Aggressive muds & weak diffs?

Trying to do a bit of reading and research but getting a bit confused, hopefully some of you wise old chaps can help.

I'm looking at some aggressive muds like Fedima Sirroco, Insa Turbo etc basically the Simex pattern. I see loads of these about on D1s, Defenders and RRC but as soon as you mention these in the same breath as a D2 the story seems to be that the diffs and shafts will turn to cheese pretty quickly.

So, do the D1 and Fender guys all have uprated drivetrains? Or are the D2s just weaker out of the box? if so what's the difference? or are people just more paranoid with D2s?

What's the cheapest way of strenghtening the diffs if it is needed?

I run 285/75 hankook muds at the moment so would like to stick to the same size if possible, which I appreciate is a factor in determining how long I'd last without blowing something

Orch said:

Trying to do a bit of reading and research but getting a bit confused, hopefully some of you wise old chaps can help.

I'm looking at some aggressive muds like Fedima Sirroco, Insa Turbo etc basically the Simex pattern. I see loads of these about on D1s, Defenders and RRC but as soon as you mention these in the same breath as a D2 the story seems to be that the diffs and shafts will turn to cheese pretty quickly.

So, do the D1 and Fender guys all have uprated drivetrains? Or are the D2s just weaker out of the box? if so what's the difference? or are people just more paranoid with D2s?

What's the cheapest way of strenghtening the diffs if it is needed?

I run 285/75 hankook muds at the moment so would like to stick to the same size if possible, which I appreciate is a factor in determining how long I'd last without blowing something

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There is no significant difference in durability bewteen D1 and D2 drivetrains. There is a difference in engine power however - manual gearbox D1 TDi 300 engine is 111bhp as std, whereas the TD5 engine is 138bhp.

Bear in mind both drivetrains support the more powerful v8 3.9 and 4.0 petrol engines as well.

So, bearing the above in mind, what should you do? Irrespective of which version you have, never, ever try to force the vehicle under any circumstances. Always plan ahead so that you can drive smoothly and sympathetically to ensure a reliable life of the vehicle.

If you want to drive like a cnut, then get ready to spend irrespective of it being a D1 or D2. I personally have never broken a transmission component even after being - for a living - an off-road guide for several years.

If you are running larger diameter tyres, have you considered changing the Discovery 1:1.2 transfer box for a Defender one? Either 1:1.4 or even 1:1.6? It won't change low ratio but will help when in high.


Dave

thebiglad said:

There is no significant difference in durability bewteen D1 and D2 drivetrains. There is a difference in engine power however - manual gearbox D1 TDi 300 engine is 111bhp as std, whereas the TD5 engine is 138bhp.

Bear in mind both drivetrains support the more powerful v8 3.9 and 4.0 petrol engines as well.

So, bearing the above in mind, what should you do? Irrespective of which version you have, never, ever try to force the vehicle under any circumstances. Always plan ahead so that you can drive smoothly and sympathetically to ensure a reliable life of the vehicle.

If you want to drive like a cnut, then get ready to spend irrespective of it being a D1 or D2. I personally have never broken a transmission component even after being - for a living - an off-road guide for several years.

If you are running larger diameter tyres, have you considered changing the Discovery 1:1.2 transfer box for a Defender one? Either 1:1.4 or even 1:1.6? It won't change low ratio but will help when in high.


Dave

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I whole heartedly agree with the comment about driving like a cnut, the only times I have popped a diff or shaft I was doing just that, the insa special tracks are super aggressive and since I have had mine on I've done 3 standard open diffs one detroit locker and numerous shafts, drive it hard and it will cost you but be careful and think ahead and it might cost you a bit less. All my recent breakages have been on a D1 300tdi. Aggressive tyres and an aggressive right foot do not go together well.

Great info Dave thank you.

I do consider myself to be pretty mechanically sympathetic when offroading, I like the old moto 'as fast as needed, as slow as possible' (or however that goes).

I guess that's an advantage the D2 has because traction control means you don't need the speed to avoid cross axle. It also means then a wheel does hit the ground spinning it's be braked and spinning slower, meaning less of a shock load?

Have thought about the defender transfer box but to be honest it drives fine on the 285s I have now, even being an auto. Ok it would be better being back to standard gearing but it's easy to live with.

I wonder whether being an auto actually helps too? As a manual has direct drive so all the torque is being transferred, whereas an auto is losing some in the transmission? just thinking out loud really and probably wrong lol

Orch said:

Great info Dave thank you.

I do consider myself to be pretty mechanically sympathetic when offroading, I like the old moto 'as fast as needed, as slow as possible' (or however that goes).

I guess that's an advantage the D2 has because traction control means you don't need the speed to avoid cross axle. It also means then a wheel does hit the ground spinning it's be braked and spinning slower, meaning less of a shock load?

Have thought about the defender transfer box but to be honest it drives fine on the 285s I have now, even being an auto. Ok it would be better being back to standard gearing but it's easy to live with.

I wonder whether being an auto actually helps too? As a manual has direct drive so all the torque is being transferred, whereas an auto is losing some in the transmission? just thinking out loud really and probably wrong lol

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You're right on both counts:

1. With all D2's having TC this does help a lot in controlling hyper-active wheel rotation and reduces shocks;

2. With the autobox having it's Torque Converter this also soften shocks on the transmission.

While I was off-road guiding I used a TD5 manual with TC and CDL and I found that to be an excellent bit of kit. Ran on 265/75/16 Kumho's at first but found them to be rubbish in mud, so swapped for BFG Mud Terrains and they were just excellent in all respects.

Dave

Interesting stuff. I'm tempted to throw them on and see what happens.

DiscoPol what size special tracks do you run?

Orch said:

Interesting stuff. I'm tempted to throw them on and see what happens.

DiscoPol what size special tracks do you run?

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235/85/16 I wood like to run bigger but I already scratch the paint on my roof every time I stick it in the garage so I'm staying with these for now. I think it's as much to do with the engine power and the right foot as the tyres, I'm decatted egr blanked pump tweaked and straight through exhaust so power delivery is about as immediate as you can get with a tdi match that with very clay heavy mud and a heavy right foot and it is always going to be heavy going for the transmission. Mine is purely a toy and I enjoy fixing it so I think I sometimes am just looking for an excuse to break it.

Thanks mate.

yeh mine has just been promoted to full time toy, wouldn't have been considering it otherwise. If a do blow something it can sit there until it gets fixed. On the other hand I would still rather it didn't!

To add to the positive comments; i've been running 235/85 x16 Special Tracks for 3 yrs on our td5 D2 with only 1 front drive shaft failure. Don't think thats too bad for a vehicle eith more than 180,000 miles & more than 30 RTV off-road events.
As said, it's all about how smooth or ham fisted you are with the throttle.

Pawl said:

To add to the positive comments; i've been running 235/85 x16 Special Tracks for 3 yrs on our td5 D2 with only 1 front drive shaft failure. Don't think thats too bad for a vehicle eith more than 180,000 miles & more than 30 RTV off-road events.
As said, it's all about how smooth or ham fisted you are with the throttle.

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I am Ham footed

Pawl said:

To add to the positive comments; i've been running 235/85 x16 Special Tracks for 3 yrs on our td5 D2 with only 1 front drive shaft failure. Don't think thats too bad for a vehicle eith more than 180,000 miles & more than 30 RTV off-road events.
As said, it's all about how smooth or ham fisted you are with the throttle.

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Good to know Paul thanks. My confidence is growing!

DiscoPol said:

I am Ham footed

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Is that why you made a pigs ear of it?