Changing my diff fluids for the first time.

[Rustypipes12]

Sooo, I'm finally getting around to changing the differential fluids on my 2009 TRX4. It's only got 84,000 original miles but they've been hard ones! The truck was never garage kept and I live up north in western New York where they love to salt the roads! I've done quite a bit of towing and ripped three sets of running boards off going off road (they're now welded to the frame). A friend of mine who owns a shop in the country suggested I go with 75w-145 full synthetic in both axles even though we're in a northern climate. I had short mileage originally because I lived close to work and only got out to the country sporadically. Now I'm retired and own two properties that are both over 100 miles away so I'm starting to pile up the mileage. I have the 3.92 LS rear in this so I know I have use that highly toxic LS additive in the rear. I just wonder If It is okay to use this oil in the front?

Also, a little lesson I learned about towing: The first picture is of me leaving Country Turf and Trail in Sunbury, PA. with my new tractor, the second is of my trailer being held on to my RAM by the safety chains on the side of a steep gravel road with it on the way home to Independence, NY.! The third picture I still can't believe every time I look at it. I've had these hitches stuck in the receiver so bad I couldn't knock them out with a sledge hammer! I had to leave my new tractor and locked trailer on the side of the road so I could go get another hitch. The only damage was a noticeable dent in my bumper which actually left my happy all things considered! I no longer leave my hitch in the receiver and keep them both well greased.

 

[Rustypipes12]

Another question would be on the tranny. Years back a guy I knew that worked at a transmission shop told me to either change the fluid every year or don't change it at all. He said because of the fluid being so high detergent if you wait to change it it will have lost some of it's ability to do it's job and the new fluid has a good chance of leaking. I never put much stock in what he said but now I'm wondering if I should change the fluid and filter.

 

[2003F350]

As for your differentials, I would use what your manual says should be in there. With a limited slip rear there's likely a particular friction modifier that needs to be in it, and I wouldn't just switch because someone said to, I'd look into it.

As for the transmission, if it's still shifting fine and the fluid isn't burnt looking or smelling, I'd be tempted to leave it alone. It's not giving you problems, why risk another variable? If you ARE going to do it, given that it's been so long I'd consider a full hot flush to get anything out, BUT realize that this could potentially loosen something that could later find itself stuck in the valve body and cause issues.

 

[KKBB]

Sooo, I'm finally getting around to changing the differential fluids on my 2009 TRX4. It's only got 84,000 original miles but they've been hard ones! The truck was never garage kept and I live up north in western New York where they love to salt the roads! I've done quite a bit of towing and ripped three sets of running boards off going off road (they're now welded to the frame). A friend of mine who owns a shop in the country suggested I go with 75w-145 full synthetic in both axles even though we're in a northern climate. I had short mileage originally because I lived close to work and only got out to the country sporadically. Now I'm retired and own two properties that are both over 100 miles away so I'm starting to pile up the mileage. I have the 3.92 LS rear in this so I know I have use that highly toxic LS additive in the rear. I just wonder If It is okay to use this oil in the front?

Also, a little lesson I learned about towing: The first picture is of me leaving Country Turf and Trail in Sunbury, PA. with my new tractor, the second is of my trailer being held on to my RAM by the safety chains on the side of a steep gravel road with it on the way home to Independence, NY.! The third picture I still can't believe every time I look at it. I've had these hitches stuck in the receiver so bad I couldn't knock them out with a sledge hammer! I had to leave my new tractor and locked trailer on the side of the road so I could go get another hitch. The only damage was a noticeable dent in my bumper which actually left my happy all things considered! I no longer leave my hitch in the receiver and keep them both well greased.

My son has a 2020 limited. We just changed his rear diff fluid. His has the 3.92 rear end and it says in the manual to use 75w-145 and 5 ounces of the Mopar limited slip additive, so that is what we did. I used Amsoil 75w-145 and 5 ounces of Mopar limited slip additive. I know the front diff takes different oil, but we didn't have time to change it yet. Like was said above. Just check you manual and use what it calls for.

 

[Rustypipes12]

They' ve actually changed the original to include 75w 140 for the rear now. I bought a bottle of that modifier . It's some nasty stuff!

 

[mtofell]

The tranny thing is always a heated debate..... I'm pretty much in the, "if it's not broke, don't fix it," camp.... As in, if it hasn't been changed in many years and things are good just leave it alone. I killed a crapper car years go by changing fluid and it could have just been a coincidence. Then, about 20 years ago I had a 1999 F150 that had no tranny problems and I got talked into changing fluid and IMMEDIATELY started getting clunking and slipping. I traded the truck in a week later and am not sure how it turned out but I don't imagine it was pretty. Are my experience just a fluke? Could be for sure but if the fluid isn't burnt and there are no other problems I'd run with it.

Fwiw, for a variety of reasons my daily driver is a 16 year old Honda Odyssey (120K miles) that I've owned since near new and nothing has ever been done to the tranny... Drives and shifts perfectly and I've never even looked at the fluid (sealed system, no dipstick). I have absolutely zero intention of doing anything until it blows up. It's paid off and a great ride so I'm just riding the wave. I'm on Maui with the Honda and my Ram (ironically been through 2 trannies despite all recommended maintenance) is sitting on the mainland.

 

[2003F350]

The tranny thing is always a heated debate..... I'm pretty much in the, "if it's not broke, don't fix it," camp.... As in, if it hasn't been changed in many years and things are good just leave it alone. I killed a crapper car years go by changing fluid and it could have just been a coincidence. Then, about 20 years ago I had a 1999 F150 that had no tranny problems and I got talked into changing fluid and IMMEDIATELY started getting clunking and slipping. I traded the truck in a week later and am not sure how it turned out but I don't imagine it was pretty. Are my experience just a fluke? Could be for sure but if the fluid isn't burnt and there are no other problems I'd run with it.

Fwiw, for a variety of reasons my daily driver is a 16 year old Honda Odyssey (120K miles) that I've owned since near new and nothing has ever been done to the tranny... Drives and shifts perfectly and I've never even looked at the fluid (sealed system, no dipstick). I have absolutely zero intention of doing anything until it blows up. It's paid off and a great ride so I'm just riding the wave. I'm on Maui with the Honda and my Ram (ironically been through 2 trannies despite all recommended maintenance) is sitting on the mainland.

Yeah, that's the boat I'm in - if it isn't giving issues don't mess with it, transmissions are supposed to be relatively trouble-free. Just check the fluid level and condition (if possible) and let 'er run. On the flip side you've got to take care of it, don't exceed its rated capabilities, etc. etc.

FWIW, every time I've changed transmission fluid it's been due to already having issues, and the fluid/filter change didn't do anything - I either lived with the issue or got rid of the vehicle.

 

[62Blazer]

My opinion is that it never hurts to change the transmission fluid. If you ever hear the whole story of those people who said they changed or flushed the transmission fluid and then the trans died, it's always the same. It's either the vehicle has 200k miles on it and has never had the trans fluid changed, or the transmission is already acting up and they do a flush in desperation to make it better. 3 months later the trans dies and they blame it on the fluid change or flush, and not on the simple fact that they ran it 200k miles or it was already on the way out.............

 

[09SilverRam]

The tranny thing is always a heated debate..... I'm pretty much in the, "if it's not broke, don't fix it," camp.... As in, if it hasn't been changed in many years and things are good just leave it alone. I killed a crapper car years go by changing fluid and it could have just been a coincidence. Then, about 20 years ago I had a 1999 F150 that had no tranny problems and I got talked into changing fluid and IMMEDIATELY started getting clunking and slipping. I traded the truck in a week later and am not sure how it turned out but I don't imagine it was pretty. Are my experience just a fluke? Could be for sure but if the fluid isn't burnt and there are no other problems I'd run with it.

Fwiw, for a variety of reasons my daily driver is a 16 year old Honda Odyssey (120K miles) that I've owned since near new and nothing has ever been done to the tranny... Drives and shifts perfectly and I've never even looked at the fluid (sealed system, no dipstick). I have absolutely zero intention of doing anything until it blows up. It's paid off and a great ride so I'm just riding the wave. I'm on Maui with the Honda and my Ram (ironically been through 2 trannies despite all recommended maintenance) is sitting on the mainland.

Honda autos behind the 3.5 have a drain plug and are specified for a drain and fill (3.x quarts) at about 30k miles and then every 45k miles. Should be prompted by the maintenance minder with code 3.

It’s honestly never too late to start changing that small amount of fluid drain and fill. Many Hondas that don’t have the fluid serviced develop a transmission shudder or torque converter problems, then you are looking at doing 3 back to back drain and fills to change 85% of the fluid and if that doesn’t work probably pulling the torque converter.

Your dipstick for say an 08 odyssey should be on the right side straight down between the engine and the battery. The dipstick tube is much smaller than the dipstick tube on a dodge RFE, but you can refill through it with a funnel that has clear tubing by sealing it over the dipstick. Transmission has a fill hole but it is hell to get to on an oddy.

Max life has been pretty well regarded as a replacement fluid. Your oddy shipped with Honda Z1 fluid, which they have replaced with DW1 which is backwards compatible but Maxlife is pretty well regarded as a replacement as well as BG Full Synthetic 312 which some dealers used when they couldn’t get Honda fluid during supply chain issues.

 

[Zoe Saldana]

Another question would be on the tranny. Years back a guy I knew that worked at a transmission shop told me to either change the fluid every year or don't change it at all. He said because of the fluid being so high detergent if you wait to change it it will have lost some of it's ability to do it's job and the new fluid has a good chance of leaking. I never put much stock in what he said but now I'm wondering if I should change the fluid and filter.

Differentials - go with what the manual says.

Transmission - get a 12v pump. Take out 2 quarts every oil change and replace with fresh.

 

[BenchTest]

Valvoline makes a 75w90 and 75w140 full synthetic, already has the LSD additive in it. $15/qt. Should meet all your requirements (API's GL's, etc.). It's readily available at just about every parts store, Walmart, Fleet stores. Swap it every 30K, cheap insurance. Trans fluid isn't "lifetime" fluid. It needs replaced as a regular service. Any trans shop or manufacturer that's being honest will say the same. There's no magic fluid that gets "filled for life". Transmission flushes are only acceptable in very specific situations (low mileage, regular interval flushes up to XX miles then stop doing them). There are a 101 threads on "do it/don't do it" regarding flushes. Again, anybody that's in the trans business and has real world application knowledge will say the same. Yes, there are "I've got 30 Million miles on my trans and never changed the fluid" stories, there are "I flush mine every 100K with 25 quarts of Super Deluxe Trans-All and drove it 500K with no issues" stories. There are the people who swap fluid with drain/fills until the drained fluid comes out "looking clean as new fluid". Take the time to get educated on what the fluid represents (what it's functions are, how soon it needs replaced, what the determining factors are) before jumping into a fluid flush or swap. I mean this as guidance, please don't take it as some forum dude $hit talking. There is no "one size fits all" guideline for trans service. Generally speaking, a general operational rule, for most traditional modern transmissions (as opposed to CVT's), 75K for first service or 50K if "severe" duty exposed (heavy towing, lots of low speed or high speed, or long duration offroad), then again, generally speaking, every 30K afterwards (speaking specifically of drain/fills). Most professionals will agree that if the trans has never been serviced and hits that magic 100k mark, don't touch the fluid. In fact, most shops won't touch a trans over 100K if the owner can't provide factual evidence that it's been previously serviced, or without having the owner sign a waiver. I'm sure somebody will **** and moan about what I've typed. Drive type, drive time, idle time, towing, environmental exposures (hot, cold, lots of water, desert) all play into "how long should the fluid be left in" considerations. Drain/fills are cheap, transmissions are not. You decide.

 

[BenchTest]

Sooo, I'm finally getting around to changing the differential fluids on my 2009 TRX4. It's only got 84,000 original miles but they've been hard ones! The truck was never garage kept and I live up north in western New York where they love to salt the roads! I've done quite a bit of towing and ripped three sets of running boards off going off road (they're now welded to the frame). A friend of mine who owns a shop in the country suggested I go with 75w-145 full synthetic in both axles even though we're in a northern climate. I had short mileage originally because I lived close to work and only got out to the country sporadically. Now I'm retired and own two properties that are both over 100 miles away so I'm starting to pile up the mileage. I have the 3.92 LS rear in this so I know I have use that highly toxic LS additive in the rear. I just wonder If It is okay to use this oil in the front?

Also, a little lesson I learned about towing: The first picture is of me leaving Country Turf and Trail in Sunbury, PA. with my new tractor, the second is of my trailer being held on to my RAM by the safety chains on the side of a steep gravel road with it on the way home to Independence, NY.! The third picture I still can't believe every time I look at it. I've had these hitches stuck in the receiver so bad I couldn't knock them out with a sledge hammer! I had to leave my new tractor and locked trailer on the side of the road so I could go get another hitch. The only damage was a noticeable dent in my bumper which actually left my happy all things considered! I no longer leave my hitch in the receiver and keep them both well greased.

That hitch photo is quite something. Reminds me of the Allstate Mayhem commercial with the "rusty boat hitch". LOL. Glad nobody was injured.

 

[BenchTest]

As for your differentials, I would use what your manual says should be in there. With a limited slip rear there's likely a particular friction modifier that needs to be in it, and I wouldn't just switch because someone said to, I'd look into it.

As for the transmission, if it's still shifting fine and the fluid isn't burnt looking or smelling, I'd be tempted to leave it alone. It's not giving you problems, why risk another variable? If you ARE going to do it, given that it's been so long I'd consider a full hot flush to get anything out, BUT realize that this could potentially loosen something that could later find itself stuck in the valve body and cause issues.

NEGATIVE on a flush for a vehicle that has "84,000 hard miles", especially when it hasn't been serviced prior. That's a high risk operation. Drain/refill will partially renew the fluids without providing a shock to the system like a flush would do. Several drain/refill operations over XX miles is considered a better approach than a full blown full fluid exchange at this kind of mileage. If the vehicle was at 50k miles of average use, then a flush would be considered.

 

[BenchTest]

Differentials - go with what the manual says.

Transmission - get a 12v pump. Take out 2 quarts every oil change and replace with fresh.

This would be the approach I'd recommend as well. 5k or 7.5k oil change intervals and doing a 2qt ATF exchange each time across 5 oil changes would put you in good ATF replacement practice. After that, drain/fill on the 30K marks. Should yield a longer trans life. Good recommendation @Zoe Saldana

 

[GTyankee]

Transmission fluid changes should depend on whether the vehicles is used for towing, even more so if you live in the hilly country.