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

[KDMatt]

I'm tackling a clutch job for the first time in my history with this car (11 years/35k miles), and as such, I cracked the drain plug for the first time in at least that long. I have no idea when it was last done -- somewhere I've got a stack of records that would probably tell me if it's been done anytime "recently" in the car's history... but for now it's an unknown.

The fluid that came out was pretty sludgy and gray, and as expected there was a pretty thick layer of metal crud on the magnet plug, but, on top of that, I found a couple of bits/chunks of metal. 

I searched some previous threads and saw someone else with something similar -- it looks like some bits from one of the gear bearings? I have no idea how long these parts have been down there. For all I know these things could have been down there for decades. 

I'm assuming the worst-case scenario is that I need to crack open the transmission and rebuild/replace these assemblies. That being the case, is there a section in the FSM that covers how to do this? I've never cracked open a transmission before (hell I've never even done a clutch before - so I'm already in unfamiliar territory), but there's no time like the present, I guess? How big of a job are we talking about here? Could it be done in a weekend? An afternoon? 

If you were me, what would you do?

 

[siteunseen]

41 minutes ago, KDMatt said:

If you were me, what would you do?

I'd load onto my truck and carry it to a transmission shop.  I had a local shop take two of mine and make one good one, new seals and gaskets when they put it back together.  $100 charge, I gave him $125.

That doesn't look good to me but maybe it's not that bad.

[Mark Maras]

 Looks like pieces of a bearing cage. The cage is what keeps the balls from touching each other as they rotate. A ball separator would be a good description. I'm surprised you haven't heard the bearing whining.

 The trans definitely has to be torn down. It's a big job to do yourself but not impossible if your desire is great enough. The first time I did a Z 4 speed, it was on a 4'x8' sheet of plywood on my shag carpeted apartment bedroom floor. Basic hand tools, not even a press. Replaced synchros and bearings. Turned out great. Except that my bedroom smelled like gear oil for a couple of months.

 Feb. 10th, Boomguy@ started a thread titled "Any ideas?". The pics of his trans bits and pieces are the same as yours. Undoubtedly there is a lot more info if you search. Note the snap-ring from @#$%. Everyone has problems with that one. The orientation of the parts during disassembly and cleaning is critical and the most difficult, for me, to keep straight. One member suggested wooden dowels to keep the parts in order.  Also start soaking all the bolts (especially the exhaust) with good penetrating fluid. 50% acetone, 50% auto trans fluid is excellant. A broken bolt or stud can make a difficult project a lot worse. It's difficult to estimate the time. Too many variables. 

[siteunseen]

Here's that thread Mark's referring to, 

 

[KDMatt]

1 minute ago, Mark Maras said:

Also start soaking all the bolts (especially the exhaust) with good penetrating fluid. 50% acetone, 50% auto trans fluid is excellant. A broken bolt or stud can make a difficult project a lot worse. It's difficult to estimate the time. Too many variables. 

Already done. The transmission is ready to come out. I spent all day yesterday getting everything everything out of the way and disconnecting all the monkey-business stuff, like speedo cable, reverse switch, neutral switch, etc. etc. Exhaust is on the floor. Shifter is out. Console is out. Starter is out. Slave cylinder disconnected. I think at this point I just need to put a couple of jacks under the thing and unbolt it. 

Also, Mark, I did see that thread ... I perused far enough to see the pictures of the bits he removed looked like mine, and that's about where I stopped. If he documented a full tear down, I didn't get that far. Good to know that it's there though -- I'll look closer.

8 minutes ago, siteunseen said:

I'd load onto my truck and carry it to a transmission shop.  I had a local shop take two of mine and make one good one, new seals and gaskets when they put it back together.  $100 charge, I gave him $125.

$100 seems pretty optimistic, but I suppose there's no harm in calling around. 

Here's the other rub -- this is a swapped 5-speed that was neither done by me nor the P.O. -- which means it was swapped at some point in the late 80's or early 90's ... and I'm not super sure if it's the ZX tranny or the 77/78 ... which I'm sure will complicate my quest for rebuild kits/components. 

11 minutes ago, Mark Maras said:

 Looks like pieces of a bearing cage. The cage is what keeps the balls from touching each other as they rotate. A ball separator would be a good description. I'm surprised you haven't heard the bearing whining.

Sorry for addressing out of order.

Yes, that's what I was trying to get at -- bearing cage. Thank you. The transmission never whined or gave any otherwise indications that a component inside had failed or fried, which is why I was astonished to discover such critically important parts just sitting at the bottom. :/ 

[Zed Head]

Dave WM just tore his transmission down.  The FSM goes in to pretty good detail about how to do it.  When the cage comes out the bearings can all move to one side.  It basically just increases the slop in the bearing assembly.  The bearing is in the adapter plate.

If the transmission works fine, why replace everything?  Old factory parts are often better than new aftermarket.  Sqwawk.  The rebuild parts market for these transmissions is full of misinformation.

[KDMatt]

7 minutes ago, Zed Head said:

Dave WM just tore his transmission down.  The FSM goes in to pretty good detail about how to do it.  When the cage comes out the bearings can all move to one side.  It basically just increases the slop in the bearing assembly.  The bearing is in the adapter plate.

If the transmission works fine, why replace everything?  Old factory parts are often better than new aftermarket.  Sqwawk.  The rebuild parts market for these transmissions is full of misinformation.

I guess I'm going to need to see some pictures to see if this is something I want to do or not. I found this thread, but alas no pics: 

 

Generally speaking though, yeah -- that's been my approach to this car over my time with it -- just replace what's broken, and leave things alone that aren't broken and just go from there. 

Dropping the transmission is a bit labor intensive though, so I don't want to go through all of this trouble only to have to do it again in a year or six month's time. I dunno. Granted, it's probably been "busted" like this for several years/thousand-miles, so who's to say. Is it less labor-intensive to crack it open -- just replace the broken bearings/cages and call it good? 

Also, I don't have a definitive clue what 5-speed I've got, so there's that.

Waiting on estimates from a  couple of places in town for a rebuild, and we'll go from there. 

[Chickenman]

Just a note. All bearings are readily available at local bearing supply shops at wholesale prices. Get SKF or NTN. All the identity numbers are stamped on the bearing races. Seals and gaskets are still available from any Nissan dealer  or places like MSA.

You'll want a front input seal and retaining plate gasket, rear tranny seal, and maybe a new O-ring and shaft seal for the Speedo sleeve. All are readily available from Nissan. Factory seals are very good quality. Some Permatex Ultra Gray for sealing the center retaining plate ( no gasket, just sealant ) or some Hylomar.

Snap rings are usually re-useable if you take care removing them, but are of a standard Metric size and can be ordered from Nissan or matched at Bearing supply shops.

 

 

[KDMatt]

I got a quote for about $700ish to pull it apart and replace the seals and bearings. Price doesn't include doing the synchros.

I dunno, I've paged through the FSM and this looks like a pretty complex ordeal. At this point, I'm almost tempted to try to snag another transmission ebay for a couple hundred bucks, and just keep this one shelved until I've got the courage or (savings?) to rebuild it. My Z is, by no means, a looker right now.  

I'm really torn though -- I can justify both decisions pretty easily.

Here's a random question though ... My transmission has two sensors on it (one for reverse light -- the other for...??) -- most of the replacement transmissions I'm seeing on ebay (allegedly out of 77/78 Z's) only have a provision for one.... am I just being dumb and not seeing it or what's the deal? I'll take a pic when I'm home.

[Mark Maras]

 Don't know about the sensors but $700.00 sounds like a lot of money for replacing seals and bearings. Especially when you're handing them the transmission. IMO, pull the outer cases off (quite easy) and take a look at the internals. Look for the bad bearing and then decide how much really needs to be done and if it's worth it have someone else do it. At the least you'll save money by pulling the cases and cleaning them yourself.

 A used trans is definitely an option but you may end up with a second one that needs to be pulled apart too. Could end up having to decide which of the two 5 speeds to rebuild. 

[KDMatt]

18 minutes ago, Mark Maras said:

 Don't know about the sensors but $700.00 sounds like a lot of money for replacing seals and bearings. Especially when you're handing them the transmission. IMO, pull the outer cases off (quite easy) and take a look at the internals. Look for the bad bearing and then decide how much really needs to be done and if it's worth it have someone else do it. At the least you'll save money by pulling the cases and cleaning them yourself.

 A used trans is definitely an option but you may end up with a second one that needs to be pulled apart too. Could end up having to decide which of the two 5 speeds to rebuild. 

I keep hoping I'll stumble across a really great, annotated writeup with tons of pictures to help me feel more confident about this... but it's not happening, lol. I guess you're right though, in that there's no harm in cracking it open just to see how bad it is.

[Zed Head]

I would pull the front bearing cover (the small one inside the bell) first.  There's a guy on Hybridz who posted last week saying that he blew up a countershaft bearing.  If it was the front bearing you could probably devise a way to pull it alone and replace just it then run it as the used transmission that it is, without tearing it down.  Or, you could pull the front case/bell and replace just the two front bearings.  

Rebuilds are always a matter of degree.  There's another guy on Hybridz who basically blueprinted his transmission, every measurement in spec., then modified it even further for high RPM shifting.