Transmission Fluid Change Questions

Hello again,

• This week I replaced both front axles and wheel bearings on my 2008 V8 T4R. No problems except for the bolts in the aftermarket wheel bearings from Rock Auto were too long and I had to cut off 3/16th of an inch on each bolt. Also, the wheel speed sensor broke from corrosion in the hole, and I had to reorder a new one. I'm waiting to drive it after I install the sensor because I thought it might throw a code otherwise???
• Next, I am changing the transmission fluid and my research has given me different answers to the following. Please advise.
  • Do I have to drop the pan? Is it possible to simply just drain and fill?
  • Does this year have a filter and if so, does it have to be changed?
  • If the pan must be dropped, does it require unhooking the exhaust?

I enjoy sharing what I'm doing and I always value your input! Thanks.

 

Answers:
-You do not have to drop the pan. Drain and fill is fine, but be aware youll only be getting maybe 1/4-1/3 the total volume of fluid in the system.
-It has a 'filter' if by filer you mean a mesh screen. Its not like a paper filter a la the oil filter. You do not have to swap it if you dont want to.
-You should not be near the exhaust for the pan strictly speaking, unless something very strange happened to your drivers side connect to the pass side/the Y-pipe. Now when you open the 24mm fill screw on the trans, then youre quite close to the pass side exhaust pipe yes.

More info: There are two screws on the underside there, the one towards the rear of the pan is the drain, the one towards the center is the overflow for verifying correct volume. Think theyre 4 or 5mm hex screws. There is a very good write up on how to verify proper level on T4R if you dont already know, just do a search. Also Hint hint most people spring to get the Lexus version of the part as its the same threads but its a 12mm(?) cap to just put a socket on. Also the trans fill is a 24mm screw, and it really helps if you have a shallow well socket, even a standard may not fit.

 

Thanks, this is helpful.

I watched the video of Eric the Car Guy changing a 4Runner trans and he had to unhook the exhaust pipes to drop the pan. It had a standard looking filter, too. Hence my confusion. Maybe he was working on a V6, but after looking today, there is nothing hampering my V8 and should be easy to drop.

 

There's no difference in the transmission filter/screen for a V8 or V6...it's just a metal screen, most who have changed it say there was nothing blocking/wrong with the original screen but they change it anyway, if you do drop the pan to change the screen, just clean it if needed no need to buy a new one...but on the V8 everyone says they had to disconnect the exhaust to get the pan completely off, the exhaust will not let it drop down enough, so I would recommend not to drop the pan.

Not sure what transmission Eric was working on but all 4th Gens except 2003 and 2004 V6s have the same transmission and don't have a "filter" only the metal screen, not sure if the early V6 transmission with the old 4 speed transmissions had a paper filter or a screen, maybe Eric was working one of those 4 speeds(?).

 

Thank you!

 

You can do a full exchange as opposed to a partial drain and fill. has the process. Highly recommend reading the entire thread if you have the time as others contributed tips based on their experience.

 

Yep, what Bluesky said. It's possible to use the coolant lines to let the ATF pump push fluid out, though I'd probably do it slightly different. I'd probably put 10 quarts or so into a giant container, and be pumping into one side as the ATF pump is pumping out the other side. Try to match pumping speeds. The goal is to put the same amount in at the same rate as the pump is putting out. That way you don't have to start/stop and do two quarts at a time.

That being said, I'd also consider whether you NEED to do all that. The ATF fluid is supposed to be "lifetime." Most people, myself included, think "lifetime" is BS. That being said, other posts have had extensive conversations about what wear-and-tear is happening. The biggest cause of wear is going to be temperature. The ATF cooler should be keeping your ATF under 200F, and there should be no thermal degradation, even after 20 years. The key being the assumption that your ATF pump and ATF radiator are all working fine. The other source of degradation would be friction or shearing forces on the fluid. I can't speak to that at all. What I will say is that my '05 has 185k on it. I did a drain-and-fill at 180k and grabbed a sample. I sent the sample to Blackstone Labs for analysis. My original ATF with 180k and 16 years or more tested basically as good as new. So I got some piece of mind by putting 1/3 new fluid in, and finding out that the old fluid was still good to go. No need to do more. Saved some money, time, and stress, and get to feel good about the results too. I'll probably do that every 3-5 years and 25-50k.

That'd be my recommendation:

1. Do a simple drain-and-fill, and be 100% sure you follow the right procedure and get it at the right level when filling.
   
2. Nab a sample of what comes out and send it to an analysis company.
   
3. Check out the results, and think about if you want to do a full change, or if it's still good to go.

 

I did the full exchange change, it feels soo good to know my fluid is nice n clean!