. Apparently the main shaft is cut and a the end that goes into the clutch has a new splined end that fits the ford sigma is welded to the remaining shaft. I was informed by a gearbox specialist that is what Quaife do.When the mechanic split the gearbox from the engine he told his boss that he thought it was made for two different parts, which is unbelievable,they both agreed when they got together to examine it further,they said it was the worst of the worst engineering they'd ever seen.This was also affirmed by my friend who was chief mechanic for Bentley when they won the 24 hours Le Mans and that ort to add credibility to the findings.Have anyone else had this issue?

Regards Graham 

 

 

[Jonathan Kay]

Thanks for adding the answer.

I don't think that I've heard of that failure before. I'll check the archives.

What's the car's history?

Jonathan

[John Vine]

Blimey O'Reilly! I've never come across that failure before in a 7.   How long have you had the car? Is there any warranty? What's the provenance of the car?

The plus is that your clutch is likely to be ok and you won't have scored the flywheel.

JV

[Gridgway]

That's interesting (astonishing)!  What gearbox is it?  It makes no sense to cut the splines off the input shaft (if that's the right descritption) to weld different ones on presumably to suit the clutch.  You couldn't do it with the input shaft in the box, so the box would have to be apart.  Then for it to break sounds like bodgery of the highest order!

But then I might be wrong and it be completely normal practice!

[Jonathan Kay]

I can't find a similar story in the archives.

Jonathan

[Wrightpayne]

I've never heard of cut/shut inputs shafts only shortening at the end to suit particular engines

Any pictures of the weld / breakage?

 

Ian

[Guy Lowe]

I don't have much knowledge of Sigma installations but I can't see CC doing this sort of thing, easier to source an alternative center plate. But I have been known to be wrong in the past  

[ECR]

Difficult to believe that Quaiffe (who are after all gear manufacturers) would do this ....

[Nick Chan]

I'm sure that the input shaft on the Sigma engine is different to the K Series one but usually it means a change of the actual input shaft itself. I wonder if this "modification" is because a replacement box has been fitted and then found the input shaft is incompatible for the current engine

[John Vine]

#27:   When the mechanic split the gearbox from the engine he told his boss that he thought it was made for two different parts..

I don't really understand what that means.  Can you elaborate?  Also, can you post some photos of the failed part?

JV

[SteWi]

The gearbox supplied for my Sigma Supersport was the standard version rather than the close ratio version I was expecting.  When I complained I was told that all the close ratio gearboxes had been fitted with input shafts suitable for a Duratec.  I suggested that they convert on back to being suitable for the Sigma which they did.  No sign, from what I remember, that it was not a single piece.

[ECR]

So Caterham supplied the box with this mod?

 

[Gibbbo]

saw from two separate parts pined,welded and sheared.

just as I said absolutely rubbish.

[Gibbbo]

picture to show you as requested. 

[John Vine]

That looks horrible.  Thanks for posting.

Re #29: 

What's the background and provenance of the car? 

Did you buy it from the trade or a private seller? 

Is there any warranty?

JV

[Gridgway]

How strange, I wasn't expecting to see a machined fitting

[Gibbbo]

Your not the only one who is mystified by this bodge up.

Thanks for the interestt 

Gibbo

[Nigel Blandin]

So, Gibbo; we are all a bit bemused by this I think it is fair to say.

Do you know the history of the box, or indeed the car before you had it? To join and machine an input shaft just seems daft- they aren't exactly difficult to find after all.

It can't be a Caterham job, surely...

[Guy Lowe]

This is amazing, I have never known anything like it, the suspense is killing me. 

[ScottR400D]

To be honest that looks like a friction weld and I wouldn't be surprised if it's not a more widespread process that we might think. 

I'm not sure why anyone would opt for that method but I very much doubt it's a one off. It might be to achieve different properties in different parts of the shaft. It's certainly used quite a bit with driveshafts. 

"OEM customers face daily challenges of material pricing vs. product performance, causing pump shaft manufacturing to become more expensive as raw material cost increases occur.

To reduce manufacturing costs, many customers have started using friction welding as an efficient option for production cost reduction.

Friction welded shafts are produced when multiple parts are pressed together through a precise rotating movement. This high speed movement creates friction that results in elevated temperature levels. The heat enables both parts to achieve a plastic like state that forges the parts together into a permanent connection.

The actual friction welded shafts require very unique technology that incorporates state of the art monitoring controls. This process is used on specific applications only.

Advantages of Friction Welded shaft manufacturing

– Friction welding allows OEMs the ability to use composite pieces rather than one piece shafts
– Versatility for customers can select the best materials for an application without concern on raw material or solid bar stock costs.
– Up to a 66% cost reduction versus traditional shaft manufacturing".

[Gridgway]

Having seen quite a lot of friction welding on youtube (it thinks I like watching it and it may be right!), that thought crossed my mind, seeing the machined shape at the end.

[ScottR400D]

On further thought I think that's just a dodgy friction weld. Looks like it's only actually welded on the outer circumference rather than across the piece. 

[jody391]

It's not a friction weld, the penetration would show all over and you no longer would see the very obvious machined male/female nub.

I would guess mig welded then machined off.

very poorly done for sure.

[7 wonders of the world]

Depends if the faces were machined correctly before they were presented for friction welding... if they were not parallel you would only achieve a partial weld as seems to have occurred in this instance.

[Tony P]

More generally:
I’ve seen friction welding in connection with an Engineering business I did some design work for. It was a rather specialized and precisely controlled procedure - but that was making propshafts for huge marine engines and the hydraulic shafts on earth-moving and mining equipment.
It never occurred to me that it would be practical (or economically viable) to use (successfully) down at the scale of making a few gearboxes for fairly obscure sportscars. And maybe it isn’t? Or is this now a widely used process?