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R50 regear


AkPrecision
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So after a ton of research about my particular r50 (2001 se 4x4 3.5) I have a r200 and h233b diff. They make 4.9 gears for them. From what I understand is the front is high pinion which uses reverse cut gears so the regular 4.9s won't work. And Noone makes a set of reverse cut that I have found. So I have 2 options after talking to steve at rugged rocks for a few days. Either I have them custom made which I have a shop that ca do it I think and may possibly be a leader to get a group buy together if that interests anyone. Or I take an xterra front diff and try to fab a mount to volt it up and they already come with 4.9s. Anyone have any suggestions s or input? Or possibly know of magical reverse cut front diff hear options other than the 4.63 factory conversion?

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Well I feel the swap would be easier and more cost effective. I read somewhere a custom mount needed to be made but wasn't very hard. I'm going to see what I can find out

 

Might've been me saying it in my R200 vs R200 thread. But it's pretty much exactly that...just need to weld/bolt on something to mimic the R50's version of the axle. Since the non-R50 axle is shorter, this helps the situation greatly.

 

D44 swap may be just as much work as a different nissan housing swap. Depends on shaft length mounts ect. Following...

 

I disagree, for the reason above and because there are much fewer challenges here:

1. Find a replacement cover; probably from a C200 rear axle (if patterns are the same).

2. Cut/grind a mounting bracket off the non-R50 axle

3. Weld/bolt new brackets to the non-R50 axle

4. Widen the axle; this can be done in two ways: 1) CNC-milled spacers between CVs and CV flanges, 2) X/FRs CVs and a spacer (this would also increase articulation)

5. Guys with missing links would need to remove them; no impact to guys without. Done correctly, a new ML could be made or incorporated.

 

There's more research needed for the above, but this how I see it happening. The finished axle would bolt right into the subframe.

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I huess what i was trying to convey was if the labor and cost were similar, your getting gears and still have an IFS front. Its no secret how much better a solid is off road. Make more sense now? Its football sunday. I may be a little drunk..

 

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I won't make this a debate about SAS vs IFS, but until an IFS wheel comes off the ground, there is no difference between a straight-axle and an IFS in terms of traction. The SAS affords being in wheel-up situation in more extreme conditions.

 

I don't think the labor or costs are nearly the same. I have no doubts I could have all that parts needed for a full-vehicle 4.9 swap and work outsourced (welding, CNC milling, laser/water cutting parts) for well under $1K. That's competitive with a normal re-gear on a non-R50 Nissan truck/SUV for aftermarket gears alone, and wouldn't require any gear setup.

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Thats a great point. R50s are not nor ever will be the chepest trucks to build. But thats what makes em so cool. If one could put together a "kit" under a grand it would be. A killer upgrade for these. I was figuring it would cost double that, but my nissan knowledge is zero other than my own pathy ive had for a few months. I thought i read someone had made gears in the 5.12 range. Any truth in that?

 

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Of course, the simpler the design, the cheaper the costs. The design in my mind is essentially a simple cradle that the axle fits into, a few inches of weld, and that's it. The only reason for the laser/water jet is because if the parts are simple enough, it's cheaper to have a few pieces made rather than one-off...the idea being that I make a few of them to justify costs.

 

There are some 5.13 (rear only) and 5.14 (front and rear) gears out there, as well as taller rear gears...Rugged Rocks sells them. The 5.14 front gears are Nismo gears and appear to be usable in the C200 axle...but the C200 and non-R50 R200 are both low-pinion. So, still SOL on front gears.

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So without a swap 4.63? Is the highest option. Ive much considered not going solid and keeping the ifs (just cuz the 60k dollar jeeps i wheel with) and gearing was my main concern. Im gonna take some measurments tomorrow on the lift. Needs aligned again anyway. My local pick and pull had tons of newer frontiers and nissans. Tge diff would cost me 89 bucks. Anyone have info how to read gears on these?

 

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Here: http://www.nissanpathfinders.net/forum/topic/40619-rear-axle-id/?p=760750

 

Yep, if you've got 4.636 already, then you're already out of options. Those with 4.363 (HG43) can swap up, which is what I did a few months back.

 

If the diffs are already pulled, the ratio is stamped on the side of the ring gear as ring teeth to pinion teeth (i.e, "49:10"). If you can get them for $90 each, that's a deal! But that's where I get some of my numbers...$200-$300 for both sets of gears from the JY, already set up in the diffs and another <$700 for the outsourced work.

 

Since you have the right tools, I would think this would be right up your alley. At minimum, it also puts a front diff in that better aftermarket gearing options, which is also key here for you if you want to push 35's.

 

 

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Mines the 43 set. I considered doing the 46 swap but figured its a mute point on 35s. However! It would be ok if i do tge d300 doubler. Wish someone had a 10 doubler cuz i got like 4 of those on hand. My only highway driving is to trails and work. No hills=no problem.

 

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No need to guess about this stuff. All you need is your OE tire size and OE gear ratio.

 

Let's use 255/65/16 and 4.363 as an example. It's best to use actual sizes from the tire manufacturer's website (even a 32" tire isn't 32"), but to convert a metric tire to inches:

  1. Double the section width: 2 x 255 = 510
  2. Multiply it by the aspect ratio: 510 x .65 = 331.5
  3. Divide it by 25.4: 331.5 / 25.4 = 13.1
  4. Add the wheel diameter: 13.1 + 16 = 29.1

Now, divide OE tire size by OE gear ratio: 29.1 / 4.363 = 6.67.

 

What gear is ideal for a tire size? 33 / 6.67 = 4.95

What tire size is ideal for a gear? 4.90 x 6.67 = 32.7

 

So let's say I jumped to a 33" but kept 4.363 gears...offset can be determined using the ideal gear or the OE tire size.

 

4.95 / 4.363 = 1.135 (or +13.5%)

33 / 29.1 = 1.134 (or +13.4%)

 

Here's how to think about it:

  • your tires are 13.5% taller and longer in circumference
  • you're going 13.5% faster than your speedo says
  • you'll travel 13.5% farther than your odometer says
  • your engine will work 13.5% harder when accelerating
  • you might see up a 13.5% increase in mileage at cruising speeds
  • your effective gear ratio and torque at the wheels decreases at least 13.5%

Long story short: bad for slow speeds, good for high speeds.

 

You can see the trade-offs of changing tire sizes with and without changing gears, though this doesn't really take into effect heaver tires, rotational mass, rolling resistance, etc. (but you can rest assured they don't help!). YMMV for accelerating and cruising loads/speeds, of course, but you get the idea.

 

Since I've had a few changes already, I have other numbers for comparing to OE: 30.5 / 4.363 = 6.99, 30.5 / 4.636 = 6.58, and 31.6 / 4.636 = 6.82.

 

6.99 / 6.67 = 1.048 (or +4.8%)

6.58 / 6.67 = 0.986 (or -0.14%)

6.82 / 6.67 = 1.022 (or +2.2%)

 

That all said, if you want to improve—or retain—your off-roading performance, you'll want to re-gear. I wouldn't really consider it until you're pushing 8% or more, though. I re-geared because I was already planning on the LSD swap/re-pack and larger tires, and the gears were a very inexpensive upgrade.

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Awesome info. I cant type well enough for this. Only thing i would add is that if its primary use is off road and you plan on deeper gears in the transfer case, say 3.7:1 then the axle gears will only affect the 2high when its at the 1:1 final drive ratio. Other wise this will get the truck back to close to factory ratios. The 2:1 t case is where the r50 suffer the most if you ask me. Too much speed for slow crawling.

 

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Small math error on my previous post...the offset on one of my setups was -1.4% not -0.14%...

 

Awesome info. I cant type well enough for this. Only thing i would add is that if its primary use is off road and you plan on deeper gears in the transfer case, say 3.7:1 then the axle gears will only affect the 2high when its at the 1:1 final drive ratio. Other wise this will get the truck back to close to factory ratios. The 2:1 t case is where the r50 suffer the most if you ask me. Too much speed for slow crawling.

 

Yes, lower low range gears will give you a mechanical advantage in 4L (and technically 2L if you dare), but axle gears affect the entire drivetrain regardless of transfer case or transmission gear. And for that reason, you're better off correcting the axle gear ratio first if it sees any on-road use (and I think this is more central to the original discussion).

 

When it comes to off-road, though, the discussion really converges on crawl ratio. It's not usually for comparing dissimilar vehicles, since it neglects engine performance and tire size, but it's a good way to calculate your own baselines. If you went from 4.363 to 4.636 and swapped your low gears from 2.02 to 3.71, you almost double your crawl ratio.

 

 

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Too much math, my head hurts now! :/

 

Since I plan on sticking with 31's until they wear out (or longer), and my max would be 33's, when I finally find the right daily for the wife and reclaim my 01, I'll be swapping the front diff and rear ham from the 96, essentially giving me factory like performance, on 31's from the 01.

Edited by 01Pathmaker
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