My owner's manual doesn't specify a change interval for the differential fluid, but at 78k I figure it's time. I have an 09 4wd Liberty with a tow package. The manual calls for 75w140 synthetic in the rear and 80w90 (dino or synthetic) in the front. I am a by the book kinda guy, but on the jeep forums the consensus was that dino oil was better in the differentials than synthetic. Also, the feeling was if the vehicle wasn't being used for off road or towing (which we don't, it's my wife's jeep) then 80w90 was fine for both front and rear. Curious as to what the BITOGers think.
Jeep Liberty Differential Fluid
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If it specs 75w140 I would not use a lighter dino oil. Valvoline Synpower is fairly reasonable, as are I'm sure aime others, why risk it for a couple of bucks?
As one of the more hardcore Jeep peeps here, I would say that from a mechanical standpoint, your Chrysler 8.25 rear end doesn’t need 75W140, but I’m a believer in following the manufacturers recommendations. Manufacturers often spec fluids for all possible situations, although for all we know, the ‘09’s were shipped with a “loud” ring & pinion and they use 75W140 to compensate. Ford has done that before.
All speculation aside, for the minimal cost difference over the operating life of the vehicle, I would run the 75W140.
All speculation aside, for the minimal cost difference over the operating life of the vehicle, I would run the 75W140.
dino oil is often a smarter bet in off-road vehicles because owners may change more often after axle submersion in deep mud, water, stream crossings, etc.
I ran amsoil 110-weight in the axle of the WK, which called for 140. it did fine, including towing.
if it were me, I'd run syn in BOTH axles. there is a slight mpg gain to be had there. the front axle spins all the time in jeeps, so having a lower-resistance fluid makes sense.
m
I ran amsoil 110-weight in the axle of the WK, which called for 140. it did fine, including towing.
if it were me, I'd run syn in BOTH axles. there is a slight mpg gain to be had there. the front axle spins all the time in jeeps, so having a lower-resistance fluid makes sense.
m
Because when the MFG builds vehicles, they don't know where each customer is going to take the vehicle whether it's only on road driving or off road & towing. So, they[the MFG] put in a gear lube that will hold up for what they are claiming the vehicles capabilities are.
You'd hate to buy a Jeep that claimed "OFF ROAD"(or "TRAIL RATED") and they only put in 80W90 gear lube. That lube is fine if you only use your 4X4 as a transportation devise.
You'd hate to buy a Jeep that claimed "OFF ROAD"(or "TRAIL RATED") and they only put in 80W90 gear lube. That lube is fine if you only use your 4X4 as a transportation devise.
Originally Posted By: outoforder
My owner's manual doesn't specify a change interval for the differential fluid, but at 78k I figure it's time. I have an 09 4wd Liberty with a tow package. The manual calls for 75w140 synthetic in the rear and 80w90 (dino or synthetic) in the front. I am a by the book kinda guy, but on the jeep forums the consensus was that dino oil was better in the differentials than synthetic. Also, the feeling was if the vehicle wasn't being used for off road or towing (which we don't, it's my wife's jeep) then 80w90 was fine for both front and rear. Curious as to what the BITOGers think.
How did the Jeep Forums come to that conclusion except as another poster menbtioned that its cheaper to change if you get it contaminated?
My owner's manual doesn't specify a change interval for the differential fluid, but at 78k I figure it's time. I have an 09 4wd Liberty with a tow package. The manual calls for 75w140 synthetic in the rear and 80w90 (dino or synthetic) in the front. I am a by the book kinda guy, but on the jeep forums the consensus was that dino oil was better in the differentials than synthetic. Also, the feeling was if the vehicle wasn't being used for off road or towing (which we don't, it's my wife's jeep) then 80w90 was fine for both front and rear. Curious as to what the BITOGers think.
How did the Jeep Forums come to that conclusion except as another poster menbtioned that its cheaper to change if you get it contaminated?
Originally Posted By: Char Baby
You'd hate to buy a Jeep that claimed "OFF ROAD"(or "TRAIL RATED") and they only put in 80W90 gear lube. That lube is fine if you only use your 4X4 as a transportation devise.
My off road rigs run 80W90 Walmart oil in the diffs. They transport me on terrain you can't even walk on.
You'd hate to buy a Jeep that claimed "OFF ROAD"(or "TRAIL RATED") and they only put in 80W90 gear lube. That lube is fine if you only use your 4X4 as a transportation devise.
My off road rigs run 80W90 Walmart oil in the diffs. They transport me on terrain you can't even walk on.
Originally Posted By: Donald
How did the Jeep Forums come to that conclusion except as another poster menbtioned that its cheaper to change if you get it contaminated?
Many of those forums are filled with kids who know better than you or I.
How did the Jeep Forums come to that conclusion except as another poster menbtioned that its cheaper to change if you get it contaminated?
Many of those forums are filled with kids who know better than you or I.
Originally Posted By: Zaedock
Originally Posted By: Char Baby
You'd hate to buy a Jeep that claimed "OFF ROAD"(or "TRAIL RATED") and they only put in 80W90 gear lube. That lube is fine if you only use your 4X4 as a transportation devise.
My off road rigs run 80W90 Walmart oil in the diffs. They transport me on terrain you can't even walk on.
Indeed, I believe ya!
I know others as well who do the same...Never an issue!
I can't answer for how a MFG determines what gear oil a diff will get, be it 80W90 or 75W140, syn or dino. Or as you stated...75W140 helps keep it quiet
Originally Posted By: Char Baby
You'd hate to buy a Jeep that claimed "OFF ROAD"(or "TRAIL RATED") and they only put in 80W90 gear lube. That lube is fine if you only use your 4X4 as a transportation devise.
My off road rigs run 80W90 Walmart oil in the diffs. They transport me on terrain you can't even walk on.
Indeed, I believe ya!
I know others as well who do the same...Never an issue!
I can't answer for how a MFG determines what gear oil a diff will get, be it 80W90 or 75W140, syn or dino. Or as you stated...75W140 helps keep it quiet
Amsoil Severe gear has been working fine in the 02 Liberty that I maintain.
75W90 in the front, 75W140 in the rear.
75W90 in the front, 75W140 in the rear.
I second "sever gear" from AMSOIL.
I've been a JEEP guy for many years with many different jeeps under my belt, and for a long time I have run severe gear in all my d30,35 or corporate (8.25) diffs, I use the stuf in both on road and offroad only JEEPS with great success. the AMSOIL stuff works well with JEEPs trac-lock (they call it something different for every platform)and regular diffs, I have NEVER had any chatter from a LSD jeep rear with the AMSOIL 75-140. I do my diffs roughly every 50k or so (we tow and wheel).
I've been a JEEP guy for many years with many different jeeps under my belt, and for a long time I have run severe gear in all my d30,35 or corporate (8.25) diffs, I use the stuf in both on road and offroad only JEEPS with great success. the AMSOIL stuff works well with JEEPs trac-lock (they call it something different for every platform)and regular diffs, I have NEVER had any chatter from a LSD jeep rear with the AMSOIL 75-140. I do my diffs roughly every 50k or so (we tow and wheel).
dnewton3
Staff member
Any decent brand GL-5 is going to work fine.
Synthetics are going to gain fluid longevity.
I understand and agree with the "dino" frequent swaps if submersion is the thing that is most often experienced. However, does not sound like that's what's happening here ...
Since the OP has 78k miles on his current fill, I'd say frequent fluid swaps are not what he had in mind.
That being the case, I'd use syn in both ends; could easily go 100k miles or more on syns. Easy to find a multitude of quality products at a price you want to pay.
Yes - you read that right; I am recommending the use of syns. Some of you can now pick your jaw up off the floor ...
Synthetics are going to gain fluid longevity.
I understand and agree with the "dino" frequent swaps if submersion is the thing that is most often experienced. However, does not sound like that's what's happening here ...
Since the OP has 78k miles on his current fill, I'd say frequent fluid swaps are not what he had in mind.
That being the case, I'd use syn in both ends; could easily go 100k miles or more on syns. Easy to find a multitude of quality products at a price you want to pay.
Yes - you read that right; I am recommending the use of syns. Some of you can now pick your jaw up off the floor ...
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75w140 synthetic was over twice as expensive as dino 85w140 at walmart (super tech) Since this jeep only sees paved roads, I'm going to go with the dino. Zaedock, do you know what the capacity for Liberty differentials is?
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Originally Posted By: outoforder
Zaedock, do you know what the capacity for Liberty differentials is?
FSM says 4.8 pints of gear lUbe with open diff. A bit less with a limited slip (5oz of friction mod if you have a limited slip). A quick gOOgle search shows anywhere from 4.4 to 5
Buy 3 quarts and you'll be good to go. After you replace the cover, pull the rubber blubber plug and fill until it just trickles from the fill hole.
Zaedock, do you know what the capacity for Liberty differentials is?
FSM says 4.8 pints of gear lUbe with open diff. A bit less with a limited slip (5oz of friction mod if you have a limited slip). A quick gOOgle search shows anywhere from 4.4 to 5
Buy 3 quarts and you'll be good to go. After you replace the cover, pull the rubber blubber plug and fill until it just trickles from the fill hole.
Originally Posted By: outoforder
75w140 synthetic was over twice as expensive as dino 85w140 at walmart (super tech) Since this jeep only sees paved roads, I'm going to go with the dino. Zaedock, do you know what the capacity for Liberty differentials is?
I think a few years ago I saw a UOA or a VOA on here that was not so flattering for the WM stuff, I know I wouldn't depend on it without evidence that its worthy.And if its LS you NEED a friction modifier additive if you go dino.
75w140 synthetic was over twice as expensive as dino 85w140 at walmart (super tech) Since this jeep only sees paved roads, I'm going to go with the dino. Zaedock, do you know what the capacity for Liberty differentials is?
I think a few years ago I saw a UOA or a VOA on here that was not so flattering for the WM stuff, I know I wouldn't depend on it without evidence that its worthy.And if its LS you NEED a friction modifier additive if you go dino.
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LS? Friction modifier? I don't know what these two things mean or why I need to do it. Perhaps I should just spend the extra and get the synthetic.
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LS is limited slip or posi-trac rear end. If you are not sure have someone who knows check what you have. The wrong fluid or not right additive can ruin the clutches in the rear end.
dnewton3
Staff member
I've not seen a bad UOA on a ST fluid that wasn't attributed to some other input (engine coolant leak, fuel dilution, etc).
IIRC, there was an issue in CA a while back where some ST fluids (gear oil, I believe) didn't meet the min API vis (below grade?) and they were cited by some CA entity? I cannot assure you of the facts here; it's been a while.
There are some VOAs of engine and ATF lubes from ST at PQIA that show they are fine overall.
I use ST fluids with great success. The fear of something being out of grade a bit is probably ...
1) overblown from a perspective of actual damage it might cause
2) just as real a fear from other brands as well; they all make mistakes from time to time (as I recall, the M1 gear oil was out of grade in the famous Amsoil white paper testing as well?)
IIRC, there was an issue in CA a while back where some ST fluids (gear oil, I believe) didn't meet the min API vis (below grade?) and they were cited by some CA entity? I cannot assure you of the facts here; it's been a while.
There are some VOAs of engine and ATF lubes from ST at PQIA that show they are fine overall.
I use ST fluids with great success. The fear of something being out of grade a bit is probably ...
1) overblown from a perspective of actual damage it might cause
2) just as real a fear from other brands as well; they all make mistakes from time to time (as I recall, the M1 gear oil was out of grade in the famous Amsoil white paper testing as well?)
The Amsoil website lists capacities. Ask a Jeep dealer for a copy of the STAR report on your vehicle (need VIN). It will list everything your Jeep was built with at the factory. Will tell you what transfer case and diff.
I would use Amsoil SVG and just change it less often.
I would use Amsoil SVG and just change it less often.
I'm not concerned about using ST, I'm just hung up on the dino vs syn. Back of ST bottle says it can be used as makeup oil in a limited slip differential. Does the Liberty have this? Mine has an ESP, is that the same? Also, why does Chrysler spec a conventional oil in front diff and a synthetic in the rear?
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