Crashtd420 Posted July 13, 2021 Author Report Share Posted July 13, 2021 36 minutes ago, Stoffregen Motorsports said: And the pills that run between the shift rods. Don't forget those. Umm where are those? And or what do they look like? 1 Quote Link to comment
Stoffregen Motorsports Posted July 13, 2021 Report Share Posted July 13, 2021 They hide in between each shift rail, so you don't shift into two gears at the same time. Sometimes they are spherical balls, but I think the 5 speed has oblong shaped pills. There is another plug to access them which is perpendicular to the shift detent ball bores. Use a pencil magnet to get the out, and vaseline or grease to keep them in place while assembling the shift rods. 1 1 Quote Link to comment
Crashtd420 Posted July 13, 2021 Author Report Share Posted July 13, 2021 Just now, Stoffregen Motorsports said: They hide in between each shift rail, so you don't shift into two gears at the same time. Sometimes they are spherical balls, but I think the 5 speed has oblong shaped pills. There is another plug to access them which is perpendicular to the shift detent ball bores. Use a pencil magnet to get the out, and vaseline or grease to keep them in place while assembling the shift rods. I'll have to have another look... thanks 1 Quote Link to comment
Crashtd420 Posted July 13, 2021 Author Report Share Posted July 13, 2021 I guess I learned something more about my transmission today, and I forgot to take pictures in my haste to see what you were talking about... So they are actually all ball bearings and they will fall out of the hole if you poke them.... glad I never lost them.... 1 each under a plug on top which i believe would be the detent balls... And the plug on the side with a long bolt must be the lock out ones... There was 1 under the spring possible the detent ball for the last shift rod then I found 4 more inbetween the shift rods... so not a pill but 2 ball bearings .... 2 Quote Link to comment
Crashtd420 Posted July 13, 2021 Author Report Share Posted July 13, 2021 I made alittle progress... I was able to reinsert the 4 lock out balls, and assemble the shift forks and shift rods.... I still need to finish installing 2 roll pins, ran out of time..... I ordered the front cover gasket from the local dealership, and picked up some gasket maker for the case and some new oil.... I should be able to have it buttoned up this weekend ready to go back in... 4 Quote Link to comment
Stoffregen Motorsports Posted July 14, 2021 Report Share Posted July 14, 2021 Eliminating the front cover gasket helps shorten up your shift stops. It's an old race trick. Spirited shifting can move the shift sleeve past where it need to be to engage the gear, and if it goes too far, it can actually get stuck, so by removing the gasket, you make that shift rod strike the cover a little bit sooner. Another trick is to actually weld a bead on the front cover, where the shift rod hits, and then grind it down to the correct depth to make the shift rod stop at the precise moment the detent pawls have engaged. Does your front cover have the one short bolt? Some did, some had all the same length bolts. If you install a too-long bolt in the lower corner, it will contact the cluster gear and cause damage. 2 Quote Link to comment
Crashtd420 Posted July 14, 2021 Author Report Share Posted July 14, 2021 37 minutes ago, Stoffregen Motorsports said: Eliminating the front cover gasket helps shorten up your shift stops. It's an old race trick. Spirited shifting can move the shift sleeve past where it need to be to engage the gear, and if it goes too far, it can actually get stuck, so by removing the gasket, you make that shift rod strike the cover a little bit sooner. Another trick is to actually weld a bead on the front cover, where the shift rod hits, and then grind it down to the correct depth to make the shift rod stop at the precise moment the detent pawls have engaged. Does your front cover have the one short bolt? Some did, some had all the same length bolts. If you install a too-long bolt in the lower corner, it will contact the cluster gear and cause damage. I'll look into that . .. As far as the bolts they are all the same length, but I'll make sure there wont be an issue during assembly.... 2 Quote Link to comment
Crashtd420 Posted July 15, 2021 Author Report Share Posted July 15, 2021 My cover actually looks a little different... it was for the smaller bearing and it had the groove connecting the 2 bearing locations... It didnt have the groove connecting the shift rod opening but I added it that last time I was working on the transmission..... 2 Quote Link to comment
Crashtd420 Posted July 15, 2021 Author Report Share Posted July 15, 2021 I did manage to get the last 2 roll pins installed tonight, and put the rest of the detent balls back in, then reassembled the cases.... Everthing feels good shifting it on the bench.... 2 Quote Link to comment
Stoffregen Motorsports Posted July 15, 2021 Report Share Posted July 15, 2021 Nice work. 2 Quote Link to comment
Crashtd420 Posted July 15, 2021 Author Report Share Posted July 15, 2021 48 minutes ago, Stoffregen Motorsports said: Nice work. I got lucky the repair didn't hold any surprises.... it was pretty straight forward and easy.... Should probably clean it up too.... I didn't realize I was leaking out the flange... never seemed to drip but made a mess... i repaired that over the winter during the suspension work...... 1 Quote Link to comment
Crashtd420 Posted July 16, 2021 Author Report Share Posted July 16, 2021 After work today it was a little to hot outside and in the garage to finish up the transmission... I'm hoping it cools down and I can head out there later. So far my timeline to get this done is working out... I also picked up some new spark plugs from autozone just incase.... 2 Quote Link to comment
Crashtd420 Posted July 16, 2021 Author Report Share Posted July 16, 2021 Well I think my timeline just went to shit..... I'm fairly certain the 5th gear synchro is bad..... After getting it all together I was just shifting it to be sure all was good and sure enough every other time it wouldnt shift into 5th.... Is that a good sign the synchro is bad? There looks like there are flat spots on the bottom edge... shouldn't they all be sort of angled ..... Pictures are the best I could get... 1 Quote Link to comment
Crashtd420 Posted July 16, 2021 Author Report Share Posted July 16, 2021 Next up on the question list is will the 5th gear synchro from the z car 5spd 71b work in my short tail 71b? https://zcardepot.com/products/synchro-transmission-5th-gear-oem-240z-260z-280z 1 Quote Link to comment
Crashtd420 Posted July 16, 2021 Author Report Share Posted July 16, 2021 (edited) And last the dumb question..... Does the gear in the back come off if I remove that nut and bearing ? I'm just hoping I don't have to remove everything from the other end of that shaft...... I'm hoping that synchro can replace by just undoing what you see..... Edited July 16, 2021 by Crashtd420 1 Quote Link to comment
mainer311 Posted July 16, 2021 Report Share Posted July 16, 2021 Hmmm, they do look pretty flat, based on pictures of other ones. 2 Quote Link to comment
mainer311 Posted July 17, 2021 Report Share Posted July 17, 2021 (edited) Having a 5th synchro wear out seems really strange to me though. That would be the least likely one to wear out. Also, don’t forget: brass synchros use gear oil as friction modifiers to work correctly. That’s part of the reason that these transmissions call for GL4. GL5 oils have extra additives that may affect the rate at which the synchro accelerates. Edited July 17, 2021 by mainer311 2 Quote Link to comment
Crashtd420 Posted July 17, 2021 Author Report Share Posted July 17, 2021 10 minutes ago, mainer311 said: Having a 5th synchro wear out seems really strange to me though. That would be the least likely one to wear out. Also, don’t forget: brass synchros use gear oil as friction modifiers to work correctly. That’s part of the reason that these transmissions call for GL4. GL5 oils have extra additives that may affect the rate at which the synchro accelerates. Trust me it seems wierd to me too.... I have a feeling I'm chasing old issues .... so Im not sure what's up... And I am using gl4 fluid.... 1 Quote Link to comment
Crashtd420 Posted July 17, 2021 Author Report Share Posted July 17, 2021 Also I'm pretty sure the z car synchro will not work.... It looks like I can actually get what I need right from nissan.... I searched for an 85 nissan 720 with the 5spd ... pretty sure the stumpy with in the 84, 85,or 86.... I think it's only 2 year so I went with the 85 .... can any one verify that I'm right... I guess it called a baulk ring... 1 Quote Link to comment
datzenmike Posted July 17, 2021 Report Share Posted July 17, 2021 GL-4 has sulfur anti scuff additives, and just enough to do their job which is to bond to the surface molecules and form a harder surface against wear. GL-5 contains about 50% more sulfur anti scuff additives and the thicker hardened surface flakes off and is reformed, only to flake off again. Like below... Some pre '80s 5th synchro was steel. I can check the part numbers. Yes, Nissan calls it a balk ring. 1 Quote Link to comment
mainer311 Posted July 17, 2021 Report Share Posted July 17, 2021 Right, the only reason I mentioned gear oil at all was that, the synchro will behave differently when “dry” vs. when there’s oil sloshed everywhere. 1 Quote Link to comment
datzenmike Posted July 17, 2021 Report Share Posted July 17, 2021 You mentioned GL 4 and 5 not how much. GL5 will work fine in a transmission it's the brass that is at risk. The additives are for the gear face. Unfortunately the same additives are also bad for copper if the amount exceed about 4%. GL5 is about 6% or 50% more. Transition gears transmit power in the same plain. Differential gears power through a 90 degree turn and need more protection from scuffing. 1 Quote Link to comment
mainer311 Posted July 17, 2021 Report Share Posted July 17, 2021 How did you turn this into an oil discussion? 1 Quote Link to comment
Crashtd420 Posted July 17, 2021 Author Report Share Posted July 17, 2021 6 minutes ago, mainer311 said: How did you turn this into an oil discussion? Cause ratsun...... 2 Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.