1991 Legacy Automatic Transmission Replacement JDM 4EAT Saga

[Corvid]

A month or three ago, I inherited a 1991 Legacy with almost 200K miles and a completely FUBAR automatic transmission. I set myself to researching which other years and models would be compatible, and after reading several threads here (mostly answered by johnceggleston) I began to look for any TZ102Zxxxx transmission with my final drive ratio. The TZ102Z2xxx is to be skipped since the EJ25's came with 4.44 final drive, and I have 4.11.

 

So I pulled the engine and transmission together, and rounded a torque converter bolt trying to work through the crappy timing window on the bellhousing. So I removed the intake and had to work across the top of the block to get the 3 normal bolts and 1 dremel victim before I split the bellhousing. I didn't rip out the TC, although I noticed afterwards, that on the bottom of the bellhousing, the little flywheel cover plate wasn't there.

 

In my FSM parts catalog, that cover plate is listed at Manual Transmission only, which seems to tell me that as long as you are pulling and installing the engine and transmission together, you can get real tools on the nasty little TC bolts from underneath effortlessly, and without pulling the intake. That would be excellent. I'll report back on this later.

 

Resealed just about the whole engine. Full new timing, cooling, and oil everything. If you search my older posts, I have a write up with part numbers for everything I ordered for the job. I went with a Dorman oil seperator plate this time, half just to see if it was any good. I'll report back on that too.

 

Then I found and ordered a JDM transmission with vaguely 50k on it from Foreign Engines in Lynnwood WA. They were nice on the phone and prompt and delivered to me for free since I'm prettty close. I asked on the phone to make sure the oil pan wasn't dented, since that'll starve the oil pickup, and I didn't want to deal with trying to reseal the transmission pan, which is supposed to always leak afterwards. They told me that they would try to get me an undented one, but that the engines and transmissions come from Japan, stacked FOUR DEEP ON TOP OF THEMSELVES in shipping containers, often seperated by a car hood, but not always. I assumed since my garbage 4$$ engine stand from harbor freight comes with like a half ton of packaging, also across the Pacific, that maybe they would spend just a little time securing objects with a higher perceived value. Well, here's your warning.

 

Transmission arrived, tail housing dust cover cup mangled, oil pan smashed in, dipstick tube bent, and with a different sized torque plate to go with the different sized torque converter. The transmission has both EJ25 and 4.11 written on it. Great.

 

Spent the day cleaning it up and replacing all the broken parts and parts that don't match my car. The tailhousing dust cap came off and went back on easily with a chisel against the rear ring and some gentle hammering. I ended up swapping the 1991 oil pan onto the 1997 JDM transmission, and noticed immeadiate differences in mounting surfaces. The damaged 1997 oil pan has a flange that looks stiffer and appears to make flatter surface contact. If someone told me that it was part of the switch from gasket to sealant, I would believe them. The 1991 oil pan is in good shape, except for the deformed bolt holes from the gasket compression, and the dark silver house paint in the bottom of the pan. The stamping work to stiffen the flange on the 1991 seems shallow and much less aggressive, creating more rounded bends and much less contact surface.

 

The case flange on each 4EAT was different too. The 1997 mating surface was smooth except for the bolt holes. I only looked at the mating surface for the dead 1991 case briefly, and at night, but I could have sworn it had shallow relief cuts from the face. Don't know why, maybe someone can explain the concept to me.

 

So I ended up using a socket supported under each bolt hole, with a small ball peen hammer held with the round point on the bolt hole deformation, and then hit the flat side of the ball peen with a deadblow hammer to flatten or barely invert the protrusions. I checked all the boltholes with a small straight edge and worked slow until they were flat. Powerfully boring. Then I hemmed and hawed for 10min about whether to use anarobic or a new rubber gasket. I went with anarobic, I'll report back once its running.

 

My next step is to start attaching everything and plumbing everything back in. There are a lot of older posts about the TSB/recall/factory add-on inline ATF filter that goes on the fenderwall, below the battery. The kit is part number 42098aa032, and the dealership says it is discontinued, so that may not be part of everyone's plan anymore. I'm going to take my old one out, since I assume its clogged with dead clutchpack guts.

 

More notes on things I've found or strugggled with as I crawl towards the finish line.

Edited July 19, 2014 by Corvid

[johnceggleston]

 

The transmission has both EJ25 and 4.11 written on it. Great.

this is entiretly possible for a JDM trans,

but not found in USDM auto trans.

 

jdm did some things differently.

regrettably you probably will not know until you have it up and running,

unless you take the time to count the teeth on the ring gear in the front diff.

you can look in the drain plug hole with a flash light and some sort of a marker or scratch-er.

[Crazyeights]

this is entiretly possible for a JDM trans,

but not found in USDM auto trans.

 

jdm did some things differently.

regrettably you probably will not know until you have it up and running,

unless you take the time to count the teeth on the ring gear in the front diff.

you can look in the drain plug hole with a flash light and some sort of a marker or scratch-er.

IMO this ^^^ would be time well spent.

[Gloyale]

I do not think the TC bolts can be accessed from below.....cover or not......it's too close to the crossmember.

[Corvid]

I do not think the TC bolts can be accessed from below.....cover or not......it's too close to the crossmember.

In car, I believe this is correct. I was specifically thinking about seperating and reattaching the engine to the transmission after they have been removed together as a unit. I think this would work well if you are pulling them both anyway, I may be prevented from reinstalling them as an attached lump, simply by the overhead clearance I have under the carport.

[Corvid]

this is entiretly possible for a JDM trans,

but not found in USDM auto trans.

 

jdm did some things differently.

regrettably you probably will not know until you have it up and running,

unless you take the time to count the teeth on the ring gear in the front diff.

you can look in the drain plug hole with a flash light and some sort of a marker or scratch-er.

 

So annoying, but it makes sense. I'm hustling 1 engine and 2 transmissions around carefully with one hoist, which is a pain in the neck.

[Corvid]

While I'm at it, can anyone give good feedback on the refill procedure for the 4EAT when the torque converter is believed to be emptyish?

[presslab]

My JDM trans has a 4.11 with the larger torque converter, mated to an EJ25D. So yes, this was available in JDM.

 

Make sure both oil pans are the same depth, some early ones were different. There is a different filter screen and dipstick for each pan as well.

[Corvid]

 

Make sure both oil pans are the same depth, some early ones were different. There is a different filter screen and dipstick for each pan as well.

 

That is a demoralizing idea.

Any advice or cross comparison notes for establishing which oil pan is which? The original 97 JDM pan was dented, so its a little hard to measure.

Would comparing the length of the dipsticks work?

Do the 2 different pans have a different stamping pattern?

[Corvid]

This nightmare never seems to end.

 

It was suggested to me that I count the teeth on the ring gear to positively establish the 4.11 final drive ratio. It took a second to figure out, but I stuck a drift punch in one of the holes in an axle stub, fiddled with the gear selector until I found a gear it liked to turn at, and removed the speedometer sensor because it was binding for some reason. The ring gear had a hand-scribed "49" on it, but the teeth counted out at 37, which is exactly what I wanted to see. I reinstalled the speed sensor and checked it, and it seems to work and not bind.

 

I got the 4EAT lowered in and slid back into something like its natural position in the transmission tunnel, resting on a low hydrolic lift table for lack of a transmission jack. That was a headache and when I finally got the bellhousing through the binding spot between the front crossmember and the firewall, I only made it with like half an inch of clearance. So be it. Didn't wreck the wiring harness or breather tubes, and I don't think I ever endangered the wiring for the VSS1. I wanted to get it installed and plumbed so I could put ATF in it and see if anything leaks before I lace up the engine install. It felt good to be close to done.

 

Lost yesterday to heavy rain, and then went out today to install transmission mounts and crossmember, only to have the outermost captive nut on the drivers side snap free. WTF. So I just spent the last hour removing the interior, so that I can drill a %#^@ing hole in the floor and figure out how I want to solve that needless problem, but the rain started up again so now I'm inside on here.

 

Anybody got any opinions on Rivnuts? Anything else you suggest for this situation?

If I can get the bolt out of there, leaving the now-free captive nut in the pocket, is there enough room to drill from the bottom and have a Rivnut shove the broken nut out of the way, so that I don't have to drill through the floor?