driveline questions

**dobbo** · 17th November 2006, 11:10 AM

Originally Posted by JDNSW

Even the biggest usual tyre size upgrade is only about 10% larger in radius than standard, so the increase in stress on the driveline from the larger tyres is only in the same proportion. Any increase in tyre grip increases the possible stress, and although this grip is independent of tyre diameter, those who increase tyre size usually seek to increase grip as well.

Failures are usually caused by impact loads, when the tyre is slipping and then grips suddenly, and larger tyres may increase the frequency of this because the higher unsprung weight makes it harder to keep the wheels in contact with the ground.

But probably the major reason for the association of larger tyres with driveline failures is simply that people who go for oversize tyres are often (usually?) the same people who drive in a manner likely to result in driveline failure.
John

The question is how can one tell if there driving style is endangering there drivline components or they are mechanically empathetic?

The things I have broken in the last 12months
Plastic bumpers, indicators and a bent draglink, the ABS sensors just go off due to mud ingress so they don't count

And that was all in the one trip!!!!

I haven't broken anything else and go bush regularly

So am I a sedate driver or a hoon hell bent on environmental destruction who has just been lucky?

**rangieman** · 17th November 2006, 11:12 AM

funny thing is i even did a rear diff on a flat straight road doing 60 kmh

mmmmm no drive go to engage cdl and the cdl actulator had failed at the same time

that was # 3 for the year the other diffs i would say the # 2 one was my fault thru diver error and too much right foot and # 1 i put down to fatigue old age on the diff part as the bloke that owned it befor me towed a caravan so with out pulling the diff out its condition was unknown to me

**rangieman** · 17th November 2006, 11:15 AM

dobbo if your car is a auto it will be a lot kinder on the driveline ect diffs

and of course a diesel doesnt have that puch as most petrols have

**JDNSW** · 17th November 2006, 11:46 AM

Originally Posted by rangieman

dobbo if your car is a auto it will be a lot kinder on the driveline ect diffs

and of course a diesel doesnt have that puch as most petrols have

This quite accurate statement about automatics gives a clue to the type of driving that does most to destroy drive lines - abrupt clutch engagement, either from standing or when changing gears without synchronising speeds.

Almost all other damage is caused by the drive wheels bouncing while under power, with similar results - this can be done with either automatics or manuals, and usually results from driving too fast for the roughness of the ground, taking into account the slope, load and effectiveness of the suspension at keeping the wheels on the ground. The excuse that "its the only way to get up the hill" begs the question as to whether you really need to go up the hill anyway, and whether that was the best route to choose.

Of course the other factor that contributes in a major way to drive train failure is load (simply because it enables a better grip by the tyres) - a good example being the habit in late Series 2a Landrovers of breaking rear halfshafts - but only in lwb Landrovers, as it is very difficult to put as much weight on the back wheels of the 88.

John

tombraider · 17th November 2006, 04:20 PM

Originally Posted by mns488

3 diffs in 1 year

. Is that driving style or V8 powers fault?

ROTFLMAO.... V8, p...p....p....p....power

Thats just funny

**Blknight.aus** · 17th November 2006, 04:30 PM

Diffs are funny things... the first diff I detonated in my disco died a week after some exceptional abuse which had been preceded by using the disco to push back an 8 ton trailer onto an LCM8 (trailer weight was probably 5 ton)

After abusing it up a nasty rocky slope, 1 low on the redline using the axle hop thing to get progess up steps, nothing.... reversed it out of a carpark and bang crunchie crunchie crunchie... no motion and Big pool of oil under the disco....

end results. 2 spider gears sitting on the ground with some shrapnel and a big rip in the casing.

bloody things still on those same axles and I know the bloke who bought it from me has been up that track twice.

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