zKars

FS5W71B Rebuild Thread - Tips tricks and discoveries!

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    10 hours ago, zKars said:

    Another idea to getting the bearing to center itself when getting started, is to un-clamp the housing from the base so when you push the bearing through, the whole thing can easily move around, Go in and out a few times until it settles, then carefully and evenly tighten down the toe clamps to lock the housing to the mill table.

    I'm not sure if it would be more accurate than using a co-ax, but that technique works too. The most important thing is to lock the X and Y directions down after you get it positioned properly. I took another look at your pics and I don't see gib lock screws. Do you not have that feature?

    PITA, but you could always just tighten up the gib adjustment screws during the boring operation. Hate to do that though...

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    No gib locks. Something I do miss. I put duct tape over the gap where the scales and the indicator on the adjuster wheels meet to prevent rotation of the handles if I run into one. Hardly ideal. I can come up something better.

     

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    Problem is that tape on the handwheels prevents changes from accidental bumpage but doesn't do anything about the play in the leadscrew threads. Even with the handwheels stationary, the table can still move in X or Y by the amount of backlash in the leadscrews. That's where gib locks would come in. They lock the table regardless of how much backlash there is in the screws.

    I've added gib locks to a couple machines in my past that didn't have any. Looks like you have plenty of room to add them. Next time you have the whole table off the machine?   LOL

    In the meantime, If you're not chattering and the ease of cut seems fine, lets hope your OK without any locks.

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    The Doctor is now in. Finally.

    Today’s news is about rebuild kit pricing. I have actually found a cheaper source for the Bk104WS kit. Rockauto!

    I found the kit when looking for 200sx parts (don’t ask, it’s what’s been keeping me ‘occupied lately) ZMBK104WS  is the part number. Was looking under 1980 200sx. 

    $87.37 CAD  ($66.76 USD) and about $25 CAD shipping. Expecting to be buying cheaper quality parts, I waited until they arrived. Well they are here.

    Everything in the box appears to be identical to the other kits from drivetrain.com and transpartsdistributors.com. Okay, one bearing is a Koyo rather than a Nachi. Everything else appears identical. Got here faster than the other kits too. One week vs two.

    Now if I can just store away of a few thousand 510 parts that just showed up, MAYBE I can actually rebuild one of these dang transmissions!  Arggghhhhhh!!!!    

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    Edited by zKars
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    1 hour ago, zKars said:

    Now if I can just store away of a few thousand 510 parts that just showed up, MAYBE I can actually rebuild one of these dang transmissions!  Arggghhhhhh!!!!    

    Damnit Jim, I'm buying as fast as I can.

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    Well shocking but true, I actually assembled ONE whole transmission over the last couple of days with new bearings and syncro's.

    It is also the one I chose to do the hybrid mix of close ratio 5 speed gears (4th gear pair) with all the other 720 truck transmission gears to give me a .65 OD, while retaining ratio's for most of the other gears that still quite reasonable. See the posts a couple of pages back with the spread sheet. Anyway, the 4 gear main and Counter shaft gears and associated bits went right on with a hitch into the other wise truck destined parts. 

    I was able to put the main and counter gear pair sets in and get the shafts pressed, well actually pulled, into the intermediate plate bears using the threaded nuts that are one both shafts, with a tube of just the right length. 3.375" long (1.25 ID tubing) works just fine for both. I had all the gears on both shafts, didn't do the front set separately like the FSM suggests, way too much work. Just takes a tiny bit of juggling of both shafts with one hand has you get the two shafts started in the bearings with a soft tap of a rubber mallet.

    Then tighten the two nuts (the big 1-1/2" one and the 27 mm smaller counter shaft) one, then the other to draw the shafts in sequentially until seated.

    maincounter_spacerNut.JPG

    Since the two shaft gear sets are mated yet, you can't throw both 1/2 and 3/4 into gear to lock the shaft, so you have to use an old drive shaft yoke and some pipe or whatever to lock the main shaft. 

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    There are plenty of "Special tools" in my arsenal now, and having old driveshafts to harvest bits from is critical. As is various lengths of pipe in handy diameters. I'll make a post later that shows all my "SFT's" as I call them (special field tools) and what I used them for. 

     

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    There is always at least one really grumpy part of every job, like spindle pins, and for this job, its a very tight bearing sleeve that lives under the 5th gear cluster.

    It is pretty easy to pull off, you use a bearing splitter in front of the 5th gear syncro hub , and a set of 18" rods to draw it all forward until the sleeve is over the threads, then its free.

    sleev.JPG

    Back on is more grumpy. 

    It sits just ahead of the threads on the main shaft for that big nut, so if you can get it far enough on to start the nut, then just tighten the nut down to drive the sleeve to the end. Well, not quite, the threads run out just before you get to the end. You can use the thick washer that goes on at this spot (the one with the ball or little dowel that sits in a groove to prevent it spinning) to add a bit of thickness to finish driving it all the way with the nut back on.

    I build a pipe with a hole in the end just the right diameter to hit the end of the sleeve. It slips over shaft that sits against the sleeve and lets me beat it in place with a mallet. You will need something like this if you can't get it on far enough to see threads that then allow you to use the nut to finish the job.

    This is not the pipe tool thing I built, but it is the world's deepest 38mm 1/2" drive socket. Probably about 18" long. I built to let me do and undo the big nut easily. Bought a 1-1/2 socket, cut it so just the hex was left, then welded it a 1-1/4 black iron pipe (standard hardware store gas or water line)  and then welded the back half of a 1/2 drive socket to the other end.

    bitnutTorqueTool.JPG

     

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    Pretty ingenious.  Easier than drilling, for sure.

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    Did the final assembly this morning, went pretty smooth. Have to work on my technique to get the tail housing on and the shift forks aligned at the same time. Good trick here is to take the reverse lock out assembly out and look in there with a flashlight. It’s in line with the shift forks and the tip of the shifter rod, so you don’t have to guess much.  

    The other part of this is to make sure you have the through/retaining pin that is just ahead of the shifter in place, and the detent/spring thingy with the 19mm hex cap by the shifter in place as well. This keeps the shifter “kept” within the correct confines of its movement while you get the shift fork finger in “just” the right spot.

    My fancy 62mm front counter bearing “schnicked” perfectly into the front cover. The C type front cover went over it without issue, needed 4mm of shim.

    I can happily select all 6 gears. 

    There are no extra parts laying around. 

    AND I tried the reverse switch function with my slimmed down shift rod. It works! Only comes on in reverse. Bought it a new switch as well.

    I stripped the cases and repainted with 2k epoxy primer (Eastwood stuff in a can) then VHT aluminum color caliper paint. 

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    So I've been back in the transmission business again last couple of days. Mostly trying to assemble all the carcasses I have laying around here with new bearings and syncro's to get at least the clusters together.

    The first I one I completed today is the one that had the very very failed counter shaft intermediate bearing. About the only thing I found that was also "Wrong" with it was the needle shell bearing under the 1st gear on the main shaft that was very very loose. I went to put it back on, and it was rattly loose. Couldn't see any damage, just worn I guess, so grabbed one of the old ones from another trans and it slipped on nice and tight. Didn't buy many new spares.

    There was also a strange bit of damage I can't explain. You know that "Insert Retainer" on the main shaft on the back of the intermediate plate? The thing with the three fingers? Always makes me think it's home made the way it looks and fits. Three little tabs of metal welded onto a tube. Locks the 5th gear syncro gear to the shaft. Anyway.

    insertRetainer.png

    Yeah, well one on fingers was bent. Toward the back. Couldn't make the shifting insert fit back in at that spot. Must have been an errant bearing cage piece got caught in there somewhere when the bearing just below it went KABLOOOWEEEE. It's quite buried, not sticking out or anything. Glad I caught it.

    Then moved on tranny #2. This was the one with worn out 1/2 shift fork. 

    Now old bright boy here stole its 4th gear set to build up that truck 5 sp I have with the custom ratio's I detailed earlier, that give me the .68 OD. Wonderful. Unfortunately, if I put the the truck 4th gear set in this tranny, I get stupid ratios, like a 0.9 OD. So now I'm kinda stuck.

    So now the interesting part. Anyone have a busted 5 speed they kept around for parts, that they are willing to maybe give up their counter gear cluster and the matching main input shaft nose part with the 4th gear on it? Otherwise I have a really nice Close ratio 5 speed without 4 gear..... or any gear actually....

    Along these lines, anyone ever see a listing that gives the tooth count of the counter cluster and main shaft gears for the common FS5*71 trans? There are a million places that list the final drive ratios, but not the internal tooth counts. I know the tooth count for the late ZX ones, (got lots of those open), but not the 79-80 and the earlier 77-78 280z. Need to know what their 4th gear tooth counts are to see what the final ratio's compute out to, should I procure some parts from those types...

     

     

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    12 hours ago, zKars said:

    anyone ever see a listing that gives the tooth count of the counter cluster and main shaft gears for the common FS5*71 trans?

    Need to know what their 4th gear tooth counts are to see what the final ratio's compute out to, should I procure some parts from those types...

    I've got one listing sheet that I "found on the internet" somewhere, but I don't like the numbers. Doesn't look right to me so I'm reluctant to even post it.

    Got a question though while I'm here... You said you want to know the "4th gear tooth counts". My understanding is that 4th gear doesn't HAVE a count. I've never been inside a Z tranny, but with the others I've been inside, it would be straight through with the input shaft locked to the output shaft. All the counter gears just coasting along for the ride. None of the intermediate gear counts matter at all.

    Is the Z tranny not like that in 4th?

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    Common misconception I believe. All the trans I've looked at have a 4th gear pair, just like any other gear. The only thing that is 'special' about the 4th gear set is that its ratio acts as a modifier to all the other gear set raw tooth pair ratios, since the drive power goes through the 4th gear set first, for all gears, all the time. It's only a matter of which of the lock up hubs (on each gear set) is engaged to the main shaft that determines the power path. The counter shaft is engaged and spinning all the time, and since all if its gears are engaged to the gears on the main shaft, THEY are spinning all the time too (except 5th), though they may all be free from the main shaft (if in neutral) or any one of them is engaged (and only one!), which then drives the main shaft at that gears ratio.   

    The confusion comes because for 4th, it's special because when its main shaft gear is locked to the mainshaft, power goes straight through the main shaft WITHOUT first going down to the counter shaft (at the 4th gear ratio) then back up to the main shaft (through that gear's ratio) through the selected gear set. That's why its ratio is automatically 1:1 no matter what the 4th gear tooth ratio is.

    Hope that's clear as 25 year old GL-4 fluid.....

    Edited by zKars
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    10 hours ago, zKars said:

    Common misconception I believe. All the trans I've looked at have a 4th gear pair, just like any other gear. The only thing that is 'special' about the 4th gear set is that its ratio acts as a modifier to all the other gear set raw tooth pair ratios, since the drive power goes through the 4th gear set first

    I don't believe I'm misconceived or confused. I've not been inside a Z tranny, but your description of operation is exactly how other transmissions I have been inside have worked.

    I guess my only confusion is why are you calling it a 4th gear pair? Does Nissan refer to that main front driving gear as the "4th gear"?

    And my point is that there is no 4th gear pair because when you're in 4th no power is being put through any gears when you're in 4th gear. In fact, you could grind all the teeth off that front gear completely and 4th gear would still work. It doesn't need a pair.

    it's just semantics really. You clearly know exactly what's going on inside. I'm just protesting the implication of the naming convention I guess.  LOL

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    I just took a quick look at the parts breakdown and they call that front gear the "Main Drive Gear, and it's mate is "The Counter Drive Gear".

    6 GEAR-MAIN DRIVE
    GEAR-COUNTER DRIVE

    The do, however, number the remaining gears:
    19 ASSY-GEAR,1ST MAIN S
    20 ASSY-GEAR,2ND MAIN S
    22 ASSY-GEAR,3RD MAIN S

    I probably should have checked first.   :beer:

     

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    Oh, and by the way. Just want to let you know that I do totally get it.

    If you slide the synchronizer onto "the first gear" to lock it to the main shaft for 1st, and
    you slide the synchro onto "the second gear" for 2nd, and
    you slide the synchro onto "the third gear" for 3rd...

    Then what would you call the gear that gets locked to the main shaft by the synchro when you're in fourth?

    I'm gonna stop talking about it now.   LOL 

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    Sorry... I'm baaaaaaack. But this time it's actually with some useful input!

    I just snipped this from the 78 FSM (MT-18). Not sure if the other years contained this info (assuming not, or you would have simply found it and not asked in the first place), but this should answer most questions about the gear tooth counts:
    teeth counts from 78 fsm.jpg

     

    In 80 they they started messing around with the ratios, but this should hold for everything up to and including 79.

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    Well now other than the need for a set of input shaft 4th gear set, I now need a main shaft too. I took apart the last of my good close ratio 5 speeds, in fact the one I’ve had rebuilt back 2008-9 and have had in my old 73 Z until its sale, and more lately in my 510. 

    It was noisy in several gears, most noticeably in 3rd and 5th, and when you’re at a stop, foot off the clutch, you get a good rattly bearing noise. Other than that it worked perfectly.

    Upon disassembly, I noticed really only one problem. The forward end of the main shaft where the little needle bearing seats inside the back end of input shaft, is all scored up. And not evenly. When I put the shaft in the lathe, it seems to have about 5 thou run out. The needle bearing is quite loose on the shaft over the damaged area.

    These videos show the problem.  Dang stroker torque bent the dang thing.... 

    The 6 bearings look just fine, and spin silently. 

    Edited by zKars
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    This transmission also has a leaking shifter shaft. The area where the shifter plugs in was always full of GL4 and causing a dribble on the floor. So I had a chance to try both my latest discoveries about removing that wedge pin to take the shifter rod out to change that little seal, AND how to remove and replace that little buried seal.

    Success on both cases. The air hammer gun popped the wedge pin out in 30 milliseconds again, and this time without any heat. 

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    I bought a set of really long seal picks, and that’s all it took to get that little seal out. You just need to put the tip of the 90 deg pick under the seal and YANK. 

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    And then to put it back in, I had no choice but to spend time on the lathe making a seal pusher-in-ner thingy. What other option would there be? Guess you could whack it with a 3/4” punch tip, but what fun is that.

    The specs are 13.9 OD on the seal ID part, 13mm long, then a section of 19.8 mm again 13 long. The nose guides into the hole, and the OD is just a tad smaller then the seal to push it home. The place it sits is about 1.5 times deeper than the width of the seal, so make sure it goes all the way to the bottom. 

    I have no clue why the old seal leaked other than it was pretty hard and fit pretty loosely on the shaft. It was not damaged.

    Oh yeah, remember to put the dang thing in the right way. Oil is in FRONT of it, so when you insert it, with the open side to the back, against the insert tool. 

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    And finally The o-ring on the outside end of the shifter rod body. Somewhere it was noted that it’s the same as the one on the outside of the speedo cog. That is in fact true. The groove ID is 24mm, and it’s 2mm deep, and just over 3 mm wide. The o-rings I pulled off were 24mm ID by 2.4mm cross section. And magically a 15/16 or 7/8 x 3/32 o-ring fits just fine. The cross section is nearly identical and tiny stretch from 7/8 to 24mm does not deform the ring. I tested the fit into the speedo cog hole and they all felt identical in drag and insertion ease.

     McMaster Carr has a 24.3 x 2.4mm oring too if you can’t get a Nissan one and you want a really close equivalent. 

    B74D0709-565A-4B69-9E09-F6D6503C16FC.png

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    Descriptions of how to replace those two seals are definitely an addition to the body of knowledge.  Many people over the years have commented about the puddle of oil in the shifter hole.  I've given bad advice about it in the past.  @FastWoman I'm not sure she still has her car but she had the leaky seals way back when.

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    Nobody caught my booboo on the little seal. I installed it backwards. The fluid your trying to keep out should be on the open U shaped side of the seal, you would then see the flat closed side looking down into the shifter housing. 

    I had just done the front cover plate seal, which you install with the open end of the seal outward, and my head for what ever reason said “ this seal too”. Not.... 

    Edited by zKars

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