Regear the diffs or the T-Case??? (1 Viewer)

[TN_LandCruiser]

I was in discussion with fellow mud'r about plans for my rig...which include 35's and 4:88's sometime in the future.
His suggestion was not to get away from the strength of the 4:10's, but to regear / replace the T-case.

Currently its about a 20% on 80% off road rig...but I am hoping to get to about 50/50.

Would regearing the t-case give me the reduction in high range to assist with moving the big meats on the highway or would that only effect the low range power?

 

[wfd175]

It is my understanding that for some reason that you cannot regear the t-case.

 

[sandcruiser]

it'll depend entirely on what gears you choose for the case.

You might look around the board some, and read what others have written about 4.88 and 35s. You might also consider 4.56 gears instead as a middle ground.

and... what style of wheeling do you do? mud? rocks? beaches? ie: how badly do you need a very low crawl ratio?

 

[chibo]

Regearing the tcase will just change the low range gears. I don't know of 80 tcase gear kits that change high range.

 

[TN_LandCruiser]

Im in the mountains of TN. Mud, hills, rocks...not partial to any one area.

The general concenus around "mud" that I have seen is the under powered, but very reliable 3Fe is very happy with 35's and 4:88's, but the integrity of the gears may be a different story...hence the suggestion for the t-case.

This is also being suggested by someone that wheels at a different level than me...just a "lessons learned" perspective from him...but he doesnt use h-range...he roles in L-range 95%, which is where my questions spawn from...will regearing the t-case in a full time 4x4 effect both high and low range or just low.

 

[chibo]

Im in the mountains of TN. Mud, hills, rocks...not partial to any one area.

The general concenus around "mud" that I have seen is the under powered, but very reliable 3Fe is very happy with 35's and 4:88's, but the integrity of the gears may be a different story...hence the suggestion for the t-case.

This is also being suggested by someone that wheels at a different level than me...just a "lessons learned" perspective from him...but he doesnt use h-range...he roles in L-range 95%, which is where my questions spawn from...will regearing the t-case in a full time 4x4 effect both high and low range or just low.

Low range, because the only two kits I know of replace just low range. They're quite a bit more expensive (3 times more so, iirc) than regearing both diffs.

Rockhopper and Marks4wd both have gearsets.

 

[CreeperSleeper]

I vote both!

 

[LilblkDuck]

Marks4wd sell the Gearmaster, reduction gear sets for the 80's HF2A t/fer case from 2.488 to 3.115 which only equates to a 25% reduction. This will not change your high range.
The other option$$ is the Cruiser Crawler which gives you both low range and a small change to high range but its 3x the cost and you'll need a 2" bodylift or mod the floor pan to fit it.

Personally I'm tending towards re-gearing my diffs to return some of the power lost to running 37's all the time. As I run an Auto, Im not overly concerned about breaking stuff given my first gear is no where near as savage as a Manual. 2.95:1 vs 4+:1! Having said that I intend to use treated crown and pinion in the front hi-pinion.
Pick the gearing that will see your 1:1 gear (3rd for an Auto, 4th for a manual)on the torque curve at what ever your cruising speed is and your OD should fall to 800-1000 below this.
So in my case @ 3000 rpm Im doing 67mph in 3rd, and 2200rpm in OverDrive when I run 5.26:1 diff's with 37" tyres.
For 35's theres about 4mph difference between 4.88's and 4.56's at the same rpm. I'd go the 4.56's if you tour alot or have a manual, and 4.88's if you tend to play more than clock up K's.

Later on you could always add those 25% gears!

 

[MJADDICTION]

Unless your going out west and hammerring on the traction of slick rock, you'll be allright with a diff gear swap. Especially the 4:88's...

Now will you be happy with 4:88's and 35's. I would say not. I would go with 5:29's for the 35's.
My 4:88's and 33's, that measure a bit over 32"es, are perfect for the cruiser. They were better with the 31's though.

Do you really need 35's?

Oh, and the gear reduction to the t-cases are usually the low range only. Unless you want to go with a STAK, or the newer Atlas. Not sure if they fit the 80. But, they cost a hell of a lot more than just regearingthe axles.

 

[alia176]

Curious, can a HF2A fit in the place of a HF2AV in a FZJ80?