Transfer Case Reduction

[Killacaviar]

This may be a silly question, but I find myself needing more control and a lower ratio when on the rocks in 4low

Are there any options out there for a transfer case reduction on a 200? Also, when installing 4.88s and a rear locker… will that have significant impact on 1st in 4low?

2peddling it and momentum advantage isn’t ideal in rock gardens.

 

[bloc]

I’ve never seen a different ratio gear set, and implementing it in our case would be complex due to the planetary nature of our low range reduction. It’s not like a mini truck box where you simply replace a couple gears.

4.88s would help a whole lot with reduction and control. It’s not too hard to work up a chart showing the rpm differences at a given speed for context.

Either way it is really your only realistic option for improving crawl ratio.. and depending on tire size and other factors with your build, could really help with drivability on the road too.

 

[TeCKis300]

Short answer, 4.88s will give you a much better crawl ratio by 25%.

From this thread

Definitive 200-series Gearing Reference

So I had a little time this morning to put together a chart combining transmission gearing of 6-speed vs 8-speed, diff ratios, and tire sizing into an overall gearing reference. Hoping this will be useful for those trying to understand how their changes are going to effect overall gearing of...

forum.ih8mud.com

Stock crawl ratio: 34.1:1.
Your current ratio with 35s: ~31:1
After 4.88s: ~38:1

For comparison, stock LC200 w/8-speed: 41.5:1. 4Runner 34:1, Wrangler 39:1, Rubicon Wrangler 73:1

 

[Killacaviar]

Much obliged. I figured as much, I also didn’t realize the massive improvement with the 8speed.

I’ll just continue on with my initial plan… thanks guys

 

[GTV]

That's interesting. TC gears are available for the 80 and 100 series, the 200 must use an entirely different TC?

 

[bloc]

That's interesting. TC gears are available for the 80 and 100 series, the 200 must use an entirely different TC?

Yes, the 80 and 100 both use a case that has a gear-driven center differential and front/rear output flanges on the same axis, (off to one side), with a low-range in the top/front of the case much like a mini truck.

The 200 has a center-exit rear output with a chain that drives the front. A center differential is on the rear output shaft, with a planetary low-range reduction gear set in front of all of that.

The latter is significantly more difficult for aftermarkets to build a gear set for..

 

[bloc]

Figured I'd add some diagrams.

100-series case.. the overall isn't very clear. If you want to look up actual photos the part number is 36130-6A470

This picture doesn't show the front output flange, but it would be to the left of the spider gears/differential in the bottom of the image.

200-series case 04362-60871

The rear output on this one is at the top right of the chain loop, the front output at the bottom left / front of that chain.

 

[Killacaviar]

That's interesting. TC gears are available for the 80 and 100 series, the 200 must use an entirely different TC?

That’s what made me curious. Marlin sells them for 80+ 100 series

 

[mcgaskins]

I would absolutely swap tcase gears if a reduction was offered, but unfortunately as mentioned above there isn’t an option and I doubt there will be.

 

[bjowett]

The issue with lowering the ratio is finding room inside the transfer case low range ring gear... it's a set diameter and we can't increase it, since it mounts and is held stationary by the aluminum housing/case. The planet gears need to grow quite considerably in diameter in order to get any significant increase in reduction over what is there. That can only happen via reduction in the diameter of the sun gear, which is part of the input shaft... there isn't much room to shrink that guy down, either. Possibly we could get it 2.9 or 3:1... and that is pushing it.... if there is interest I'll revisit what might be possible?

In the mean time have fun with this... Planetary Gear Simulator - https://www.thecatalystis.com/gears/

 

[turbo8]

Don't forget you can add Portal axles for some gear reduction

200 Series Portal Axles

An initial search didn't turn anything up, but thought some folks might be interested to see that Werewolf Tech out of the Ukraine has a Portal Axle solution option for the 200 series...looks like it nets about 5" of ground clearance and of course the OBA capability is nice too. Not sure on...

forum.ih8mud.com

 

[Killacaviar]

The issue with lowering the ratio is finding room inside the transfer case low range ring gear... it's a set diameter and we can't increase it, since it mounts and is held stationary by the aluminum housing/case. The planet gears need to grow quite considerably in diameter in order to get any significant increase in reduction over what is there. That can only happen via reduction in the diameter of the sun gear, which is part of the input shaft... there isn't much room to shrink that guy down, either. Possibly we could get it 2.9 or 3:1... and that is pushing it.... if there is interest I'll revisit what might be possible?

In the mean time have fun with this... Planetary Gear Simulator - https://www.thecatalystis.com/gears/

4.88s or Portals seem to be my only option at the moment. If there was any serious consideration that there is a reduction option, I would Love to hear about it. With that being said, please don't waste your time if its a shot in the dark. I do think there would be a market for something like this, the 5.7 does its job fairly well turning 35s everywhere except crawling.

 

[Killacaviar]

Don't forget you can add Portal axles for some gear reduction

200 Series Portal Axles

An initial search didn't turn anything up, but thought some folks might be interested to see that Werewolf Tech out of the Ukraine has a Portal Axle solution option for the 200 series...looks like it nets about 5" of ground clearance and of course the OBA capability is nice too. Not sure on...

forum.ih8mud.com

I have been on the Warewolf site quite a few times in the last few weeks...

 

[krice118]

With 4.88s that will affect both Low and High range. this should be what youre looking for.