regearing a colorado for bigger tyres - whats involved ?

[roy]

hi there,

regearing a colorado for bigger tyres - whats involved ?

i am trying to understand what is involved with regearing for bigger tyres , i have tried looking over the net but i am still confused.

is it changing a gear in the transfer box or in the axles ?

can anyone shed some light on it ?

what are the costs involoved ?

i may well not put bigger tyres on but would like to know more about this subject.

cheers roy

 

[Chris]

The only comment that I can make is that you are unlikely to get big enough tyres on to need to re-gear.

But that doesn't answer your question. Re-gearing the T box would be neat but would also probably be a first in history.

Diffs wouldn't be that hard it would be finding the parts that would be the challenge. The auto and manual are different ratios which means going one way might be possible.


Chris

 

[Beau]

From what I have heard you can run up to 33" With out too many mods needed. I think in most cases you will need a small body lift and a bit of body grinding, and to remove the mud flap.

Anything more than 33" will need an actual suspension lift, a good body lift, body and mud flap removal. You will get away with driving it, but it will be under geared and underpowered off the line.

What sort of "bigger tyres" were you looking at?

 

[Chris]

Well close, but not quite accurate. It depends also on which profile you go for to get 33" in the first place. After that fitting bigger tyres is really more that a suspension lift, which you'd probably do for a 33" tyre anyway. Once you lift the suspension more than a couple of inches you run into all sorts of problems with the wishbones, drive shaft angles diff angle etc. Frankly, it really isn't worth it. The 90 drives fine on 33" and certainly doesn't suffer much from gearing issues. But it's lot of work and money for little gain other than an enormous sense of satisfaction.

The 90 series is a great car, but in terms of 'normal' range mods, there isn't a great deal that you can do. I have seen a front live axle conversion, now that was a thing. There does seem to be a odd variance from car to car and it perhaps depends on the state of the wishbone bushes. Sometimes fitting 33" is a doddle and other times they can be a bugger to stop from catching.

Chris

 

[Jon Wildsmith]

you don't usually start considering a re-gear until you get to 35's or bigger.

 

[roy]

the truck has a suspension lift with ome, and a body lift and is running 33" bfg at.

the idea i had was , i was going to make some factory style arches but make them wider and larger in the areas where a larger tyres would rub.

i like the look of the truck with a wider stance and larger wheels and tyres.

i am not looking to build a monster truck but something more like the trucks that artic trucks produce, like this one
http://www.arctictrucks.com/Pages/1324

this is why i was enquiriing about regearing,

it does mention on their site that to run tyres around 38 you need 4:88/1 gear ratio,
so this would be new differentials at the revised ratio ?
if so where can you purchase such differentials ?

there is no great need to do this , i am just into modifying my cars.

 

[Jon Wildsmith]

See if www.justdifferentials.com have gears for a colorado, that's where we get them from for 80's and 100's.

 

[Graham]

When Artic Trucks modded them 120's and the Hi Lux, I am sure they ended up moving the 2 axles from the original positions by a few inches.

What I do find interesting is they said they fit 15 x 12,5 inch wheels.
How on earth do they get the 15 inch over the front calipers.
I guess the brake disc itself is not far off 15 inch even without the brake assemblies themselves.

Gra.

 

[fridayman]

There is a chap on PP (GlenEP95, or something like that...) that has re-geared his diff I think. Might be worth contacting him.

 

[roy]

on PP ????

what is this

 

[AndyCook]

prado point
http://www.pradopoint.com/

our ozi friends

 

[glen_ep]

The core change is to swap out the crown and pinion gears in both front/rear diffs. They must both be done at the same time.

When mine were changed from 4.3 to 4.88, I also had new bearings installed, seals, solid pinion spacers and ARB lockers. I sourced the lockers locally, and everything else from USA. I removed the diffs myself, and had a local diff specialist perform the gear installation. It's essential that a professional install the gears in order to get the pinion pre-load correct. The new gears are quite cheap but when you add up everything including labour, it's an expensive upgrade.

These are the gears I used:

4.88 front 7.5" reverse cut clamshell diff:
http://www.justdifferentials.com/index. ... ts_id=3502

4.88 rear 8" v6 standard diff:
http://www.justdifferentials.com/index. ... ts_id=3496

Some more info on my build up thread:
http://www.pradopoint.com/showthread.ph ... post310591

 

[glen_ep]

A couple prior responses have indicated that regearing isn't necessary for 33's, only for 35's and upwards. I disagree, BUT, it does depend on what kind of driving you intend on doing.

I tend to favour steep and rocky trails, and I run dual lockers, so the torque advantage of the gearing helps to crawl through the challenging terrain. It also helps significantly on highways with a heavy load, especially with the automatic transmission. I frequently travel 3-6 hours to reach a camping destination here in Aus, so having the power on the highway becomes quite important.

On the other hand, many others tend to just play in mud, and that doesn't require much torque, so it wouldn't be worth it in that case, IMO.

 

[Chris]

Interesting post. I don't think that we have seen a 95 series re gear on here before. In the UK all Colorados (that's a Prado to you guys) come with rear and centre diff locks from the factory. Some of us have fitted front ARB lockers too. But a re gear would be about as much money here as simply swapping the car for an 80 series! They all have triple lockers here. I think that you'll find the comments about 35" tyres being ok on std diffs relates to the 80 series. I don't think we have anyone on here who's managed to squeeze 35" under their arches yet on a Collie.

I'd like to see that.

Chris

 

[roy]

Thanks glen_ep thats all the info i was looking for ,

cheers roy

 

[glen_ep]

libraboy on PP has Simex 35's on his (which would be like 36's), but there's some rubbing issues ATM...
http://www.pradopoint.com/showthread.ph ... -evolution

We've also found a few other massive Colorado/Prado's around the web, check all pages of this thread...
http://www.pradopoint.com/showthread.ph ... ter-Prado/

 

[roy]

some of the trucks on those links are sweet , just gives me more encouragement to go mad with mine.

 

[Chris]

Good Lord, that's a UK vehicle. Be interesting to know a bit more.

Looks like quite a big BL on there which is fun but doesn't add ground clearance. But if it allows for much bigger rubber then it's worth doing. I have seen a front solid axle conversion but at that point you really might as well go with an 80 unless you have enough money to indulge your engineering fantasies.

IFS has it's limitations in terms of mods.
The emergency vehicle look nice. I like that one.

Chris

 

[Beau]

Those 90 series look like monsters with 35's! Very cooool!