Forum,

I'm Thinking I would like to run A modern Detroit soft/auto locker rear, Perhaps True trac in the front.

R= C8.25 29 spline 3.73
F= HP D30 idk spline 27? also 3.73

Who has run this combo or similar (not lunch box, its not an option) and what are the pros, or cons if you have experienced any?

On these gears ive gone MTR kevlars 32" max, but wouldnt mind the ability to go bigger. How does the drivability on/offroad and any noise pertaining to this LSD/Locker set up deliver in daily driving and wheeling?

 

I have TrueTracs front and rear and lov'em. Great on the street, dry, rain and snow. They also do great off road.

 

I run full case Detroit Lockers front and rear and have no issues either. If I did it over again I would install an OX selectable in my D30. You never know the front locker is there till you go into 4wd and the rear is quiet and very smooth operating.


I would suggest for that size tire or larger use at least a 4.56 gear for the best power and MPG's on highway with least amount of stress on engine and trans. I run both 33's and 35's wish I had gone with 4.88's even with the 33's.

 

My 4.56 gears and worn 33s was awful. Way too low gearing for highway use. Was really buzzing the engine with AW4 trans. Manuals are different.
Got new Duratrac 35" and the 4.56 gears are perfect.
That's just my experience and opinion, to each his own.

 

I would disagree on that and its hard on the engine and the AW4 trans not using the correct gearing, and 4.56 with a 33 is the same as stock and increased my MPGs when they were installed. The trans did not up/down shift all the time either any more from running the wrong gear and overheating on hills.

 

I think 3.73 gearing would be to tall a gear for an auto trans with 33 tall tires.
3.73 would work ok for a 30 or 31 inch tire with a standard 5 speed .
4.56 with a 33 inch tire and auto trans would be like stock gearing .

 

I'm currently running 4.10s with a nv3550 and 35s and I am actually enjoying the gearing much more than when I had my 32s.

 

I feel that 4.56's with 35's (aw4) drives pretty comparable to stock. Excellent cruising on the highway and plenty of go for stoplights around town. I would have went 4.88's but you really start getting into a tiny pinion in a D30 with that kind of gearing. I went with an ARB in my rear D44 and a lockright in the front HP30. The combination works pretty good IMO. Unfortunately the front never unlocks when you're in 4wd. IDC what you do, that thing is solid. It'll just understeer you to death. Maybe even literally one day

 

Am I compromising highway speeds for running 4.56 & 33s?

 

Auto or stick?

 

I'm running lunch box lockers front and rear. I have 4.88 gears, and the AW4 trans. The Jeep does great in town and on the highway. I turn around 2500 rpm at 70. Seems like stock. I also got 14.7mpg average on a wheeling trip a couple months ago.

 

Auto, and if i remember correctly a friend with 31st and 4.56 said 65mph was his practical highwayspeed

 

Yeah 4.56 is great for an auto and 33s but that's too much gearing for a highway driven rig on 31s.

With the 5 speed, locked front and rear, 4.10s, and 35s at 70mph I am running 2500rpms. I wish I had selectable lockers though because the Detroit causes me to nearly change lanes on occasion.

 

i run a detroit locker rear & a E- locker front 4.56 gears , 35's , aw4. perfect combo to me. on & off road. had trutracs once long ago , hated them , hardly better then open diffs.

 

And no 33s or 35s measure a true 33" or 35", especially when worn. Use next size smaller for better accuracy.

This might help the most- IIRC it is for the AW4. Stock is 27-28" and 3.55