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2014 GS350 AWD Transfer Case & Differential Oil Change Question
Hi guys, loving my 2014 GS350 AWD and I want to change the oil in the drivetrain at 50k miles. I know we have a front and rear differential, I found good info on changing the oil in the differentials. But what I'm not sure about is the transfer case and transmission. Is the transfer case a separate unit from the transmission, or is the transfer case oil shared with the transmission?
Hi guys, loving my 2014 GS350 AWD and I want to change the oil in the drivetrain at 50k miles. I know we have a front and rear differential, I found good info on changing the oil in the differentials. But what I'm not sure about is the transfer case and transmission. Is the transfer case a separate unit from the transmission, or is the transfer case oil shared with the transmission?
Thanks!
Sam
+1 I'd be interested to know this as well, and definitely interested in a DIY instruction vid or pics if anyone has them. Great vids exist for the differentials, that's on my list of things to do soon.
+1 I'd be interested to know this as well, and definitely interested in a DIY instruction vid or pics if anyone has them. Great vids exist for the differentials, that's on my list of things to do soon.
We have a member here named Dan who has produced fine DIY videos for both front and rear differential. You should be able to find them by simply searching "GS350 differential" on Youtube.
I have personally done both front and rear on my car as well, it's not a difficult job - besides getting the fill plug out for those of us in the north east with salted roads. I actually had to replace my fill plug because it was so stripped.
Transmission is a different story because filling it to the right levels is a much more involving process.
Thanks for the info guys/gals. I did already find good info on the differential. My question is about the "Transfer Case" and if the Transfer Case shares the oil with the Transmission. (Transfer case is not part of the differential)
OK, so I kept getting conflicting information on the AWD setup and Oil changes for the 4GS. (I have a 2014 GS350 AWD) And now that I have done the oil change, I wanted to post here to confirm 2ltrgsr was spot on in his advice and that the info here is the way to go.
I decided to post here now that I have definitive and clear information on the oil changes for the Front, Rear Differentials and the Transfer case. I have verified this with the head Lexus Mechanic at my dealership, then I verified this information by me using the Lexus Microfiche and then compared that to Pictures of the Transfer case, Transmission and Differentials:
In summary, 4GS Lexus GS350 AWD systems have:
Front Differential
Rear Differential
Transfer Case (Part of the Transmission)
The Front & Rear Differential are separate sealed units with their own oil supply.
The Transfer Case is part of the Transmission and shares the Transmission Oil supply.
General consensus seems to be that the Front & Rear Differentials get oil changes after 50-60k miles.
The Transmission & Transfer Case should be changed after 100-120k miles.
Hope this clears things up for some people, as this has been a bit frustrating to figure out for me with the conflicting information out there.
I have now completed the differential oil changes at 50k miles, I will wait for the transmission/transfer case oil change until 100k miles.
I ended up having the dealer do it, using the standard Toyota/Lexus fluid. Was tempted to go with the Mobile 1, but decided to just go OEM and do it again in 50k miles. Cost was $280 for front and rear diff at the Lexus dealer.
Should also be noted that the Service Advisor at the dealer at first told me that all 3 are separate units. (Even those dealing with it on a daily basis can get this wrong, hence my post) We then got the master tech involved and he knew exactly what to do, I double checked him with those pictures, just in case.
General consensus seems to be that the Front & Rear Differentials get oil changes after 50-60k miles.
The Transmission & Transfer Case should be changed after 100-120k miles.
General consensus by who?
The Lexus Scheduled Service Manual indicates only 'Inspection' of Front Differential (AWD) and Rear Differential through 150,000 miles with no replacement of (gear oil) fluids. The transmission (which includes the transfer case for AWD) is not even mentioned in the Lexus Scheduled Service Manual through 150,000 miles.
If you want to replace fluids before Lexus recommends doing so - you are far (FAR) better served by replacing the transmission fluid before replacing the gear oil in the differential(s). The transmission has many times more parts and moving pieces compared to the differential - with many of the transmission parts required to operate with exacting friction parameters unlike a differential's simple ring and pinion gear. And, the transmission is subject to much higher temperatures compared to the differential.
If I was planning to keep the car beyond 150k miles I would change the transmission fluid at around 100k miles. However, I would not replace the differential gear oil.
I understand what the manual says, I don't adhere to the manufacturers recommendation and I don't believe in lifetime fluids. It was not my intention to suggest this is what others should do.
I said general consensus "seems" to be, simply based on what I have been reading and after having seen videos and photos of the magnetic oil plug from other GS owners who have changed the fluid. I have therefore decided that I want to change the oil to clean it out and give myself peace of mind.
Since many people have their own opinions, especially pertaining to oil changes of lifetime fluids, I'm not suggesting anyone follow my schedule, I'm simply stating that this is what I'm doing.
The purpose for this post was to bring clarity to what driveline components have dedicated fluid and shared fluid in the driveline of the GS350, it was not intended to give suggestions on the frequency of these oil changes.
The Lexus Scheduled Service Manual indicates only 'Inspection' of Front Differential (AWD) and Rear Differential through 150,000 miles with no replacement of (gear oil) fluids.
How would you suggest to "inspect" differential fluid? Are you taking samples and sending it to a lab for proper analysis? With that effort, why wouldn't you just drain and fill it? Front+rear diffs combined takes about 3qts of oil and this is an easy DIY job that can be done in <2 hours even for a beginner.
Why do any other cars with differentials specify change intervals? Are the Lexus differentials that much different from every other manufacturer or the Lexus fluid is that much better than anything else when it's not even synthetic? With differential oil, the first drain is especially important because most of the wear occurs while the car is broken in, and that metal stays inside. If you are lucky, the magnetic drain plug might capture some of it, but otherwise that metal stays inside meshing against your gears.
You may be right that differential gear oil probably doesn't face the same amount of high temperature than tranny fluid, but the mechanical stresses inside differentials are also much different from those of a transmission and that's what will contribute to shearing and reduce protection. That's why the transmission and diffs require different fluids to begin with.
If you go by the manual, I think the brakes are also "inspection" items - fairly certain that doesn't mean "no replacement" required.
How would you suggest to "inspect" differential fluid? Are you taking samples and sending it to a lab for proper analysis? With that effort, why wouldn't you just drain and fill it? Front+rear diffs combined takes about 3qts of oil and this is an easy DIY job that can be done in <2 hours even for a beginner.
Why do any other cars with differentials specify change intervals? Are the Lexus differentials that much different from every other manufacturer or the Lexus fluid is that much better than anything else when it's not even synthetic? With differential oil, the first drain is especially important because most of the wear occurs while the car is broken in, and that metal stays inside. If you are lucky, the magnetic drain plug might capture some of it, but otherwise that metal stays inside meshing against your gears.
You may be right that differential gear oil probably doesn't face the same amount of high temperature than tranny fluid, but the mechanical stresses inside differentials are also much different from those of a transmission and that's what will contribute to shearing and reduce protection. That's why the transmission and diffs require different fluids to begin with.
If you go by the manual, I think the brakes are also "inspection" items - fairly certain that doesn't mean "no replacement" required.
'Inspection' means to check the level, not to send a sample off for evaluation analysis.
I would say that a rear differential can easily go for 250,0000 miles without replacing the gear oil - and likely 500,000 miles without being touched. Decades ago (long before the better lubricants of today) all rear differentials received was just a courtesy inspection check for proper gear oil level and if needed, a top-up.
the first drain is especially important because most of the wear occurs while the car is broken in
That was my concern also, based on experience with some of my previous vehicles. After seeing the magnetic drain plug of a GS changed at 60k, I knew I wanted to change it and get that initial wear out of there.
I bought the Lexus to keep it for a long while, if long term ownership wasn't an issue for me, then I would still be driving a Benz. (Even though my Benz's proved very reliable, never owned one past 80k miles)
10-12-17, 02:15 PM
2014 GS350 AWD Transfer Case & Differential Oil Change Question
