4:1 gears in a 34mm split case (1 Viewer)

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I usually left it in 1-2 with 37s. Really looking forward to the lower speeds. Will help having more control Is all terrains but specifically the rocky parts. My only saving grace before was the F engine could really lug down low RPMs.
 

wngrog

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4.11's with 33" tires is very close to 3.70's with 235/70's or 4.56 with 35's. The 10% reduction only applies to high range. It make 3.70 into 4.10s, 4.10's into 4.56's, 4.56's into 5.0's. The Sumo gears are $1000.
Funny you say this.

I made this photo today to show that ON THE HIGHWAY it’s hard to justify the expense of an H55 and 4.10 gear swap over 3.70s and an H42

Top.....3000 RPM in my FJ60 with 32.5” tires, H42, 3.70s
Bottom 3000 RPM in my FJ55 with 32.5” tires, H55 and 4.11s

The 60 speedo is 10 mph slow. The 55 is dead on.

78 mph v 81 mph for about $5000........

Again. For the road? No. The trail? Yeah that 1st gear is great in the H55. On the street it sucks.

If I did a lot of technical rocks I would do a 3:1 set of Tcase gears over the 4:1 because the 3:1 retains the stock high range gear and you don’t get the noise of the straight cut gears on the highway.

Also as I said above. The Snioer does an amazing job making up for lack of low gearing as well keeping you at idle speed. I was pretty shocked how well my Fj60 with the H42/3.70s did on technical climbs now versus when it had a carburetor

939F33BA-A53D-45FB-B7A7-77A491AC6D1C.jpeg
 

MoaByte

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Funny you say this.

I made this photo today to show that ON THE HIGHWAY it’s hard to justify the expense of an H55 and 4.10 gear swap over 3.70s and an H42

Top.....3000 RPM in my FJ60 with 32.5” tires, H42, 3.70s
Bottom 3000 RPM in my FJ55 with 32.5” tires, H55 and 4.11s

The 60 speedo is 10 mph slow. The 55 is dead on.

78 mph v 81 mph for about $5000........

Again. For the road? No. The trail? Yeah that 1st gear is great in the H55. On the street it sucks.

If I did a lot of technical rocks I would do a 3:1 set of Tcase gears over the 4:1 because the 3:1 retains the stock high range gear and you don’t get the noise of the straight cut gears on the highway.

Also as I said above. The Snioer does an amazing job making up for lack of low gearing as well keeping you at idle speed. I was pretty shocked how well my Fj60 with the H42/3.70s did on technical climbs now versus when it had a carburetor

View attachment 2457535
I do agree with you. The Sniper works well with the stock gearing on the street. If you went H55 and kept the 3.70's Ol' Blue would get more grunt in 1-3, 4 would be the same, and fifth would be either 92 mph (2900 rpm) or a 400 rpm reduction. Granny low, would be slightly slower by about 2 ft per second at 1400 rpm.
4.10 R&P and you would be shifting too often in traffic.
I've always liked having reverse close to my knee with the H42. It also leaves room for the Black Box or Marlin Crawler.
 

HemiAlex

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Not saying that at all.

But how does efi change gearing at idle? Just wondering.
 

wngrog

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Not saying that at all.

But how does efi change gearing at idle? Just wondering.
You don’t have to work the clutch. It keeps the idle at crawl speed for you without dying.
It’s actually a real different feel than any of my other vehicles. Just keeps you steady and allows you to take your mind off one thing....keeping the truck running.

My 55 with H55/split/4.11 is plenty slow for what it is. I don’t Rock crawl it often but where I have had to....the 41:1 seems fine. Sure it could be slower but again, that’s maybe 1% or less of my driving and I can deal with it.
 
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Ran into a little snag on reassembly today. I ordered the gears and adapter idler pin from advance.
The idler pin came with 34mm bronze thrust washers but I’m pretty sure they need to be 38mm.

Also does the 38mm case use a spacer between the bearings on the idler shaft?

Thanks, Max
 
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Not sure the fsm will help much. I was referring to the “Idler gear shaft”.

The 4:1 gear set is manufactured around a 38mm idler shaft, mine is a 34mm. There is an additional kit that is used to make the gears work in a 34mm. It utilizes a 38mm shaft that steps down to 34mm on the ends where it fits in the case.

Im curious if the thrust washers need to have an inner diameter of 38mm instead of the 34mm ones that advance adapters sent me with the adapter idler shaft. Because they currently willget smashed between the step in the idler shaft and the case half’s.

1732FF8E-630B-4730-9203-A15EB0E45290.jpeg


31B586B2-FA4C-4B45-BEF9-421C3648F1DC.jpeg
 

NookShneer

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Not sure the fsm will help much. I was referring to the “Idler gear shaft”.

The 4:1 gear set is manufactured around a 38mm idler shaft, mine is a 34mm. There is an additional kit that is used to make the gears work in a 34mm. It utilizes a 38mm shaft that steps down to 34mm on the ends where it fits in the case.

Im curious if the thrust washers need to have an inner diameter of 38mm instead of the 34mm ones that advance adapters sent me with the adapter idler shaft. Because they currently willget smashed between the step in the idler shaft and the case half’s.

View attachment 2458825

View attachment 2458826
I’ve never used the 34 step set-up, but that looks correct. The thrust washers have a tab that is pressed into them that you index in the exterior case halve. It should eliminate them from spinning against the outer case half and wearing the aluminum. How you have them currently looks like it would work fine.
 
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I’ve never used the 34 step set-up, but that looks correct. The thrust washers have a tab that is pressed into them that you index in the exterior case halve. It should eliminate them from spinning against the outer case half and wearing the aluminum. How you have them currently looks like it would work fine.
With a stepped pin the clearances will a fixed measurement, but with a regular style, they will be variable.

You don’t think it may add too much clearance and not allow the case halves to fully bolt together? Also causing excessive play in the idler gears?
 
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cruisermatt

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With a stepped pin the clearances will a fixed measurement, but with a regular style, they will be variable.

You don’t think it may add too much clearance and not allow the case halves to fully bolt together? Also causing excessive play in the idler gears?
I see what you are asking.
Did you take any measurements of anything? I would first just put the case 1/2's together with the idler pin and the thrust washers but without any gears and see if it seats all the way nicely. That should pretty much tell you.
 
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I see what you are asking.
Did you take any measurements of anything? I would first just put the case 1/2's together with the idler pin and the thrust washers but without any gears and see if it seats all the way nicely. That should pretty much tell you.
Was planning to give this a try on my lunch break today. I’ll see what I come up with.
 
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I see what you are asking.
Did you take any measurements of anything? I would first just put the case 1/2's together with the idler pin and the thrust washers but without any gears and see if it seats all the way nicely. That should pretty much tell you.
I’m pretty confident that I will need 38mm thrust washers. In your thread 34mm vs 38mm Kurt talks about their Japanese stepped idler shaft and specifically states it uses 38mm thrust washers
 

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