4th gen 4runner transmission slipping

Hey ya'll. I have a 2005 4runner Limited with 327k miles. Yesterday when I was driving, I noticed what felt like the transmission slipping, around 38mph, as soon as I went into 4th gear. It continued as I accelerated into 5th. I put the gear shifter to neutral as I came to a stop, and decided to put it into 3 so that I wouldn't be using the higher gears. I did not have the issue as I drove home slowly in 3rd. Unfortunately, I discovered on the forums that '05 was the first year that Toyota stopped using the dipstick to measure transmission fluid, as I was reading that low tranny could be the issue. Has anyone had this same issue and been able to resolve it with a transmission fluid flush/fill? Will I be able to safely drive it to the mechanic to get serviced(mechanic is about 45 mins from my place)? I am the second owner of this vehicle and bought it at 295k miles. I have not serviced the transmission, and I am assuming the previous owner hasn't either. It sounds like Toyota made these models with the thought of "lifetime" transmission fluid, but that seems to not be the case. Any advice or suggestions would be greatly appreciated, and please let me know if you need any further info.

 

I would recommend against a flush at that high mileage. Drain and fill is the safer bet.

 

Welcome

 

From Toyota’s POV, it is lifetime fluid, because they define “lifetime” differently than owners do. Some say it’s the warranty period, but whatever it is, it’s less than the 20+ years that some of us have with these vehicles. No fluid can possibly perform adequately for that long.

As noted above, don’t do a pressurized flush. if anything, do a drain and fill. You could start conservatively with a pan drain and fill, which will replace about 3 1/2 quarts. If it goes away, great, if not, do it again and eventually you will have virtually replaced all of the fluid. Not the most convenient approach, but probably the most conservative if it’s true that the transmission has never been serviced at 295K.

Now to transmission fluid. Check to be sure, but I believe 2005 was the first year that Toyota specified World Standard (WS) fluid. Some, me included, only use that. Others swear by Valvoline MaxLife, which is much less expensive. FWIW, I don’t see how MaxLife can possibly meet the standards of so many different manufacturers and transmissions, and I know WS works. Your truck, your call.

In fairness, some might argue that a full drain and fill with MaxLife would at least be something different. That’s the tough part about an older, high mileage vehicle where you don’t have service records - who knows what’s in there now?

Which reminds me, you may be aware, but the 4th Gen power steering system does not use power steering fluid, it uses Dexron ATF. Toyota would have to tell you why, but just FYI whenever you might decide to do a drain and fill on your PS system.

 

welcome

 

Slipping could mean lots of different things. There are DIY self tests to try and narrow causes. Does your runner shift timely? Does it start from stopped smoothly? Does stomping gas cause reving without acceleration? Does putting shifter into S4 change behavior of slip?

 

This chart is supposed to be for the A750 tranny we have. I have verified some of it sorting out my former tranny valve body flex lock issues.
Maybe it will help you with possible torque converter issues.

 

Drive in "4" instead of "D" until your in the 50 mph range or higher.

If the slipping goes away driving in "4", do one drain and fill, to include a

$12 Lubegard 60902 Automatic Transmission Fluid Protectant, 10 oz

transmission additive. Additive can take upwards of 1000 miles to fully eliminate slippage.

 

Welcome from Wisconsin! Good advice on the drain and fill above. Hopefully this cures it, if not, well rebuilding isn't totally that bad. Good luck.