4EAT Advice

[cj91legss]

I just recently swapped a transmission into a car for a friend so he could sell it. He bought a used transmission off of craigslist, and we didn't get much history on it. The swap was pretty straight forward and I had no issues at all.

So the girl that bought the car also got my phone number from my friend in case she needed any more work in the future, making her a customer basically.

After the trans swap, I drove the car around a bit. I even took it on the highway. Shifted great, drove good, and pulled like it should. Had it idling for an hour after i finished so i could make sure there was plenty of fluid in the trans, going thru the gears after each quart in 10-15 minute intervals.

Girl bought it 3 days later. My friend was using it as a daily during those 3 days, had no complaints.

Here it is 3 weeks later, got my first call on a problem, it's acting up.

She described to me "I pulled up to a red light, when the light turned green I gave it gas and it just rev'd up and wouldn't go. I put it in park turned the ignition off and started the gar, put it in drive and it drove. Then it did it again at the next stop light."

I went and checked out the car, Listened to it as it ran and it seemed fine. It does sound like there is a faint grinding sound in the bell housing.

I did install the torque converter the correct way, I listened for all three clicks as i installed it on the transmission.

I called Steven and picked his brain for a bit. He said next time it happens, put it in 1st and see if it helps.

This morning, The girl texted me and said she did that and it wouldn't go above 20 now.

All I did was swap transmissions, I'm no auto expert nor do I want to be because I hate them and there's not much I can do to diagnose an issue because im not familiar. Never even had an interest in learning auto transmissions.

So if anyone has any ideas that could help me out, I would really appreciate it.

[alexandermf]

When its just reving is it normal operating temp or cold?

[cj91legss]

Normal.

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[alexandermf]

Hmmm cuz after my auto to auto swap mine was doing the same thing when the atf levels were all off or when it wasn't warmed up

[Legacy777]

Has it acted up when you've tested it?

If it's something inside the trans, there's really not much you're going to be able to do other than rebuild it.

Out of curiosity, have you looked under the car at the transmission pan? Does it look dented in at all? I ask because if they pan is bent in, there may be limited room between the pump inlet and the pan and may be starving the pump.

Also, I've heard that if the trans is starting to go that it pukes out a lot of material that gets stuck in the screen on the inlet. When you shut off the car, the fluid back flows through the screen and cleans the stuck material out. When you start it up again it builds back up and you have a restriction.

At a minimum, if you wanted, you could drop the ATF pan, check the magnet in there to see if it's got any metai shavings and what the screen looks like.

[cj91legss]

Ill probably do that the next time she texts me. Hasnt said anything the last day or two.

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[turbo970]

when my inhibitor switch went out it was doing that. after i replaced it it shifts great. any codes on the tcu ?

[cj91legss]

I dont have access to the car at the moment. Ill have to do some searching on the switch. You guys are giving me some great ideas.

Like I saif I hate autos, and never wanna work on them. This was just to help a close friend out. I never imagined I would be taking time to fix a 4eat trans when I don't care to know nothing about haha.

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[wtdash]

Hi,
- What happened to the original trans you pulled out? If this car had the externally added trans filter - ensure it's not plugged.

- Get the codes checked - ask her if the POWER light is flashing when car is turned on. >>16 flashes = stored codes.

-The 4EAT is known to be picky about trans fluid level - albeit you checked that well....but check for leaks??

-Check the Pan for dents - if it was used to support the trans during install, it could have gotten dented enough to break the wires internally (but should have showed up from the beginning). - I did this one on a '98 OB-

-Check the fluid - Unfortunately, if the trans was bad and you only drove it w/fresh fluid, it might have masked the problem. When my AT trans finally died - lost 2nd gear - , I tried the $pendy Red Line ATF as a last ditch effort. It ran like new for about 10 miles then it reverted back.
Here's the fresh (left) vs. the bad fluid:


GL,
TD

[cj91legss]

She just texted me this morning and said the trans fluid is full. I made sure to let her know it had to idle till normal operating temp and she did that before checking.

Depending on her financial situation and when we can meet up, ill probably service the trans.

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[turbo970]

check the solenoids too

[cj91legss]

Is that something that's in the haynes manual?

[Legacy777]

They may, but if they're not, you can d/l the diagnostic procedures from me on the solenoids. Search for solenoid in the links and you should see links for the duty a, b, & c solenoids.

http://www.main.experiencetherave.com/s ... FSM_Scans/

[cj91legss]

Ok so the car has been here for a week now. I finally got some time to mess with it a little today.

First, it took me quite some time researching just to figure out how to pull the codes and find a code list...

http://www.ultimatesubaru.org/forum/top ... ion-codes/

Now I did test drive it for the first time today after it was warmed up.

First off, the fluid level is at the cold dot on the atf stick when it's warmed up, so obviously there's not enough fluid in it. Will take care of that. There is a small dent in the trans pan, maybe pushed in 1/8"-1/4" I'll pull the pan and pound that back out and check the wiring.

Second, Yes the tcu is throwing codes. I haven't checked them yet because i just found the information.

Third, I think a bearing in the rear diff is out. There's a god aweful howl when i drove it that sounds like it's coming from the back end that gets louder with increase in speed. However when i got to the end of my road to turn around (i turned around in a left handed circle) it stopped until i started going straight again. What doesn't make sense to me is why? I swapped the transmission out for a transmission with the same code on the bellhousing.

Fourth, there's this awkward growling sound coming from the bellhousing/TC area that makes the sound both when idling in my driveway, and when the car is driving. It increases with RPM, video below.



Any opinions would be greatly appreciated.

I'll update when i get back from the store and follow said steps to check codes and get numbers. I still have the old transmission that came out so I have parts I need from it if need be.

[cj91legss]

After the trans swap, I drove the car around a bit. I even took it on the highway. Shifted great, drove good, and pulled like it should. Had it idling for an hour after i finished so i could make sure there was plenty of fluid in the trans, going thru the gears after each quart in 10-15 minute intervals.

Also, this is what bugs me about the current fluid levels.....

In the 10-15 minute intervals, I ran the shift selector from P to 1 slowly a few times each quart of ATF.

[cj91legss]

One more thing to add, If it matters...

Tire sizes
FL 215/60R15
FR 215/60R15
RL 195/60R15
RR 195/60R15

Less tread on the left than the right.

[cj91legss]

Well I'm not able to get the stupid codes. I've tried this "secret handshake method" several times today and I'm getting nothing but a solid AT TEMP light. It will not show codes. There is no Manual button or Power light on this dashboard either.

Car is 1996 Impreza

[wtdash]

Hi,
Did you see this POST on the USMB?

It should be relevant to your '96....but may be the same as above.

I didn't look thoroughly and didn't see a list of codes displayed....but I'd 'bet' if you can get a code using the diagnostic method the code # is likely the same as in the '90-94 TCU list.

BTW, the green diagnostic connectors should be under the dash near the driver's RIGHT knee....but not sure those are used for TCU diagnosis. Also, if you can get another TCU for the same car '95 and '96 should be the same, that may be an option (but doubt it helps).

The video sounds like the flexplate or its bolts are rubbing.

And the code on the trans is like this one from an '04 Forester XT (TZxxxxxxx)- that matches the old one - correct?

[cj91legss]

Yes That's the correct code location. I don't have access to another TCU. After talking it over with a friend, I'm wondering if previous owner of car replaced the rear diff with an incorrect matching final drive ratio. It sounds like there may be some clunking starting in the Impreza along with the nast rear end howl I'm starting to believe thats a BIG possibility on why the original ring and pinion grenaded. Here's the OLD pinion and front diff/bell housing.





With all of the problems, I'm almost certain I'm just going to recommend a new trans and matching rear diff. It sucks that she just got the car, It sucks that it drove fine for 3 weeks and then started acting up. There's no tags or anything on the rear diff that I can see, so it's a mystery rear end. The trans should have a 4.11 final drive based on what I read.

[cj91legss]

wtdash, thanks for that link. I hope it helps. I'm surprised that didnt come up in any of my searches and I came across alot of hits on USMB.

I'll report back. Mike told me a trick about reading the rear diff, so maybe i'll lower it tomorrow and check the splines on the rear end.

One thing I'd like to ask, is if the rear end is different and i pull the second half of the driveline, would it be fine to drive until the owner can buy the correct diff? If so How long would it last? Would there be any damage to the transmission in this scenario?

[wtdash]

U should be able to jack up the rear end and turn the rear wheels and compare to the rotation of the drive line to determine the FD ratio, from what I've read online.

[wtdash]

One thing I'd like to ask, is if the rear end is different and i pull the second half of the driveline, would it be fine to drive until the owner can buy the correct diff? If so How long would it last? Would there be any damage to the transmission in this scenario?

I'd think it'd be fine, but you'll need to put the FWD fuse in under the hood - by the pass. strut tower -(or in the fuse box by the battery on the newer stuff).

The FWD fuse might work w/out touching the drive line, but I'm not sure.

[cj91legss]

I put the FWD fuse this morning when I was messing with the car. With the fuse in, there was no difference in driveability. I may need to inspect that issue as well.

I may also have to find another TCU to see if this one is faulty.

I'm going to try the methods you pointed me to as far as checking the TCU codes. If these don't work, surely there's an electrical probelm with the TCU/wiring. With that, It'll be hard to diagnose anything else.

[Plazma]

Actually you might be in luck. What's the MY?

I'm wrapping up a 4EAT to 5MT swap right now. I have a TCU that I'm no longer in need of. It's literally sitting on top of the refrigerator in my garage.

It came off a 1990 Legacy.

[cj91legss]

Its a 96 impreza.