Have you changed Diff Ratios?

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Have you changed Diff Ratios?

Postby timbo9431 on Thu, 01 Nov 2018 3:43 +0000

Hi,
I am looking to change the diff ratios in my SR5 M/T to a 4.1 ratio. I have read the discussions about the various ratios and tyre sizes etc but have not read much from anyone who has actually done a re-diff on a current series. I would really like to hear about;
1. What ratio did you go to and what tyre size are you running. Have you been happy with outcome?
2. Did you use Nitro Gears, Genuine Toyota or other?
3. I have the factory locker in the rear and an E Locker in the front. Will the Toyota or Nitro Gears be a straight swap?
4. I can't find a workshop that has done this swap. Does anyone know of a workshop in Melbourne that has
done this diff swap?

Thanks for any suggestions....
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Re: Have you changed Diff Ratios?

Postby timbo9431 on Thu, 06 Dec 2018 1:59 +0000

Really? no one has changed ratios??? Well I can't wait any longer. The holidays are coming and I have a Wake Boat to tow so I have decided to give it a whirl. I should have just enough time to get the new cogs run-in before I have to tow. Car goes in tomorrow to have 4.1's installed.
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Re: Have you changed Diff Ratios?

Postby CB23 on Thu, 06 Dec 2018 2:30 +0000

I haven't done the swap, but keen to do it soon.

I was planning 4.5 ratio with 33 or 34" tyres, so hope you can post how the 4.1 ratio goes and your tyre size.
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Re: Have you changed Diff Ratios?

Postby timbo9431 on Fri, 07 Dec 2018 12:47 +0000

Will do. Car went in this morning...
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Re: Have you changed Diff Ratios?

Postby CB23 on Fri, 07 Dec 2018 3:08 +0000

timbo9431 wrote:Will do. Car went in this morning...


Cool, bet you can't wait. Chance to test 6th gear :lol:
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Re: Have you changed Diff Ratios?

Postby Hilux Max on Sun, 09 Dec 2018 5:50 +0000

timbo9431 wrote:Hi,
I am looking to change the diff ratios in my SR5 M/T to a 4.1 ratio. I have read the discussions about the various ratios and tyre sizes etc but have not read much from anyone who has actually done a re-diff on a current series. I would really like to hear about;
1. What ratio did you go to and what tyre size are you running. Have you been happy with outcome?
2. Did you use Nitro Gears, Genuine Toyota or other?
3. I have the factory locker in the rear and an E Locker in the front. Will the Toyota or Nitro Gears be a straight swap?
4. I can't find a workshop that has done this swap. Does anyone know of a workshop in Melbourne that has
done this diff swap?

Thanks for any suggestions....



Timbo…..I regeared my Diesel auto back in Jan of this year.


1. What ratio did you go to and what tyre size are you running. Have you been happy with outcome?

I went to 4.8 Nitro Gears. I run 295/70r17 Toyo MT's as daily tyres and I run 35/12.5x17 Nitto Trailgrapplers on Beadlocked 17x9's for offroading. I am very happy with the outcome. Given, the 4.8's suit the 295's beautifully.....on the 35's....the vehicle "feels" like it could dowith a little more but hopefully a future remap will give that little extra bit of torque it needs when on the highway. In low range it is great.

2. Did you use Nitro Gears, Genuine Toyota or other?

I went went with Nitro gears and the Master Install kits that they also sell with them. I had good results with Nitro gears on my N70 Hilux and was a no brainer to use them again.

3. I have the factory locker in the rear and an E Locker in the front. Will the Toyota or Nitro Gears be a straight swap?

I too run a factory locker rear and E-Locker front. You sir have 3.5 standard diff ratio in the manual. You have two 4.1 ratio options:

1 - Toyota 4.1 - this is a standard cut/thickness gear. If you use this, you will need to swap over your front E-Locker to one that suit the 3.9 and higher ratio'd diff gears as the offset position of the gears is different.

2. Nitro 4.1 - This is a "thick cut" gear, the extra thickness makes up for the offset issue with standard gear thickness and can be used in the existing E-Locker you have. Nitro gears would be cheaper than Toyota (unless you found a second hand set) but even if you found a second hand set, you wil still need to change the front locker so your begtter off going Nitro from the start.

4. I can't find a workshop that has done this swap. Does anyone know of a workshop in Melbourne that has
done this diff swap?


I had Brett from 4x4Obsession in Melton do my regear. They've done several of them and I was happy with their customer service and workmanship.

Additional Notes:

1. I found that the Master Install Kits from Nitro, like last time, make the install so much easier with everything being on hand. If you use this kit, just buy an additional front diff driveshaft seal because we found one of the seals provided did "seat" properly and a little bit of weepage of oil was coming out. We put this down to possibly a slight difference in this area with the Tacoma's. wasnt a big deal and fixed quickly.

2. Your diff regear is only as good as your run in process....do you research and ensure you take your time with this. IM happy to help when the time comes for advice.

Hope that helps.
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Re: Have you changed Diff Ratios?

Postby timbo9431 on Sun, 09 Dec 2018 7:15 +0000

Thanks for the detailed reply Max. Exactly the stuff I was looking for. I have followed your build and also the Diff Ratio discussion you have contributed and that has been really useful. I am only planning to go to 33's for low range track work and I'll stick with the 275/70/18, which I have on now, for daily driving and towing. I contacted 4X4 Obsession based on your earlier thread but they are a bit too far from Eltham.
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Re: Have you changed Diff Ratios?

Postby timbo9431 on Sun, 23 Dec 2018 12:50 +0000

Well, the ratio change has been done and only a few headaches along the way but nothing major. The diff specialist had not done a current Hilux before so of course there were "unknowns" which held up proceedings and the three day job took seven days (despite me providing them with all the useful info from Max prior to commencement).
Here is a brief summary;
- Installed brand new genuine Toyota gears (yes it hurt!).
- Pulled out a perfectly good ELocker and replaced with new ratio ELocker (that also really hurt!).
- I have only done 500km of the 1000K run in procedure so I have not really tested the new ratios properly yet.
Although I can say that after you drive from Geelong to Melbourne a few times at 80kmh (with two coffee stops each
way to allow the diffs to cool) you kinda get used to the sedate pace.
- My initial observation is that in day to day and highway driving the lower ratio feels only subtly different. The vehicle
does not feel under geared for general use. I am running 275 tyres and it feels similar to what it did with the factory
265's and 3.5 diffs)
- Looking forward to using 6th gear when I can hit full highway speeds.

I will update once I have given the ratios a proper test out.
PS I have a very good condition Front ELocker available for sale if anyone is interested!!
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Re: Have you changed Diff Ratios?

Postby timbo9431 on Fri, 11 Jan 2019 8:05 +0000

The Joy of Sixth!
The diffs are bedded and I have been able to appreciate the benefits of the lower ratios. In short, the car feels right. This tyre/diff ratio size feels as if it should come from the factory in this configuration.
Whilst I would not describe the change in feel as radical, the benefits are showing themselves over time.
Today I towed the 2Tonne wake boat up the hill from my house. The standing start was a breeze where in the past I was literally smoking the clutch. I now use gear number six which until now, lay dormant in the gearbox.
While it is too early to be definitive, I think I am experiencing improved fuel economy (possibly from accessing sixth gear).
Speed as measured by two different mobile phone GPS speedos is spot on (perhaps 1% under speed).
I am yet to test low range gearing.

Running Cooper AT3 275/65/18 tyres with 4.1 ratio diffs I measured the following.
SPEED GEAR RPM
80kph 5 1800
80kph 6 1400
100kph 5 2300
100kph 6 1800
110kph 6 1900

Hope this information is useful and just a PS...there is a great condition front ELocker for sale on Gumtree,,,,,
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Re: Have you changed Diff Ratios?

Postby nicebike on Sat, 12 Jan 2019 11:28 +0000

Good report, thank you.

I'm a bit surprised that it doesn't feel a bit busy with 4.1s given that your current nominal tyre size is only 32" (approx)

Just goes to underline how overgeared all this later model stuff is.

"In short, the car feels right" is a very telling summation. I have a 2014 manual with the 3.5whatevers, and the gearing is a pain, but for the use I give it, I can't bring myself to bite the $$$ bullet. Forget chips and all that stuff - if I could change one single thing it would be the diff ratios.

Interesting to note that Toyota transfer case gearing has been adjusted so that even with the stupid high factory diffs, low range first is still 40.1, give or take. Your regear will take you to around 46.1, which is getting into old Landy territory. Should be great for slow work.
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