Transmission internals question

[redfogo]

Video of it taken back apart

 

[Dave WM]

that dog looks like it has metal chewed out from the slider ramming into it (would not happen if the pad stayed under the slider). With it assembled try turning the output shaft and then see if it will come out of rev. I still don't like the way the 5th gear blocking ring (brass) can turn independently of the hub. That brass ring has cutouts that are supposed to stay lined up with the shift dogs. Anyway of asking the PO if it was ever rebuilt? Also those teeth on the 5th gear that engage the slider look very rounded over, may cause issues (but maybe typical wear, mine did not seem so great either).

Edited November 16, 2017 by Dave WM

[Dave WM]

this is a good video on the process

 

[redfogo]

58 minutes ago, Dave WM said:

that dog looks like it has metal chewed out from the slider ramming into it (would not happen if the pad stayed under the slider). With it assembled try turning the output shaft and then see if it will come out of rev. I still don't like the way the 5th gear blocking ring (brass) can turn independently of the hub. That brass ring has cutouts that are supposed to stay lined up with the shift dogs. Anyway of asking the PO if it was ever rebuilt? Also those teeth on the 5th gear that engage the slider look very rounded over, may cause issues (but maybe typical wear, mine did not seem so great either).

Did you see the other video I posted  ? When assembled everything worked fine even When I spun the input shaft it still popped out gear just fine when assembled.

[Dave WM]

yes I did, still think there is a problem, that dog is getting chewed up for a reason. I understand not wanting to take it apart, just seems like its not right. Hope EuroDat chimes in. Worse case is you get a severe block out making getting out of reverse difficult, once out and the blocking ring is back to where it should be, then all is ok. try with it assembled in reverse, turn the output shaft, then see how well it comes out. Maybe the same as spinning the input, but you need to try various combos before assuming all will be ok.

Edited November 16, 2017 by Dave WM

[redfogo]

34 minutes ago, Dave WM said:

yes I did, still think there is a problem, that dog is getting chewed up for a reason. I understand not wanting to take it apart, just seems like its not right. Hope EuroDat chimes in. Worse case is you get a severe block out making getting out of reverse difficult, once out and the blocking ring is back to where it should be, then all is ok. try with it assembled in reverse, turn the output shaft, then see how well it comes out.

Yeah at 0:30 I get it into reverse spin the input shaft you can see the outshaft move and then I bump it into neutral without any problem.

 

Video in reference

 

Edited November 16, 2017 by redfogo

[Dave WM]

that's what bothers me, that blocking ring (brass) should never get out of index with the dog. The way it is, you can prob use the transmission, just may have times when getting out of rev takes a few tries. Again I am NO expert, its just my opinion from hours of research and my one rebuild.

Edited November 16, 2017 by Dave WM

[redfogo]

25 minutes ago, Dave WM said:

that's what bothers me, that blocking ring (brass) should never get out of index with the dog. The way it is, you can prob use the transmission, just may have times when getting out of rev takes a few tries. Again I am NO expert, its just my opinion from hours of research and my one rebuild.

I don't think that the brass ring gets out of index when assembled I tried a good amount of times off camera and never had any sign of miss alignment. It came in and went out off reverse every time both off camera as well as on camera (and I spun that input shaft a bunch of times! ). I could see the dog getting chewed up from all the years of use if its OEM. Your configuration on the other hand may be an improvement from OEM. Or my trans is not OEM was not built right and they just got lucky it works great when fully assembled.

It would be nice if there was one more transmission out there that someone else was going to take apart that could test this whole thing out @EuroDat

Edited November 16, 2017 by redfogo

[Dave WM]

1 hour ago, redfogo said:

I don't think that the brass ring gets out of index when assembled I tried a good amount of times off camera and never had any sign of miss alignment. It came in and went out off reverse every time both off camera as well as on camera (and I spun that input shaft a bunch of times! ). I could see the dog getting chewed up from all the years of use if its OEM. Your configuration on the other hand may be an improvement from OEM. Or my trans is not OEM was not built right and they just got lucky it works great when fully assembled.

It would be nice if there was one more transmission out there that someone else was going to take apart that could test this whole thing out @EuroDat

go to 38.48

[redfogo]

Is there any like official nissan documents  we could compare? One that's like known 100% correct ? I agree that video looks just like yours but it's post assembly. 

[Dave WM]

I have looked and looked, the closest I could find was that one cross sectional view. It really comes down to how its supposed to work. That animation video demos how the dogs are suppose to work, the way the pad functions etc... My guess is that at some point some one was in yours and reversed those, understandable mistake, evidenced by the odd digging in on the pad. You can always just install the trans and try it out, if it works it works, if you have shifting issues with 5th and or rev, well, you know where to start. I know it kinda stinks the idea of having to try it and maybe remove and fix and try again, but that is pretty much where you are. I agree the FSM should have been a LOT more clear on the way those should be installed (since the dogs are asymmetric on that sychro).

[EuroDat]

Hi Guys,

Sorry for being a little late replying. Been away for work.

A little background info about the 5th baulk ring (synchro):

A good idea to use the Nissan terms for the parts. It makes it easier when refering to the manual and the parts catalogue. Synchronizer assembly: Hub, Inserts, Baulk ring and Coupling Sleeve

The "carbon ring 5th baulk ring" was in the 280Z wide ratio transmission. Its not the porsche type synchro, people talk about, in the 5 speed that was available in the 240Z outside the north amaerican market. Nissan changed to the brass ring in the later 280ZX transmissions, and the wide ratio 280ZX 2+2 eventually got the brass ring 5th synchro. The synchro rings are the same for the 71C model without the reverse synchro. 1st to 4th are all the same size synchro rings (P/N: 32604-P0100) and 5th is smaller (P/N: 32604-E9801)

Looking at your video: Part 3 of reverse lock out on 280Z.

The reason you can’t get it to engage 5^th is simple. The coupling sleeve is moving too far forward allowing the insert to lift up out of the slot in the baulk ring. See snapshot (Not aligned). This is because you are doing it by hand. The selector mechanism should not move it so far forward, like you mentioned towards the end of the video. You also confirmed it when you assembled the rear case and selected 5^th gear.

If you look closely in the video at 1:05 (were you got lucky) you will see the slot was very close in line with the insert so the insert could pop back in.

Still, if I look at the inserts, they look ragged. A lot of damage at the front section where the coupling sleeve rides over it. It will work, but it won’t have that silky smooth action. Move like a “jam it in there” kind of feel.

Do you plan on rebuilding it?