4.10 gears for front diff

Edwin · **Posted:** Wed Jan 11, 2006 11:43 pm

Does anyone offer 4.10 gears for the front diff besides the dealer yet? Has anyone got a price from a dealer yet?

ManicMechanicJoe · **Posted:** Thu Jan 12, 2006 1:47 am

i believe you cheapest and only option besides the dealer is go find a wrecked 4 cylinder KJ in the junkyard and buy that diff... RRO says they offer front gears but I doubt they will fit (probably D30 gears not D30a gears)

Jeepin Al · **Posted:** Thu Jan 12, 2006 9:38 am

Ok Guys and Gals,

I am having (I only trust OK 4 WD in Stewartsville, NJ to fondle my loved one, no other shop, unless I was there helping has worked on her :shock:

) 4.10 gears installed, along with a new diff case, and one of the first sets of JE Reel HD half shafts installed. The 4.10 gears for the front are still only available from the dealer (as of the end of last year). If I remember correctly the gear set and rebuild kit from MOPAR cost me $300. I paid $650 for the front gears and empty case. The rear 4.10 gears from MOPAR were really expensive. The cheapest way to get the gears most likely would be to get a unit out of a wrecked KJ. They are hard to find. The diff case I had reinforced by welding a ring around the pinion bearing seat, and I had a plate welded to the one side closest to the engine. Hopefully a light foot and the reinforcement will bring me to Moab, wheeling in Moab, and back home!

I have been collecting the parts for the swap for a little over 2.5 years now. I finally am getting everything installed :lol:

Let everyone know how the acceleration, and off roading improves (I hope) with the new gear set.

Al

JJsTJ · **Posted:** Thu Jan 12, 2006 12:10 pm

Got any pics of those diff case reinforcements?

Eddo · **Joined:** Thu Jul 07, 2005 7:01 pm **Posts:** 1214

Thats cool Al. Let us know how it goes and please do post some pictures.

Edwin · **Posted:** Thu Jan 12, 2006 3:43 pm

I got a price from the dealer of $350 plus tax for 4.10 gearset. Hows that sound?

Eddo · **Joined:** Thu Jul 07, 2005 7:01 pm **Posts:** 1214

Will the 4.10 gear set from the dealer fit in the current diff case? Also do you need a different carrier for the 4.10s?

ManicMechanicJoe · **Posted:** Thu Jan 12, 2006 4:32 pm

the 4.10 gear set will work in our case as it was designed for 4 cylinder KJ's with the same case. I believe you do need a new carrier but don't quote me on that.

benmar2000 · **Posted:** Thu Jan 12, 2006 6:04 pm

Hey Jeepin Al - I got my Ford 8.8 for my YJ from OK 4WD.. They were pretty cool when I ordered it..

Ben

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

The dealership 4.10's will fit the front, but you'll need a new carrier. My mechanic found a low milage front diff from a 4 cylinder for $550 for mine. The 4.10's on RRO's site will not work and they've known that for almost a year now after selling them to me. The rear's on their site are Yukons fron Randy's Ring and Pinion, and will work. Make sure you get the rebuild kit. The 4.10's will make it a little quicker off the line, and give it some more torque at low rpm. It will cost you about 2-3 mpg at interstate speeds, but I got about an extra 1 mpg in the city.

Jeepin Al · **Posted:** Thu Jan 12, 2006 7:21 pm

Just got my KJ back. I can't really notice any difference except of the shift points are different and the speed in which my driveshaft vibrates is different. The new JE Reel half shafts make no noise at all, and the front end feels tighter (my imagination most likely). My KJ is lifted in the front around 3.75-4 inches, even my arms are hitting the springs at full droop. The half shafts are nice and quiet, time will tell if they stay that way.

The 4.10, at least in my 2002 didn't need a new carrier, but what I didn't have in the bag of tricks I gave OK 4WD was the carrier bearings. As a rule they change the carrier bearings when they do a gear change.

So hopefully pulling my trailer will be easier, and the true test will come on the 21st, at Paragon.

Al

PS if any of you out there in KJ land order from OK 4wd ask for either Chuck, or Cortney and tell them that Al Handy recommended them. They may hang up on you after you say that, but at least they know I am thinking of them!!

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

I forgot about the shift points. Mine were all messed up after going to the 4.10's also. I also went with a custom torque converter at the same time which may have caused part of the problem. You probably need to reset your ECU to get it to learn the new setup quicker. Like I said, the 4.10's will only make it a little quicker off the line, and add a little more torque. There just isn't a big difference from 3.73's.

hankwood · **Posted:** Fri Jan 13, 2006 7:03 pm

great, jeepin al. i was glad to hear the front gears worked out with the welding modifications you made to the case. since i custom build axles myself, i know how careful you have to be when welding on the case not to affect the centerline relationship between the ring and pinion, otherwise it can be very hard to get the lash and pattern right so they will not make lots of noise, or wear out the pinion bearings in a hurry.

Jeepin Al · **Posted:** Fri Jan 13, 2006 7:20 pm

Thanks!

I have to put all the complements on my buddy who owns the tool and machine shop and his top welder. The company makes all kinds of hi-tech weapons for the military. So when I went over there, the welder came out said, "hmmm.. I have to be careful not to warp this...and I will have Joey machine a ring out of a plate for the pinion". It was really great watching real machinists working at their trade!

Al

Eddo · **Joined:** Thu Jul 07, 2005 7:01 pm **Posts:** 1214

Jeepin Al wrote:

Thanks!

I have to put all the complements on my buddy who owns the tool and machine shop and his top welder. The company makes all kinds of hi-tech weapons for the military. So when I went over there, the welder came out said, "hmmm.. I have to be careful not to warp this...and I will have Joey machine a ring out of a plate for the pinion". It was really great watching real machinists working at their trade!

Al

You have any picture of it Al?

4.10 gears for front diff

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