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View Full Version : tall tyres bad idea on standard diffs?



macey918
13th July 2007, 01:39 PM
Hey guys,
I'm not worried about the ability to fit tall tyres to my Disco 1 200TDi (2" susp lift and about to be body lifted 2 1/2" with significant cutting and flaring already done:D)
But is it a bad idea to fit say 33's muddies, for daily drivers/ touring/ lighter off road use and 35's for serious play, on standard diffs, ratios and axles?
I'm not amazingly mechanically minded but i'm guessing there could be big time dramas with lack of torque/ accelaration and fuel economy on and off road as well as a high likelyhood of breaking stuff with 35's spinning then catching traction under the truck off road??
Any advice greatly recieved

Tusker
13th July 2007, 01:58 PM
Breakages are in direct proportion to the application of the right foot. Its only a matter of time on 35s. Even 33s.

It'll be a dog to drive. You'll go through clutches. It'll be illegal without the speedo corrected amongst other things.

Far better to throw in some 1.4s into the transfer case, or drop the cw&ps to say 4.11. That'll make it more drivable, but breakages are inevitable unless you upgrade cvs, axles & maybe diffs.

Regards
Max P

JDNSW
13th July 2007, 02:00 PM
Your effective gearing will be significantly higher, giving lower engine rpm in the same gears (but you can always use a lower gear) and also speedo error.

The loading on the drive train will also be significantly greater - whether this leads to breakages is very much a matter of how you drive, but most with this sort of increase in tyre size look at beefed up axles and diffs at least. If you have automatic transmission the probability of damage is much less.

You need also to check the legality of both the lift and increase in tyre size proposed - recently state authorities seem to be cracking down on this sort of thing, although I am not sure about Vic.

John

LandyAndy
14th July 2007, 07:11 PM
I have just fitted 32s to my manual TD5 Disco.
5th gear is now like a 6th,its too overgeared,now need to use 4th a lot more than before.Doesnt tow a big heap of firewood anywhere near as easy as before.
Andrew

justinc
14th July 2007, 07:28 PM
And just to add to what MaxP said, If you don't cane it you won't hurt it. I have standard 10 spline axles still with my RR, and have more torque than the 4.6 I took out, and now have 33's BUT I drive gently. I haven't broken any axle yet, EVER in any of my RR's.( And I do use it thanks!!!)

As a precaution I am fitting a Sals from a Defender and it already has Maxi axles. I am also fitting the Defender front diff internals and swivels as they are fine spline.

I may also fit twin tru tracks later down the line, $$$$ permitting.

Just drive gently and you will save a lot more than your diffs and axles.


JC

macey918
14th July 2007, 08:35 PM
thanks for the advice guys, I've been offered a loan of some 35 pedes to chuck on and see what it feels like so I'll probably do that before I commit to anything.

justinc
14th July 2007, 08:38 PM
Well, there will be no need for a stereo in your car then will there!
:p
JC

lokka
14th July 2007, 09:36 PM
Im runing 33's on std 10 spline axles and now have an ARB airlocker center fitted to the rear as i broke 2 rear centers with the 33's its the poxy diff center that will fail first the center pin shears and thats the end of it when i broke my last rear it locked the drive line half way upa steep enbankment and as i slid backdown i smashed teeth off the front crown wheel yep 2 diffs in one go i wasent happy ....

If you go to the bigger wheels and like to drive get some maxis or arb's or truetracs as they will be stronger than the cr@py rover center as for the axles i havent broke one yet and i dont pussy foot either its a learning curve i call it you learn by your mistakes or the pile of busted cr@p out side ya shed :D:D:D:D:D:D:D:D