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CRS

5 speed swap

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Hello all,

Getting ready to take the plunge and swap the 4 speed trans and diff from an '83 280zx non-turbo to my '75 280z.

From everything I've read this is the desirable swap for the stock 280z. Better than the late 70's 5 speed setup.

Setup was removed from a running car with 100k+ miles. 

Differential is the R200 with 3.90 ratio.

Any things I should watch out for with the swap?

I plan on changing seals in the trans and diff before installation.

Should I completely rebuild the trans while out of the car, eg syncros or gears?

For the trans tear down is the process straight forward any unusual things to be careful with?

I have rebuilt many engines, trans both manual and auto for GM's (and other domestics) but this will be my first import.

Thanks!

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I would open it up and inspect for your own peace of mind. Don't be surprised if the rev idler has some chips. You may want to replace the front countershaft bearing if it sounds the least bit bad. Its a little bit on the small side and is very easy to get at. You can take a look at the brass and see if you still have decent gaps. At 100k I would think its going to be ok unless it was abused.

new seals of course and look at the brass tail shaft bushing. If it looks scored up you may want to replace it while the tail shaft housing it out. there is a company that makes the "correct" bush, its longer than the ones most often listed (they are shorter than OE if that matters).

careful not to break the oil gutter its right next to the 1st gear on the ouput shaft, easy to knock off when separating the front section from the adaptor plate. If you do break it replace, as it supples the oil to the tail shaft bushing. On the one I got, it was broken (stuck to the magnet) before I opened up the trans, and the tail shaft bushing was toast (no oil).

you may want to R&R the various o rings for the shifter if you have oil accumulating where the shifter fits into the striker bar. there are 3 IIRC that need to be replaced. And finally make sure you have the right pinion for the 390 gear. you can replace the o rings on that as well to prevent oil loss at the speedo cable.

with the 390 its going to give up some of its hiway cruzing but will be more fun since you can use the 5th more often. On mine (3.54) I don't go into 5th until I am over 70, below that and its bogging (80 is about 3k, 70 2.7k I think).

 

Edited by Dave WM

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the oil gutter is on the same side as the reverse lockout, so when separating the front section, try to make sure when pulling apart that side gets preference to any sideways movement. you want to make sure the front does not come inwards and break of the gutter.

there is a good video on rebuild look up villageland on you tube.

 

Edited by Dave WM

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Thanks Dave for the feedback. 

I saw a video of a broken oil gutter and hopefully mine is in tact. I don't think this trans has been taken apart. 

I do have the leaks by the shifter you mentioned. I've seen lots for the front and rear seals as well as the gasket in the middle. Have also seen the master rebuild with bearings and seals. Not sure if I've seen the 3 IIRC ones you mention. Do have a recommendation on which ones to buy?

 

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I would just buy seals, no reason to buy the brass if yours is ok. Pretty sure you can get the OE seals from Nissan. You will need to spend some time going over the drawings to get the right part numbers. You want the front and rear as well as the paper gasket for the front cover. the o rings for the shifter you need to just look up, same with pinion. I don't have those handy. I would save my money on the kits you see on ebay. just get OE stuff that you need. No gasket in the middle (adapter plate) just reg sealant on both sides. One thing to watch out for, IF you decide to take the main nut off the output shaft its most likely rev thread (CW to loosen), but I am not positive if that is the case for EVERY EARLY 81 trans. IF you have the CCW to loosen you may find its NLA, so you would need to reuse it. They have a punch to lock them in place. I wish I could tell you how to know for sure if its reversed or not. The only reason I even think there is an issue is while watching the video I seem to see village land guy remove that one by turning CCW.

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I'll start the teardown later this week and post my findings.

I'll also post the rotation of the main nut; left or right handed thread.

Hopefully just the seals/o-rings need to be replaced. I didn't hear any noise or feel any hard spots when turning by hand.

Of course this is low revs compared to the engine output.

Thanks again.

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A word of caution if you open up the trans....it is tricky to get the shift fork rods and shifter mechanism to mate up properly.  I purchased a used late seventies 5 speed off Ebay (wide ratio due to my automatic differential gearing) and upon receipt I could not move the shifter...uh oh.  I opened up the case, replaced the seals and everything seemed to be fine inside the trans.  Upon reassembly, I apparently made the same mistake and could not shift gears.  Opened it up again and made sure I got the shift rods and shifter lever to mate up properly and all was well.  It was a frustrating.

Otherwise, good luck...should be straight forward swap.

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Thanks. Good to know. Right now the trans shifts into the 5 forward and reverse. If it doesn't after I open I'll know why.

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Opened the trans today. Oil gutter still in tact. Small amount of metal on the magnetic. Looks like it's from the reverse gear. Also looks like the tail housing brass is worn.

See pics.

Also how do you remove the pin that hold the selector fork on? I removed the nut and washers but the pin won't move. Even tried a bit of force. Any suggestions? 

20180407_211215.jpg

20180407_211134.jpg

20180407_211124.jpg

20180407_211100.jpg

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Remove the spring and ball out of the hole with a magnet.

Edited by munters

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Seems like it's common for the speedo connection to leak after swapping the transmissions.  Mine did and after reading around on here a lot of others had the same problem.  The seal gets worn in then after you change the position for the new 5 speed it begins to leak.  Here's the part number for the oil seal.

Mine wouldn't stay in 5th or reverse with the S shaped shift rod that I kept from the 240's 4 speed.  Ended up grinding some off the snout and now all is good.

Edited by siteunseen

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Hello. 

Thanks, I found the o-ring parts on a Nissan site. Yes a very common leak on these trans.

@munters is there a ball and spring on the fork in the picture? I know the other selector rods have them. This looks like a pin with threads to hold it in place.

20180407_211215.jpg

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7 minutes ago, CRS said:

is there a ball and spring on the fork in the picture? I know the other selector rods have them. This looks like a pin with threads to hold it in place.

I remember trying to figure out that puzzle when I took a 5 speed apart.  I wasn't rebuilding, just tearing a broken one down.  I think that I used a long drift through that opening in the case.  There might have been some channel-locks involved also to squeeze the pin out.  It's wedge-shaped on the end, like the lock bolt for the spindle pin.  Apparently, it's supposed to be easy to get out.

image.png

image.png

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Thanks. That makes sense. It will just need more force when I remove. I was worried about breaking it the first time. 

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Just remembered also that I placed something under the fork, inside the case, before hitting it with the drift.  I think that was the hardest part, getting it supported.

Edited by Zed Head

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Right, I had something under it yesterday but I just didn't hit the pin hard enough. Hopefully this will keep the arm from bending. 

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Success. Had to hit the pin several times to break the tapper. Though it might break but it came out.

Now I can replace the o-ring on the rod and the seal the rod slides into. I think this was the worse leak in the top.

20180408_133000.jpg

20180408_133056.jpg

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Good job...I could not get that pin out and did not have the hole in my case to use a drift.   My input shaft is noisy while in neutral with clutch engage, so eventually I will send to trans specialist and get a full rebuild..including the shift rod seals.

 

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yep that pin was tricky, did what ZH said, use the reverse lockout opening to access. Hard to say if its worth it to remove the brass bush. I did try to find the long one. there is ONE suppler that had it, I cant recall. It was a bit pricy like 20 plus 9 more for delivery to the east coast. You also have to be careful to line up the opening in it with the oil channel. If the input shaft of the drive shaft feels good (no slop) I would think its fine. Don't worry about that reverse gear idler, you will not notice it in use. If you look at the spacing of the brass rings and how much gap there is left when pushed up tight on the cone, you can get a ruff idea on the condition. The right way to do it would of be to disassemble it and look for wear (should have visable grooves and the brass should firmly grasp the cone). But prob the best thing to do would be fix the leaks, replace the front counter shaft and call it done.  IF you assemble it and have some issues then pull it for a complete rebuild. I know it sounds logical to rebuild before installing but my bet is if the gears look good and only a little metal was found tin the magnet then its likely going to be fine. One word of caution on replacing the front counter shaft bearing. Use the heat the bear and go for a drop on fit, you will Ideally you can support the back side of the counter shaft and use a press to push on the inner race to seat it. If you resort to banging in on with a hammer (like village land shows IIRC) just be prepared to tap the counter shaft back forward. You will know its right by observing the gear mesh. The counter shaft moves pretty easy in the main bearing on the adapter plate. even light tapping will move it around. I think this is why the shims are so important on the front of the counter shaft bearing (don't lose that by the way, it tends to stick to the inside of the input shaft housing). I presume the CS wants to push forward due to the cut of the gears, the shim limits this forward movement to locate precisely the gears.

Edited by Dave WM

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1 hour ago, Dave WM said:

yep that pin was tricky, did what ZH said, use the reverse lockout opening to access. Hard to say if its worth it to remove the brass bush. I did try to find the long one. there is ONE suppler that had it, I cant recall. It was a bit pricy like 20 plus 9 more for delivery to the east coast. You also have to be careful to line up the opening in it with the oil channel. If the input shaft of the drive shaft feels good (no slop) I would think its fine. Don't worry about that reverse gear idler, you will not notice it in use. If you look at the spacing of the brass rings and how much gap there is left when pushed up tight on the cone, you can get a ruff idea on the condition. The right way to do it would of be to disassemble it and look for wear (should have visable grooves and the brass should firmly grasp the cone). But prob the best thing to do would be fix the leaks, replace the front counter shaft and call it done.  IF you assemble it and have some issues then pull it for a complete rebuild. I know it sounds logical to rebuild before installing but my bet is if the gears look good and only a little metal was found tin the magnet then its likely going to be fine. One word of caution on replacing the front counter shaft bearing. Use the heat the bear and go for a drop on fit, you will Ideally you can support the back side of the counter shaft and use a press to push on the inner race to seat it. If you resort to banging in on with a hammer (like village land shows IIRC) just be prepared to tap the counter shaft back forward. You will know its right by observing the gear mesh. The counter shaft moves pretty easy in the main bearing on the adapter plate. even light tapping will move it around. I think this is why the shims are so important on the front of the counter shaft bearing (don't lose that by the way, it tends to stick to the inside of the input shaft housing). I presume the CS wants to push forward due to the cut of the gears, the shim limits this forward movement to locate precisely the gears.

 

Edited by CRS

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Right, had to go through the opening in the case to drive the pin out.  I think I will just leave the reverse gear as is, not worth the effort.

I think I found the correct brass for the tail shaft housing. It just looks worn, can't recall how much play.

I'll look at the counter shaft bearing. I recall the shim at the front of the housing. It fell down once I pulled the cover off.

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Thanks. The one from the link doesn't match the style I have. I have 2 holes were this one only has one. The spiral groove seems to be the same.

I rotated and rocked the bearings and they seem to be in good shape. Will probably just stay with them.

I may just install the new seals, o-rings, etc and see how it goes.

I plan on installing a new clutch kit, slave cylinder, hose and flywheel while there.

 

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that's prob the best bet. On mine the OE fly was in good shape, I just scuffed it up with some sandpaper. I did not see any signs of chatter or scoring. I tried to get a new 225mm flywheel but did not have one at the local autoparts place. Make sure you pressure plate fits (bolt pattern) before you get under the car and find out its not right.

Edited by Dave WM

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fyi, I checked, my old one had two holes (ovals actually) where as the omega machine had one. IIRC, one of the hole lines up with the oil supply channel, the other hole was just blocked off by the housing. I of course made sure the single hole on the replacement bush was lined up with the channel. I guess the grooves in the bush are supposed to transport the oil to the rest of the bushing.

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