Removed (1 Viewer)
- Thread starter OwnerCS
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
- Status
JunkCrzr89
Competent Ignoramoose
I have two sets of the 3:1 gears sitting here since April waiting for me to install in my 80 and 100… My plan was to install them in the 100 without dropping the t-case because it currently has no leaks or any reason for me to suspect bearing wear (knock on wood). The 80’s t-case is pissing oil everywhere though, so I had planned to drop it and do a full reseal when swapping the gears.
I think @peacesells63 has done a few of these installs on both 80s and 100s, so he can probably advise on the best approach.
I think @peacesells63 has done a few of these installs on both 80s and 100s, so he can probably advise on the best approach.
JunkCrzr89
Competent Ignoramoose
I overlooked this part. You’re in AR, right? Ozark Overland Outfitters in West Plains, MO is just across the border and they’re a Cruiser specialty shop that may be able to do it for you.
Anyone on here have some insight on the price difference here:
~$500
cruiserteq.com
Vs. your link for the Sumo Gear at $725? Figured I'd ask here before calling...
rjones
~$500
Trail Gear Land Cruiser Transfer Case 3.1:1 Low Range Gear Set - Fits 8x/100 Series
Low Range Gear Reduction Sets for Toyota Land Cruiser Applications
cruiserteq.com
Vs. your link for the Sumo Gear at $725? Figured I'd ask here before calling...
rjones
Trail Gear isn't exactly known for quality but I have zero experience with their gear sets. Hope this helps!Anyone on here have some insight on the price difference here:
~$500
Trail Gear Land Cruiser Transfer Case 3.1:1 Low Range Gear Set - Fits 8x/100 Series
Low Range Gear Reduction Sets for Toyota Land Cruiser Applications
Vs. your link for the Sumo Gear at $725? Figured I'd ask here before calling...
rjones
JunkCrzr89
Competent Ignoramoose
TrailGear is made in China. Sumo is made in Japan. Definite and well-known quality difference.Anyone on here have some insight on the price difference here:
~$500
Trail Gear Land Cruiser Transfer Case 3.1:1 Low Range Gear Set - Fits 8x/100 Series
Low Range Gear Reduction Sets for Toyota Land Cruiser Applications
Vs. your link for the Sumo Gear at $725? Figured I'd ask here before calling...
rjones
Bomar
SILVER Star
I installed the trail gear set at 180k miles. Have 293k on the rig now with a lot of 4 low miles. Definitely a noticeable increase in gear noise in 4 low but only when in higher gears and higher RPM. The control is absolute worth it! No changes at all in 4 high and daily driving.Anyone on here have some insight on the price difference here:
~$500
Trail Gear Land Cruiser Transfer Case 3.1:1 Low Range Gear Set - Fits 8x/100 Series
Low Range Gear Reduction Sets for Toyota Land Cruiser Applications
Vs. your link for the Sumo Gear at $725? Figured I'd ask here before calling...
rjones
I’m going to assume that the Japanese made gear are of superior quality, but over 100k on the TG stuff now with plenty of extended high RPM 4low In the snow and dunes using all the ponies. Zero issues or complaints
hoser
SILVER Star
Late to the discussion but if low speed engine braking is what you want, another possible way to do it would be a manual torque converter lock-up and valve body modification to get it to work in 1st and 2nd gear. Probably about the same cost as 3:1 gear swap though.
hoser
SILVER Star
IIRC, even with just changing the low range, I think you still have the possibility of added gear whine in HI range.... and that was what you mentioned as your concern.
With 3:11 LRR you’ll need the 80series input shaft- that’s some extra cost and labor- did you order that as well? Cruiser tech was supposed to update the web page to make sure you ordered that kit for a 100 series.
I did the math on low gear reduction and input shaft and for the money re gearing diffs to 4.88 came out on top. 3.11 low range reduction gearing and adding the 10% high range gets you a comparable to 3.56 re gear. 10% high range under drive gets you better drive ability with 33’s & 34’s. consider doing both tc while you got it all apart.
I did the math on low gear reduction and input shaft and for the money re gearing diffs to 4.88 came out on top. 3.11 low range reduction gearing and adding the 10% high range gets you a comparable to 3.56 re gear. 10% high range under drive gets you better drive ability with 33’s & 34’s. consider doing both tc while you got it all apart.
Last edited:
Question for installation of Sumo under drive gears in the transfer case of a 2006 Land Cruiser 100 series!
Guys, I purchase Sumo transfer case gears for my 2006 land cruiser 100 series, to reduce the High gears in the transfer case by about 10%. I had a local shop who specializes in land cruisers install the gears in the transfer case. They have installed transfer case gears many times before. And...
forum.ih8mud.com
Following with interest. My truck is riding on 34 5" tires and has 4.88 diffs. I still think the first gear is too high in low range.
No input shaft needed for just low range gear set. Your literally just changing out the gears. Clearencing of the inside of the case with a grinding wheel is required but pretty easy.
Input shaft swap is needed for certain years for the high range only. I’m a little muddy on those years but cruiser outfitters can set you straight. Was required for my 2000. That and whine is why I haven’t gone that route as well.
I have noticed no increase in gear noise in high range, center diff locked or unlocked for over 100k with just the 3.1:1 low range gears.
In my opinion one of the best mods for off road control in the 100 series.
Thank you to all that contributed to answering my questions. I want to provide an ending to the thread.
1) 4H is a bit quieter than before the modification. Jason Harris found the original rear output shaft bearing was worn. This may have been contributing to the seal leak. Before the new gears and bearing, I could feel some transfer case vibrations being transmitted via the shifter. The slight vibration is now gone.
2) I can now crawl and descend rocky ledges at a walking speed. 4L in 1st has a top speed of 10 to 12 MPH before I start revving higher than I want.
3) 4L is now just another lower gear ratio. I control CDL through the CDL button via the 7-pin modification.
4) I can use 2nd start in 4L if I need to start with higher gearing.
5) I have not noticed any abnormal noise in 4L. It sounds like it did before the mod. It may be less noise now because of the new rear output shaft bearing.
6) I can now cut short on switchbacks in 4L without worrying about CDL binding. This may let me turn some 2 point switchbacks into 1 point.
7) No leaks with the new seals.
At this point, I have no plans to regear the front or rear diffs. If I'm not off-roading in a lower gear, then I'm looking for economy on the highway.
Driving through the mountains and in town traffic, I turn off OD on the 100 and my other vehicles with this option. Nothing new there.
Thanks to Jason Harris at Ozark Overland Outfitters for installation and Cruiser Outfitters for stocking this part, I am very satisfied with this modification.
Specializing in Toyota Land Cruisers
Full service shop providing all your offroad parts, and fabrication and Mechanical needs. Ozark Overland Outfitters, 80 series, 100 series, 200 series.ozarkoverlandoutfitters.com
Sumo Gear Land Cruiser Transfer Case 3.1:1 Low Range Gear Set - Fits 8x/100 Series
Low Range Gear Reduction Sets for Toyota Land Cruiser Applications
Thank you!
Just curious if I install the 10% under drive high range gear set, would that also have any effect at all on my low range gearing? I’m going to order some gears from Cruiser Outfitters in the morning.
jLB
Another one followed me home. Can we keep it?
If I remember correctly, Kurt ( @cruiseroutfit ) did post a chart on this forum at one point, that showed the interaction between the overdrive/underdrive high range gears, and the low range gearing, and I believe that it did have a minor effect.
(Edited to add the post/chart that I was thinking about)
YWST: Low Range T-Case Gear Sets for the 1980-2007 Cruisers
How about the High range reduction and the low range reduction kit in the same case? is it possible? 100% doable!
forum.ih8mud.com
Last edited:
Here is what I found out ... does the high range underdrive also affect the low range ... yes ... slightly.
Stock idler (39t) / stock input (33t) ~ 1.182:1
UD idler (39t) / UD input (31t) ~ 1.258:1
1.258/1.182 = 1.065
Where in high range the UD set output (34t) / input (31t) gets you 1.097 and X the 4.10 gives an effective 4.50 gear ratio with the UD gears. If I upgrade to 4.88 it gives a 5.35 effective differential gear ratio, a little much for 35's I think.
Following the above maths, after installing the 25% low range kit as well we get to multiply 1.065 to the 3.11 Low Range gears to give me an effective 3.31 low range gear. Not bad.
If I keep the 4.10 stock ring and pinions in 1st gear low range the ratio will be 1.065 x 3.11 x 3.52 x 4.10 = 47.8 (where 3.52 is the stock 1st gear of the A750F 5 speed)
If I upgrade my 4.10s to 4.88s (this is primarily an off-road rig) then the lowest possible crawl ratio on a 100 series will be 56.9 to 1 with BOTH Sumo Low and Sumo High Range reduction gear sets in the T Case.
This being correct, a 56.9 to 1 ratio with an automatic is pretty wild considering a stock for my year truck is 35.21 to 1 ... in a manual transmission, you would need about an 85 to 1 ratio to be equivalent which is subsequently about what the stock Rubicons have.
Can any of you guru's check my maths? I may not do the 4.88s when I do my e-lockers (whenever I can find a shop that can put them in) and opt for one step down. I don't think I will ever run bigger than the 35" tires I have now.
(Don't forget Kit part# TCG9807HRKIT which incidentally is more expensive than the gears themselves? Not b*@#&ing I already bought them, just didn't get a very good explanation as to why the $$ and wasn't prepared for it). I know the HF2A in the 100 series, Toyota decided to use a one-piece input shaft so that High Range gear can't just be swapped out, need to have a new input shaft.
Stock idler (39t) / stock input (33t) ~ 1.182:1
UD idler (39t) / UD input (31t) ~ 1.258:1
1.258/1.182 = 1.065
Where in high range the UD set output (34t) / input (31t) gets you 1.097 and X the 4.10 gives an effective 4.50 gear ratio with the UD gears. If I upgrade to 4.88 it gives a 5.35 effective differential gear ratio, a little much for 35's I think.
Following the above maths, after installing the 25% low range kit as well we get to multiply 1.065 to the 3.11 Low Range gears to give me an effective 3.31 low range gear. Not bad.
If I keep the 4.10 stock ring and pinions in 1st gear low range the ratio will be 1.065 x 3.11 x 3.52 x 4.10 = 47.8 (where 3.52 is the stock 1st gear of the A750F 5 speed)
If I upgrade my 4.10s to 4.88s (this is primarily an off-road rig) then the lowest possible crawl ratio on a 100 series will be 56.9 to 1 with BOTH Sumo Low and Sumo High Range reduction gear sets in the T Case.
This being correct, a 56.9 to 1 ratio with an automatic is pretty wild considering a stock for my year truck is 35.21 to 1 ... in a manual transmission, you would need about an 85 to 1 ratio to be equivalent which is subsequently about what the stock Rubicons have.
Can any of you guru's check my maths? I may not do the 4.88s when I do my e-lockers (whenever I can find a shop that can put them in) and opt for one step down. I don't think I will ever run bigger than the 35" tires I have now.
(Don't forget Kit part# TCG9807HRKIT which incidentally is more expensive than the gears themselves? Not b*@#&ing I already bought them, just didn't get a very good explanation as to why the $$ and wasn't prepared for it). I know the HF2A in the 100 series, Toyota decided to use a one-piece input shaft so that High Range gear can't just be swapped out, need to have a new input shaft.
Last edited:
hoser
SILVER Star
If you really wanted to, you can use 80 series gears (in 5.29 ratio). But you would have to piece together a hybrid rear locker.
- Status
