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Gear Oils to use?

F

forthehalibut

NAXJA Forum User
Location
Colorado
Ok--I did a search, and didn't find the answers I am looking for [which means it was probably right in front of me].

I have a 95 Cherokee Sport. I need to change out the oils in the tranny, x-fer case, and both diffs. I called Checkers and they said I should use 75-90 for the x-mission and x-fer case, and 75-140 for the diffs. I was looking at getting the valvoline 85-140 durablend to use. Would that be ok in the diffs? Also, how would it do in the tranny and x-fer cases? I was able to use the durablend in my 84 toyota, and got good performance results with it there.

What would be the best oils to use in all of the above cases? Also, how often should I take off the diff covers to clean out the gears? I know I gotta get a siphon pump to get the old gear oil out, but figure every once-in-a-while take off the diff covers and give them a good cleaning [too bad they didn't install drain plugs in these things like Toyota did]. Thanks in advance for the help.
 
GL-3 for the transmission, GL-5 for the axles, and the transfer case (NP231 or NP242) will take Dexron II/IIE/III or ATF +3/+4 (If you have an AW4 four-speed automatic, just use Dexron in both boxes.)

GL-5 is beneficial for the axles, but the added sulphur in GL-5 gear oil will dissolve your bronze synchronisers! You'll put it in with a nice amber colour, and drain it with a buch of gold glitter - those are your synchroniser rings.

For simplicity, I just use GL-3 in everything, with some LSD Friction Modifier added (simplifies the logistical train - I've got a couple of Trac-Loks from the factory, and LSD FM can be used as an additive, even if you don't need it.)

I wouldn't bother using a suction pump to drain the axle - you won't get it all. Gaskets are cheap, and if you install a 5/16" stud in the uppermost screw hole, you can keep the cover from falling into the gear oil and getting it all over you - and it goes together a lot easier. Screws are 5/16"-18 x 3/4", if you need to replace any.

Capacities are listed on my website, in the "Technical Index and Reference" - which is why I'm not going to list them here. I believe I've corrected the recommendation for the AX-15 gearbox (which you've got,) but if I've still got "GL-5" listed, the FSM is also wrong and I need to correct that you use GL3, not RPT not GL-5. All other fluid recommendations are correct, and capacities are from the FSMs.
 
Thanks for that info. I do have the 5-speed manual tranny in it, so would the GL-3 be fine with that then? Also, what is GL-3? Is it a certain brand? I am just more familiar with the usual gear oils I mentioned above.
 
chrysler now recomends 10w 30 motor oil in the AX-15/AX-5 (5 speed manual) for better cold shifting performance...I live in southern california and I am using it in mine without any problems..

Justin
 
That seems a bit thin for the tranny--especially since summer is here.

5-90--I check out your capacities on your website, and noticed no 1995 [nor 1996] models are listed there.
 
Gear Lube/Oil

Part Numbers:

04897622A$
04761839A$ Issue Description:

04897622AA is a 75W90 oil. 04761839AC is 10W30 oil. The 04761839AC is recommended to be used in place of 04897622AA for improved transmission shift properties.
 
forthehalibut said:
That seems a bit thin for the tranny--especially since summer is here.

5-90--I check out your capacities on your website, and noticed no 1995 [nor 1996] models are listed there.
Click to expand...

I list specs only from FSMs - you can use a similar year (like 1994 or 1996.) I've got a 1996 FSM, so I should check that out (see why I haven't put them up yet.) I'm still working on my collection of FSMs - I've got them from 1960-up, but there are some huge holes there. But, I'm still collecting, so there will be some more changes an updates.
 
my .02....get some Lube Locker gaskets for your diff covers - makes changing your diff fluid MUCH easier....
(i like royal purple gear oil for my diffs too)
 
I do appreciate all the help, people. :)

Too bad Jeep wasn't wise enought to install drain plugs on the diffs--it would make it so much easier and cleaner. :(
 
forthehalibut said:
I do appreciate all the help, people. :)

Too bad Jeep wasn't wise enought to install drain plugs on the diffs--it would make it so much easier and cleaner. :(
Click to expand...

Don't worry - from what I've seen, most of the Toy and Nissan axles have the drain plug sticking out - and I'd really prefer seeing it either flush or very slightly recessed. Having the head sticking out is just gagging for whacking it on something...

Drill out the bottom of the cover and weld a bung in - that will keep it off the bottom off the diff, allow you to drain all but a couple ounces, and obviate pulling the cover (except at intervals, for inspection.)

Considering that it's very low pressure involve, you could probably braze one on just as easily.
 
The biggest reason they do NOT put in drain plugs is because they believe you should open up the area if your draining the fluid. With an Auto Trans, they want you to clean out the magnet and gunk in the pan, same thing with differential.

Just pull the cover and clean it up well as you change the oil.

75-140 for differentials is if your using Synthetic. I believe its 75-90 if your using conventional gear oil. If your towing, your supposed to use the synthetic. Don't forget, if you have a LSD, you need some friction modifier added to the gear lube.

Motor Oil and Gear Oil use different viscosity indexes, if you convert them over, they are very close, I "think" 75W-80 is like 10W-30.

GL5 high-pressure additives that are corrosive to synchros, I "think" the oil has to reach a certain temperature for it too become corrosive. That still doesn't mean you can use it, just keep that in mind when you hear testimonials like, "I used GL-5 and my trans was fine", there are far more testimonials claiming they damaged their trans using GL-5. The few that get away without damage when using GL-5, I'm guessing they were just lucky enough to avoid heating up the GL-5 hot enough to become corrosive to the synchros.

Friction Modifier reduces the slipperiness of the oil, if you have friction surfaces in the mechanism that is being lubricated, it helps those friction surfaces engage better and the mechanism work better overall. Thats why you need it for a LSD.

Although regular Gear Oil (GL-3) is recommended for the Manual Trans, a "Manual Transmission Fluid" that contains Friction Modifiers will help the trans shift smoother and better. Redline MT-90 is very popular for the AX-5/AX-15. Its a Synthetic GL-4 fluid, the literature from Redline says it won't become corrosive to synchros until something crazy like 450°F, lots of people have used it on this board and did NOT have any troubles. In fact they liked the improvement in shifting.
 
kevin s said:
75-140 synth in the rear is for towing. If you are not towing, regular 80-90 or 75-90 synth for both ends.
Click to expand...


I tow a fishing boat to the lakes from time to time--it is under 2000lbs weight, though. Does that count? Since I didn't see any 75-140, would the 85-140 synth blend work ok then?

I am learning quite a few things from this post--a lot more than I expected--thanks! :D
 
Mobil1 makes a 75-140 Synthetic Gear Lube, BUT, I haven't seen less than $14 a quart, and you'll need just over 2 for a Chrysler 8.25, meaning you have to buy 3 quarts. Might be a bit too expensive.

How often and how far do you have to tow the boat, and do you have to tow it up mountains? That would also factor into the recommendation, for those with the experience, I haven't towed, so I don't really know how stressful it is on the rear-end, I'm hoping some of the more experienced guys will pipe in.
 
Since you dug it up :D

Redline synthetic MT-90 in tranny
valvoline synthetic 75 90 in diffs :thumbup:
 
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