Changed The Transmission Fluid Again....

[RX in NC]

I changed the Type T-IV ATF in my wife's 2000 RX300 AWD at my chosen 30,000-mile interval again this morning. Drained the transmission pan as well as the differential by pulling both drain plugs. The old fluid was still in fairly good shape - slight discoloration, no burned smell or taste, and a little bit of debris build-up on the magnet attached to the tip of the differential drain plug. All in all, the old fluid looked better than I thought it would.

I needed slightly under 5 quarts of fresh fluid to get it back up to specs, just like last time. I'll continue to check the fluid level over the next few days to ensure that I have the level where it needs to be.

For those of you with AWD versions of the RX300, I can't stress enough that you should perform this procedure at least every 30,000 miles. It may give you a fighting chance at keeping your transmission alive for a significantly longer period of time. We're now approaching 60,000 miles on our replaced-under-warranty-by-Lexus second transmission that was installed back in November 2003. Although neither the original nor the replacement transmission has ever been as smooth as it should be for a vehicle that originally stickered for more than $40,000, this replacement transmission has never exhibited signs of the infamous "freeze-up" that our original transmission did. I'll keep changing the Type T-IV fluid every 30,000 miles and keep Lexus on the hook for as long as I can....

[bluestu]

RX,

With all that money you made working for Corporate America, you should invest in your own flush machine. It would give you something extra to do in your old age, and maybe you would finally realize that the RX300 transaxle holds way more than 5qts. of fluid. You could still clean the filter and magnet manually to ensure that your replacement transmission lasts well into next year.

[lenore]

Hey RX NC he is just jealous, I too have quit my corporation job, but am by no means as well off as you are, but I am OK, I baby sit one of my grandaughters 4 days a week and look forward to my evenings and weekends to do the DIY stuff. Have a great weekend.

[wwest]

I have grown suspicious of late that the ATF problem might be related to the VC, viscous clutch.

The viscous clutch was dropped from the design of the RX330 and remained that way for the entire RX330 production run.

Now I see that the new RX350 again has the VC incorporated within the PTO.

When the VC was dropped for the RX330 series the F/R final drive ratios were also revised, giving more engine torque bias toward the front. Now with the RX350 the RX300 final drive ratios are back in use again.

Some of you have noted, I'm sure, that the PTO has numerous heat disapating vanes/fins incorporated externally on the case. The way the VC operates is that differing front and rear driveline rotational rates result in "churning" the viscous fluid which heats it fairly rapidly. The fluid is formulated such that its volume would expand dramatically with temperature. But since it is hermetically sealed within the VC cannister instead of expanding the fluid pressure increases dramatically. That results in an increased coupling coefficient between the two sets of clutch plates causing more of the engine torque to be routed toward the rear. With the rear driveline "overdriven" (versus) the front, the increased coupling coefficient has a more dramatic affect on torque distribution to the rear than it would otherwise.

But what if the heat generated by the VC could not be wicked away by the cooling fins as rapidly as necessary to keep the PTO's 90 weight from over-heating and then passing that heat on to the ATF in the adjacent diff'l case?

Somewhere after about 1999 Toyota adopted the transaxle shift procedures proposed by Sierra Research to improve fleet average fuel economy by 9.8%. I have no doubt whatsoever that the adoption of those technique lead directly to the later adoption of DBW to protect the "drive train".

What if, between the two, the heat contribution from the VC, and the additional clutch use/wear due to the additional shifts required to get the 9.8%, the result was "inadvertent", unforeseeable, premature transaxle failures in our AWD RX300s?

Has anyone yet seen, looked over, the PTO case in the new RX350?

Additional cooling vanes, maybe?

Or did the adoption of DBW in the RX330 solve the ATF "problem" and leaving out the VC turned out to be needless?

[wwest]

Just after I walked away from posting the above a new thought occurred to me.

The ATF in the diff't case has a separate drain plug, must be drianed separately from the transaxle itself.....

Could that possibly mean that the ATF within the diff'l cannot very freely circulate with/into the main transaxle case? If so then it becomes even more probable that the fluid "trapped" in the diff'l is being overheated via the nearby/adjacent PTO case and then slowly over a long period remixes with the bulk of the ATF.

The ATF in the "main" transaxle case is being continuously circulated through the external ATF cooler in my AWD RX300.

[mikey00]

RX,

With all that money you made working for Corporate America, you should invest in your own flush machine. It would give you something extra to do in your old age, and maybe you would finally realize that the RX300 transaxle holds way more than 5qts. of fluid. You could still clean the filter and magnet manually to ensure that your replacement transmission lasts well into next year.

The RX trans only holds a little less than 10 qts. Not 16 qts like many believe, which is what they use when they use a flushing machine. A drain and fill of 5 qts every 30,000 should be sufficient. I am on a drain and fill every 15k schedule which is most likely a little overkill but I am convinced this trans will eventually fail even if it is flushed weekly. If you really feel the need to get all the fluid out, there is a procedure in which you disconnect one the the trans cooler lines, which is a lot better than letting someone hook up a flush machine to your trans.

The April 2000 Consumer Reports Annual Auto Issue lists engine and trans flushes under mechanic rip-offs.

[artbuc]

Just after I walked away from posting the above a new thought occurred to me.

The ATF in the diff't case has a separate drain plug, must be drianed separately from the transaxle itself.....

Could that possibly mean that the ATF within the diff'l cannot very freely circulate with/into the main transaxle case? If so then it becomes even more probable that the fluid "trapped" in the diff'l is being overheated via the nearby/adjacent PTO case and then slowly over a long period remixes with the bulk of the ATF.

The ATF in the "main" transaxle case is being continuously circulated through the external ATF cooler in my AWD RX300.

wwest, based on my experience, the differential fluid definitely does not circulate very much. The last time I did a drain & refill on my 99 RX, ATF from the pan looked new while ATF from the differential looked nasty. A very marked difference after just 15k miles.

[lenore]

Is the VC fluid replaceable? Or is it part of the coupling assembly? Just another reason I will not buy another Lexus, Lexus refuses to admit a design problem or at least find a remedy for our RX300 AWD tranny failures. I know it is a dead product and they have moved on, but their customers have not. Nice automobile except for that major failure in the tranny. I too Like RX NC change the fluid religously, just like I did before my two tranny failures. I was changing at 30k intervals, now I change at 15k or less.

[wwest]

Is the VC fluid replaceable? Or is it part of the coupling assembly? Just another reason I will not buy another Lexus, Lexus refuses to admit a design problem or at least find a remedy for our RX300 AWD tranny failures. I know it is a dead product and they have moved on, but their customers have not. Nice automobile except for that major failure in the tranny. I too Like RX NC change the fluid religously, just like I did before my two tranny failures. I was changing at 30k intervals, now I change at 15k or less.

No, but the entire VC assembly, cannister, can be purchased for $1100.00.

But I can't be sure the viscous fluid is a problem, in and of itsself. It is possibly a source of the heat that eventually compromises the ATF, but that is part of the VC design. Self heating of the VC is what results in tighter, increased coupling of engine torque to the rear wheels.

[RX in NC]

I agree that these transmission flushes are rip-offs and carry the potential of doing far more harm than good. Bluestu has been suckered into the hype and believes that it is an essential procedure for keeping his transmission alive. If someone gave me a flush machine, Bluestu, the only thing I would risk running through it would be a lawnmower. And if you really believe that I'm an old geezer sitting around eating bran flakes and waiting for my Social Security check in the mail, next time you're in Raleigh, let me know. I'd be more than happy to meet you at a local gym and go a few rounds with you....

[bluestu]

RX,

Obviously, I was just kidding around with you. Where is your humor? I know you hate transmission flushes, but you're still only changing half the fluid with your drain and fill. Next time I'm in Raleigh, I'll be happy to go a few rounds with you. Sounds like big fun. I'll even let you check my transmission fluid. Just don't get jealous when you see it.

[RX in NC]

Bluestu,

Your're on. I've got two pair of 10-ounce Everlast gloves and four pair of 14-ounce Everlast gloves. Your choice. I can supply all the pre-wrap and athletic tape you'll need for your hands. Headgear is required, and you'll need to size and acquire that yourself. Don't forget your mouthpiece. The Durham Armory hosts some great local amateur and challenge cards on many Friday evenings. To ensure ring space, I'd need to book us a couple of weeks in advance. If you want a corner guy, I'll let my long-time guy know and he'll have one ready for you (but I can't guarantee the quality). Just let me know when you're coming and I'll set it up. We'll need to talk prior to the chosen evening to ensure that everything is settled and legit.

The only problem is that if you're more than one weight class below me, they won't let us spar there. Age is not a factor, but size is. I'm 6'7", 247 to 250 pounds. With a couple weeks of training and prep, my ring weight will be closer to 240. What's your height and weight?

[scoobie]

Bluestu,

Your're on. I've got two pair of 10-ounce Everlast gloves and four pair of 14-ounce Everlast gloves. Your choice. I can supply all the pre-wrap and athletic tape you'll need for your hands. Headgear is required, and you'll need to size and acquire that yourself. Don't forget your mouthpiece. The Durham Armory hosts some great local amateur and challenge cards on many Friday evenings. To ensure ring space, I'd need to book us a couple of weeks in advance. If you want a corner guy, I'll let my long-time guy know and he'll have one ready for you (but I can't guarantee the quality). Just let me know when you're coming and I'll set it up. We'll need to talk prior to the chosen evening to ensure that everything is settled and legit.

The only problem is that if you're more than one weight class below me, they won't let us spar there. Age is not a factor, but size is. I'm 6'7", 247 to 250 pounds. With a couple weeks of training and prep, my ring weight will be closer to 240. What's your height and weight?

When you guys set up the date, please post it here, if I'm in the area I don't want to miss it. :lol:

[bluestu]

RX, sounds like you should be a member of the Hummer Forum. Maybe a round of basketball would better suit me. I don't believe I'll be boxing with anyone. Being a saxophonist and pianist, it would be kind of difficult to play with no teeth and a broken neck.

[lexuschuck]

RX, sounds like you should be a member of the Hummer Forum. Maybe a round of basketball would better suit me. I don't believe I'll be boxing with anyone. Being a saxophonist and pianist, it would be kind of difficult to play with no teeth and a broken neck.

Or you could race your RX's against each other (1/4 mile, Autocross, etc.). Infact, you ought to sign up to be on the show pinks...they'd love to have you guys on. http://www.pinks.tv/

[RX in NC]

Bluestu,

No Hummer for me, thanks. Too much of a gas guzzler and a totally impractical and pretentious vehicle in my opinion. I could never justify spending the money on something that unnecessary and stupid.

I'm up for some hoops instead of a bout in the ring. I've had a team in a local 35+ league for years and even though most of my guys are in our early 40s through early 50s, we still usually win the tournament every April by playing smarter, finding the open man, and boxing out hard in the lane to set the tone (my favorite strategy, as you probably guessed). After our tournament ends in mid-April, I'd enjoy shooting hoops with you.

Saxophone, huh? Alto? Soprano? I was fortunate enough to catch Bela Fleck and the Flecktones live at a local venue in late January and was blown away by Jeff Coffin's incredible skills. Do you know of him?

[mek88]

Mine is a 99 RX300 AWD @ 136K-miles with original engine & original tranny. I always use mobil-1-5w30 every 5K, and toyota type-IV-ATF every-15K.

Does front differential & transmission share the same filling hole for ATF?

So far I only changed the ATF for tranny by opening the drain bolt at the bottom of black-color ATF pan. I've never changed the front diff oil because I'm not sure how to fill it up. And I;ve never dropped the pan at all, never had any flush at all.

Shall it fill it up all the way to whatever amount drain from tranny+diff at once from tranny filler(approx 5 qt of T-IV)?

I'm just affraid if I drained them & fill them up, the ATF takes a while to circulate into Diff. On the meantime diff doesn't get lubricated after few miles or until it filled up.

Please advise.

Thanks

email: mek88@yahoo.com in Los Angeles

[RX in NC]

Yes, the front differential and the transmission pan share the same "filling hole" - you fill both through the transmission dipstick tube.

You'll find the front differential's drain plug behind, above, and slightly towards the passenger side from the transmission pan drain plug. I have to jack up the front end and crawl under the front of the vehicle to be able to get to it properly. The front differential's drain plug is mounted horizontally, whereas the transmission pan's drain plug is mounted vertically on the bottom of the pan. Both drain plugs require a 10mm Allen (hex) wrench.

You're correct - it probably does take a few minutes for the new T-IV fluid to circulate into the front differential from the transmission pan once you crank the engine and engage the transmission. Just drive slowly and carefully for the first few miles, or don't drive at all. Instead, allow the engine to run while you shift the transmission lever through the entire gear range multiple times very slowly.

Some have reported here that their old T-IV fluid drained from their front differentials was much darker and dirtier than the old fluid drained from their transmission pans. I have not found that to be the case in our vehicle - the fluid looked, smelled, and tasted pretty much the same from either source.

After draining all the old fluid out of both the transmission pan and the front differential, our vehicle requires just under 5 quarts to get the fluid level back up to specs.

Good luck to you.

[bluestu]

Bluestu,

No Hummer for me, thanks. Too much of a gas guzzler and a totally impractical and pretentious vehicle in my opinion. I could never justify spending the money on something that unnecessary and stupid.

I'm up for some hoops instead of a bout in the ring. I've had a team in a local 35+ league for years and even though most of my guys are in our early 40s through early 50s, we still usually win the tournament every April by playing smarter, finding the open man, and boxing out hard in the lane to set the tone (my favorite strategy, as you probably guessed). After our tournament ends in mid-April, I'd enjoy shooting hoops with you.

Saxophone, huh? Alto? Soprano? I was fortunate enough to catch Bela Fleck and the Flecktones live at a local venue in late January and was blown away by Jeff Coffin's incredible skills. Do you know of him?

I play tenor and soprano saxophone. I do know who Jeff Coffin is, and he is an excellent player. If I ever get down to Raleigh, I'll let you know. I love to play basketball. Too bad NC State and Carolina were knocked out of the NCAA Tournament. My dad is an alumnus of NC State and my brother an alumnus of Carolina. I graduated from UT and they were eliminated also. I guess I'll have to pull for Duke. Sorry.

[wwest]

Yes, the front differential and the transmission pan share the same "filling hole" - you fill both through the transmission dipstick tube.

You'll find the front differential's drain plug behind, above, and slightly towards the passenger side from the transmission pan drain plug. I have to jack up the front end and crawl under the front of the vehicle to be able to get to it properly. The front differential's drain plug is mounted horizontally, whereas the transmission pan's drain plug is mounted vertically on the bottom of the pan. Both drain plugs require a 10mm Allen (hex) wrench.

You're correct - it probably does take a few minutes for the new T-IV fluid to circulate into the front differential from the transmission pan once you crank the engine and engage the transmission. Just drive slowly and carefully for the first few miles, or don't drive at all. Instead, allow the engine to run while you shift the transmission lever through the entire gear range multiple times very slowly.

Some have reported here that their old T-IV fluid drained from their front differentials was much darker and dirtier than the old fluid drained from their transmission pans. I have not found that to be the case in our vehicle - the fluid looked, smelled, and tasted pretty much the same from either source.

After draining all the old fluid out of both the transmission pan and the front differential, our vehicle requires just under 5 quarts to get the fluid level back up to specs.

Good luck to you.

".....tasted...."???

YUK..!!

[TunedRX300]

".....tasted...."???

YUK..!!

Well, burned tranny fluid look like chocolate milk. The man is thirsty...

[RX in NC]

Just a drop on the tip of the tongue can tell you a lot about certain automotive fluids. Keeps you regular, too. Just don't do it with antifreeze....

[lenore]

I like your style RX, You have a good answer for all the folks out there, sorry you are on the east coast and i am on the west coast, I think we could be good friends. Lenore (tom)

[RX in NC]

I fully agree, Tom. We certainly share some common interests.

I haven't been skiing at Lake Tahoe in more than 20 years now, but every autumn we talk about what a great time we had and that we should do another ski trip out there again and we just never get around to it. If we manage to finally pull it off, I'll let you know in advance. If memory serves me correctly, Sacramento can't be too far away. I'd enjoy getting together for dinner with you.

I'll never forget that while we were at Heavenly Valley in February 1986, the Lake Tahoe area received NINE FEET of fresh snowfall during the five days we were there. Best powder skiing of my life, and the town did a great job of keeping the roads relatively plowed so we could get around for dinner, clubs, and the casinos at night. We had a K-5 full-size Chevy Blazer 4x4 as our rental vehicle and that sucker never missed a beat in all that snow. We skiied our fannies off and had a blast. My only regret is that my camera pretty much stayed in the room the whole time because I didn't want to tote it around on the slopes, so we have almost no pictures of that great time in Tahoe. But I still have the brochure from the resort where we stayed, and if it's still around, we'll book it again if we ever make it back to that gorgeous area....