Jump to content
Ultimate Subaru Message Board

Dropped an allen wrench inside transmission!

Recommended Posts

I had a moment today in troubleshooting my 89 GL Wagon's transmission neutral switch. I've had a trouble code 51 for "neutral switch", so I tested the old one and found it permanently open. The replacement switch from the dealer, which I installed today, also would not close when the transmission was in gear. I was poking around with a 5mm allen wrench to see if there was anything in there to depress the switch, and lo and behold, it slipped out of my hand and fell completely into the hole.


So far, I have drained the fluid, pulled off the exhaust pipe, first section of the rear driveshaft, and shifter connectors, and my plan is to remove what Subaru calls the extension, hopefully finding it inside the part to the front of it, which I believe is the rear transfer case. From the diagrams I have found, it seems possible, but the service manual I downloaded from this site is missing the transmission section, so I don't know if there will be any surprises.


Anybody with experience with these transmissions have any advice for me? I'm gonna try this tomorrow morning, and I'll report back if I have any success, or if I end up with a pile of random gears on the ground.


For reference, the neutral switch is 21 in this diagram of the transfer case:


A10_121A0160.png and this is the extension that bolts to the rear of it:


Link to comment
Share on other sites

You might want to get one of those camera probes to look inside and see if you can spot the wrench.  Once you see it then you can find a tool to try and retrieve it.  A simple magnetic pickup tool might suffice.

  • Like 1
Link to comment
Share on other sites

I would think you should be able to retrieve the tool by using a magnet on a flexible long shaft you can purchase at any good parts store. Even if you can't get it out hopefully it will just lay at the bottom of the fluid pan. I know that wouldn't leave you with a good feeling about doing that even if it didn't hurt anything.

Link to comment
Share on other sites

Thanks for the magnet tip. I tried fishing a magnet in from the drain hole, but I couldn't maneuver it back to where the wrench was dropped. The neutral switch hole is only about 8mm diameter in the side, so I couldn't even fit the magnet in the hole! It turns out that there is an wall (not shown in my diagrams :rolleyes:) between the extension case and the transfer case, so I couldn't get at it that way, and the case would only come off about a centimeter without me removing an impossible to remove internal snap clip. So basically all I did was destroy that gasket.


Unfortunately, it looks like my next step will be to pull the transmission. I tried to remove just the transfer case, but there are some bolts that my tools simply cannot reach with it mounted. With it off, I can just remove the access panel on top of the transfer case to get at this :mad: wrench. At least then I will also have the chance to overhaul the clutch, fix any leaky oil seals, and figure out this neutral switch thing for good.


Problem is I'll have to move it somewhere else because the neighborhood I'm currently in is done with tolerating my amateur mechanic hobby. Anyone in Albuquerque who can tow on this board?

Link to comment
Share on other sites

what about make someone really scratch their head in the future about their unique gearbox with an extra drain plug ? Drill a hole correct to tap a standard drain plug thread right where you think the allen key is ???

Link to comment
Share on other sites

I think I like Jono's idea the most. Or adapt the thing to have the oil pan it should have had to begin with. I hear you all on the magnet approach, but even if I had one that could fit in that hole, it would have to make an immediate 90° turn and would probably get caught up on the giant pinion shaft that is right there, and I think the chances of it grabbing the wrench in such a way that I could actually get it out of the hole are minimal. I welcome any of you to come over and try! But with me having to pull things further apart to reseal the extension case, I'm really ok with pulling the whole thing and giving it the thorough inspection and cleaning it probably needs.


Again, I will report back with my results and take some photos for reference. I do appreciate your tips!

Link to comment
Share on other sites

or make your own magnet ? Remember how coiling insulate wire over a screwdriver shaft and attach an end to pos, and end to neg of the wire and magnetises the screwdriver ? what about a custom bend coat hanger dood dad and wire wrap it for magnet on approach? Or one of those super duper magnets from something industrial that would go through the casing ?

  • Like 1
Link to comment
Share on other sites

Ok, you've convinced me to give it another try with a better magnet tool. I am in no way attached to pulling the transmission if I have a way to avoid it!


I'm still afraid that I won't be able to seal the case that I removed, but I bought the Permatex green sealant made for gear oil, so I guess that's my best bet. I'll just try not to get it everywhere when I try to get it into the hard to reach areas. The dealer still has the proper gasket, but I can't seem to the case off of the shaft or the 4wd selector rod.

Link to comment
Share on other sites

Well it turns out that the transmission can be slightly dropped without removing it. I just supported it with a jack while I removed the mounting bracket, then lowered it slightly on the jack. I loosened the motor mounts and made sure it wouldn't put stress on any cables, and got it down low enough to take off the access panel. After doing this, I fished around for about an hour with a magnet tool on a copper wire, and then just for fun, tried to pull it out of the original hole, and I got it out! :unsure: So much for tearing it apart. You can say you told me so.


This is where it gets interesting. I put the new switch back in, and it still wasn't closing, at least until I put it into reverse. So apparently this is the reverse switch. I went back to my manuals and tried to locate the neutral switch, but there are only three switches on my transmission: one for 4wd, 4wd low, and reverse. Where the neutral switch should be, there is an unthreaded hole that doesn't go all the way through. I read in this car's records that the transmission was replaced at some point. The one they swapped in must have from an earlier year that didn't use that switch.


When I opened the top plate, I was surprised to find a broken off piece right there. I believe it is part of the top of part 30 in the first diagram I posted. I just pulled it out, and it didn't seem to affect the movement of anything. But it makes me think I should flush out my transmission to get any remaining shards out. It seems like it would probably be good anyhow since it's dusty around here and I had it open for a while.


Also, the question remains of what to do with the missing neutral switch. I'm thinking of just tying it into a clutch switch. I don't really want to mess around with drilling into my transmission and threading it, and I don't know if that would even be possible to make work. I'd like it to run as efficiently as possible, but my main concern now is just getting the CEL off so I can pass emissions testing. Any other ideas for detecting if it's in neutral?

Link to comment
Share on other sites

Im not as experienced as these guys, but to my understanding when retrofitting a spfi system onto a carbed car, the fix for the neutral switch error code is to put a switch under your clutch pedal, zome cars have a switch there not connected to anything fromthe factory i guess, but like i said im sure ill be corrected but im doing a spfi swap into my ea81 hatch and swear i read this

Link to comment
Share on other sites

When they do the emissions test, how do they have the car running? Ie do they sit in the car with their foot on the clutch, or will they have the clutch out with the car in neutral, or do they shift through the gears? If its the 2nd option, installing a clutch switch will be useless.

Does the neutral switch give current when in neutral or does it stop giving current? Cars will cruise control already have a clutch switch that breaks the circuit when the clutch is pressed, otherwise you can use a brake switch.

Another option is to put a switch on the shifter somehow.

If you decide to drill the trans, fill the oil up passed the hole level so that when you break through (after drilling very slowly, its only alloy) the oil coming out your new hole will try to drag the filings with it (will get messy though, so be warned)

Link to comment
Share on other sites

The neutral

switch provides information to the ECU on the gear state of the transmission. It's a simple switch that is closed when in

gear, and open when not. Some claim that not hooking this switch up at all is "ok", but I prefer to hook as much up as I

can as it's not possible for us to look into the ECU's software and forsee all possible consequences of the alternative,

and even though it might run fine, the ECU will complain with a "check engine" lamp after driving for only a few miles. Also

if another component fails it could setup a scenario where the ECU is forced into "limp mode" due to too many system

failures when it would not otherwise have done so had the neutral switch code not been present. Thus I sugest you make

every effort to install the system the way it was intended to be installed. One solution I've found with a transmission

that does not have the switch is to use a clutch pedal switch used with EA81's and EA82's (and possibly others) to

control the cruise control. This switch is shaped like a bolt with two nuts on it and it threads into the stop-bolt location on the clutch pedal. Just like the transmission neutral switch, the cruise control switch is designed to be closed when the

clutch is released (in gear), and open when the clutch is engaged (neutral). So as a surrogate neutral switch it works

well, and is acceptable enough to the ECU to prevent the code 51 error indicating the ECU can't find the switch.

Link to comment
Share on other sites

My main concern right now is getting the CEL to go off. They won't even test the car if it is on, and I'm not about to go the pulling the lamp route. This is the last remaining code on my computer after repairing the PCV/EGR solenoid wiring and the engine oil temperature sensor.


I think your suggestion is good, superooo, and I will see if I can scavenge one of these clutch switches, as my car does not have cruise control. And good to know that it is in fact open in neutral. This should satisfy the computer, but I'm still not in love with it as a solution, since my car will be in neutral idle mode up until I release the clutch. This means it will be lacking power when I need it the most, that is, starting from a stop.


Here's my update: I sealed the rear extension case with the gasket maker after cleaning it very thoroughly. I squeezed a crapload in there since it was hard to reach some spots, hopefully it will ooze its way through the whole interface. I will find out in 24 hours when I put the new oil in, and whether I made any other horrible errors. :huh:

Link to comment
Share on other sites

I'm going to talk largely about the SPFI as it applies to manual transmission applications. The automatic's have an "inhibitor

switch" responsible for telling the ECU what state the transmission is in, and a kickdown system with a relay that is

controlled by the ECU and operates a solenoid on the side of the transmission. I have no experience with hooking these up, but

it seems fairly straightforward - the inhibitor switch looks to be inside the shifter of the EA82, and the kickdown solenoid is

on the side of the tranny. Being the EA81 used the same automatic transmission, I'm guessing it wouldn't be a huge deal to

hook it up. However I have no exprience with them. The manual transmission setup is what I want to discuss, and specifically

the differences between the older black ECU, and the later silver ECU.

The black ECU used in 1986 was only used on automatic transmissions according to my research. Only 2WD automatics

got the SPFI in 86, and the 2WD 5 speed version was probably either carburated, MPFI, and possibly some turbo models.

4WD's did not begin receiving the SPFI system till the 88 model year (late 87). This makes the 86 ECU unsuitable for

anything but automatic installations, and the wiring harness has some unusual connectors for things like the distributor,

coolant temp sensor, 02 sensor, and possibly some others. Personally I avoid this early 86 system's wireing harness,

and ECU because of these differences. They are, fortunately, pretty rare as well but it's important to know the differences

in case you do run across one or aquire one for parts. Most of the components other than the wireing and ECU are the

same and can be used with later systems either directly, or sometimes by just changing the wireing plug.

The black ECU used from 87 to 89 uses only a single neutral switch located on the side of the transmission. This is

obviously a problem for the EA81 4WD, 4 speed manual and the 2WD, 5 speed manual because they were never

equipped with this switch and sadly have no provision for adding one. Additionally, the 86 and 87 4WD, 5 speed

transmissions (a common upgrade for the EA81) do not have the neutral switch either. The 88 and up transmissions should

all have the switch as carburators were discontinued after 87 and all the forms of fuel injection require it.

Link to comment
Share on other sites

I'm in Albuquerque. I'll see what I can manage with regards to emissions, but I don't care to play any games with them.


On to the good news, my car is back together! Took me a week and a half but I have four wheels again, and it doesn't appear to be leaking anywhere it wasn't leaking before. Only odd thing is the 4wd light doesn't come on until I push it past 4wd high. I can live with that for now though. Now on to figuring out the neutral switch deal, now that the situation's a little cleared up. I'm still considering how I could add something to the shifter.


Lessons learned: check the color of the wires! And get the proper manual and do your homework. :)

Link to comment
Share on other sites

  • 1 year later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...