4.56 gears

[Overlanding_USA]

Okay everyone, its time for gears. The truck is mostly stock, just a lift, rack and 33's. The reason im looking at gears is i town an 1800 lb off road trailer on the weekends and would love a little help going up hills and such. Right now im looking at 4.56's gears from Nitro. The question is do you think gears will help with towing the trailer and will the gears be ok to live with while just driving around town without the trailer.

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[Swarty]

Yes.

I have 4.56 and just normal driving they make the shift points so much better.

 

[Gabex35]

Yes, I have 4.56 and a lot of weight and tow a steel trailer and I think its fine. for your stockish weight and a similarly weighted trailer I think 4.56 would be just fine.

 

[comtn4x4]

I agree with everyone else. I carry a lot of extra weight, especially when all the family and dogs come along. As well I am on 285/75/17's and the re gear is great, even in the mountains. Possibly best mod I made. I would highly recommend the change. Check out East Coast Gear Supply

 

[BigredTEX]

I too agree with all above. It's a mod I wish I had done years ago. You'll see a great performance improvement around town and possibly a slight MPG improvement, but you will lose a couple of MPG on the highway, a trade-off I don't mind at all. Around here the speed limits are 75 mph and it's no problem with 33's. I'm planning to go to 34's with my next tire change.

I don't tow very often, but I can only imagine positive results.

 

[JSparky]

I'm liking this for the potato chip cubby.

 

[WLSchroder]

I too agree with all above. It's a mod I wish I had done years ago. You'll see a great performance improvement around town and possibly a slight MPG improvement, but you will lose a couple of MPG on the highway, a trade-off I don't mind at all. Around here the speed limits are 75 mph and it's no problem with 33's. I'm planning to go to 34's with my next tire change.

I don't tow very often, but I can only imagine positive results.

At 75, what kind of RPM are you looking at? I had an old Ranger with 4.10s and the thing was screaming on the highway...

 

[comtn4x4]

With the 4:56 gears and 33"-34" tires the gearing gets closer to as it was stock. So the RPM's are in line with that. At 75 mph on the flat I am typically around 3000-3500 RPM. Before the regear at 75 mph the gearing would wander up and down like crazy. In the mountains or fully loaded it was awful. (Let alone both) Now I drive at 75-85 mph all the time and it's greatly improved. Although mpg does suffer as was mentioned above. According to the Scangauge at 85 I get about 9-11 mpg.

 

[EddieV4runnin]

With the 4:56 gears and 33"-34" tires the gearing gets closer to as it was stock. So the RPM's are in line with that. At 75 mph on the flat I am typically around 3000-3500 RPM. Before the regear at 75 mph the gearing would wander up and down like crazy. In the mountains or fully loaded it was awful. (Let alone both) Now I drive at 75-85 mph all the time and it's greatly improved. Although mpg does suffer as was mentioned above. According to the Scangauge at 85 I get about 9-11 mpg.

What is your MPG driving around town? And what do you think you might get at 70 mph?

 

[comtn4x4]

What is your MPG driving around town? And what do you think you might get at 70 mph?

I average about 15.2 mpg. That's a mix of highway and around town driving probably leaning towards around town. With purely around town it's more like 16.5 mpg. Pure highway at 70-75 mph is 13-14 mpg. Over 70 mph it dips really fast. That's when its gets down into the 9-11 mpg range. At 90 it says its 6-7 mpg when I have infrequently gotten up to that speed on a flat. When I switched to the bigger, heavier tires (1.2 inch and 12 lbs per tire increase) the mpg really took a hit. Regearing helped but not more that about 1 mpg on average

 

[Titanpat57]

I'm pulling #2650...most of the time I forget it's there....straight up hills are slower going.

 

[Jetboy]

I've been looking at doing a gear swap, but I'm really on the fence. I REALLY wish we had options like 4.10 or 4.30. IMO those would work a lot better for my situation. I like my current MPG. With 285/s I can still get 19mpg pretty regularly on the highway. I'm not sure I want to drop down to 14. But I also run less lift than most and no bolt on stuff like roof racks that cut the MPG down. So maybe it'll be closer than I think. I'm trying to run part of a tank in 4th gear and then compare in 5th gear with my new taller 285/75/17 (34") tires to see if there's a big difference. If not I'll probably swap gears.

Anyway - I'm curious who's done their own gear sets? Has anyone on here done an 8.2 diff R&P setup? How did it go? Any special thoughts? I'll probably do my own gear setup if I go to 4.56. Toyota diffs are pretty easy typically if you have a shop press and a bearing removal kit - especially if they are the threaded end caps for the carrier. The shim versions like the 8.4 are a bit more work.

My biggest question for anyone who's done their own is with respect to the bearings. How did the pinion bearings come off on the 8.2? Were they reused or did you go with new? And if you did reuse them how bad was it to remove them - meaning did they come off pretty easy or are they so tight that you'd probably better have backups ready because you'll probably ruin one? And did you need to pre-heat them to put back on or could you just press them on?

Thanks.

 

[rochmpr]

With the 4.56 and 285/75's (34"), gearing is about 6% - 7% lower than stock. So at about 70 mph on the speedo, you're actually about 74 - 75 mph. With my heavy ass 4Runner, 4 of us, plus 2 dogs and all our luggage for a week long road trip of about 3,400 miles averaged about 16 mpg. Took a big hit on MPG going Colorado to Nevada with a 40+ mph head wind for the entire day.

 

[comtn4x4]

With the 4.56 and 285/75's (34"), gearing is about 6% - 7% lower than stock. So at about 70 mph on the speedo, you're actually about 74 - 75 mph. With my heavy ass 4Runner, 4 of us, plus 2 dogs and all our luggage for a week long road trip of about 3,400 miles averaged about 16 mpg. Took a big hit on MPG going Colorado to Nevada with a 40+ mph head wind for the entire day.

That’s interesting. Before the swap to 4.56 gears I was off 6-7% on 285/75/17’s. After thw swap I’m off 2% or about 2-3 mph faster than the speedometer at 75. We appear to be generally equipped similarly and carry similar abounts of people/gear

 

[Jetboy]

The vehicle speed is taken from the ABS sensors at the wheels. The gearing should make no difference in your speedometer reading. Tire change does though.

By my math going from 3.73 to 4.56 would require 39" tires to remain equal gearing to stock. Going to the 3.91 gears from the GX/Prado would equal the difference to a 33.3" tall tire. And 4.10 gears would be almost a perfect fit for 35" tires. BUT - that assumes that stock gearing is what you want. I think it's barely adequate stock with stock tires. Larger tires + lift = significantly higher resistance and is reasonable to move to lower gearing than stock. IMO 4.30 would still be ideal - for me, being light weight and not towing all that often. The debate I'm having is whether to look for a different rear axle that has more gear ratio options. Visually a LC100 rear axle looks like it would damn near be a bolt in swap if you change the bolt pattern. I think you could just re-drill the axles since the 5 lug is 6.5" spacing compared to 5.5" for the 6 lug pattern. but... I can also buy a LOT of gas for the difference in cost.

 

[comtn4x4]

The vehicle speed is taken from the ABS sensors at the wheels. The gearing should make no difference in your speedometer reading. Tire change does though.

By my math going from 3.73 to 4.56 would require 39" tires to remain equal gearing to stock. Going to the 3.91 gears from the GX/Prado would equal the difference to a 33.3" tall tire. And 4.10 gears would be almost a perfect fit for 35" tires. BUT - that assumes that stock gearing is what you want. I think it's barely adequate stock with stock tires. Larger tires + lift = significantly higher resistance and is reasonable to move to lower gearing than stock. IMO 4.30 would still be ideal - for me, being light weight and not towing all that often. The debate I'm having is whether to look for a different rear axle that has more gear ratio options. Visually a LC100 rear axle looks like it would damn near be a bolt in swap if you change the bolt pattern. I think you could just re-drill the axles since the 5 lug is 6.5" spacing compared to 5.5" for the 6 lug pattern. but... I can also buy a LOT of gas for the difference in cost.

There must be something I don’t understand about the gearing and the speedometer/abs. I started on 285/70’s. At that time I calculated and it was verified on my Scanguage that my speedo was off 3-4%. Then I switched to 285/75’s and the speedo was off 6-7%. After a couple months I switched the gearing to 4:56. After that speedo was off about 2%. How was the abs sensor involved in that? No other changes were made during that time. Forgive my ignorance and sidetracking the thread.

I’ll look forward to hearing more about the axle swap!

 

[Engineer]

Anyway - I'm curious who's done their own gear sets? Has anyone on here done an 8.2 diff R&P setup? How did it go? Any special thoughts? I'll probably do my own gear setup if I go to 4.56. Toyota diffs are pretty easy typically if you have a shop press and a bearing removal kit - especially if they are the threaded end caps for the carrier. The shim versions like the 8.4 are a bit more work.

My biggest question for anyone who's done their own is with respect to the bearings. How did the pinion bearings come off on the 8.2? Were they reused or did you go with new? And if you did reuse them how bad was it to remove them - meaning did they come off pretty easy or are they so tight that you'd probably better have backups ready because you'll probably ruin one? And did you need to pre-heat them to put back on or could you just press them on?

Thanks.

I would love to know as well, I think 4.56 would be perfect for me (I have more drag then you) and was not a fan of the stock gearing in stock form so even with 35's, doubt ill ever go that far, I think I would be fine and really ideal for 285/75s which are likely going on this summer as my 285/70s are in need of replacement (40k+ miles on KM2s - happy camper).

Anyways, I don't recall ever seeing anyone do there own gears on here, I found either a Tacoma or FJ guy who did a nice write up and its saved somewhere on my home computer. I was planning to DIY BUT at the time I added up all the costs of the tools that I didn't have and didn't think the savings was worth the lack of warranty/expertise of someone like ECGS doing the 3rds for me and then I would install. - I don't still have those numbers but when I did it that's what I was thinking. Still think gears will be my next big mod but with the 1st kiddo on the way - priorities are changing (couldn't be more excited)

If you do end up diy, document for us - the installation instructions I have seen are fairly straight forward and personally think this job is over hyped to how hard it is to get right which is of course my main reason for wanting to diy - are they wrong or are they right!

 

[Jetboy]

There must be something I don’t understand about the gearing and the speedometer/abs. I started on 285/70’s. At that time I calculated and it was verified on my Scanguage that my speedo was off 3-4%. Then I switched to 285/75’s and the speedo was off 6-7%. After a couple months I switched the gearing to 4:56. After that speedo was off about 2%. How was the abs sensor involved in that? No other changes were made during that time. Forgive my ignorance and sidetracking the thread.

I’ll look forward to hearing more about the axle swap!

I think you have bad data from scangauge.

I'm not sure how your scanguage is identifying actual speed. I assume using your phone's GPS? The current 4runners do not have any vehicle speed sensor built into the transfer case like prior generations did. Or certainly not that I'm aware of. The location on the output shaft is no longer used. The only signal the computer has to generate speedometer readings is from the tone rings from the for ABS at each wheel. As a result - the speed is calculated by tire rotations/time. It simply lacks any sensor data to do it any other way. And nothing upstream would change it. It's possible it can re-calibrate internally somehow, but I've never heard of anything like that on these.

4.56 is a 22% gear reduction from 3.73. If the speed data were from the transfer case, your change in gearing would have gone from 7% under-reading to 15% over-reading.

 

[comtn4x4]

I think you have bad data from scangauge.

I'm not sure how your scanguage is identifying actual speed. I assume using your phone's GPS? The current 4runners do not have any vehicle speed sensor built into the transfer case like prior generations did. Or certainly not that I'm aware of. The location on the output shaft is no longer used. The only signal the computer has to generate speedometer readings is from the tone rings from the for ABS at each wheel. As a result - the speed is calculated by tire rotations/time. It simply lacks any sensor data to do it any other way. And nothing upstream would change it. It's possible it can re-calibrate internally somehow, but I've never heard of anything like that on these.

4.56 is a 22% gear reduction from 3.73. If the speed data were from the transfer case, your change in gearing would have gone from 7% under-reading to 15% over-reading.

Ok I see. I determined speed using a gps receiver and maping software. Verified by a friend with a radar gun. The percentage difference I am referring to is the % change needed to correct the speedometer which isn’t directly related to the gearing change if I understand correctly

Thanks for explaining

 

[BigredTEX]

At 75, what kind of RPM are you looking at? I had an old Ranger with 4.10s and the thing was screaming on the highway...

I'm turning approx. 2,600 rpm at 75 with 33's. This is actual 75 mph, not indicated. Indicated 75 is actually around 78 mph.