I have my jeep differential service coming up soon and was wondering if it would hurt to use 75w-90 gear oil instead of 75w-140. Im trying to save some money and im looking at saving around 50 dollars just switching to 75w-90.
75w-90 instead of 75w-140
- Thread starter brenden15s
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Many of gears have spun many of miles on dino, 75w-140 is only really available in synthetic $$$$. With that said my D44s have Mobil1 75w-140, lol because I couldn't make up my mind. I think I was looking at 80w-90 at the time. Mobil1 was $16qt. ouch! Not sure I would do it again because of the cash flow.
Yeah mobil 75w-140 is 19 now and 5 quarts to do my diffs that not a cost i want to add along with tranny at the 120k service
Depends on the interval your wanting to run it. Is this for a srt8?
If so I'd stick with the 140 if your lead footed.
If so I'd stick with the 140 if your lead footed.
Nope just a plain old lifted grand im far from lead footed
What rear axle? Do you have limited slip? Tow often?
I have a Dana 35 rear in my Cherokee and tow every once in awhile. I switched from 85w140 to Mobil 1 75w90. Seems a tad bit quieter. If you tow often or have limited slip go for the 140, and don't forget the additive for limited slip.
I have a Dana 35 rear in my Cherokee and tow every once in awhile. I switched from 85w140 to Mobil 1 75w90. Seems a tad bit quieter. If you tow often or have limited slip go for the 140, and don't forget the additive for limited slip.
My ford shop manual says the synthetic lasts for 100k miles and if you decide to use 75w-90, you should change it every 3k miles. They don't seem too confident that 75w90 is good enough....
Wally world synthetic 75w140 is about $5 per quart and I'd bet it better than dino 75w90. Might be a good compromise for you.
Wally world synthetic 75w140 is about $5 per quart and I'd bet it better than dino 75w90. Might be a good compromise for you.
Originally Posted By: brenden15s
Nope just a plain old lifted grand im far from lead footed
75w-90 it then. I'm lead foot and it held up fine in 44 I ran.
Nope just a plain old lifted grand im far from lead footed
75w-90 it then. I'm lead foot and it held up fine in 44 I ran.
75-140 is an unusual factory recommendation. It is much thicker than the normal 75-90 that is almost universal.
I have to believe that they have a problem or or other good reason to require it.
Sure, MAYBE it is only for the odd time that high heat towing is involved, but I would not take the chance.
Can you go to Jeep forums and see what the guys are using with success over the long term?
I have to believe that they have a problem or or other good reason to require it.
Sure, MAYBE it is only for the odd time that high heat towing is involved, but I would not take the chance.
Can you go to Jeep forums and see what the guys are using with success over the long term?
my jeep also calls for 75-140 syn. it's the 2wd 3.7. I'd love to just put a 90 in it and grab back another .5 mpg. I think that same axle is rated to tow 7500 lbs if you've got the V8 and towing package... so if not towing large loads it *should* be fine with a 90. As gas prices go up, it's on my mind.
Maybe the 140 wt is how they claim the 100,000 or however long service interval, etc.... The 4400lb car shouldn't need a 140... but I am afraid to swap it out and botch the warranty.
M
Maybe the 140 wt is how they claim the 100,000 or however long service interval, etc.... The 4400lb car shouldn't need a 140... but I am afraid to swap it out and botch the warranty.
M
Might want to research the application further. I want to remember they spec the 140 to help the LSD (the trac-loc?) last in those applications...that's why the "current" Corp 9.25 also specs 140. If you don't have an LSD, then 90 would probably do fine as others have indicated. If you have the access, look and see if there is a TSB about it? I'm pretty sure the Corp 9.25 has a TSB regarding the 140.
The 140 is good for the LSD, but I think you would be fine with 75w90. They probably use 75w140 like you said for the long service interval. A buddy of mine owns a shop and he says he frequently sees differential failure on higher mileage vehicles, mostly because the owner doesn't even realize the fluid should be changed. When I got my current Cherokee at 85k miles it had the original gear oil, tranny fluid, and t-case fluid in it. My friend has a 2001 Ford Ranger. His rear diff started howling pretty bad. Turns out he never changed the fluid in the 170k miles he had it. Fluid was full of water.
Originally Posted By: mechtech2
75-140 is an unusual factory recommendation. It is much thicker than the normal 75-90 that is almost universal.
I have to believe that they have a problem or or other good reason to require it.
Sure, MAYBE it is only for the odd time that high heat towing is involved, but I would not take the chance.
Can you go to Jeep forums and see what the guys are using with success over the long term?
Now, wait a second: 75w90 and 75w140 are the same viscosity at zero. Its just that the synthetic oil stays thicker relative to the dino oil as the temp rises, such that the 75w140 "behaves" like 140 straight weight dino at 200 degrees.
Having pumped them both, they are pretty much the same at room temps as well.
I lied in my first post though -- today at Walmart, their 75w140 Supertech is $10.50 or so per quart....
75-140 is an unusual factory recommendation. It is much thicker than the normal 75-90 that is almost universal.
I have to believe that they have a problem or or other good reason to require it.
Sure, MAYBE it is only for the odd time that high heat towing is involved, but I would not take the chance.
Can you go to Jeep forums and see what the guys are using with success over the long term?
Now, wait a second: 75w90 and 75w140 are the same viscosity at zero. Its just that the synthetic oil stays thicker relative to the dino oil as the temp rises, such that the 75w140 "behaves" like 140 straight weight dino at 200 degrees.
Having pumped them both, they are pretty much the same at room temps as well.
I lied in my first post though -- today at Walmart, their 75w140 Supertech is $10.50 or so per quart....
The D35 has been around for years... 85w-140 might save you some $$. Where do you live AL? Doubt it gets freezing down there to often.
The Wally stuff was under law suite over vis. issues a while back and the label now says "Recommended for".
The Wally stuff was under law suite over vis. issues a while back and the label now says "Recommended for".
Originally Posted By: cdherman
I lied in my first post though -- today at Walmart, their 75w140 Supertech is $10.50 or so per quart....
I was going to call you out on that. The Chrysler 8.25 in my Nitro calls for 75w-140, and I used the Supertech. This really isn't that hard to do, and for about $40 ( inc. RTV or gasket) you can put the recommended weight oil in.
I lied in my first post though -- today at Walmart, their 75w140 Supertech is $10.50 or so per quart....
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I see lots of false economy/"penny-wide/pound-foolish" thinking around here. Anyone price a new rear end? Use what the mfg recommends! If it is 75W140, use it and don't worry about the cost! Otherwise, buy a cheaper vehicle or take the bus.
Charlie
Charlie
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I don't think these axles are D35. They are either D40 or chrysler corporate. The 2wd diesels get the heftier rear, I don't know about the 2wd gassers. If it specs a 140 I'm thinking it's the chryco rear.
While not as common as axle failures in the gen 1 & 2 GCs, I have heard (was talking to a mechanic friend about this friday) that even the newer GCs suffer from axle problems, but it seems more QC-related. You either get a good one that's been set up properly, or you don't and it grinds at 30k. In this case, I'm not sure the fluid is going to matter.
If it's lifted and you are running bigger tires, I think I'd stay with the 140. Are you running the 3.07?
M
While not as common as axle failures in the gen 1 & 2 GCs, I have heard (was talking to a mechanic friend about this friday) that even the newer GCs suffer from axle problems, but it seems more QC-related. You either get a good one that's been set up properly, or you don't and it grinds at 30k. In this case, I'm not sure the fluid is going to matter.
If it's lifted and you are running bigger tires, I think I'd stay with the 140. Are you running the 3.07?
M
Originally Posted By: cdherman
Originally Posted By: mechtech2
75-140 is an unusual factory recommendation. It is much thicker than the normal 75-90 that is almost universal.
I have to believe that they have a problem or or other good reason to require it.
Sure, MAYBE it is only for the odd time that high heat towing is involved, but I would not take the chance.
Can you go to Jeep forums and see what the guys are using with success over the long term?
Now, wait a second: 75w90 and 75w140 are the same viscosity at zero. Its just that the synthetic oil stays thicker relative to the dino oil as the temp rises, such that the 75w140 "behaves" like 140 straight weight dino at 200 degrees.
Having pumped them both, they are pretty much the same at room temps as well.
I lied in my first post though -- today at Walmart, their 75w140 Supertech is $10.50 or so per quart....
What I said is correct. Who cares about singling out room temperature?
Originally Posted By: mechtech2
75-140 is an unusual factory recommendation. It is much thicker than the normal 75-90 that is almost universal.
I have to believe that they have a problem or or other good reason to require it.
Sure, MAYBE it is only for the odd time that high heat towing is involved, but I would not take the chance.
Can you go to Jeep forums and see what the guys are using with success over the long term?
Now, wait a second: 75w90 and 75w140 are the same viscosity at zero. Its just that the synthetic oil stays thicker relative to the dino oil as the temp rises, such that the 75w140 "behaves" like 140 straight weight dino at 200 degrees.
Having pumped them both, they are pretty much the same at room temps as well.
I lied in my first post though -- today at Walmart, their 75w140 Supertech is $10.50 or so per quart....
What I said is correct. Who cares about singling out room temperature?
Just did my F250 with 75w140 Valvoline Synthetic. 13.99 a quart at NAPA. Valvoline also has Durablend 75w140. NAPA carries it at 6.99 a quart.
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