Clutch slip or DMF problem?

On another forum a while back a chap was explaining that sometimes his engine raced whilst doing 60mph on a motorway (in a Fiat based motorhome
IRRC).
The clutched never slipped on hills and I think wheelspin is unlikely. The consensus on the forum seemed to be that it was a DMF problem but short of massive failure and complete uncoupling of the parts of the DMF, I've never understood how this could be possible.
Can this be anything other than clutch slip? 60mph on a motorway seems an odd time for it to reveal itself if it is though.
Tim
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On Fri, 12 Sep 2014 11:29:15 +0100, Tim+ wrote:

Not that I can see.

Plenty of torque versus serious aerodynamic drag.
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No it's not. Clutch slip is most likely when the engine is developing maximum torque. Which it might well need at a high speed in something like a motor home. If you use a low enough gear on a hill and keep the engine speed away from max torque it may not slip then.
Of course wheel spin is impossible.
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Ah yes. Obvious in hindsight.

Not quite. High sided vehicle and a strong crosswind could reduce traction enough.
Tim
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On 12/09/2014 13:26, Tim+ wrote:

Now that would need a seriously mad driver.
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On Fri, 12 Sep 2014 13:32:27 +0100, Mrcheerful wrote:

B'sides, I'd expect traction control if it's even vaguely recent.
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Nonsense. Unless on ice. In which case travelling at 60 mph would be stupid.
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Do you drive a motorhome?
Tim
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I know enough about them to be certain they won't spin their wheels at 60 mph other than on ice.
Do you drive at all?
There is likely no production vehicle which can spin its wheels in top gear. It would be stupid if it could.
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I'll take that as a "no" then.
I don't think wheelspin is at all likely BUT, it's not impossible. A FWD van with a full water tank behind the rear axle, a couple of bikes on the back, combined with a gusting crosswind *could* reduce front wheel traction momentarily.
Tim
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On Sat, 13 Sep 2014 08:10:19 +0100, Tim+

I don't think losing all grip on the front wheels whilst going that fast in a crosswind would lead to reports of the engine racing though.
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Well if you lost *all* grip, there's not a lot stopping the engine racing under load. That said, in the incident concerned, I'm sure it must have been clutch slip.
Tim
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"Tim+" wrote in message wrote:

You don't need to lose all grip on both wheels, you just need to reduce the load on one wheel to produce wheelspin. I'm not saying this is case here though, the driver would have known that it was seriously windy, and would know that that was the cause, especially as he would be struggling to keep it in a straight line. At least, unless he was seriously stupid.
Steve
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Have you ever driven a low powered heavy vehicle like a motor home on a motorway? It's possible that if you hit a pothole a wheel might loose traction for a fraction of a second - but to suggest that could be confused with wheel spin is, as I said before, bollocks.
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If you've got no grip on the front wheels of a motorhome travelling that fast then the engine racing will be very low down the list of things you'l be worried about.
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On Sat, 13 Sep 2014 08:10:19 +0100, Tim+ wrote:

The water tanks aren't behind the rear axle. That would be silly.
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FFS if your going to pretend to know something please do try harder.
Both my motorhomes have had water tanks behind the rear axle. It may be silly, but that's where it is.
Tim
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On Sat, 13 Sep 2014 08:01:35 +0000, Tim+ wrote:

But not on all, probably the majority.
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Who said all??
Tim
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So lets get things straight. You regularly get wheelspin in top gear on your motorhome? Because of poor weight distribution? Please give the make so we know never to buy such a crappy design.
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