Re-gear for H55 w/ 33s? (1 Viewer)

[LazarusTaxa]

Ok ok, I know similar questions have been asked a million times, BUT they havent been asked exactly like this AND everyone seems to love talking about it...

I've got my diffs, axles, etc all torn apart now in preparation for powder coating as part of my frame off. I'll be replacing all the bearings, seals, etc in the drive train. I'll also be adding an H55F, a 2" OME lift, and 33" KO2s (aka 32" tires).

While I'm in there, should I re-gear my diffs to 4.10?

I've driven the exact same truck I'll have with stock 3.7 gears and around town it felt great. But, pulling in 3rd or 4th, or taking it up hills in those gears, it felt a little restrained. I've looked at all the gear charts and it's hard to picture those numbers in reality.

So everyone with an H55 and larger tires, what gears do you have and what do you want?

 

[Seth S]

What I can answer is that every time I read about a 62 owner doing a H55 swap they seem very happy with 33's and the 5 speed. I think if you have everything apart then you won't be unhappy with the 4.1 diffs. I'm guessing the 3.7 diffs were intended to be paired with the 4 speed during the 50 mph road era...it was intended to optimize the stock tires with the 4 speed.

 

[OSS]

5th gear on the H55F with the 2F engine turning 31” tires (not 33”) and the stock FJ60 3:70 gears is too tall in my opinion. I had that combo for 30 years.
The sweet RPM cruising spot for the 2F is 2300 RPMs. You’ve got to be traveling over 70mph to get there with that combo - hauling ass.
I would have LOVED to have 4:10 gears in the axles, I just never could justify the expense.
Obviously 3:70 gears can and are used with even bigger tires - but it takes the engine out of its ideal powerband and loss of torque and power will leave you unsatisfied with the outcome.

 

[Godwin]

Yes regear to 4.11s or 4.10s. You can use good FJ62 front or rear differentials if you can find them. A pair of lightly used front diffs would be ideal. Another option is using FJ80/FZJ80 open rear diffs only. Either option is a direct drop in and bolt up. 80 series rear will also fit the front axle in the 60 series. FJ62 diffs are 4.11 while 80 series are 4.10, too small of a difference to matter so mixing and matching is not an issue.

I've been running H55F+4.11s+33s for ca. 15 years, it's the perfect combo.

 

[dbbowen]

4.11 will definitely be better, but I ran H55f with 3.73 on my 60 for a while with no issues on 33x12.5 tires. Your highway RPM will increase slightly with the 4.10s but with the 3.73 as long as there wasnt a bunch of hills i could cruise 70 ish mph at a good rpm no problem. This is in Arkansas though. Oregon has a bit more elevation.

 

[60Works]

2F, H55F, 4.11, and 33's is a tried and true combo.

My personal experience is that 3.70 and 32's is too high for the 2F. And that 4.11 with 32's is too low.

Its important to note that the H55F has a lower 1st that the H42. Low enough that you may launch in 2nd most of the time with 4.11's. It's tempting to want to gear for 1st knowing you may be driving in 4th some of the time. What no one talks about is that reverse is not granny low like 1st. So, if you gear high with 3.70 you'll be hating reverse.

If only we could add a 5th gear to the H42 for the city cruisers.

 

[2mbb]

I am running 33" BFGs with the H55F and 4.56 differentials. As I live in the San Francisco Bay Area, I spend a lot of time on the freeway. I find this gearing a little low (engine RPM too high at speed) especially for "normal" freeway speeds >70mph. I agree with OSS that 70mph is probably too fast for an otherwise stock FJ60, but if I want to even pretend to keep up, I am turning ~3000rpm. You have to be OK with EVERYONE passing you by...

I got the table below from this website after inputting my specifics. I'm sure my "33 inch" tires don't measure 33", so my true speeds are probably a little lower.

 

[HemiAlex]

I’ve run 3.70 gears with the h55f for 40,000 miles.

I had 33x10.5-15 k02 that we’re never more than 31.25” from new and now my 255/85-16 km3 that are 33.2” @40psi.

On my last wheeling trip I was always hunting between 2/3 on steep grades for paved roads and I found that in low range, that my i really needed to be able to stay in 2nd for my low speed travel from obstacle to obstacle gear.

4.11 would have fixed this all. It would feel perfect in my opinion. That would be comfy at 70-75 max and put me in 3rd uphill at 3250rpm going 25 for some of those steep climbs like 550 north into Ouray.

Need to get back on my 80 axle and air locker project.

 

[HemiAlex]

Gear Ratio Calculator

A great calculator for figuring out this stuff.

 

[MDH33]

I`m running an h55 with 4.88's and 255/85r16, which are basically 33's. I have my speedo corrected and I seem to be around 3000 rpm at 70. It's happier cruising around 65. You can't go wrong going up from the 3.7's with that trans tire combo. It's a 60 and 2F though, so I`ll always be in the slow lane or at the gas pump.

 

[Willard]

@HemiAlex is dead on. While great running around the flats and light hills anything to steep and if loaded up (Camping gear, RTT etc) you will want 4.11 for sure. I had just over 32" tires on mine and loaded it was a slug up hills many time dropping to 3rd or lower. In the flats 5th was the bomb, but I needed to gain momentum for the next big hill.

 

[reddog90]

We are talking about true 33s here right? Like @HemiAlex mentioned, my 33x10.5 KM3s have maybe 2k miles on them and are 31.25" on the truck. I plan to switch to 255/85/16 G003s which should feel better with my H42 and 3.70s.

 

[LazarusTaxa]

Well, seems like there is a consensus... Thanks for all the input. I will be swapping out with new gears.

 

[Dynosoar]

The speedo will be spot on with 33" tires and 4.10/4.11 difs. a great combo with the H55F.
Dyno

 

[reddog90]

Paging @FJ62DadWagon

 

[FJ62DadWagon]

Haha, @reddog90

 

[FJ62DadWagon]

I just completed 4.56s in my FJ62 w/ H55. I’m also running 33’s, Mastercraft 255/85/16s.

I’ve been running the H55 for 3 years and a few trips from Texas to Colorado. In my opinion the 4.11s have been great for highway cruiser across the plains of SE Texas but wanted to change ratios while going thru the rear diff to replace a bad pinion bearing.

The truck really struggled on some of the more challenging passes like Monarch Pass. Unable to hold 3rd gear but 2nd would be too slow. Hoping 4.56’s improve the hill highway climbs.

Just completed the job this week and will be happy to post some updates as I get more driving in.

Initial experience is that my speedometer is now spot on with a GPS. The gearing should put the trucks behavior more inline with an FJ62 with stock tires. Im now running right about 2900-3000 rpm at 70 mph. I’ll post more later.

 

[FJ60Seth]

I’m running a stock 2F, 35” tires, 4.11 diffs & an H55. I feel like it’s geared a little high. I think with 33’s it’d be perfect.

 

[2mountainfish]

I am running a fresh 2F,33s,H55 and 4:11 gears. It is absolutely perfect for a 60. I ran a H42, 33s and 4:11gears for over three years and around town and wheeling it was good but long trips sucked due to high rpm’s. Now I get better gearing off road and a much better experience on the highway.

 

[77CruiserDog]

Hey @LazarusTaxa I just came across this thread as I am contemplating 4.10 vs 4.56. As you know I'm in the midst of tossing a H55 in my rig that has 33" tires. Pretty much copying what you're doing because you're so cool.

One thing that I noticed here in Bend is that the elevation plays a large role in this discussion. My stock gears and 33" tires feel great in Seattle, not so great here in Bend.

I'm going to drive my rig for a bit both in Bend and in Seattle once it's all back together with the new trans and stock gears. But my initial thought is to go with 4.56 because 4.10 might not be enough at this altitude. I'm okay if my max speed is 65 mph.