Under-drive plus Low-Range review (1 Viewer)

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I also did the UD and low range gears, echo everything LC4LIFE stated above. I still am considering going to 4.56s in the future, if I go to 37s then I may go the 4.88s. I think the 4.88s would be too low for 35s with the UD grear set for freeway driving but would be an animal in the dirt.

I can't speak highly enough about the low range gears on the trail, they made a significant impact. More controllable over and down obstacles.
 
Well I like my stock highway gears now 🤔

But I’m still on the fence about swapping gears and if I do, 4.56 or 4.88? 🤔


After turbo why would you need to gear up or lower gearing? You have both the HP and torque for be humming along at lower RPM and get better MPG, it’s like having your cake and eat it too. I would have regeared already if wasn’t for the the turbo you are making......or swap.

Granted ideal setup is go to 4.88 then install both lower low range and higher high range. This way you get lower low and relative low rpm on the highway.
 
After turbo why would you need to gear up? You have both the HP and torque for be humming along at lower RPM and get better MPG, it’s like having your cake and eat it too. I would have regeared already if wasn’t for the the turbo you are making......or swap.

Granted ideal setup is go to 4.88 then install both lower low range and higher high range. This way you get lower low and relative low rpm on the highway.

It’s why I’m on the fence
 
I also did the UD and low range gears, echo everything LC4LIFE stated above. I still am considering going to 4.56s in the future, if I go to 37s then I may go the 4.88s. I think the 4.88s would be too low for 35s with the UD grear set for freeway driving but would be an animal in the dirt.

I can't speak highly enough about the low range gears on the trail, they made a significant impact. More controllable over and down obstacles.

Many complain about additional noise with UD do you find that to be true or noticeable?
 
It’s why I’m on the fence


I have to admit, when I tried the lower low range with 5.29 on 35s I was blow away! With my stock gear and lower range gear and 35s was nice but no where near how great the full combo is.

So if you gonna go rehear you have to go go big and get the full combo(4.88/5.29 WITH lower low range AND under drive for high range). That combo is so ridiculously sick! Also expensive. For my overlanding/occasional harder trail usage stock gear with lower low range is pretty damn nice already.

Go big or go home!
 
Well I like my stock highway gears now 🤔

But I’m still on the fence about swapping gears and if I do, 4.56 or 4.88? 🤔
Posted the same thing in your turbo thread. Currently considering the same dilemma. May just go full retard and throw 5.29 in the diffs plus overdrive high range/the lowlow in the tcase + turbo with 35s just for grins. The thought being the overdrive would keep the 5.29/35s managable at speed if I don't get insane with boost 😆
 
Posted the same thing in your turbo thread. Currently considering the same dilemma. May just go full retard and throw 5.29 in the diffs plus overdrive high range/the lowlow in the tcase + turbo with 35s just for grins. The thought being the overdrive would keep the 5.29/35s managable at speed if I don't get insane with boost 😆


If you do that you should go 37s, without doubt!!! Plus the rubber over drive should keep your highway cruising speed under 3k. Honestly with 35s and 5.29 I don’t feel the need for turbo since it’s geared so low, pretty preppy already and only down side is 60mph top speed without going into 4k range.
 
If you do that you should go 37s, without doubt!!! Plus the rubber over drive should keep your highway cruising speed under 3k. Honestly with 35s and 5.29 I don’t feel the need for turbo since it’s geared so low, pretty preppy already and only down side is 60mph top speed without going into 4k range.
Have been tempted by the lure of the 37 for quite some time now. Realistically I only need 35s but sweet lord do 37s look awesome as hell
 
Have been tempted by the lure of the 37 for quite some time now. Realistically I only need 35s but sweet lord do 37s look awesome as hell

Hell yeah! They also wheel a lot better too! If you gonna regear diff and transfer and turbo? 37 will be a must!!! That’s really having your cake and eat a all of it! Super jelly here!

I’m stopping at stock gears, low range and turbo......ok maybe 37s too.
 
Hell yeah! They also wheel a lot better too! If you gonna regear diff and transfer and turbo? 37 will be a must!!! That’s really having your cake and eat a all of it! Super jelly here!

I’m stopping at stock gears, low range and turbo......ok maybe 37s too.
Still developing a final plan, diff gears are for certain a first and then turbo down the line. Will more than likely add low range t-case at some point too so why not add overdrive high-range at that point :hmm: while its open. Need to decide what gears will go into the diffs first, plan to stay with 35s but 5.29s are very tempting especially if paired with overdrive high range gears.
 
Many complain about additional noise with UD do you find that to be true or noticeable?
Yes, true and noticeable but not loud or obnoxious, IMO. At first, you probably will not really recognize it while driving. You become tuned into the noise as you understand what to listen for. My mud terrains are MUCH louder. I notice the whine start around 20 mph. It sounds like electronic hum to me. When I pick up the Puma compressor mount from you, I will have you drive it and get your impression of the install, noise etc.
 
Yes, true and noticeable but not loud or obnoxious, IMO. At first, you probably will not really recognize it while driving. You become tuned into the noise as you understand what to listen for. My mud terrains are MUCH louder. I notice the whine start around 20 mph. It sounds like electronic hum to me. When I pick up the Puma compressor mount from you, I will have you drive it and get your impression of the install, noise etc.
That would be great. 🙂
 
Yes, true and noticeable but not loud or obnoxious, IMO. At first, you probably will not really recognize it while driving. You become tuned into the noise as you understand what to listen for. My mud terrains are MUCH louder. I notice the whine start around 20 mph. It sounds like electronic hum to me. When I pick up the Puma compressor mount from you, I will have you drive it and get your impression of the install, noise etc.

Now I’m curious how come the stock gears are silent.
 
That’s a little annoying the speedo isn’t corrected by the TC underdrive hi range gears. Its definitely not stopping me from doing it, I guess it’s just one of those things you find that has to be done as well.
 
Still developing a final plan, diff gears are for certain a first and then turbo down the line. Will more than likely add low range t-case at some point too so why not add overdrive high-range at that point :hmm: while its open. Need to decide what gears will go into the diffs first, plan to stay with 35s but 5.29s are very tempting especially if paired with overdrive high range gears.
So what's the plan? 5.29 or 4.88 with 35s?
 
Excited to see how you like your setup @Bludozer and don't forget to make a video. It helps to show how it actually rides and sounds.

In case anyone is looking for info about the UD T-case gears WITHOUT the low range gears(I couldn't really find it easily when I was looking for it). Overall, it is a great setup, it is a simple install by a competent installer or shop. I had a shop do it while I was getting a bunch of higher :banana:
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stuff done at the same time. My rig is a camping rig with some use in snow/mountain conditions. I do not rock crawl but do hit light trails every so often. As such, the lower low range gears would not have suited my needs. Moreover, the UD gears do lower the stock low range once installed, which was a nice ancillary benefit. My rig has 295/75/16 KO2s on stock FZJ80 wheels. The truck feels much more responsive from a stop and gets up to freeway traffic speed at a respectable pace now (without flooring it, which was required with the same tires and stock gears). It has made DD'ing my cruiser a much more pleasurable experience. The whine is present at over 20mph as others have noted. However, it is very low and not noticed by almost all who ride in my 80 at highway speeds. The best description is that it is like a low electronic noise/interference from the radio. It is usually drown out by road noise, the radio, or conversation. At 65 mph, it is quieter than M/T and many aggressive A/T tires. I am extremely happy I made the change and would do it again if I had the chance. If anyone is interested, I used the Sumo 10% UD gears supplied by Cruiser Brothers.

Hope that helps someone down the road.
 

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