Axle Tech Info

[marshal]

G
G
G
G
G

Now what?

 

[jwkilgore]

Not unless you get an entire rear axle with the elocker for nearly free. You'll need the diff, elocker motor, and the axle tube, or do some cutting and welding on your axle tube to fit it.

Yeah, that's what I've discovered. By the time I find a rear axle from a junked 5th Gen Trail then do all the wiring and screwing with the computer it'll be easier to just find a unicorn and ride it to the base of a rainbow. Or simpler to install an ARB air locker. And since I'll have on-board air anyway, the front will be ARB also. That's a $3k upgrade, so better get to saving (that's "k", not "G" :nono.

 

[wfo9]

I think you would go through CVs way too often with an autolocker up front. I don't know this for a fact, but I think you would find yourself in lots of trouble.

Personally, I would not even think of going with anything besides an ARB. I understand the air line has disadvantages... but it has major advantages also. The main one being it is frigging instant. Anyone who has air in the front and E-locker in the rear wishes they had air in both.
.
The key on the ARBs is doing the install correctly.

The other thing is that they are very proven in the Toyota clam shells. Seems like a no brainier

 

[Jeremy556]

Yeah, that's what I've discovered. By the time I find a rear axle from a junked 5th Gen Trail then do all the wiring and screwing with the computer it'll be easier to just find a unicorn and ride it to the base of a rainbow. Or simpler to install an ARB air locker. And since I'll have on-board air anyway, the front will be ARB also. That's a $3k upgrade, so better get to saving (that's "k", not "G" :nono.

Don't forget, you'll want to do 4.56 gears while you're in there. BTDT.

 

[CruzadoBlanco]

Not unless you get an entire rear axle with the elocker for nearly free. You'll need the diff, elocker motor, and the axle tube, or do some cutting and welding on your axle tube to fit it.

i just did an elocker retrofit on mine, with the newer housings that were first used in the 4th gens you no longer need to weld anything. you "simply" cut the notches and drill and tap the holes. i know 5th gens are the "8.2" however the rear axle housings are the exact same with the same axle shafts. the difference is in pinion spline count and R&P bolt count along with bearing size. this is what causes the 8in and 8.2 to not be interchangeable. ill dig up some of the pictures from mine and post em for yall to see.

 

[jwkilgore]

Don't forget, you'll want to do 4.56 gears while you're in there. BTDT.

That's another question I had. I hate to hijack a thread, but since you asked...

I believe the stock gear ratio is 3.73:1. Going to 4.56 seems like a drastic change that would seriously kill highway mileage.

I am planning on going up in tire size the next change in 45k miles or so. I'd like to try and push 34's, which with 4.56 gears would put me almost exactly back to stock engine speed/wheel speed (about 2k rpm at 70mph), but it doesn't look like anyone makes AT tires in that size. It's looking like 33's are about it, which will be about an 18% increase in engine speed to maintain the same road speed.

Are there any other gearing options between 3.73 and 4.56? I couldn't find anything to fit the current differentials after a quick search.

 

[Jeremy556]

That's another question I had. I hate to hijack a thread, but since you asked...

I believe the stock gear ratio is 3.73:1. Going to 4.56 seems like a drastic change that would seriously kill highway mileage.

I am planning on going up in tire size the next change in 45k miles or so. I'd like to try and push 34's, which with 4.56 gears would put me almost exactly back to stock engine speed/wheel speed (about 2k rpm at 70mph), but it doesn't look like anyone makes AT tires in that size. It's looking like 33's are about it, which will be about an 18% increase in engine speed to maintain the same road speed.

Are there any other gearing options between 3.73 and 4.56? I couldn't find anything to fit the current differentials after a quick search.

The only available ratios right now are 3.73, 4.56, and 4.88. I loved 4.56 with 33" MTRs, now with 34s I kinda wish I had 4.88 gears.

BFG has the KO2 in 34x10.5 which is listed as 33.5" diameter

 

[Jetboy]

Lockers are on my long-term upgrade list, and I thought ARB was the only option. Do you know of a viable rear e-locker for a 2011 SR5? Is it feasible to install an OEM Trail rear locker on an SR5?

Harrop makes one for the rear as well. They are somehow affiliated with eaton. They have one for almost every Toyota application. I have never owned one. The design IMO is a clear winner over air actuation. I don't know about the quality of production.

 

[wfo9]

Lockers are on my long-term upgrade list, and I thought ARB was the only option. Do you know of a viable rear e-locker for a 2011 SR5? Is it feasible to install an OEM Trail rear locker on an SR5?

Go with an ARB. Simple, proven results. Retrofit of a Toyota E-Locker would only be good if you got the parts really cheap and liked to do the fab work on your own or scored a full axle housing as part of the deal. Activation would still be iffy....

 

[Taco04]

That's another question I had. I hate to hijack a thread, but since you asked...

I believe the stock gear ratio is 3.73:1. Going to 4.56 seems like a drastic change that would seriously kill highway mileage.

I am planning on going up in tire size the next change in 45k miles or so. I'd like to try and push 34's, which with 4.56 gears would put me almost exactly back to stock engine speed/wheel speed (about 2k rpm at 70mph), but it doesn't look like anyone makes AT tires in that size. It's looking like 33's are about it, which will be about an 18% increase in engine speed to maintain the same road speed.

Are there any other gearing options between 3.73 and 4.56? I couldn't find anything to fit the current differentials after a quick search.

There are also 3:90 gears from Toyota I have a F&R R&P set I will be installing soon with my rear locker since my rig is going to stay on smaller tires.

BFG is making a 34" AT it's just not metric but it's in the table..
http://www.bfgoodrichtires.com/assets/bfg/content/document/Easy PIPO_KO2_June 4.pdf

Also TJM has a new 8.2 air locker available now as well so one more to throw in the hat...
__________________

 

[Jeremy556]

There are also 3:90 gears from Toyota I have a F&R R&P set I will be installing soon with my rear locker since my rig is going to stay on smaller tires.

Oh yea, I forgot, there are 3.91 Toyota gears out of the 6 speed 2010+ FJC. They are a bit pricey, but if you can stick with stock size tires, they are as close as you can get to 4.10, which would be ideal, IMHO.

 

[wfo9]

BFG is making a 34" AT it's just not metric but it's in the table..
http://www.bfgoodrichtires.com/assets/bfg/content/document/Easy PIPO_KO2_June 4.pdf

That was mentioned earlier. It' probably a good choice for an AT tire, but is actually right in the middle at 33.5".

 

[jwkilgore]

I understand that all "English" tire sizes are nominal and are actually 0.5"ø smaller. So 33's are actually 32.5" and so forth. Like a 2x4.

Anyway, I love options. Curious though... what's with Australia and aftermarket lockers?

Oh yea, I forgot, there are 3.91 Toyota gears out of the 6 speed 2010+ FJC. They are a bit pricey, but if you can stick with stock size tires, they are as close as you can get to 4.10, which would be ideal, IMHO.

The engineer in me rejoiced at this... According to this site, a 3.91 gear set with 285-70R-17 (32.7") puts me almost exactly back to stock power! :whoo: And going to 4.10 (this set should fit up front) would give slightly more torque without a significant loss in speed.

Except...
Going from 3.73 to 3.91 isn't worth the cost, and while they make a 4.10 for the 8" reverse front I can't find one for the 8.2" rear. And the more I read, by the time I get to this point I'll have significant more weight in underarmor and maybe even bumpers and a rack, plus the extra rolling resistance from the larger tires... so it's looking like 4.56 may be the ratio to get with 33's. You know, just like what everybody who knows anything about offroading seems to be screaming.

 

[marshal]

Don't fear the gear. Do 4.56

 

[wfo9]

I understand that all "English" tire sizes are nominal and are actually 0.5"ø smaller. So 33's are actually 32.5" and so forth. Like a 2x4.

Anyway, I love options. Curious though... what's with Australia and aftermarket lockers?

The engineer in me rejoiced at this... According to this site, a 3.91 gear set with 285-70R-17 (32.7") puts me almost exactly back to stock power! :whoo: And going to 4.10 (this set should fit up front) would give slightly more torque without a significant loss in speed.

Except...
Going from 3.73 to 3.91 isn't worth the cost, and while they make a 4.10 for the 8" reverse front I can't find one for the 8.2" rear. And the more I read, by the time I get to this point I'll have significant more weight in underarmor and maybe even bumpers and a rack, plus the extra rolling resistance from the larger tires... so it's looking like 4.56 may be the ratio to get with 33's. You know, just like what everybody who knows anything about offroading seems to be screaming.

It's always trade offs My 34s feel so much heavier and harder to turn than my 33s did. Offroad, I really wish I had 4:88s now. It's pretty good compromise on the road. The difference between 3:73 and 4:56 offroad in crawl situations is amazing. I don't think most people understand the added control you get. I really want a dual speed case at some point.

 

[marshal]

heres my dream list

Currie Fab9 IFS front center section, Camburg Race9 rear axle, 5.38 gears, camburg 3.5" IFS, PSC ram assist steering with 1-ton outer links, fully boxed and gusseted spindles, 37" DOT Grabbers on Trail Ready beadlocks

i think i just got a boner.

 

[wfo9]

I understand that all "English" tire sizes are nominal and are actually 0.5"ø smaller. So 33's are actually 32.5" and so forth. Like a 2x4.

I don't think it works quite like that. From my experience each tire has an advertised size and a measured size. Some are a little larger than advertised, some are actually a little smaller. It just depends on the tire. They are usually within .5", but not always.

 

[marshal]

I don't think it works quite like that. From my experience each tire has an advertised size and a measured size. Some are a little larger than advertised, some are actually a little smaller. It just depends on the tire. They are usually withing .5", but not always.

i think he's talking about BFG tires, you know - when a 33" tire is actually 31" tall

my Grabbers are a true 35" tall. it varies across manufacturers as there is not set standard.

 

[jwkilgore]

No, it was based on the fact that the several sizes I checked were all exactly 1/2" smaller. 33's were 32.5, 35's were 34.5, etc.

Even Nitto Terra Grappler G2's are 34.53" and 36.54" for 35's and 37's, respectively.

But... checking more brands, looks like I was wrong. :Cry:

It's random. Nitto Mud Grapplers are closer to nominal size (35's are 34.84"), but still not 35.00".

 

[Jetboy]

No, it was based on the fact that the several sizes I checked were all exactly 1/2" smaller. 33's were 32.5, 35's were 34.5, etc.

Even Nitto Terra Grappler G2's are 34.53" and 36.54" for 35's and 37's, respectively.

But... checking more brands, looks like I was wrong. :Cry:

It's random. Nitto Mud Grapplers are closer to nominal size (35's are 34.84"), but still not 35.00".

Take a look at interco sizing. They're all over the place. Bigger. Smaller. Two tires with the same nominal diameter will be as much as 1 inch off. And for an example an IROK "36" size is actually taller than the "37" size. The 36 is spec'd at 36.8 and some of the 37's are 36.7 Go figure.