To H55 or not, that is the question (1 Viewer)

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Guessing 100lbs? I've checked a ton of auto parts around the world but you're my hero if you pull it off.
Hello Kurt, @cruiseroutfit , I've gotten the response from Delta and their policy is they will take it if it's not 1oz over 100lbs. If it is, then it will be refused. On top of that it will be another 200$ surcharge. At this point it's too risky to fly with but wanted to post this up to spread the knowledge. Other airlines might have different weight restrictions. Thanks for all the great information and support, as always.

Cheers, James
 
Hello Kurt, @cruiseroutfit , I've gotten the response from Delta and their policy is they will take it if it's not 1oz over 100lbs. If it is, then it will be refused. On top of that it will be another 200$ surcharge. At this point it's too risky to fly with but wanted to post this up to spread the knowledge. Other airlines might have different weight restrictions. Thanks for all the great information and support, as always.

Cheers, James

Good to know. Should you decide to ship. We can have it on a pallet headed your way as soon as today!
 
I am of the opinion that the h55f is only good with 31-33” tires if you are mostly stock. If you add weight, 4th and 5th can really lug the engine down below 2000rpm at speed.

The more weight I add and wheeling I do, the more I want 4.11 gears. I’ve got the stuff, I just need to take it apart.

The bottom line for me is that I don’t need to be going above 75 mph, 4.11 will put my cruise at 2600rpm and keep me in a power and rpm sweet spot.


I’ll have 2F/h55/4.11/ 255/85-16 @ 33.2” tall in my 60 and 3FE/h55/4.11 in my wife’s 62. The 62 will be on stock tires.

If you ever drive a 3FE/h55 truck; it will blow your mind as to how good they can drive with proper fuel control and more rpm.
 
Good to know. Should you decide to ship. We can have it on a pallet headed your way as soon as today!
Great, thanks Kurt! My 2F engine is still in process so I have a bit of time before the heart transplant, so to speak. I'll definitely pick up your transfer case rebuild kit shortly so I can knock that out while I'm waiting and saving up for the H55.

Cheers, James
 
I should know this, but what year did the H55 swap become a straight swap? '85? Earlier is a nightmare?
 
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I should know this, but what year did the H55 swap become a straight swap? '85? Earlier is a nightmare?
My understanding was that builds after 5/1985 ( Mine has a build date of 7/1985) are a straight swap. If the collective wisdom can verify, that would be great.

Cheers, James
 
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I should know this, but what year did the H55 swap become a straight swap? '85? Earlier is a nightmare?

Mid 85 is the cut. However I wouldn't call it a nightmare on the earlier stuff, rather you need to work out drivelines, shift linkage and some minor things... nothing drastic.
 
I should know this, but what year did the H55 swap become a straight swap? '85? Earlier is a nightmare?
Not a night mare, you just need to work with a vendor who can work through it with you and there are several on here. I upgraded my '83. I used Valley Hybrids, bought an H55 and a transfer case shell from them and had the transfer case rebuilt at the same time. I had them ship it to me already mated and ready to install. I took out the old and sold them both. You have to exchange a couple linkage parts and have your drive shaft shortened (or lengthened? cant remember). Sounds involved but I think the driveshaft work was only $300 and not a big deal to a driveshaft shop.
 
I should know this, but what year did the H55 swap become a straight swap? '85? Earlier is a nightmare?

Completely not a nightmare. Longer driveshafts, a possible bit of grinding on the bellhousing and different shifter linkage.
 
I've been trying to wrap my brain around this gearing question and I think it's starting to make sense to me. I came up with a spreadsheet that lets me play with the numbers and work through some scenarios. This probably deserves a blog post or something but I'll just take a crack at expressing it here for now. I've marked my key assumptions in bold.

Let's say you're cruising down the highway at 70mph with a heavy FJ60. When you reach a hill you want to shift to get as much power and torque out of your beloved carbed 2F engine as possible. That means you want to be between 3000rpm and 3400rpm according to the power curves I've seen. Here are your gearing scenarios assuming true 33" tires:
  1. With the h42 and 3.73s you'll be at 2650rpm in 4th gear. To maintain 70mph in 3rd you'd have to rev to 3700rpm, completely missing the sweet spot. You'll probably slow down to 64mph and rev 3400rpm in 3rd.
  2. With the h55 and 3.73s you'll be at 2250rpm in 5th gear. When you shift down to 4th you'll rev at 2650 to maintain 70mph. This is below the sweet spot. To maintain 70mph in 3rd you'd have to rev to 4000rpm and that's not gonna happen. You'll probably slow down to 60mph and rev 3400rpm in 3rd.
  3. With the h55 and 4.10s you'll be at 2500rpm in 5th gear. When you shift down to 4th you'll rev at 2900rpm to maintain 70mph. This might be good enough for the hill. If not, you'll probably slow down to 54mph and rev 3400rpm in 3rd.
When @HemiAlex claimed the h55 and 3.73s are a bad combo for a heavy 60 series on the highway it didn't really make sense to me. This is my way of digging into the math behind that claim and I can see that it clearly holds up. The downshift to 3rd sounds pretty brutal but if we adjusted the cruising speed to 75mph I think the combo shines even better (that's 3150rpm in 4th gear).

I want to find a way to visualize this better... either a chart or a graph. Gonna sleep on it and see what comes to me.
 
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I've been trying to wrap my brain around this gearing question and I think it's starting to make sense to me. I came up with a spreadsheet that lets me play with the numbers and work through some scenarios. This probably deserves a blog post or something but I'll just take a crack at expressing it here for now. I've marked my key assumptions in bold.

Let's say you're cruising down the highway at 70mph with a heavy FJ60. When you reach a hill you want to shift to get as much power and torque out of your beloved carbed 2F engine as possible. That means you want to be between 3000rpm and 3400rpm according to the power curves I've seen. Here are your gearing scenarios assuming true 33" tires:
  1. With the h42 and 3.73s you'll be at 2650rpm in 4th gear. To maintain 70mph in 3rd you'd have to rev to 3700rpm, completely missing the sweet spot. You'll probably slow down to 64mph and rev 3400rpm in 3rd.
  2. With the h55 and 3.73s you'll be at 2250rpm in 5th gear. When you shift down to 4th you'll rev at 2650 to maintain 70mph. This is below the sweet spot. To maintain 70mph in 3rd you'd have to rev to 4000rpm and that's not gonna happen. You'll probably slow down to 60mph and rev 3400rpm in 3rd.
  3. With the h55 and 4.10s you'll be at 2500rpm in 5th gear. When you shift down to 4th you'll rev at 2900rpm to maintain 70mph. This might be good enough for the hill. If not, you'll probably slow down to 54mph and rev 3400rpm in 3rd.
When @HemiAlex claimed the h55 and 3.73s are a bad combo for a heavy 60 series on the highway it didn't really make sense to me. This is my way of digging into the math behind that claim and I can see that it clearly holds up. The downshift to 3rd sounds pretty brutal but if we adjusted the cruising speed to 75mph I think the combo shines even better (that's 3150rpm in 4th gear).

I want to find a way to visualize this better... either a chart or a graph. Gonna sleep on it and see what comes to me.

Very minor correction, but I see often repeated and I've done so myself in the past, and regarding your calculations will not make a significant difference but the Land Cruiser diff ratio is 3.70 not 3.73.
 
Very minor correction, but I see often repeated and I've done so myself in the past, and regarding your calculations will not make a significant difference but the Land Cruiser diff ratio is 3.70 not 3.73.
That helps resolve a very minor inconsistency I observed on my own rig last night, thanks. :) I'll update my original post so avoid perpetuating the confusion.
 
I too built a spreadsheet and geeked out on it for far too long. It was fun to play with all the combos and now I want 3:1 TC gearing when H55 time comes. Also, you can add 10% Under Drive to the TC instead of 4.10's.
 
That is a beauty of the H41/H42/H55F and the split case... OPTIONS!

For the t-case we have 10% overdrive and underdrive, 1:1 for high range. And 2:1, 2.3:1, 3:1, 3.3:1 and 4:1 options for low range.

You can interpolate these into your gearing options :D

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I really like my H55/4.11/35s setup for highway and off-road. But I do miss the H42 for in-city driving.

First gear is good for about 7 feet of intersection at this point.
 
I imagine this is the worst trait of the H55. Then again hard launches with H42 with 33's can be hard on clutches.
I dnt remember any "hard launches" with this set up...
 
I dnt remember any "hard launches" with this set up...
I'm talking about those times when you really wanna get moving quickly so you rev it up like you are about to drag race and have to slip the clutch to keep from stalling. I avoid doing this.
 
I imagine this is the worst trait of the H55. Then again hard launches with H42 with 33's can be hard on clutches.
It doesn’t bother me. It can roll off in 2nd with a 2F and 3.70 gears. 4.11 would be second gear starts for sure.
 

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