Originally Posted by thegipper

Gipper here, author of said post.

It's a good thing that it shifts manually, that leads me to believe that you may just have a faulty solenoid and not the failure I had.

Do the easy/obvious stuff first, check the level of your fluid and the condition.

I would then drop the pan, replace the filter, inspect/test the solenoids and replace the fluid. There are three tests that need to be done for each solenoid:

1. 12v power to the solenoid checking that it opens and closes
2. Ohm test (should be between 11-15 ohm)
3. Pressure test, solenoid should be able to hold 71 psi of air pressure and not leak

If they fail any of these tests, replace them.

And just to be clear, it is 100% normal for the transmission to not shift from 2nd into 3rd gear until the truck warms up a bit. It is NOT normal for it to not shift out of 1st gear no matter how cold it is, that's what mine was doing.

Bad solenoids won't always throw a code, keep that in mind.

Originally Posted by jross20

My girl has a delay shifting into 3rd when she is cold. The first shift into 3rd is also a pretty strong bump (but not a violent jerk). She also makes a semi loud (but not violent sounding) noise when I am slowing to come to a stop. I think it is when she shifts back into 1st.

Is there anyway to test solenoids without dropping the pan? I feel like if I am going to drop the pan I might as well replace all of them if they are not too expensive... A 20 year old solenoid is pretty old I reckon.

Originally Posted by jross20

My girl has a delay shifting into 3rd when she is cold. The first shift into 3rd is also a pretty strong bump (but not a violent jerk). She also makes a semi loud (but not violent sounding) noise when I am slowing to come to a stop. I think it is when she shifts back into 1st.

Is there anyway to test solenoids without dropping the pan? I feel like if I am going to drop the pan I might as well replace all of them if they are not too expensive... A 20 year old solenoid is pretty old I reckon.

Originally Posted by gamefreakgc

You just described my 4Runner from 3 years ago!

Two separate things. The hard shift into 3rd is completely normal. If it bothers you, switch to full synthetic trans fluid and that goes away. The delay is just because of fluid temp and it needs to warm up more.

Slowing to the stop, it's like a humm/grind/whirr coming from the rear correct? Most likely it's your rear diff bearings on their way out. Not an urgent fix, just an annoying one. You only hear it when you are slowing down with 0 throttle right?

Originally Posted by Satter

Some of y’all are recommending a tranny flush. I thought a flush in old transmissions was a big no no?

Originally Posted by tvpierce

I've posted this before, but here it is again.



This comes up a lot, and there seems to be confusion surrounding the word "flush". Let's see if we can add some clarity.



For starters, some definitions:



1) Drain & fill: as simple as it gets. Remove the plug, most of the contents of the transmission pan is drained, re-install plug, and refill with the same amount of fluid that was drained. This replaces about 1/3 of the total capacity of fluid in the transmission.



2) Flush: remove the output/return line from the transmission cooler, run a piece of vinyl tubing from the cooler output to a one gallon container with quart markings, start the engine and run it until 2 quarts of fluid is pumped out (about 10 -15 seconds), turn off engine. Add 2 quarts of ATF through the dipstick tube, and repeat until the fluid coming out of the cooler looks as clean as the new fluid going in. This is generally done following a drain & fill.



3) Power Flush: this is a service sold at some repair facilities and dealerships. It requires special equipment that connects to the tansmission cooler lines, then draws old fluid out of the transmission and pumps new fluid in.



The Power Flush (#3) is the service that's frequently warned against that can apparently have some ill affects -- although I have no first hand experience with the process or any resulting problems.



The Flush (#2) is perfectly safe and will give you the best results for replacing the fluid in your transmission. It operates the transmission exactly as it operates whenever the engine is running. The only difference is that instead of recirculating old fluid, you're removing it, and replacing it with new. It will take a lot of fluid -- 20+ quarts -- to do completely and properly. But you'll know you're starting with a transmission full of clean, new fluid. Follow up with your periodic drain & fill (#1) and your transmission will last a long, long time.



This process has been done for decades with RWD Volvo cars which use a similar Aisin Warner transmission (in fact the later model 960s and V90s used this exact A340 transmission). Automatic transmission failures are virtually unheard of in those vehicles even with many hundreds of thousands of miles.