3rd Gen 4Runner Automatic Transmission Slipping?

[RunnerLimited]

Hey guys I attached a video of my 99 4Runner Automatic, I noticed my RPM would jump from 700-1900 RPMS when i let off the gas and accelerate. Especially at a complete stop then accelerate it would jump 750 to 1800-2000 RPM.
I drive this car around 800-1000 km per week (hell of a lot of gas) LOL, i havent had much problems with the transmission, but if i can avoid and fix anything now i should. I noticed this when i bought the car 2 years ago when it was around 220,xxx km it is now 297,000 km. Thanks in advance for your input

I dont know how to embedd a video so here is the link..

https://www.youtube.com/watch?v=X8UxmzD0lxc&feature=youtu.be

 

[LittleCaesar]

If the tranny is slipping you will feel it almost not engage. There could be a problem with the shift solenoids. How does the fluid look?

Any codes?

I would say in a hunch it may be a bad TPS where the computer isn't throwing the code, which I have seen happen on other cars and trucks. Do you have a scan gauge or something that reads live data?

 

[mtbtim]

When a transmission slips, your rpms go up but your speed doesn't increase. In your video, when the rpms advanced, so did the speed of the vehicle. So, your transmission isn't slipping.

My vote is also a bad Throttle Position Sensor.

 

[thegipper]

The tranny can be slipping and you can still increase in speed although I'm not convinced that's what I'm seeing in the video. If it was totally slipping, then you wouldn't be increasing in speed at all.

We have a ford fusion at work with only 50k miles on it and it slips when it shifts into third gear. It still increases in speed but it "slips" until it finally catches and then revs up like normal. It's like the equivalent of partially releasing the clutch on a manual, the truck will move but the clutch is slipping and not fully engaged.

I do agree that when most people claim their tranny is slipping, the assumption is it is unable to increase in speed.

I would check the fluid but also the TPS like Tim suggested.

 

[zoombyu86]

Mine does something similar. When it shifts into 3rd, it just revs up sometimes. But if I rev the shit out of it, when it hits almost 4-5k i can feel it start to grab. If I shift into N and back into D, it then shifts into 3rd and goes on its merry way. its ONLY for 3rd though. Have yet to get any solid testing done for it though.

 

[TorqueOfTheDevil]

Mine slips too, slipping generate more heat, and makes the problem worse, as the oil viscosity changes.

"Slipping" is also relative, as by the very nature, auto boxes are designed to slip, its where they get the smoothness from.

Mine really needs a rebuild (It's also dealing with more power than it should) but I found the problem was a lot better with fresh oil and some lucas transmission fix helped. I also shimmed the accumulators and upped the gearbox line pressure to sharpen up shifts, and reduce deliberate slip to keep temperatures down

 

[ridefast]

When a transmission slips, your rpms go up but your speed doesn't increase. In your video, when the rpms advanced, so did the speed of the vehicle. So, your transmission isn't slipping.

My vote is also a bad Throttle Position Sensor.

Agreed!!!

:hello:

 

[mtbtim]

The tranny can be slipping and you can still increase in speed although I'm not convinced that's what I'm seeing in the video. If it was totally slipping, then you wouldn't be increasing in speed at all.

We have a ford fusion at work with only 50k miles on it and it slips when it shifts into third gear. It still increases in speed but it "slips" until it finally catches and then revs up like normal. It's like the equivalent of partially releasing the clutch on a manual, the truck will move but the clutch is slipping and not fully engaged.

I do agree that when most people claim their tranny is slipping, the assumption is it is unable to increase in speed.

I would check the fluid but also the TPS like Tim suggested.

Yeah, you're right Mike. The trans could be slipping and the vehicle is still gaining speed. I guess what I should have said is the rpm increase in the video seemed to match the speed increase.

My experience with slipping transmissions is it either slips when you're accelerating from a stop and then it finally grabs or your climbing a grade and the rpms start to rise but the vehicle is actually slowing down.

 

[vwtech]

Mine slips too, slipping generate more heat, and makes the problem worse, as the oil viscosity changes.

"Slipping" is also relative, as by the very nature, auto boxes are designed to slip, its where they get the smoothness from.

Mine really needs a rebuild (It's also dealing with more power than it should) but I found the problem was a lot better with fresh oil and some lucas transmission fix helped. I also shimmed the accumulators and upped the gearbox line pressure to sharpen up shifts, and reduce deliberate slip to keep temperatures down

Just be careful of fluid changes at high mileages. You run the risk of removing all the viscous materials floating around in the fluid that came off your friction plates over time. Once that material is gone, it could cause more slipping than you started with. Obviously in TOTD had good luck with his, but just something to be aware of.

 

[TorqueOfTheDevil]

Truedat.

From most of my experiences though, the thermal stability of the fresher fluid outweighs the benefits of particulate matter in there (most of which sludges up the filter anyway).

At the end of the day if the friction surfaces are worn, they need replacing, and anything we do to make to it better is just delaying the inevitable!

 

[RunnerLimited]

Agreed!!!

:hello:

Thanks for the replies guys Ill definitely check out the throttle position sensor,
I guess i should have done a different video as well, since the surge of RPMS is more noticeable at a stop. It usually surges from 700-2000 RPM then it starts going...
thats why I suspected it was slipping. Its just fast enough from 700-2000 that you dont really notice the delay.

Yeah this spring time i was going to change the Transmission Fluid with either Toyota OEM or Synthetic Oil, I will also check out the TPS, see if there are signs of wear.

 

[phattyduck]

Are we sure this isn't just the torque converter doing its job? When its unlocked, there is a difference between coasting and accelerating RPM at the same road speed in the same gear.

-Charlie

 

[mtbtim]

Thanks for the replies guys Ill definitely check out the throttle position sensor,
I guess i should have done a different video as well, since the surge of RPMS is more noticeable at a stop. It usually surges from 700-2000 RPM then it starts going...
thats why I suspected it was slipping. Its just fast enough from 700-2000 that you dont really notice the delay.

Yeah this spring time i was going to change the Transmission Fluid with either Toyota OEM or Synthetic Oil, I will also check out the TPS, see if there are signs of wear.

From a stop, if the engine RPMs rise and then the vehicle starts to move, your trans is slipping.

Sounds like you're due for a rebuilt transmission. [MENTION=102606]infamousRNR[/MENTION] and I just swapped the trans on his rig and the video will be coming out in the next few weeks. If you're a DIYer mechanic, you could use the video to help you with the swap.

 

[4racer]

Are we sure this isn't just the torque converter doing its job? When its unlocked, there is a difference between coasting and accelerating RPM at the same road speed in the same gear.

-Charlie

Kinda going to have to agree here. It doesn't seem as its slipping. Why not find a steep hill and test your theory? I think there is some inherent slip in the transmission. How are your trans temps.

I just swapped trans due to a failing pump in my old one. On the hill to my house I used to hit over 210F going up the grade. On the same hill i now struggle to get it over 180F. So my previous transmission was slipping much more but it could have also been the torque converter.

 

[thegipper]

Kinda going to have to agree here. It doesn't seem as its slipping. Why not find a steep hill and test your theory? I think there is some inherent slip in the transmission. How are your trans temps.

I just swapped trans due to a failing pump in my old one. On the hill to my house I used to hit over 210F going up the grade. On the same hill i now struggle to get it over 180F. So my previous transmission was slipping much more but it could have also been the torque converter.

Did your tranny pump whine before it started to fail? Mine started whining when it gets really cold out (in the teens) just a week ago. I'm hoping it is just a clogged filter. Going to check it out this weekend.

The tranny otherwise shifts perfectly normal other than a slight delay in shifting into D or R when its super cold out. It never used to do that. The whine goes away after about 20 seconds and everything is totally fine after that.

 

[4racer]

Did your tranny pump whine before it started to fail? Mine started whining when it gets really cold out (in the teens) just a week ago. I'm hoping it is just a clogged filter. Going to check it out this weekend.

The tranny otherwise shifts perfectly normal other than a slight delay in shifting into D or R when its super cold out. It never used to do that. The whine goes away after about 20 seconds and everything is totally fine after that.

Yup. I had a whine when cold. Drove just find and shifted great. Probably had the whine for 3 months before it completely took a dump and sounded like marbles in the trans in all gears and the whine became supercharger like.

 

[thegipper]

Thanks for the feed back. I've read others had the same whine when cold because their filter was plugged. Once the filter was cleaned, the noise went away.

Did you ever check your filter? I imagine if the pump is starved for fluid, over time, it screws up the pump. It just started on mine so I'm going to clean out the filter this weekend. I'll report back on what I find and if it fixes the whine. If the whine doesn't go away, looks like a tranny swap is in my future...

 

[4racer]

Here are some videos of the trans.

https://youtu.be/C7MVRaoK7Fo

https://youtu.be/LtoE156qh3g

 

[4racer]

Thanks for the feed back. I've read others had the same whine when cold because their filter was plugged. Once the filter was cleaned, the noise went away.

Did you ever check your filter? I imagine if the pump is starved for fluid, over time, it screws up the pump. It just started on mine so I'm going to clean out the filter this weekend. I'll report back on what I find and if it fixes the whine. If the whine doesn't go away, looks like a tranny swap is in my future...

My filter was fine and not clogged at all. It is a basic mesh filter and nothing that I can see getting clogged all too easy.

 

[thegipper]

Here are some videos of the trans.

https://youtu.be/C7MVRaoK7Fo

https://youtu.be/LtoE156qh3g

Hmm.. Mine doesn't sound like that at all. I'll try to make a video of it tonight and post it.

Hopefully mine is just a clogged filter.