diff fluid? with arbs

[dmille4.6]

i know i am going to reopen a can of worms but i wanted to know if there is any certain diff fluid to use on a 02 Tj with arbs front and rear. ive read several threads here but didnt see anything specific to arbs? i was planning on using syncromesh.

[Bounty__Hunter]

Standard gear oil is fine, I would avoid synthetics in the differentials.

[dmille4.6]

why would you avoid synthetics? do you just use like napa 90w? even with arbs?

[jfrabat]

I hav ARB's fron and rear, and I just use regular oils. I dont use synthetics ecause I change them often (especally if wheeling in Mud or crossing rivers, you better change them often!)

[dmille4.6]

ok, yeah thats why im changing them now. we through a couple of creek crossings saturday and had water rolling in over the rockers. ended up tearing a rear pinion seal somehow. i replaced it saturday evening and was refilling the diff. i just got this jeep and was goin to go ahead and change everything anyway. thanks what weight do you use jfra?

[jfrabat]

75W-90 is fine. If you run in very hot weather, or tow a lot (or both), you can go up to 80W-140 (according to the Jeep service manual; I have not gone that high myself even though I live in Miami).

[dmille4.6]

ok thanks. jfra how often does your arb compressor kick on when your locked?

[jfrabat]

Typically, once; more than that and you have an air leak somewhere... Of course I also use it for airing up and runing air tools (I have a small portable tank; it only gives you a couple of uses, but sometimes that's all you need!).

[dmille4.6]

alright, mine kicks on once when i first turn it on and prob every few min if i stay locked, so i probably got an air leak somewhere? any easy ways to track it down besides spraying everything with soapy water? ie. first places to look? i also have the tire inflation kit where you can just hook up a hose.

[jfrabat]

The only way other than that is to measure the air pressure in each line, but that will be a bit complicated without actually cutting the lines... Of course, you can always use a quick connector after cutting the lines (I always arry them in the Jeep in case I break a line), but I dont like to do more cuts than necessary. If you have a compressor at home, you can probably cut the line right at the ARB compressor and do a pressure test that wat, and later just run a slightly (less than an inch) air line... To be honest, I have never tried any of these ideas before as I have not had the need, so it may be better to ask someone with more experience. I can tell you, though, that my compresor quits at about 90PSI and kicks in at about 75PSI, so you are loosing about 15 PSI for the compressor to engage again.

[dmille4.6]

alright thanks. now i have another problem. has anyone ever had gear fluid come out of their vent tube. mine did today after an hour drive at about 70. i just put a new pinion seal in it sat evening. now the gear fluid poured out of my vent tube and all over my gas tank. whats the deal?

[jfrabat]

Did you overfill the differential?

[dmille4.6]

no i filled it up until it started coming out of the drain hole. could it have had fluid stuck in the tube?

[Utah_jeepster]

it could be that you didn't cut the oil drain slots on the bearing seats big enough to allow sufficient drainage. As to air leaking lock in your diffs and listen at the over flow/drain tubes to make sure your air ring , o-rings are not leaking, then trace the air lines with soap and water.
Once mine are locked I get a compressor cycle every 45 minutes or so.
Personally I run 75-90 front and 80-140 in the rear full syn, and change every 15,000. But I try to stay away from mud puddles and river crossings.

[dmille4.6]

i put a pinion seal in sat. because it started leaking really bad. i didnt cut anything, was i supposed to? could the bearing have went bad to cause the leak in the first place? can i do that or does it have to be pressed in/out?

as for the air leak, i know for sure the part in the picture is leaking. i was cleaning the compressor off and it started bubbling. does any one know the part name and where i can get it?

[dmille4.6]

anyone have an idea? the air leak i can live with for now but i would like to get the diff problem fixed. iv got a trip planned to windrock this weekend!

[dmille4.6]

pretty sure i solved my own problem. iv been doing some research read on another jeep forum and called arb. arbs with aftermarket gears require more venting either bigger hole or multiple vents, just in case someone else runs into this problem.

[Utah_jeepster]

the part your pointing at is your solenoid valve.

[dmille4.6]

utah or anyone with ARBs, is your rear diff vented more than stock? more vents or bigger hole? ARB told me it needs to be but it only pukes fluid when i drive interstate speeds so i havnt done it just yet.

[jfrabat]

Originally Posted by dmille4.6

utah or anyone with ARBs, is your rear diff vented more than stock? more vents or bigger hole? ARB told me it needs to be but it only pukes fluid when i drive interstate speeds so i havnt done it just yet.

I have 4.88 gears and ARB, and my Jeep is a daily driver. I have not changed the vent and I have no puking... I did adjust the rear pinion angle, though. The front angle is the stock angle, and it aso has ARB (and in my case, everything spins inside because I have TJ style alloy D30 shafts) and also no puking.