Crown wheel and Pinion swap

[Mark Smith Junior Member Find all posts View Profile Close Mark Smith]

Ok, the diff swap is done along with a general service. The diff swap went remarkably smoothly with the only minor hiccup being that the flange that attaches to the prop shaft on the new front diff was a different sise to the one on my diff. Fortunately they swapped the flanges and all was well.

I now have the only 90 series TD in the country running 4.3 to 1 ratio diffs ( as far as I know anyway :wink: )

Drove home with the little wheels on and the gearing is noticably lower with around 70kph registering on the speedo to keep up with traffic in a 60 zone. A 9% undergearing as predicted and ready for the big tyres to be fitted tomorrow which will send the gearing 8% the other way :lol:

The diffs feel really smooth and solid and the shudder and vibrations from my stuffed LSD have gone as has quite a bit of driveline backlash.

I'll post again after the tyres are fitted.

[raydes Advanced Member Find all posts View Profile Close raydes]

Mark you may also want to upgrade the brakes as well . I used to have a 90 series and fitted some bigger tyres The car was harder to stop , I noticed this within 50metres at the first corner . I fitted some Bendix 4WD pads made a big difference.

[Mark Smith Junior Member Find all posts View Profile Close Mark Smith]

Hi Raydes

Good idea. The current brake pads are pretty new so I'll see how things go for a while maybe. Did you give my parts man a call? I asked him about those springs when I picked up the diffs and he does have a set :wink:

Cheers

Mark

[Rainman Advanced Member Find all posts View Profile Close Rainman]

What was the damage for the swap Mark if you dont mind me asking? I know it was included in a general service, but I'm interested in how much the whole exercise ended up costing.

Its probably out of my price range (SWMBO has had enough of me spending on upgrades), but I can always dream.

How do you explain the benefits of swapping diff ratios as opposed to saving for a new lounge suite?

[marc1 Lurker Find all posts View Profile Close marc1]

Hi Mark.

My diff ratio is 4.1 at present. Diesel engine.
Not interested in changing tyres but achieving more pulling power to tow.
Do you think that from 4.1 up to 4.3 would make a difference without change of tyres or should I go 4.5?

[Mark Smith Junior Member Find all posts View Profile Close Mark Smith]

Rainman

The diffs were $500 each and the labour about 500 to swap them over. Included oils for the diffs, etc. Not a cheap exersise but I now have the big tyres on and the gearing feels perfect. Doing a long run this weekend so will report back. Gee the Prado feels very sure footed with the wider track and bigger tyres Just need some flares now :roll:

Marc1, if you are running 265/70 I think changing to 4.3's would undergear the car a bit too much. But if 265/75 I reckon it would help heaps. Basically it will pull like a standard one. Forget 4.5's unless you want to run 285/75's

Edit, Marc1 I've been thinking a bit more about your question. If your gearing is standard at present on your TD, Look at installing a power module like a DTronic, etc. I think you will get more power for your towing and keep the gearing right which will save you fuel on the highway runs. You would need to be towing BIG weights to want to under gear the car IMO.

Cheers

Mark

[marc1 Lurker Find all posts View Profile Close marc1]

My gearing and tyre size is all standard.
In OD I do 2000 revs at 110 k/h

I thought in the chip option even the LPG one, yet extra power means extra heat and then I have to worry about overheating.

[Kalex Junior Member Find all posts View Profile Close Kalex]

Re: Crown wheel and Pinion swap

Can anyone tell me if hilux Crown and pinion fit our prado's.
I just fitted 265/75's to my 2.7 prado. I think these run 4.3 ratio's as standard and i need 4.54 to get my power (or lack there of) back.
thanks

[KZJ90 Member Find all posts View Profile Close KZJ90]

Re: Crown wheel and Pinion swap

IŽd like to go 4.10:1 with 285/75R16 tires. Now I have 4.30:1 and IŽd like to change to 6th gear, but I havenŽt one. :cry:
4.10 ratio would reduce rpm about 100 rpm when driving at highway 90-100 km/h. It would reduce fuel consumption, because IŽm sure there is enough power/torque for that ratio.

[Landcrusher Junior Member Find all posts View Profile Close Landcrusher]

Altering the gearing

Talking theoretically, wouldn't it be possible to achieve this through changing part of the drive train in the centre transfer box? The all the front and rear components would remain the same - or is there no potential for reduction in the centre ie it's 1:1 drive all of the time, input to output. I've never seen inside the middle section before so no idea if this would be easy. I have to agree with the desire to go for 6th gear on a long highway. The diesel has such good torque that it could pull at much lower revs for sure and get better economy. Mine's at around 2500 when cruising at 65 mph. I'm sure that my old auto was less than this and subsequently more economical. I have 265 75 16 MT's and my speedo is now 1mph out (checked several ways)

LC