Hi!

I just signed onto the forum and hope I'm posting this in the right place. Need a little help...

95 Toyota Camry LE, 6-cyl, Auto trans w/O-D, air con, power everything, etc.....

Was leaking from the axle seal. Kept adding fluid and driving it. It'd slip when low on fluid, and when cold. OK when warm or within fluid limits, though.

Was adding fluid one day and brought it right up to the full mark a bit at a time, while taking it for test drives inbetween. Car was driving great until I added that last bit of fluid; the we lost function in all three forward gears.

Now, the engine starts and runs fine. When I shift into reverse, you can hear and feel the transmission engage and she drives backwards OK; but when I put it into any of the forward gears, she moves forward sometimes just barely, but mostly not at all.

NOTE: When I started it today, we had reverse but no forward gears. It sounds like the transmission is trying to engage when I move the lever into a drive detent, but she no go.

QUESTION: So, does that mean that the electrical function (forward drive solenoids) are working, and the drive failure is attributable to other internal / mechanical part of the transmission: a plugged fluid filter or valve body, maybe?

The fluid never looked dirty or smelled burnt; but I bought the car used and for all I know the transmission filter is an old one.

QUESTION: Anybody ever experience this kind of problem and get lucky by just changing the filter?

If we can't figure it out, I'll have to tow it to the transmission shop.

Thanks in advance.

Very Best Regards,

Pat

 

How much fluid was being added after the trans began to slip?

How are you measuring the trans fluid level? If using the hot mark on the stick, the fluid needs to be hot, trans in park, engine on. The cold mark is less accurate.

Electric solenoids are for shifting through the forward gears.

The selection of D or R is done manually with the shift lever.

One test is to disconnect the electrical plug to the trans solenoids then drive the car. If the fluid level is correct and the same problems occur the issue is trans. A trans clutch or brake.

 

Thanks for the help, Joey.

"How are you measuring the trans fluid level?"

Per manufacturer's instructions all the way. Running, hot, in park at idle, car level. Last time, I added the last bit of fluid just a tiny bit at a time, test driving it inbetween, until I got it right up to the line, hot and level, idling in park. I suppose it could be slightly over, but don't think so.

If it was slightly overfilled, would this cause the trans from engaging in drive gears? Or does the sudden stoppage seem more like a blocked hydraulic passage somewhere? Filter or valve body, maybe? Whatayathink?

"Electric solenoids are for shifting through the forward gears."

Interesting. I'm learning here. An explanation of that would help. I thought the electric solenoids began the shift functions (on command from the driver through the linkage, of course) and then it became a hydraulic mechanical function of the transmission. No?


"The selection of D or R is done manually with the shift lever."

Yep. And when I move the lever I can hear / feel it dropping into reverse and she backs up fine. I also sense what seems like it might be the solenoids engaging for forward drive in detents 1, 2, or 3; but she just slips and revs the tach. No go.

"One test is to disconnect the electrical plug to the trans solenoids then drive the car. If the fluid level is correct and the same problems occur the issue is trans. A trans clutch or brake."

Interesting. So if I understand what you're saying, if the fluid level is correct and with the solenoids disconnected, the car should move forward unless there's an serious internal mechanical problem with the trans itself? Is that correct?

Where exactly is that electrical plug?

Thanks again.

VBR,

Pat

 

A few things to check.

Check for broken shift cable. Follow the shift cable to the shift lever arm on the trans. Run the gear shift lever through the gears and determine if the lever on the trans move with the shift lever in the car.

Make sure the parking pawl is not still engaged when the trans is in gear. Engine off, place the trans in D and determine if you push the car forward. If you can push the car the pawl is not engaged.

Make sure the differential is not damaged. Place the trans in P and gently attempt to push the car. If it moves the differential has problems, if not the diff would appear to be OK. The pawl is mounted on the trans, not the diff.

As you stated the differential was leaking at the axle, determine if the trans has a separate fluid chamber for the trans fluid and differential fluid. Or the diff fluid comes from the trans via the trans filler tube.

There may be a filler plug on the diff housing facing the drivers side of the car or the side facing the firewall. Or the could be just a boss that has not been drilled for a plug.

If the diff has a separate fluid chamber and all the fluid ran out will obviously cause problems.

The trans fluid being a little higher or lower on the stick is not going to cause the car not to move. The trans holds 7 - 8 quarts, about 1/3 of this is in the trans pan. Being slightly low on fluid is not going cause slippage.

The electric solenoids control shift timing, however the gear shift lever can also control shifting.

If the electrical wires running from the trans computer to the solenoids on the trans are disconnected the trans will still operate. There should be a plug between the trans wiring and chassis harness that can be disconnected. Take note there is also wiring for the gear shift indicator on the dash board. There is a multi-position switch located behind the gear shift level arm on the trans. As the lever moves the switch changes position.

Look for solenoid wires on the firewall side of the trans and follow these to the plug.

With the wiring plug for the shift solenoids disconnected the gear shifter should be able to engage the gears by manual selection.

The gear shift lever controls a shift valve body inside the trans. This body directs trans oil pressure to the appropriate items. When the trans is put into drive, the valving is set to engage the drive gears, same for reverse.

If all of the above checks out: Pawl not engaged when in D but when in P, fluid is still in the diff housing, the plug to the solenoids disconnected, the gear selector is in a forward or reverse gear and the car does not move under its own power the issue is most likely inside the trans itself.

 

Excellent! Thank you for painting a clear picture of it. Exactly what I needed to know.

One thing I'm thinking: could be a plugged fluid passageway in that part of the valve body which actuates the forward gears, maybe?

I've done valve bodies on American transmissions. Is the Toyota valve body accessible without pulling the trans out of the car? (Through the removed pan, hopefully?)

I recently received the Service Manual on CD: will start reading up on the tranny overhaul next.

Meanwhile, one more question if I may: Is the Toyota valve body like others I've seen, where there are, say, ball bearing and spring "checkvalves" that will leap out unexpectedly when I split the valve body halves?

Can you tell me about when and where I should expect to encounter that problem during an overhaul of the valve body?

 

Yes on the shift body problems but my money is some place else.

The body is accessible if the pan is dropped. Nothing is going to spring out of the body but it does have those small check valve *****.

Note: Some Toyota factory info on this trans are much better then others! The best has extreme detailed repair info on all portions of the trans. Some only cover the basics and no detailed info on the body, etc. If you have the right manual taking the body apart will be very straight forward.

Make sure the trans info is for the model of trans the car has. The trans number should be on the side of drivers door mixed in with other data on a sticker.

You should be able to investigate possible throttle body issues by checking trans fluid pressure with a gauge. This might be easier then taking the throttle body off. The manual has details.

There should be a couple of magnets inside the pan to hold any steel debris to inspect.

If you end up pulling the trans make sure you check the torque converter one-way clutch (see manual for details) which can and does fail. If the trans is out, suggest checking this first before digging into the trans itself.

 

Outasight! You've been a great help. I'll take a shot at it and let you know how it turns out. Many thanks!

VBR,

Pat