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Dana 30 Gear Oil

C

CodyB

NAXJA Forum User
Location
AR
Whats the recomended gear oil for a stock dana 30? Also after having water in the Gear oil, what all should I change out, or would I just have to inspect as I go?
 
Either 75 or 90 wt gear oil, remove the bolts but leave one bolt in the top loose, slide the catch basin under and pry the cover off, let it drain. The one bolt in the top will stop it from dropping on you or in the catch basin and splashing the stuff all over. Might want to remove the fill plug first though, it's easier to loosen it while the bolts and front axle are holding the cover otherwise you will stand around holding it trying to figure out what to clamp it in without bending it up to remove the fill plug. Just some advice from someone who has done the standing and looking around the shop then rebolting it back on to get the plug out. :D
 
On mine, I dont know if its from the added water, but the oil leaks out from the fill plug(the one half way up the cover where you need a ratchet to remove), like its filled above that plug. Also do I need the vent line going to the top of the firewall? if not could I just plug it up close to the axle housing?

I took a nose dive into a pond today...

07-03-07_1129.jpg

Those are 31/10.50 R15 its sittin on...
 
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You might have to change it more than once to make sure you got all the water out. As suggested by Rich 74-90 wt oil should be fine depending on the mileage on that set of gears higher requires a heavier (higher numeric) weight oil. Extend the vent up to the highest point on the firewall and you should be fine on that.
 
tupton said:
Lucky water in the diff was your only problem. No, don't cap the vent tube. I run mine all the way up as high as it will go. When you add new oil, just fill it to where oil just starts to come out of the fill hole and you will be ok.
Click to expand...
No thats not all, i gotta do the same for my T-Case metal shards are in its oil... 90w good for it too?
 
I think the most common is 85w-90 gear oil. Also known as GL5. It's relatively cheap. Oh and be weary when your working with it.. it's a pain to get off of stuff and it smells like buttcrack.
It should also be the same stuff you use in your t-case.
 
That was a fun night, dont really wanna do that again. Were there supposed to be seals on the outter ends of the 30? I know the plastic things, but I mean any rubber seals. Bed now, too tired to stay up any later.
 
no seals on the outer ends of the tubes. the seal is way in the inner end of the tube next to the carrier bearings. unless you have adisconnect axle and there is a seal out-board of the disconnect mechanism.
i run synthetic 85w140, mfg suggests the synthetic in both axles if you spend any time towing. i run it anyways.
 
If you are changing out the Diffs, you might as well avoid the RTV mess associated with this task. Get

www.lubelocker.com

gaskets. They are installed "dry" and are reusable. They make them for all the Jeep diffs. They are a fantastic product. I use them on my XJ and KJ.

Sure beats scraping off the old RTV and making a mess by reapplying that junk. Will sure make sure that you don't have a leak because you didn't apply RTV right or let it set up.

I use Amsoil 75w90 Severe Gear in the front diffs of both Jeeps and 75w140 Severe Gear in the rear diffs. Offers really good protection and, unless you are burying your Jeep in a river all the time, allows extended gear oil changes. There are other good gear oils out there, unfortunately, there are many owners who overlook changing out the diff oils regularly like they should.
 
No, the reason you can't seal up the vent on the axle is because as the gears turn, the fluids heats up, and it expands, and the pressure needs somewhere to go.

CodyB said:
No thats not all, i gotta do the same for my T-Case metal shards are in its oil... 90w good for it too?
Click to expand...
DO NOT USE GEAR OIL FOR THE T-CASE. Your Owners manual has all the fluids recomended and type in it. ATF, the same stuff you use for your transmission, goes in the T-case. Mercon/Dexron III

If you keep having trouble with oil leaking out of the fill plug after you refill it, (as stated before, only fill the oil up to the point where it startes leaking out the hole then plug it) you could maybe try some of that white pipe tape that goes on the threads of faucets and such to prevent leaks.
 
Begster said:
No, the reason you can't seal up the vent on the axle is because as the gears turn, the fluids heats up, and it expands, and the pressure needs somewhere to go.


DO NOT USE GEAR OIL FOR THE T-CASE. Your Owners manual has all the fluids recomended and type in it. ATF, the same stuff you use for your transmission, goes in the T-case. Mercon/Dexron III

If you keep having trouble with oil leaking out of the fill plug after you refill it, (as stated before, only fill the oil up to the point where it startes leaking out the hole then plug it) you could maybe try some of that white pipe tape that goes on the threads of faucets and such to prevent leaks.
Click to expand...
The oil wasn't leaking, just when I pulled the plug, it came out because of so much water entering into the diff. I'm not having trouble with leaks from that end. But after I got the driver side tire off, I saw oil had slung all over the place under there. I replaced the two seals after pulling the planetary out and cleaning up everything inside as good as I could while laying under a vehicle. popped the new seals in, replaced everything, and used a gasket from Advanced Auto Parts. I used 80w-90 gear oil. No RTV mess or anything. All done, now to just see how she holds up... And this time, im gonna try to avoid the big water holes...
 
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On my 2001 XJ I have
Dana 30 and Chrysler 8.25... any drawbacks of using 75w140 on both the front and rear or do you recommend 80W90 for both?
Thanks


BTW thanks for the LUBELOCKER headsup Cowpie1 That's gonna make life a piece of cake.
 
This thread is NINE YEARS OLD.

Other than that...
Both weights are fine. 75w140 would be preferred if you do a lot of towing. I run 80w90 front and 75w140 rear since I tow a good bit.
 
Pretty much the same here.

80w90 in the front (and it is quiet with the locker) and 85w-140 in the rear. I'd go with a more expensive 75w140 but it's too expensive to be changing that all the time
 
90Blue_XJ said:
You might have to change it more than once to make sure you got all the water out. As suggested by Rich 74-90 wt oil should be fine depending on the mileage on that set of gears higher requires a heavier (higher numeric) weight oil. Extend the vent up to the highest point on the firewall and you should be fine on that.
Click to expand...
for the first change use cheap oil. store brand.run a couple days then change again to a better quality of oil. and just because you got it in the water doesnt mean the diff is contaminated. if the oil is clean no worries. if it is foamed out chocolate looking junk then clean it all out.
do 2 or 3 oil changes over the next month if it is contaminated. each change will get most of it out but it cant clear all of it.
 
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