Everyone should change the differential fluids sooner rather than later

[AZCooWhip]

@AZCooWhip

For starter's, I'm far from the lets say go to guy for info on this.. I do know quite a bit, thanks to my age, exposure to this stuff and a lot of time to research, etc.....

You wording "no towing to be done" ..... ? Do you or do you not have the tow package. Also, are you absolutely sure you are not going to tow... Also, are you off roading a lot.... what type of service is your JT going to face.

The reason I ask is guys will run 75/140 front and rear if daily use of the vehicle is particularly hard..

Also, do know that if you were to run 75/140 in the rear and not necessarily need it there is no foul / no harm done. Reality is running 75/140 means in front, rear or both, you would say have a tad poorer gas mileage and that's pretty much it.

Probably the gist of it is 75/90 that has additive in the front and rear... IF you have tow package do use 75/140 in the rear.. IF your vehicles service will be particularly hard, you can / may want to go with 75/140 front and rear..

For the record..... Talking this stuffing is like talking about what oil is best..... There are so many opinions.... Just listen to all the opinions... learn learn and then decide how YOU want to proceed in regard to your vehicle..

With the availability of gear oils (i.e. Valvoline, Royal Purple, etc.) that have additive in them , DO forgo all the newbe angst let say.... No need to worry about additive... IF your vehicle needs additive it is in there.... if your vehicle does not need it, it is still aok to use fluid in it that has additive.

Plain and simple, no angst, you just be sure to use a gear oil that has additive in it. I mentioned two brands.. Pick of the litter in my opinion is the Valvoline... Decent gear oil with the additive and the FlexFill pouches are the hoot... easy to use... 0 clean-up compared to pump use.... terrific..

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Really appreciate the insight. I find each Motorsport has its own set of rules on stuff. Coming from my open road course days, in the rear diff it was oil out, oil in And back out on track.

4 wheeling is a slightly different ball game and trying to apply my my racing knowledge to it isn’t exact although similar.

This Gladiator build will serve 2 purposes. Around town open air driving here in AZ as well as I want the ability to tackle 98% of off road applications. Wether that’s rocks, sand or dirt. I don’t ever expect to tackle highly mod or pro level 10 level off road.

It does have tow package and as said, don‘t ever expect to tow. Never say never I guess.

Really do appreciate the insight and will keep on learning this new Motorsport!

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[hjdca]

For those with Rubicon Lockers, it is also good to change the fluid regularly. No need for friction modifier without LSD. It seems the Locker switches may malfunction with too much metal in the diff. oil...

Note: With the OEM Dana Spicer 4:10s, I have found very little metal powder on my drain magnets. I went with Dana Spicer for my 5:13s and also have found again very little metal powder on my drain magnets. I think this speaks very well for Dana Spicer, and with this alleged Locker situation, good insurance. Knock on wood, my lockers have been working great and the Gladiator is a beast with the 5:13s and lockers.

 

[cb4017]

When I had my 08 JKU I changed the diff fluids at about 25k with Amsoil Severe Gear. 75w-90 in front and 75w-140 in the back. It had a LSD but I did not use friction modifier. It was still going strong at over 100k when I sold it. Even a 5.3L LS conversion didn't kill it.

My 19 JLU got the diff fluids changed at about 10k. Again Amsoil 75w-90 and 75w-140. In the JLU I did use the Mopar Friction Modifier for the LSD. At 10k the old rear diff fluid was pretty dark and lots of fur on the drain plug magnet.

My JT will probably get the same differential treatment as my JLU at about the same mileage. I do haul a small travel trailer and it gets pretty hot here.

 

[whiteglad]

I changed lube and installed Motobilt covers at 1k miles.

 

[guarnibl]

For those with Rubicon Lockers, it is also good to change the fluid regularly. No need for friction modifier without LSD. It seems the Locker switches may malfunction with too much metal in the diff. oil...

Note: With the OEM Dana Spicer 4:10s, I have found very little metal powder on my drain magnets. I went with Dana Spicer for my 5:13s and also have found again very little metal powder on my drain magnets. I think this speaks very well for Dana Spicer, and with this alleged Locker situation, good insurance. Knock on wood, my lockers have been working great and the Gladiator is a beast with the 5:13s and lockers.

Yep, that's right about the locker switches. Better just to pot them but my lockers started working instantaneously again (they had trouble engaging prior) after I changed the oil at 27k. Unfortunately, I didn't get to use them a lot prior to that due to pandemic and EJS was canceled (and the other trails I did were not as gnarly).

 

[SwampNut]

"Looked like it needed to be changed" is completely meaningless. I've sent 20k mile diff oil that looked horrible to Blackstone Labs for analysis, and they said I could have kept running it. Nearly zero loss of effectiveness, but it LOOKED bad. Changing oil often is way over-rated and does so little.

 

[Blade1668]

IMHO: Best options is to run about 500-1000 miles of use or certain number of hours (engine) then change the fluids normal break in then flush out. I did that with my LJ to include the "lube for life" 6 speed M.T. after that every few years I change T-case, Tranny and axle gear oil. Engine oil from 3500 to 6000 miles running synthetic oil a few oil change went over close to 7000 or 8000 miles with just a oil filter change. It's still going strong at over 250000 miles. I regret that I didn't follow this on my JT. I do think the first change of fluids is more critical than later at set intervals to get left over machining scraps out.
After playing in water definitely a thing to do for axles. I've seen quite a few trashed due to water, a little water in some things not a big deal if it runs above boiling point of water.... 212°f and can boil it out/off. The axle can act like a pressure cooker blowing out seals and oil. You don't want a axle hitting that temp.. I've seen a few cooked and diff cover red hot you can guess what happened with the axle and vehicle short time down the road.

 

[sdk131]

I would suggest everyone change the differential fluids sooner rather than later. Just opened up the plugs on mine with less that 3000 miles and the rear looked like it needed changed. The front was good but i am changing it also. Sport S with the tow package but not diff lock.

Thanks for the reminder. I definitely tend to take an over-cautious approach as well. I just got my JT (only about 900 miles on it so far) but I have been meaning to just pop the fill plugs and do a quick level and color check. Will also do the same at 5,000 miles. I have found too many of our cars slightly low on various fluids straight from the factory over the years, and I'll sleep better knowing I took a peek.

Some folks also should keep in mind that this pandemic may mean that they are driving their vehicles far less and should switch to the time and severe service interval on some fluids. I was just reminded of this on my commuter car. It was only driven 2k miles (mostly short trips of 10 miles or less) since march of 2020, and I just did an oil change. Despite the fact that it was a high end synthetic the oil was incredibly dirty and was showing signs of major moisture accumulation. It truly looked far worse than it would even after an 8,000 mile interval of highway speed commuting.

 

[Whatscooking]

"Looked like it needed to be changed" is completely meaningless. I've sent 20k mile diff oil that looked horrible to Blackstone Labs for analysis, and they said I could have kept running it. Nearly zero loss of effectiveness, but it LOOKED bad. Changing oil often is way over-rated and does so little.

 

[Whatscooking]

I have brought home brand new motorcycles 50 miles and have dropped the oil and filter.
I just know anything man made needs all the help it can get.
The oil i just took out of my Gladiator rear diff with 3000 miles on it looked like you ground up a nickel. The magnet i took to the glob of black goo on a shop towel was picked right up, metal !

 

[SwampNut]

Modern machines need very little help, and pretty much never fail due to oil issues. Looks mean nothing, and the oil test lab's newsletters, which LOOK for problems, show that there are almost no oil-caused failures. Messing with it is an emotional response with no statistical backing at all. Wasting oil and money, while potentially creating new problems if a mistake is made, with zero benefit. It's one of the stupid old wives' tales that really needs to die.

I bought a 2020 KTM 390 Adv late last year. I changed the oil per spec, at 600 miles. Sent a sample to Blackstone. Here's the report:

This oil appears to be a Motorex formulation and is normal in all metrics. There is a small amount of nickel consistent with engine break-in. There are insignificant changes in viscosity, lubricity, and contaminants. This oil can be re-used for at least several thousand miles.

 

[MrZappo]

Yep your right but my money my Jeep. I also replaced the engine oil at 950. Did i send off the oil for analysis, no. I cut open the filter and I inspected myself and found significant metal which I know is not unusual . I do not care for that slurry circulating inside my new engine. Didn't need a labs recomeditition to see that.
I have spent a considerable ammount of time on this fourm reading about maintence. There have been several discussions about the rear diff oil being black so i thought i should check. No metal only this black goo that has filled up the drain plug well. It looks like friction materal from a limited slip disc but mine doesnt have LS according to the build sheet.
I made my living for 25 years maintaining a fleet of 40 delivery trucks from one end to the other. I can safely say i have seen more internals of engines and differentials than most people would ever care to see. Do what you want, really i do not care but for the person that wants to get the max life out of their 45,000 dollar investment you better take a look. For the measly cost of a quart of oil i will change my oil as i see needed.
Ow and dont worry i recycle the used stuff. I use it to help heat my shop.

Well, yes but you are "suggesting" that others follow your over the top recommendations ... There are lot of people on this site looking for information/advice and what you have outlined is clearly your opinion that ls considerably more aggressive than most anyone would "need" to do ...

As far as stuff in your filter at 950 miles that is great ... The stuff was "IN" the filter and not circulating inside of your engine. So, I don't understand the argument ... Your basically saying that the filter did its job ... You aren't saying that the filter was full ...

And for the record, no one needs to change differential fluid at 3000 miles as you suggest. It wont hurt anything so I cant call it "bad advice" but it certainly wont help anything either with the exception of some prior posts regarding water ingress etc. So it may make you feel good but that does not mean that it is reasonable ...

If you made a living maintaining fleet vehicles for 25 years, I would think that you more than most would rely on testing and analysis rather than "look".

Oils contain additives that wear over the oil life span and the oil is "good" until those things are used up. It has nothing whatsoever to do with oil color ...

Ill agree with you that proper and diligent maintenance is the best thing anyone can do to get the maximum mileage out of any mechanical device ... But maintenance before it is needed for the sake of it will have no effect other than to waste money ... There is a point of diminishing returns.

So, as I said originally do what you want. And I applaud your tenacity ... But your recommendations are far in excess of what is necessary and other folks here who are trying to learn should not feel as if they need to change perfectly good fluids beyond the manufacturer recommendations except in the case of extenuating circumstances such as (High duty cycle/water ingress etc)...

 

[SwampNut]

Well said. Empirical evidence is what matters, not emotions and "look." Also many of us are old enough to have grown up with 3k oil changes and engines that failed in 80-120k miles. Those days are WAAAAAY behind us and need to be forgotten. Times change, oil is better than ever, mechanical parts are so much better.

 

[Whatscooking]

Ok, what is the cost involved sending a sample to be tested,including postage and supplys and time, bet that will buy a quart ot two. My 96 4.0 has 175000 miles doesnt smoke and the dipstick stays cleen for quite awhile. My BMW GS and my Indian Roadmaster use no oil and keep their oil cleen. I back off the intervals and even push it AFTER the inital change but i want that orignal factory fill replaced . I keep things longer than most people and have for years.

 

[SwampNut]

Around $25, they provide the supplies to capture and ship. The point of testing is LEARNING about your machines, and knowing what to do in the future. I used to be paranoid too, and changed oil too often. When I first started testing, I was driving a Cummins diesel with expensive oil changes, and towing a heavy load. By testing, I saved hundreds or thousands of dollars over the time I owned it, while maximizing engine life. I've done the same with boats, motorcycles, and Jeeps. The lab gives me a narrative of what is going on and I not only know what that machine needs, but I learned a lot about oils. Bottom line is they last far longer than they used to, and we mostly change them too often.

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