IS350 differential fluid change DIY
09-01-14, 07:50 AM
#91
So today I took the opportunity to finally do the DIY rear carrier gear oil change. Was pretty straight-forward, as I expected. Instead of using a hand pump or some other off-the-shelf item, I went straight-up backyard mechanic and just used gravity and 6ft of clear tubing. 
Used Lucas full syn 80w-90 gear oil, and the right from the get-go I could tell it is smoother. So for those that don't wanna spend unnecessary funds on a "pump" you'll use once, twice...whatever, spend the $3 on tubing and do this : Used some electrical tape around the end of the hose and wrapped it around the diff to ensure it didn't pop out of the housing during feeding. Definitely worth the 1hr!
Used Lucas full syn 80w-90 gear oil, and the right from the get-go I could tell it is smoother. So for those that don't wanna spend unnecessary funds on a "pump" you'll use once, twice...whatever, spend the $3 on tubing and do this : Used some electrical tape around the end of the hose and wrapped it around the diff to ensure it didn't pop out of the housing during feeding. Definitely worth the 1hr!
09-01-14, 09:05 AM
#92
no need to remove tires. you will have to jack the car up a bit to get under there. Make sure to use stands or block the car somehow. I don't know how Gville350 knew when to stop pouring. I used a 1L plastic suction gun to squirt stuff in. That cost me about $8. When I saw a few drips coming out, I sucked back in a bit of fluid and checked and level was good.
09-01-14, 11:23 AM
#94
Like in my pic, obviously I left the wheel on.
Sure did; you just need the help the fluid down by squeezing the bottle.
no need to remove tires. you will have to jack the car up a bit to get under there. Make sure to use stands or block the car somehow. I don't know how Gville350 knew when to stop pouring. I used a 1L plastic suction gun to squirt stuff in. That cost me about $8. When I saw a few drips coming out, I sucked back in a bit of fluid and checked and level was good.
09-01-14, 05:03 PM
#95
I have an IS350 RWD, so yes...RWD, no matter if 250 or 350. Like in my pic, obviously I left the wheel on. Sure did; you just need the help the fluid down by squeezing the bottle. You remove the fill plug to obviously fill the carrier; once it starts spilling out of that hole, put the plug back in with the new crush washer.
05-15-17, 07:05 AM
#96
Driver School Candidate
hey guys, I just replaced my 07 IS350's differential fluid and thought I would post some pictures of the fill/drain bolts as the ones from the front page are down. fyi the fill/drain bolts are on the passenger side.
the following pic is from the rear passenger point of view with the wheel off. the hole in the picture is the fill hole. i do not have a picture of the fill bolt but the bolt has some writing on it, something along the lines of "see owner's manual for oil type", so it should be easy to recognize.
the next picture is also from the passenger side but at a lower angle. the hole at the bottom of the differential is the drain hole.
it was a pain in the butt to remove the bolts. i ended up using a 10mm hex socket and a 3/8 breaker bar (no extensions) on the bolts to remove them. it would help to jack the car up as high up as possible so that the breaker bar clears the floor. I used mobil 1 75/90. good luck.
the following pic is from the rear passenger point of view with the wheel off. the hole in the picture is the fill hole. i do not have a picture of the fill bolt but the bolt has some writing on it, something along the lines of "see owner's manual for oil type", so it should be easy to recognize.
the next picture is also from the passenger side but at a lower angle. the hole at the bottom of the differential is the drain hole.
it was a pain in the butt to remove the bolts. i ended up using a 10mm hex socket and a 3/8 breaker bar (no extensions) on the bolts to remove them. it would help to jack the car up as high up as possible so that the breaker bar clears the floor. I used mobil 1 75/90. good luck.
05-19-17, 09:23 AM
#98
I haven't seen a UOA for the diff fluid yet. Although, at 190k, and if original fluid, it probably should be changed. I'm sure the drain plug has a ton of metal shavings on it.
Last edited by Zmon; 05-20-17 at 09:43 PM. Reason: lol, cleaned. Meant to say changed.
The following users liked this post:
Leander311 (05-19-17)
05-19-17, 01:17 PM
#101
@ myself for misreading the thread title. My UOA was for the transmission fluid.I did get the rear differential fluid changed a couple months back but unfortunately I didn't get the used fluid sampled. It's not a bad idea though as it would help me to determine on whether or not I'm changing out the gear oil too frequently (currently changing out fluid every 30k miles).
05-19-17, 05:30 PM
#102
@ myself for misreading the thread title. My UOA was for the transmission fluid.I did get the rear differential fluid changed a couple months back but unfortunately I didn't get the used fluid sampled. It's not a bad idea though as it would help me to determine on whether or not I'm changing out the gear oil too frequently (currently changing out fluid every 30k miles).
I may end up sending mine in for a UOA, changed it about 40k ago, may end up changing it soon.
05-20-17, 09:23 PM
#104
The following 2 users liked this post by andper10:
Leander311 (05-22-17),
Zmon (05-20-17)
05-22-17, 07:18 AM
#105
Wow - Lots of good info here... much appreciated, andper10 and redspencer!! From these two UOA's, I'd be more tempted to replace the tranny fluid than the diff fluid, despite Lexus' claims they are both good for the life of the car... What do they consider said "life" to be? If it's 200k, I'm getting close!