dpw2552

I have a 2008 RX350. Car is hesitating at 40 mph consistently. Would a transmission fluid change help? Don't believe it has been changed. 175k miles.

Lexuswiz

iTrader: (1)

This is tough to say, if it's never been changed, it should not hurt to change the fluid but if the trans has been in bad shape prior to the fluid change, it could fail soon after the fluid change leaving the user to believe it was the fluid change's fault when the trans was failing anyways. Personally I would do it, when I got my 330 with 72K on the clock, changing the fluid helped with the hesitation around 40-60mph but YMMV.

BlackLexRX

Definitely a drain and fill. I'd even drop the pan and do the filter too; there's a few DIY's on both if you search the forum. Refurb'd trans are 3k, plus install so it's probably worth a chance to try and get some of the metal out of that system. There's plenty of modifiers and additives out there too that can help recreate some friction on the clutches, etc, so maybe take that as a next step after drain/fill/filter.
Feel where your RX's gear changes are having problems. 3rd to 4th maybe? And baby it.

jmu2004

After not touching my trans fluid until 140k, I have since done 3 drain and fills concurrent with my oil changes using Toyota fluid. The fluid is now pristine.

Anyway, the surging that I used to experience at lower speeds (especially after not coming to a full stop and then accelerating) is mostly gone. No more jerky/uneven accelerations.

I should disclose that I have recently changed the rear diff and transfer case fluids as well. Those fluids were thick and worn out. All of this maintenance has improved my MPG and made my 2005 RX330 feel like new.

RedGemini

I know I have to do a couple more drain and fills of my tranny, and I'm sure the transfer case and rear diff fluids have never been touched, either.

I'm curious what your gas mileage was like prior to doing this, and what you're seeing now.

BlackLexRX

I've gone through all three systems and it does improve fuel economy, but it's minor. In my case, drain and fill on the transfer case made biggest difference in feel. RX just feels smoother after new fluid in transfer case. Drain and fill all three systems and you'll feel the difference.

jmu2004

I've noticed about a 5-15% difference on fuel economy...from 18.5ish mpg to just over 20.5 in mixed driving.

Not a big enough difference that you'd really notice, but combined with the improvement in drive ability, I'm happy.

RedGemini

Since I'm barely averaging over 16 with about 60% highway, I'll take any improvement I can get. I'm going to attempt to do the transfer case and rear diff today, as long as I can get a socket or wrench to fit on the TC drain plug. No, I'm not hard on the throttle. Tires are at about 36 psi. Full synthetic 0w20 oil. New air filter. I've been literally trying everything within budget. I usually use 91+ octane, sometimes 89, sometimes 87. I'm not seeing a difference between either of them. I've also done 2 different fuel system treatments, including one bottle of Chevron Techron and one bottle of CataClean, as I got a P0430 on a trip the beginning of this month. It hasn't come back, but I'm all too familiar with the P0420/P0430 PITA codes. I'm sure it'll come back at some point.

I did the second drain and fill of the transmission fluid yesterday. It's a little early to tell, but seems a bit more responsive in early testing. I'm planning to do the third within the next two weeks, weather permitting.

dmanwi

I was going to do another drain and fill at the dealer. I didn't even realized there is a transmission filter. How much should the Toyota dealer charge for dropping the pan and changing the filter? I've had a 2007 RX 350 for a year now. I already did one drain and fill but I dont think the filter has ever been done.

RedGemini

I was quoted 1-1/2 hours labor by my cousin's garage. Your best bet is to call the dealer to inquire.

05RX330AWD

Same here, not the gas millage I expected, same steps taken (Air Filter etc) with no real improvement, actually the RX had a leak for the differential when purchased.
The seal was changed, differential oil changed, again, no noticeable change for gas millage...
I was in the 21 miles per gallon range for city driving with an 05 Equinox LS 6 Cyl 3.4L AWD only with an oil change, air filter & correct pressure for tires.
The RX has me stumped, especially in winter when the DIYs are difficult to accomplish.
I also was dealing with a P0420 & a P0430 Code for good measure although hasn't returned in quite a while from filling up with 91 Octane.
Also a P0304 misfire code popped up once, erased it, it never returned.
Transmission fluid & filter should be next, doubtful that was ever changed since the timing belt wasn't at 137,000 miles which was first item on the to do list when I purchased the RX.

RX3302004

No issues with my transmission on my 04. I would definitely change the fluid if it hasn't been done at the OP's mileage.
Fuel mileage, my vehicle shows 20.5mpg with none of it highway other than around town.

jmu2004

The RX330 doesn't have a true filter in the transmission...it is just a screen. By changing your fluid and cleaning off the drain plug, you should be fine.

Think of it this way....if you had large enough metal pieces/debris to get stuck on the screen, then your transmission is probably toast anyway.

I think you're likely to introduce MORE contaminants into the transmission by dropping the pan and putting in a new screen.

Just my opinion. Do drain and fills every so often and I think you're golden.

BlackLexRX

330s and 350s have a filter. 300s have a screen. Drain and fills are what is typically needed. However, if for example, after drain and fill several times a trans still has shift flares, etc, pan should be dropped and filter changed. Search around these forums, people have done the filter, and it comes out black and full of debris.