A few years ago I trashed a transmission on my GXL (go figure); pretty sure I sheared 3rd gear, and found a replacement transmission. Unfortunately, the guy didn't tell me that the damn thing leaked transmission fluid from the bottom of the transmission. I pour in fluid, and it pours out right away. Luckily I was smart enough to try putting a little in before putting it on the car, and found this while on the ground.

I assume that there is a seal there that has just worn away, and I was wondering if this was a repair I could perform myself. I'm no professional, and age and experience has taught me I'm not as good as I once thought I was. I'm somewhat concerned about pulling apart the transmission and not being able to put it back together again. But I'm not sure exactly what seal I would need regardless; would I be correct in assuming this is the seal I need? (http://www.rockauto.com/catalog/x,ca...,parttype,8754)

Tips and advice would be very much appreciated, and I'd hate to have wasted the money on the replacement transmission just to not be able to use it. I know the NA transmissions are notoriously weak, and so it's just not worth it to take this to a transmission shop so I can bend over for them.

 

If you just need to remove the tail housing, that's actually a fairly simple job. Put the transmission on its bell housing pointed up, undo the 6(?) bolts, and lift/rotate the housing to remove it. The arm on the shifter linkage will have to clear ends of the 3 shift rods inside, but after that it will come free. Move the shifter around a little if needed. You can reseal the mating surface with RTV or a new gasket. It's hard to tell from the picture in your link, but that gasket kit may work. When you reassemble it be sure the arm goes back where it's supposed to.

 

On the subject of tail housing removal: I've got a broken s4 n/a tranny sitting around that I've been trying to pull apart. I've been following the disassembly procedure in the FSM but it's rather vague to me.



I don't know if it's in 1st gear or not, does this really matter? I don't have a spare shifter right now and I really don't feel like the pulling one out of my car. What are they talking about in step 6? What is this bolt?

I've got all the bolts undone and this is the part where I'm stuck. You're saying I should just keep rotating the tail housing until it comes out? Or rotate the control rod? Is there some trick to this I'm not getting? The tranny is dead so I've been real close to busting out the sledge to assist in disassembly

 

Thanks for posting that diagram btw. On my replacement transmission there is no clutch or clutch fork installed yet, but I'm pretty sure that it is not in neutral; it won't budge at all when I put the shifter in.

 

I did this on the S5 TII transmission that I'm now using. I don't think there's a difference with NA transmissions, but I can't be 100% sure without taking one apart. When I pulled the tail housing, the transmission was stuck in 2nd and reverse. It had been dropped during shipping or something, and the shift rods fell downward into gear. All I did was lift and rotate the tail housing until the control rod came free. I did not remove the cover on the extension housing to mess with that end of the rod. I didn't need to. Here's a MS paint diagram that may help:



There are 3 shift rods (black) all next to each other (1st/2nd, 3rd/4th, 5th/Rev), and the control rod end (blue) moves between them. The end has to get free of the grooves in the shift rod ends before the housing will come loose.

 

Alright, I'll give it a shot next time I mess with the thing. Thanks.

 

Just an update: I got the back housing (extension housing, tail housing, whatever you want to call it) off . I looked back at and realized that i had loosened all the bolts but they weren't completely removed, so that kept me from being able to rotate it and free the control rod.

 

since you have it off, is there a gasket back there? Don't suppose you could get a picture of it so I can try not to go into it blindly?

 

You should check out section 7 of the s4 service manual (see the sticky), which is the transmission section. On the non turbo transmission, it is divided into three sections

1) the extension/tail housing, which is the part that the driveshaft slides into
2) the bearing housing (the middle part), which is the real guts of the transmission and contains the drain plug
3) the "transmission case" as the FSM calls it, which includes the bell housing.

They are sealed together with some kind of sealant at each housing. When I had my turbo transmission rebuilt by a reputable local specialist, they used what looks like black RTV to seal each section together. Where exactly is it leaking? I couldn't tell from your pic. Is it seeping out from between the extension housing and the bearing housing?

As far as pics go, I haven't gotten this tranny I'm messing with fully apart yet. I was messing around with a snap ring for the speedometer drive gear last night. I need to get a decent set of snap ring pliers. I can take some pics of the tail housing removed though. I have not been taking it apart methodically since this will never go back together. I have used a sledgehammer a couple times already.

Just FYI, the turbo transmissions have an additional section and two fill plugs. Basically it is a detachable bell housing. The bottom part where the drain plug is has its own gasket on the turbo tranny, but on the n/a there isn't a gasket there. The turbo transmission is part of the "R" family of Mazda transmissions which includes the FD transmission and certain Ford and Mazda truck transmissions. The non turbo transmission is part of the "M" family of transmissions I believe, which includes the Miata transmission. That's why the turbo and non turbo look a little different.

 

If you look on the picture there's a little green arrow that points to a gap between the tail housing and the bearing housing. It's leaking from that entire gap

 

Yes, that's where the tail housing bolts up. You absolutely need a gasket or seal of some kind there. That section is filled with oil too.

 

See attached pics of tail housing removed from a non turbo transmission. On the tail housing I pulled out more stuff than you really need to remove. You will need something to help separate the two housings (unless there really is no sealent left on there). I just banged that **** with a sledge hammer but I have zero intention of putting this back together.