Found metal at the bottom of my 5-speed. What next?

[Dave WM]

the snap on the reverse gear is a MAJOR pita, don't think that one has to come off for the countershaft bearing replacement.

Get a decent dial caliper (not digital), a good tool to have. You will need the Nissan shaft and counter shaft nuts that need to be staked.

I can see there are a little keys and such from videos of disassembly, did not do that much on mine so cant help there.

on seals there is often an open side of the seal where you can see the spring that goes around the inside, it look like a U shaped channel.

You want the open side of the U to be facing what ever you are trying to seal in. On the front face plate for instance you need to drive the seal in from the open side not the back closed side (the open side faces the oil, the closed side faces the front cover). This means getting a tool like a large socket that fits the outside edge of the seal I used a very large socket and made sure it was pressing the outer edge of the seal. Also used my drill press like a regular press to push it in smoothly, rather than banging on it with a mallet. You want that seal seated evenly into the face plate. Now on the tail shaft you press the back side in since the oil is inside the tail case. Just Play close attention to how the seal are installed, they tend to pop out when pulling and then you may lose the orig orientation. Better still take a pic of the seal before removing.

Edited May 9, 2016 by Dave WM

[Zed Head]

Seems like you might get to a point where you think that you're moving too fast.  If you do, I'd say you were right to think that.  You've already found a mystery part, and probably came close to throwing away a very important shim.  Dave WM spent a few posts, with pictures, talking about that mystery piece in his detailed thread.  And the shim is described in the MT chapter.

Just saying, you're on the edge.  You had a transmission that worked well, just had some loose metal in it.  You might end up with no loose metal and one that's noisy and difficult.

[Dave WM]

oops and I was completely off on that mystery part (not enough coffee) that was the part used to spring load the shifter out of the 5/rev position. Zed head is right I was all over that in my ZX trans thread. the anti balk thing was on the same side. the mystery part should have a spring and resides under a large hollow nut right near the shifter.

Edited May 9, 2016 by Dave WM

[KDMatt]

Seems like you might get to a point where you think that you're moving too fast.  If you do, I'd say you were right to think that.  You've already found a mystery part, and probably came close to throwing away a very important shim.  Dave WM spent a few posts, with pictures, talking about that mystery piece in his detailed thread.  And the shim is described in the MT chapter.

Just saying, you're on the edge.  You had a transmission that worked well, just had some loose metal in it.  You might end up with no loose metal and one that's noisy and difficult.

For the record I haven't come close to throwing anything away. The only thing in the trash right now are heaps and heaps of shop towels, soggy with gear oil.

"Just had some loose metal in it" sounds strange to me. I was under the impression that we're talking about a pretty severe failure. Are you suggesting that I button it back up as-is and keep my fingers crossed? I'm honestly just poking around in here to see how hard it would be to fix. I don't feel like I've disassembled anything to that point yet where I'm clueless if I want to just slap it all back together (save for the "mystery piece" that I'm checking Dave's thread to reference.) Just saying.

This whole venture from the get-go was meant to be more exploratory than anything. I'm still not above trying to source a different 5-speed and call it a day.

I might still be at a point where I can take this assembly down to the transmission shop and ask real nicely to have them replace just that one bearing, who knows. 

Look, I defer to all of you guys on here because you know more than me. If I'm clearly in over my head on this one, I'll stop. 

[Zed Head]

Wasn't trying to offend you.  People get lost on these kinds of projects all the time though.  You don't seem to be reading the stuff we're referring you to.  No biggy, it's more fun to tear stuff down and see what's in there, I get it.  On the loose metal comment I was just talking about your driving experience, before and after.  You didn't know you had a problem until you saw the bearing cage on the magnet.  We see people "upgrading" things on the forum all the time and ending up with downgrades in driving experience.  That's all I'm saying.  You could end up with a new bearing and a poor driving experience because you lost a piece.

Carry on and good luck.

[KDMatt]

10 minutes ago, Zed Head said:

Wasn't trying to offend you.  People get lost on these kinds of projects all the time though.  You don't seem to be reading the stuff we're referring you to.  No biggy, it's more fun to tear stuff down and see what's in there, I get it.  On the loose metal comment I was just talking about your driving experience, before and after.  You didn't know you had a problem until you saw the bearing cage on the magnet.  We see people "upgrading" things on the forum all the time and ending up with downgrades in driving experience.  That's all I'm saying.  You could end up with a new bearing and a poor driving experience because you lost a piece.

Carry on and good luck.

No worries, no offense taken. I was just feeling pretty good about this project overall (i.e. feeling like I'm not in over my head just yet) and your reply got me a tiny bit discouraged, so forgive me if I seemed a little too defensive in my reply. I felt like things were going swimmingly and you just had to remind me to not get cocky, haha. 

As for reading, I'm sticking to the FSM and looking over Dave's thread at the same time. What else were you referring me to read?

This was the only mention of the "mystery part" I could find in that thread, btw: 

 -- and I see now it's related to shifter return spring (though I think the FSM refers to this as a plunger) which I did remove as per the FSM instructions.

 

I'm honestly trying to take this slow -- to be as methodical as I can -- I stopped where I did because I don't want to get lost.

I suppose every man's got his limits, and I do genuinely appreciate you guys trying to keep me on track. 

[EuroDat]

Here is the list of all the parts I used and a couple of extra parts to make it complete.

I have incuded as much extra information as possible so other vendors can be used for parts like bearings and seals. You don't need to replace all the parts That will depend on the condition of the transmission. Don't be tempted to buy aftermarket synchros. Its very tempting, but you will very likly notice the difference.

I was thinking it will be the (32276) 6306 C3, but the bearing under it (32219M) 6305 C3 on the countershaft was going to be my second bet. Both are in the transmission case adapter plate and seem to be vunerable. See the pfd for a detailed parts diagram on page 2.

BTW. That mystery part is the reverse checking assembly. Its not mentioned on the parts diagrams, but it is in the 280ZX FSM. Make notes of things like the front cluster gear direction. It fits on both ways, but could cause a whine if it goes back on backwards. It will work both ways.

Warming the front cluster gear up a LITTLE will help a lot with getting it off. Just hot enough that you can still hold it (60 degrees C). Makes it easier to pull off. 

You could be right about it being a 720 or it could be a 280ZX 2+2. The 720 2wd with the L20B engine had several sets of ratios. I think one was like the 280Z and the 280ZX 2+2, but the other one is very low in first gear: 3.592 - 2.057 - 1.361 - 1.0 - 0.813.

There is also a possibility it could come from a 79/80 620 truck with the L16 or L20B engine. It supposably had 3.592 - 2.246 - 1.415 - 1.1 - 0.813. I'm no expert on trucks, but came across this info a lot and it doesn't seem to be rejected by the guys in the know on ratsun.

Chas

Tranny_Rebuild_FEB2012.pdf

[Dave WM]

he has your oil gutter in there!

[KDMatt]

Hey Chas, I'm not sure I'm seeing the correct bearing reflected on this list and in this diagram. I see the main-shaft bearing (#32276) but nothing listed for the one below it (which is the one that's broken on mine.)

You're correct though, the number on the busted bearing is 6305, and I've already poked around some local suppliers (online) and it doesn't seem like it will be hard to source. Will any 6305 do, or is there something specific I should look for?

... and here's a random thought/idea/question (I'm at work, so I don't have the assembly right in front of me)... Is it possible to disengage all of the gears/bearings from the rear-half of the transmission (including the reverse idler) and slide both shafts toward the front at the same time, keeping them meshed and assembled? ... at least far enough to get that busted bearing out and put a new one in? I don't like to half-arse things, but I also want to minimize the amount of disassembly I have to do, lest I get something wrong. Just a random thought. 

 

The reason I brought up the 720 was because after hours and hours of endlessly googling different combinations of Datsun and Nissan transmissions, the closest one I saw (that still wasn't an exact match for mine) was out of an '80 720. 

... and your warning on aftermarket parts has not fallen on deaf ears, I promise! The transmission was in pretty good working order before I pulled it, so I don't want to replace anything that doesn't seem broken. If it ain't broke...

It never ground or stuck -- the only issue I ever had with this transmission was that it would make a wobble or "whine" noise when I let the clutch out in neutral, which could very well have been the worn countershaft bearing wiggling around a bit. I got a new throwout bearing as part of my clutch kit just in case, so that'll be covered too. 

[KDMatt]

13 minutes ago, Dave WM said:

he has your oil gutter in there!

Holy crap he does! BOOM! 

[EuroDat]

19 minutes ago, KDMatt said:

Hey Chas, I'm not sure I'm seeing the correct bearing reflected on this list and in this diagram. I see the main-shaft bearing (#32276) but nothing listed for the one below it (which is the one that's broken on mine.)

You're correct though, the number on the busted bearing is 6305, and I've already poked around some local suppliers (online) and it doesn't seem like it will be hard to source. Will any 6305 do, or is there something specific I should look for?

... and here's a random thought/idea/question (I'm at work, so I don't have the assembly right in front of me)... Is it possible to disengage all of the gears/bearings from the rear-half of the transmission (including the reverse idler) and slide both shafts toward the front at the same time, keeping them meshed and assembled? ... at least far enough to get that busted bearing out and put a new one in? I don't like to half-arse things, but I also want to minimize the amount of disassembly I have to do, lest I get something wrong. Just a random thought. 

 

The reason I brought up the 720 was because after hours and hours of endlessly googling different combinations of Datsun and Nissan transmissions, the closest one I saw (that still wasn't an exact match for mine) was out of an '80 720. 

... and your warning on aftermarket parts has not fallen on deaf ears, I promise! The transmission was in pretty good working order before I pulled it, so I don't want to replace anything that doesn't seem broken. If it ain't broke...

It never ground or stuck -- the only issue I ever had with this transmission was that it would make a wobble or "whine" noise when I let the clutch out in neutral, which could very well have been the worn countershaft bearing wiggling around a bit. I got a new throwout bearing as part of my clutch kit just in case, so that'll be covered too. 

The bearing is listed. Its the second bearing in the Counter Gears section. P/N: 32219M (32203-E9800). I use SKF, just make sure the tolerance is C3 which is most common.

You can remove all the gears behind the adapter and pull the front gears with shaft out of the center bearing. You will still need to remove the front cluster gear and you will have to pull the counter shaft out at the same time.

The selectors will need to be dismantled before you start pulling the shafts. I don't know if its going to save much time.

The whine you heard in neautral it very possible the bad counter gear bearing in the adapter plate. Its good news when you find something, but it always pays to run through the checks. You could find something else and now you have it apart its easy to replace.

Checking the ratios will tell you more about the transmission. Take a photo, count the teeeth on all the gears and note it on the photo for future reference. Excel can workout the ratios and then you know for sure. No more guessing and in the end its not important where it came from. If the ratios are what you want, thats important.

[EuroDat]

Here are some photo's of the oil gutter and the reverse checking assembly