Automatic transmission, add a dipstick to check level

Let me start off by saying, I am not mechanically inclined when it comes to engines and transmissions. With that said, has anyone thought of doing this or could it be done. Just a thought.

 

Based on what it looks like when I did my flush yesterday, I can't say it would be very possible unless you removed the transmission and added a provision for a dipstick hole. That would require drilling into the transmission case somewhere by where the pan bolts up. After that you would have to build or find a transmission dipstick and tube that is long enough to fit and protrude itself out by the engine bay.

In short, what I am saying is that it would not be a simple task. If you do your own work though, you will know how much fluid to use because all of Toyota's diff's, t-cases, and related in the truck use the same 24mm drain and fill style plugs and once you are topped off the excess fluid will come dribbling out..

 

I was just curious. I guess they seal them so most people just go to the dealer and get them serviced. Thanks for your input.

 

As far as I know it is unable to work because our trannys are closed trannys which means there is no way to really check them unless flushing the whole system and adding new fluid

 

There are no provisions for a dipstick in either the transmission casing or the pan. So you would have to either drill into the case or weld a bung to the side of the pan. More trouble than it's worth, since the transmission fluid is in a closed system with no practical means to get "burned off" as it is the case with engine oil. Check the fluid level once through the inspection plug on the pan and you are good until the next fluid replacement interval.

 

Yeah see, I didn't think it was possible myself. Welding a bung to add the dipstick into pan would be potentially dangerous too as you can flash ignite the transmission fluid and start a fire.

Unfortunately this is just the hand we are dealt with and we just have to live with it. I don't like it either, but what can we do..

 

your best easy and craptacular
bet would be install a drain plug tube

like a fumoto valve with hose attached

clear tube attached, permanently attached and run upward and tied down

then you can look at the level in the tube when you know it is perfect, and mark the tube

then check anytime afterward for comparison. as long as the tube has not shifted.

the problem is this is now a weak spot you cannot let the tube get ripped

 

The system isn't "sealed". It's just in lieu of a dipstick, Toyota designed the transmission with an inspection plug on the pan.

 

Next idea is source an a750e transmission pan from a vehicle that does use a dipstick

aisin transmissions are everywhere. some maker has to use an a750e with dipstick somewhere

You would need a pan and dipstick from an earlier model 4Runner with a dipstick.

 

Gotcha. It never hurts to ask if you don't know. Thanks.

 

Never have seen one of these before. I am guessing they must exist though. A750e trannys have been around for quite some time. Surely they weren't always sealed?

 

Often wondered if an AT fluid level sight glass could be added?

 

That's a good idea.

 

I knew I could get some of you smarter guys than me, to chime in on this. Thanks everybody.

 

you can do anything you want with s sight glass but you need to machine a port
to stuff the glass into...


would be better to drill 2 holes in casing and use one of these oil level tubes/banjo bolts...but you can't do this on vehicle this is bench work (drop tranny)

 

I've never seen that on a car. Is that some kind of industrial equipment?

 

^motorcycle I bet

 

^Looks like it's from a motorcycle, and manual transmission, where you can check the level cold.
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For automatics:

Traditional method: Drive/idle vehicle until transmission fluid reaches operating temperature. While engine is running, check dipstick level.

Toyota method for A750E/F: Drive/idle vehicle until transmission fluid reaches operating temperature. While engine is running, open inspection plug on the pan and check a slow trickle of fluid comes out.

Most of the "complexity" is making sure the transmission fluid reaches operating temperature. This is where you have to either plug in an OBD2 tool or jumper the OBD2 connector and get the truck into temp check mode.

The Land Cruiser Prado I drove in Costa Rica had a 3.0L diesel mated to the A750. It too lacked a trans dipstick. I think it's in fact a quirk of Aisin transmissions that use WS fluid. It explains why the 3rd gen's 6-speed is like this as well.

 

I think it is because WS fluid is partly hygroscopic ? and no dipstick means fluid is more guaranteed to be dry
as there will be no chance like a loose dipstick

a loose check bolt means tranny will dump out, it is either tight or obviously it is loose

 

Transmission fluid expands as it heats up, I'm guessing? If that is the case, could you drill into the side of the pan and install a fitting that a flexible tube could be attached to? A dipstick would have to fabricated to go in the tube to check level. This is just all hypothetical. Not that I would try doing this. Just random thinking.