The automatic tranny in my 92 4 runner is acting strange and I wonder if anyone has any ideas what it might be. It started last weekend and it acts like someone is shifting the tranny from drive to neutral while I'm going down the road. The engine will suddenly tack up and then when I let off the gas the tranny will "re engage." After this happend I check the tranny fluid and sure enough it was very low. I added 2 quarts to it and she drove great for 3 days. Now its acting up again. I rechecked the fluid and its full, actually a little over. Also the fluid doesn't appear to have any water in it either. This will happen after the vehicle is warmed up. I think I'll change the tranny fluid this weekend and see if that fixes anything.

Another strange thing thats been happening is the speedometer quits working for a few seconds. It jumps back and forth and sometime quits for 5 minutes or more. I can't believe this might be related to the tranny, but who knows!

Anyone have any ideas? If the auto is toast I'm leaning heavily to swapping in a manual. Anyone have a 2nd gen 4 runner or tacoma doner I can pull parts from?!

Thanks

Gary
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An overfilled tranny sometimes makes the fluid foam. This can lead to both overheating (which it did in my case) or to hydraulic pressure loss. The fluid level really has to be 'right on'. Drive the 4Runner until you are sure that all the fluids are up to operating temp. Then park on level ground, tranny in neutral (set the parking brake), engine idling and check the fluid. It should be within the 'HOT" full mark on the dipstick.

What you may also be experiencing is 1: the tranny shifting in and out of Overdrive (depending on the engine load and ground speed), or 2: the torque converter locking and unlocking (also depending on engine load). Try turning the O/D Off. The switch is on the shift knob. When it's off, the O/D Off light will illuminate on the dash (if its not burn out). This will prevent the tranny from shifting into overdrive and you will have, essentially, a 3-speed transmission. There's really not a way to switch the torque converter lock off, since it's controlled by the ECM.

You can usually tell the difference between which one of the two systems are engaging by noting how much the RPMs drop when one engages. There will be a smaller drop when the converter locks and a much larger drop (on the tach) when the O/D kicks in. The O/D is about 30% overdriven ,which is a BIG difference than the 1:1 ration 3rd gear.

From what I understand, the swap to a manual will be a pretty big endeavor, especially if you have a 3.0 V6 engine. There can be fitment issues between the 3.0 and manual tranny's. You'll likely have to locat an R150F manual tranny, since it appears that was about the only 5-speed manual found behind 3.0 V6's between 1988 and 1995. If you have the 22re, you have more manual tranny options.

MIke in AR

 

The speedometer problem could be a speed sensor failing. That could send wrong info to the computer, which controls the transmission in 4Runners. If the computer is confused as to how fast the vehicle is going it might be sending weird info to the tranny.

If the sensor fails completely it'll throw a trouble code, but interment problems might not.

 

Auto tranny codes can be had via the O/D Off light on the dash,,just like the CEL for the engine codes. Just have to be sure the O/D switch is 'on',, so the light on the dash will be 'off' and so it will flash when the diagnostic port is jumpered. Heck, even the cruise control system has a similar diagnostic system.

Mike in AR

 

My OD Works. But, the Light on the Dash does Not. Need A New Bulb! Hopefully.

 

Thanks for the info guys! I heard from a buddy whose a toyota tech and his thinking is it's the speed senosor which is giving the ECU bad dat and causing the tranny problems. Tomorrow I'm going to change the fluid and filter in the tranny and inspect the wiring to the speed sensor incase the connetor is corroded or the wires are melted. If nothing wrong with that and the fluid change doesn;t help I'll replace the speed sensor. Thanks for all the info!!

Gary

 

My tranny does the same thing from time to time. Like going around corners as soon as I hit the gas it will rev like in neutral for a couple of seconds before it engages. I think its a common problem with these transmissions. Not sure the fix. I learned to live with it. It still gets me around fine. I,m still quite interested in finding the solution. But in the mean time I drive as gentle as possible. Also When I first bought my runner , I was driving for about 10 mins got on to the freeway going 100 km/h , tack @ 2.5 , and all of a sudden the tack went up to 5, pulled over thought I blew the motor. I put it in park and everything seems fine. Drove home fine no problems. Next day on my way to work the same thing happened , but this time I tried to down shift manually and realized the shifter was in between gears. I gave the shifter a little push and right away the revs dropped.The shifters red line was in the right spot but the shifter wasn,t. I found that there has to be play in my shifter or I,m in between gears.

 

I have the same shifter-hang problem. Sounds like it is pretty common on these auto trannys. I just wiggle the shifter a little after I put it in Drive, just to make sure. I've done it so long now, I don't even think about it.

Mike in AR