Tackling transmissions (inspecting, fixing, and swapping a used 1988 d/r 4wd MT)

[errantalmond]

Hi all

Long time reader, first time poster here. 
 

My ‘90 loyale’s push-button awd manual transmission is a lot of fun to drive, but with worn bushings; leaky seals, and occasional funky sounds, I decided I had to do something about it. After browsing google, usmb, youtube, ‘how to keep your Subaru alive,’ what I could find of ea82 fsms online, and even a chilton, I decided it would be cool to try and accumulate a wealth of information about dealing with Subaru manual transmissions on usmb in the form of me asking lots of questions about a transmission diagnostic and potential swap. Below is some of the information I’ve gleaned from here and elsewhere. Always, correct me if I’m wrong.

I know some folks here have dared to split and rebuild their transmissions themselves, and I’d love to hear about your results.

Some categories I think would be helpful:

-how to inspect and troubleshoot an installed transmission.

-how to inspect a removed transmission

-which parts of your transmission can be replaced or fixed without splitting the transmission
-resources for diy rebuilds for the adventurous

-swapping ea82 transmissions, compatibility, etc.

=========================

Here’s the plan so far in my case:

1) get rid of the rattlesnake soup in my current shifter by fixing the shift linkage. Lots of info for that elsewhere. Ordered the bushing from Subaru and poked around under the car a bit to find the source(s) of the problem.

Then, I’ll actually be able to hear what’s going on with the transmission itself. 
 

2) check transmission fluid and change as needed. 
Here is a big point of obscurity for me…as the transmission collects metal shavings over time, and if the fluid was not changed regularly, what will REALLY happen if you flush or clean out or reseal your transmission? Does the metal shaving sludge help the gears grab each other? 
I haven’t found a definitive answer to this, and am not even sure if it only applies to manual transmissions? Anyways, bonus points for clearing that up.

Rislone and ATF have been recommended for helping clean/extend the life of/improve older manual transmissions. 
Probably a good idea to try that as well before swapping out an alright transmission.

3) Find the TRANSAXLE section of an EA82 factory service manual (usually section 3 I believe).

I’ve looked through all the resources linked in various usmb threads and elsewhere online, but every pdf of the FSM cuts from section 2 (engine) to section 6 (electrical).

It would be SUPER cool if that section was available online somewhere. Please post a link if you have access to it.

4) fix what you can without fully removing or splitting your transmission

-what can you do without removing the transmission? 
Sensors, fluid, seals, bushings?

-what can you do without splitting the transmission?

Seals, some bearings, shifter linkage?

Gasket and seal repair kits are no longer available from Subaru for many of these older transmissions, and more and more of the individual parts are out of stock, so it ain’t easy.

 

5) Get a replacement transmission or rebuild your transmission

So I guess a rebuild for one of these older MTs could run me anywhere from 6-20 hundred dollars. Worth considering alternatives!

Being proactive and curious, I bought a junkyard manual transmission from a guy in Portland for 250 dollars recently after realizing that my own tranny might be starting to lose its youthful splendor. It was pulled by a guy in Redding, CA from an 88 GL with 176k miles and is a dual-range 5spd MT. Seemed in pretty good shape, so I saw it as an opportunity to learn about transmissions and hopefully find a transmission worthy of my car.

It was covered in grime all over, especially near the back end. Maybe leaky gaskets, seals. Spun free and quiet in every gear, although I couldn’t find reverse using a screwdriver, and in neutral, the input shaft tugs on the output shaft lightly, unless I hold them still.

I cleaned it up a bit using carb cleaner and gasoline and mostly elbow grease, avoiding rubber, seams, sensors, etc. In retrospect I don’t think it was the best choice of degreaser, although it was extremely effective and cheap. With everything more visible, I noticed a few dings on the bell housing to engine, probably from prying it off. Not sure if that is a problem? 

Everything else looks in good condition, no missing parts, although I couldn’t find an identification number on it.

The oil on the dipstick looked pretty good, just a bit dark. I opened up the drain plug to pour out a sip of fluid into a cup and I spect the drain plug magnet.

 

Only tiny shavings on the magnet, I’m guessing it’s a pretty normal amount for an older transmission. The fluid that came out was really dark, and quite thick from the settled sludge of greasy metal shavings. Could mean that it was topped off recently, or that the gunk settles to the bottom? 
Again, does it make sense to remove the metal shavings by sticking a magnet in there on popping the drain plug on and off over and over? I’m assuming I shouldn’t and don’t need to flush it.

Next, I’ll take it to a transmission shop for a visual inspection. I’ve only looked at this particular transmission, so I have no comparison. 


In any case, putting a used transmission into a car without inspecting the guts of the transmission is a gamble. That, combined with my curiosity, is tempting me to split it myself. Especially if it doesn’t look like a good candidate for my car!
I would love to take on the challenge, but I can’t do it without the FSM section about transaxles. Send it over! Lol

 

If I do end up trying to open one up, I’d be happy to share my documentation of it for the forums. 
 
This is what the transmission looks like (before and after cleaning up):

please pitch in your knowledge, advice, and questions so this can become a very useful source of information. 
I’ll continue to add photos to go along with things.

cheers

jon

Edited September 20, 2021 by errantalmond

[el_freddo]

Don’t split your trans if you don’t have to! 

Fix the shifter slop, relatively straightforward job, just tricky in the space to work with. 

You can replace any leaky seals. You won’t have any gaskets leaking, that’s unheard of unless the box was opened up and poorly resealed. 

The typical sign that your trans is on the way out is odd noises. If it’s whining in a particular gear, or if there’s a noise the winds up with the vehicle speed it typically spells trouble. 

Change your gearbox oil. If you’ve not done it it’ll be worth the effort and it’s easy to do. If you’re keen to flush metal out use some cheap oil and do several flushes, then put in good oil. Personally I’d just drop the oil and put in good quality oil that meets the requirements in the specs list. 

The dual range is probably leaking out the various seals, particularly the ones associated with the dual range 4wd system. Do not open up this box - the rear drive transfer is a bloody Pandora’s box of springs, dedent balls and other metal parts that’s a bit of a nightmare to put back together. But it’s awesome when you do get it back together, it works and you didn’t drop any of the parts into the gearbox! 

Cheers 

Bennie

[errantalmond]

23 hours ago, el_freddo said:

You can replace any leaky seals.

I haven’t replaced seals myself before; are the ones you are referring to all removable from the outside? My understanding is that you kind of take a screwdriver or better tools to carefully pry out an old seal, clean up the surfaces, and press fit a new seal in. Is that right? 
These seals are probably only available from Subaru?

 

23 hours ago, el_freddo said:

Change your gearbox oil. If you’ve not done it it’ll be worth the effort and it’s easy to do. If you’re keen to flush metal out use some cheap oil and do several flushes, then put in good oil. Personally I’d just drop the oil and put in good quality oil that meets the requirements in the specs list. 

Thanks for addressing this. It sounds like flushing metal out isn’t necessary? I imagine metal shavings don’t hugely affect the workings of the transmission, but I would think that they at least get pushed up with the fluid to cover all the moving parts while running. 
Is flushing no big deal then? I still don’t really get the ‘to flush or not to flush’ thing.

And by ‘drop the oil’ do you mean drain and add new to fill plug? The change/flush/drop/replace/etc. terminology still throws me off. 

On 9/19/2021 at 7:24 AM, el_freddo said:

Do not open up this box - the rear drive transfer is a bloody Pandora’s box of springs, dedent balls and other metal parts that’s a bit of a nightmare to put back together. But it’s awesome when you do get it back together, it works and you didn’t drop any of the parts into the gearbox! 

If I ever get my hands on the FSM transaxle section, I will weigh your warning against my curiosity.

[el_freddo]

I can see pics now! That drain plug magnet looks pretty good, I’d consider that normal. 

Change/flush/drop/replace are all the same thing. 

Don’t refill the gearbox through a plug hole, use the dip stick - one quirk of the Subaru models that’s really handy! From memory 3.5ltrs is what’s required for the PT4wd box. 

“to flush or not to flush” - I’ve only ever changed oil in a vehicle that’s new to me. This gives me piece of mind knowing there’s fresh fluid in the various places - and I know what age/quality it is. I’m still yet to change the trans fluid in the auto of our family bus, it’s the last one to do - I’m not looking forward to it, hence why I’ve put it off... 

Seals: Clean up the area around the old seal, then I jimmy them out with a flat headed screw driver trying not to touch any of the mating surfaces as you don’t want to damage these. Lube the new seal with a rubber grease. Gently tap the new seal in with a hammer and flat punch, be gentle! Subaru seals will last the longest generally. The selector shaft seems to only be available through Subaru.

The front diff stub seals are done from the “inside” - you need to remove the “sundial” bearing tensioner. Mark the case and the dial at the same point, count how many times it takes to wind them out until it comes out. Put another mark on the case so you know where to start winding in from. Knockout old seal, lube up new seal (only on the moving surface contact areas), fit new seal, replace dials to the count and marks you made previously. Do one side at a time so you don’t get the parts and your reference marks mixed up - this will change the diff setting that could lead to premature failure. 

Front diff seals are directional, ensure you fit the correct side according to its designated direction. The seal for the shafts and the big O rings are the same as the Liberty/legacy phase 1 and phase 2 gearboxes with the diff stub axles  

Cheers 

Bennie

[errantalmond]

Thanks Bennie, that‘s all great info. 
more specifically about the changing of the fluid:

- Changing/flushing/etc. the fluid means letting it drain out, then filling it back up, I believe. As I understand it, only a portion of the fluid will drain when the drain plug is opened, so you are always just replacing part of the fluid. Is that true?

Let’s say I take some folk’s advice and decide to run ATF for a few hundred miles to clean things out, before switching to a quality gear oil like Go Extra S. Would I simply open the drain plug, let everything drip out, then top up with ATF, or is there some incentive to empty the gearbox of fluid completely first? I guess that applies more so to switching back from ATF. 

Is this just a misconception of mine, and opening the drain plug does in fact completely drain the gearbox?

 

cheers!

[el_freddo]

Opening the drain plug of a Subaru gearbox will get out 98% of the oil in the box. The drain and some remains is usually to do with Auto transmissions where the torque converter can hold a lot of fluid that doesn’t get drained out. 

I don’t recommend running ATF in a manual box, unless it’s some sort of mix it even then I would be very cautious, actually I probably still wouldn’t do it! 

I should’ve added that a “flush” is the term used when fluid is replaced, run for a short period of time, then replaced and run for a short period of time then replaced. You can do this as many times as you like, but I feel it’s usually a waste doing it anymore than once before putting in good fluid. 

Cheers 

Bennie

[errantalmond]

Thanks for clearing that up, Bennie. That was exactly where the confusion was. 
The oil in my car’s transmission was pretty clean and there were very minimal shavings, and I haven’t changed it in the 20000 miles I’ve driven this car. Not sure if it was flushed right before I bought it, but I guess that’s a good sign in any case. I added a half quart of rislone engine treatment to the new gear oil after much back and forth. Based on all the responses on usmb about it, I figured it’s worth a shot. Definitely runs better now. But because it feels cleaner, the resistance (accompanied by a light clicking sound) going into and out of fourth feels a bit sharper. Reverse is much easier to get into now. (Before I usually had to shift into a different gear and then into reverse for the gears to mesh.)

I feel like I read somewhere that rislone can just stay in there permanently. Sounds unnecessary, but if it’s true, I’d love to run this gear oil a while before chucking it out…hoping someone can chime in on that.

so, do I need to ‘flush’ the transmission with rislone, or can I just ‘change’ the fluid with gear oil + rislone?

terrible shot of the dipstick level; it was full and looked clean (like I probably didn’t even need to change it, huh.)

huge relief to see this drain plug looking so fine

The previous oil, I wish I knew what kind it was. Pretty clean, looks darker at the bottom in this picture than I remember it being…