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Dead 4EAT Transmission ?

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Just bought a '92 Legacy L sedan to fix and put back on the road.....it has automatic tranny issues.

-140K Miles

 

Car won't move @ all in 1st.

 

Moves in 2, 3 & D, but has only one gear - 3rd- Doesn't shift up or down - Hey, it's a CVT! :rolleyes:

 

Reverse works, but car is slow to engage.

 

I drove it home on back roads @ up to 45 mph, and started to whine the longer I drove it (just like the ol' 4EAT in my '90 except all its gears still worked 'til I swapped in the turbo 4EAT).

 

Once up to speed (30+) it would accelerate up to 50, and it climbed the previous owner's steep 1/4-mile long driveway w/out too much complaint.Tranny fluid doesn't look too bad, but does smell 'crispy'.

 

NO TCU codes stored, either.

 

 

 

I found this POST from Feb. '09, w/the same symptoms, although the car was OBDII.

 

I'll do Nipper's TC test tomorrow:

"Do it exactly as i say. We call this a stall speed test.

 

Start the car. Set the parking brake. Stand on the brake pedal. Make sure the car is pointed away from everything. Put the car in drive. Floor the car untill peak engine RPM that is possibel is acheived. This may be as low as 2800 rpm or there abouts. Do this only once, never holding the max engine RPM for any length of time (you can hurt the transmission).

 

This will tell us if it is a Torque Converter problem or something else."

 

In that same post OB99W suggested an endwrench article that stated it was in 'limp' mode, which could be electrical or mechanical....since there are no codes, I'm guessing it's mechanical, which means repair the tranny's internals or replace it?

 

Just wanted to confirm it's beyond a flush/refill/pray.

Thanks

TD

4EAT's will mechanically run in 3rd gear without any TCU or wiring in place. Maybe it's unplugged - either the harness (in the engine bay) or the TCU (in the cabin). It would also have torque bind like this as well though.

 

Fluid change is nice, seeing whether it has metal in it or not is very telling.

 

Sounds like you're going to need a new transmission though.

 

I've driven 4EAT's compeltely disconnected (3rd gear only) as daily drivers, interstate at 70+mph. That was in an XT6, drove it like that for a long time. I had a manual switch so i could control the duty C solenoid and not have torque bind.

  • Author
4EAT's will mechanically run in 3rd gear without any TCU or wiring in place. Maybe it's unplugged - either the harness (in the engine bay) or the TCU (in the cabin). It would also have torque bind like this as well though.

 

Fluid change is nice, seeing whether it has metal in it or not is very telling.

 

 

Thanks Gary....I'll check the fluid and connectors @ the tranny and under the dash, too.

TD

Thanks Gary....I'll check the fluid and connectors @ the tranny and under the dash, too.

TD

Sure thing. If you don't have torque bind then this can not be the problem...unless they messed with the wiring of the Duty C circuit - they would have to supply 12 volts to it in order to have it "not locked" so to speak.
  • Author

I do NOT have Torque Bind...so doesn't sound electrical....which would be the easy(er) fix.

 

Missed that the 1st time...tranny swapping time.

Thanks

pull the plug on it and see what it does.

 

if it runs better then maybe it is electrical (sensor, etc)

if it still runs bad then the guts are definitely problematic.

 

might even entertain the idea of running it like that like i did for awhile?!:lol: wiring the Duty C to control lock up of 4WD is really easy, one wire only.

 

good luck with it.

[...]NO TCU codes stored, either.

[...]

In that same post OB99W suggested an endwrench article that stated it was in 'limp' mode, which could be electrical or mechanical....since there are no codes, I'm guessing it's mechanical, which means repair the tranny's internals or replace it?

 

As Gary suggested, it's worthwhile looking for obvious problems. However, if you're able to ''talk'' to the TCU, but it reports no codes, then (as you suspect) the trans likely has mechanical problems. Given the ''crispy'' smell of the ATF, a good used 4EAT should probably be considered.

This is not limp mode, as limp mode would allow shifting and max speed of about 50 mph.

 

This is cooked mode.

 

What kind of condition is the fluid in?

 

nipper

  • Author

1. Checked the plugs and they were tight. Everything around the top of the tranny look untouched/original. I decided not to disconnect and drive it based on others' comments.

 

2. For the TC Stall test, I floored it w/the brakes on, and it wouldn't go higher than 2500 RPM in D.

 

 

3.

What kind of condition is the fluid in?

nipper

 

Please take a look below - very dark, but didn't really see metal in the fluid:

tranny%20fluid%20%28Large%29.jpg

tranny%20fluid%20%281%29%20%28Large%29.JPG

Edited by wtdash

  • Author

My replacement transmission is from a '92 Turbo 4EAT. I know they're both 3.90 diff ratio, but the flex plate/torque converters are different.

 

Anyone know if I can use the TC from the bad NA tranny and put it in the turbo tranny?

 

Removing the flex plate is a PITA.

 

 

Thanks for the help!

  • Author
Dark is bad.

 

What does it smell like?

 

 

Smells very burnt.

  • Author

The stall test 'normal' values for the Phase 1 4EAT are:

Non-turbo: 2550-2950 RPM

Turbo: 2850-3250 RPM

 

(Thanks to Legacy777 for this INFO - open this FILE: 4EAT_performance_test.zip.)

 

For reference I found the WRX 4eat Phase II is 3200 RPM

 

Stall Test Results

Higher than normal RPM indicates one or more of the following:

• Slippage of the forward clutch

• O.W.C. not holding

• Low/Reverse brake slipping

• Overall low line pressure

Lower than normal RPM indicates one or more of the following:

• Incorrect throttle adjustment

• Poor engine operation

• Torque converter stator slippage

 

 

FIXED w/a '92 Turbo 4eat transmission. I used the NA Torque Converter so I didn't have to swap the flex plate. I also used the NA TCU, which was working fine, according the guy I sold the car to. :-)

Edited by wtdash
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