I’m sure anything is possible with enough money and bravery, would imagine you’d have a lot of cutting to do. As a matter of interest why do you need them?
 
I’d check it’s possible before ordering them, will affect your gearing significantly too.
 
I have a 96 300TDI, when i bought it she had 35"x12.50x15 fited with 2" suspension lift and 2" body lift.
looked rely smart, down side gearing too high it was an effort to get her in to 5th gearwithout using high reves
bad mpg, and needed a step ladder to get in.
I come up to Scotland for Christmas from North Wales so i put the wheels off my S3 on 245x16 what a difference
it made, they are staying on for now.
 
Tbh They Look So F***king Cool ! will post up a pic when they arrive :D
If your planned change is just for cosmetics, why would you screw up the handling and driveability of an already quite capable on and off-road vehicle? Or is your local supermarket car park really that bad?
 
Hi is it possible to fit the 40" tyre to a land rover discovery 2 td5 ?

Not without loads of work and money .. and unlikely there's any guides to doing so.

Ultimately pointless though unless you're planning racing off-road, Ultra 4 or winch challenges etc ...
 
Not without loads of work and money .. and unlikely there's any guides to doing so.

Ultimately pointless though unless you're planning racing off-road, Ultra 4 or winch challenges etc ... or driving to some chopped up supermarket car park in Portugal
Edited.
 
Well i live in portugal we have some huge rock ect and cool trails i can take it on witch will be perfect for the large tyre my only worry is the gearing as not sure where to start with this ?
 
Not sure why exactly, but if it floats your boat to go extreme then you'll want to drop your diff ratios to 4.7HD ring and pinion, maybe look at a 1.66 ratio transfer box too as means of dropping the gearing, I checked it over on the Ashcroft transmissions ratio calculator and can say that 40 inch tyres on standard gearing will see 100kph @1400rpm in 5th gear is really not realistic.

I will try and get a screen shot up of what it will be and where you ideally want it to be.
 
This is the 40s with standard gearing
 

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It isn't just gearing, it's the whole drive train. 40" Treps will screw the stock diffs etc very quickly, especially if you give them a little welly to get over stuff!

The Ultra4 guys use them with high power engines, but none of them run standard drive trains, even if it's only diffs and half-shafts .. but increasingly it's not .. it's completely different axles/suspension/gearboxes etc etc.
 
These are your 40s with a 1.667 transfer box and 4.75 HD ashcroft ring and pinions, probably the best gearing that will be as close to standard as you'll get.
 

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It isn't just gearing, it's the whole drive train. 40" Treps will screw the stock diffs etc very quickly, especially if you give them a little welly to get over stuff!

The Ultra4 guys use them with high power engines, but none of them run standard drive trains, even if it's only diffs and half-shafts .. but increasingly it's not .. it's completely different axles/suspension/gearboxes etc etc.
I wouldn't bother going over 33 inch, maybe 35 at a push if they were really cheap TBH, even then I would be looking to upgrade to locking diffs, HD 4.37 ring and pinions, most likely pegged diffs too with HD shafts & stock drive flanges (I like the idea of a cheap throw away fusible link that saves the gear boxes).

Suspension and bodywork becomes your next compromise, if you want super flexy trick suspension, you have to then think about the wheel arches and wings, turning radius becomes the next issue here and will need ultra offset rims which then has knock on effects with swivel pins & bushes (actually ball joints on a D2) and wheel bearing longevity. I had actually thought about having spacer tubes machined up that could space the swivel balls 4 inches further out and coupled with the "cut to length" full length splined drive shafts it could be a winner, but would be better to have the axle tubes extended and re-flanged, might be better than relying on wheel spacers at the hub end?

Anyways, fitting earth moving tyres are one thing and keeping it a road legal daily driver is something else.
 
Pretty good points there. Mate fitted 35s on a Defender had has been thru 4 diffs I think because of the big tyres

My 110 has 33"s even thats blown a front and damaged a rear because of tyre size. Really anything above 33"s or 285/75 you need pegged diffs at the very least.
 
Comparing stock rover 3.54 ring and pinions to Ashcroft or KAM HD ones is a night and day thing, ratio change with HD+pegged with HD center or better still an AshLocker is the way to go but it starts getting uber expensive when you start going down that road.

I quickly priced a built up diff from Ashcroft

Rebuilt diff
+AshLocker
+Pegged
+HD 4.37 R&P
= £1,085 X2 (front and rear matched) = £2,170
Then we have to look at half shafts and CV joints as they will be the next in line to explode.
CV joints £435
Half shafts £245 fronts £260 rears £505 for all 4.
Drive flanges £90/pair £180 for all 4.

TOTAL £3190

That's hardly chump change is it.
 

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