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It's great when a plan comes together (regearing to 4.88) :) - David at Northridge got my 4.88 gears and master kits quickly out his door and UPS delivered them today. We'll drop off the Rubi tomorrow at the shop. Forgot to ask how long it was going to take.

Ordered a Yellow Box last night from Skinny Pedal - I'll get that installed next week, it will be nice to have a speedo that I can actually use.

I know everybody likes pictures, so I took a few of the parts - hopefully I'll never see them again :cheesy:
 

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Jeepless in PA
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Those are nice. What fluid are you going to put in the axles?
 

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Use plain old gear oil for the first 500-1000 miles! It is very important for break in. Then you get to drain it all out, throw it away and put you in some good/better oil. Many on here use/recommend Royal Purple or full synthetic Mobil 1. I prefer the Royal Purple in this situation.
 

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Discussion Starter #6
SweetPee said:
Use plain old gear oil for the first 500-1000 miles! It is very important for break in. Then you get to drain it all out, throw it away and put you in some good/better oil. Many on here use/recommend Royal Purple or full synthetic Mobil 1. I prefer the Royal Purple in this situation.
I read (I think) on Jeep Forum the guys like Royal Purple as well. Some of our auto parts stores carry RP - I'll have to try to remember which ones.

Thanks guys!

Edit: I suppose I should hang on to the 4.11 gears - any value in the stock ratio gears?
 

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johncanfield said:
gregert12 said:
Those are nice. What fluid are you going to put in the axles?
Um, whatever you recommend? :laugh:
Talk to Dave at Northridge 4x4. He uses a synthetic oil for break-in and has a very stringent break-in procedure. It is very important that you keep the new gears from getting too hot during the break-in period.
 

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Regarding break-in, I would stick EXACTLY to what your INSTALLER says. He's the guy doing the work and performing warranty repairs should there need any. There are tons of gear "break-in" procedures and it seems they all vary by who is installing them. Regardless of what you've heard elsewhere, who says to do what which way, ultimately the guy who installs them is the one you need to listen to regarding break-in. If you don't do it his way, he likely won't warranty them if they fail. This is one area I play by the rules and do as I'm told. Some guys "break-in" is drive it like you stole it from the get go. Some say it's not needed at all, others have very strict procedures involving driving certain mph for x amount of time then let it cool sufficiently and repeat cycle over x amount of miles, then swap at 500 or 1000 or whatever... There is no RIGHT way to do this, just what your installer recommends.

On oils, huge can of worms there and tons of compost to sift through. As RP was mentioned above, I will agree I've been running this throughout my rig since my original OPDG failure at under 1000 miles. I run RP Syncromax in tranny and t-case, have been running RP 10w30 in engine but due to higher ZDDP levels in 10w40, I'm switching that in shortly. In the diff's I run RP max gear 85w140 due to my wheeling and towing which tend to work things more than standard highway driving. Works great with both my factory front locker and ARB in the rear, very smooth, very quiet and no issues thus far. Some will argue the price makes it tough to swallow and I agree, but the local boys here buy it by the pallet for the race track so we get good discounts buying a full case of stuff. For me, it's about the same as every other synthetic out there and cheaper than a few. Do what your gear guy says on install and when you flush and swap to regular fluid, run what you feel comfortable with. As to change intervals, I change mine when needed. That means if I run through deep water, I change it out. If I'm towing hard more than normal, I change it earlier. Same for tranny and t-case. DC says it's a lifetime fluid in the tranny-mine was near empty when I changed it from stock. I change it often too. Peace of mind and swapping fluids out early are cheap insurance to help avoid costly larger repairs-especially if water is in play.

Best of Luck,

Mike
 

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Discussion Starter #9
Thanks Mike!

I read the 50 page long or so thread on Jeep Forum about the OPDG failures and one line of thought about the root cause of the gear failures was reformulated oils with lower zinc levels. It certainly got my attention and I have been listening for the 'angry sparrows' every time I start the engine :wink:

Looked in my owner's manual and noticed DC recommends a dino gear oil for the front differential and a synthetic for the rear diff if you tow (or I assume hard wheeling.) I'll talk to the mechanic about his recommendations for oil, but running synthetic sounds like a good plan for me.

I need to change the engine oil, so I might as well go with the good stuff. Noticed the transmission fluid level is way too high for a cold engine :eek: . I asked the mechanic to give the suspension and drive train a good look-over, so I'll report back with any news.
 

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Discussion Starter #10
Yea! We're regeared!!

Whoo-hoo :D We're re-geared!

Drove it home the 25-odd miles, mostly Interstate with pretty decent grades and our somewhat hilly ranch road and the 4.88 gears made a humongous difference :cheesy: . On the interstate the speed control kept the speed +- 1 MPH. We were running at 2500 RPM and doing 70 MPH (with about 78 MPH indicated on the speedo.) On our ranch road, we were +- 1-2 MPH which was great.

Back home I put it in 4-low and checked the lockers - all good.

The mechanic said no problem getting the R&P's set up and I can confirm all is quiet.

Edit: 4.11 gears for sale!
 

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Discussion Starter #12
No vibration and no gear noise :) - I'm very pleased with the work quality. Closest city to us is Kerrville, TX and we're about an hour NW of San Antonio in the hill country (as they say around here.)
 
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