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4.10 versus 4.56

Thanks for the feedback. I trailer it to the events that I go to.... well as long as I am able to borrow a truck and trailer. Been lucky in that front over the last year and 4 events.
I've heard about the Tera issues but came across this one and figured I'd give it a shot.


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On my 33's, 65 mph is about as fast as I need to go. I have a vehicle built for going slow. Usually when the question comes up as to use 4.10 or 4.56, the tire size in question is 32 inch. My vote is for the 4.56 ratio.
 
The planetary gear set will sometimes self destruct. There is a bronze bushing in there which does not like high RPMs. Terra recommends not exceeding 2800 RPM in any gear so as to keep the bronze bushing from self destructing. I ran one for a while, never had an issue. Ran Redline synthetic ATF fluid in it. Sold the case to someone else, that person still runs it.

Interesting.
Shouldn't be hard to spec out a better bushing.
 
Interesting.
Shouldn't be hard to spec out a better bushing.

the bushing is only have the issue. the other half is oiling.

at high RPMs it suffers from oil starvation. this is why tera does not recommend it for high RPM applications. if you like mud, hill climbs, sand, or going fast and doing so in low range... the tera kit is not the kit for you.
 
Since you operate your rig in sub-2500ft elevation, 4:56's with an auto is my suggestion.
Ive run this combo at my elevation (4300 street -10,000ft trails) and 4:56's suck on the freeway. I've run 4:88's with 33's /auto trans for 9 years and never regretted this gearing choice. 75mph =2850 RPM =16mpg on a 215k mile engine.
 
I run 33's (Well, 285/75/16's actually, but close enough) A HP30 with a Detroit TrueTrac and a D44 with a factory Trac Lok.

I run 4.5" of lift and have a WJ brake and OTK conversion up front.

I have 4.56 gears installed and I have zero complaints with driveability.

On the freeway at 60 mph I'm at 2,100 rpm. There's sufficient power for passing and the fuel economy is reasonable for what the vehicle is intended for.

I did a lot of research before choosing 4.56's and I would go with them again if I were to build another XJ.
 
On my 33's, 65 mph is about as fast as I need to go. I have a vehicle built for going slow. Usually when the question comes up as to use 4.10 or 4.56, the tire size in question is 32 inch. My vote is for the 4.56 ratio.

I have 4.56 gears and 32" (31.5" actual). It runs about 300 rpm over stock, which helps on hills.
 
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