FS5W71B Rebuild Thread - Tips tricks and discoveries!

[Zed Head]

And side forces on the bearing will cause more movement.  The indicator probe isn't putting much push on the outer race.

Stuff like this is why good machinists make good money and bad ones go out of business.

No offense intended, just trying to point out how important the numbers are and how difficult it can be to get them, then use them.

Edited December 31, 2019 by Zed Head

[zKars]

Making it’s first hole and plenty of chips in a piece of scrap. Starting with a 57mm hole.

Slowly sneaking up on the correct size by tapping the insert over, then drilling again to enlarge. Test fitting the 62mm bearing at each stage. 

 

Edited January 1, 2020 by zKars

[zKars]

Success! Only took 5 tweaks of the cutter position to achieve hole size Nirvana. It has that nice rough scrapie sound as the bearing easily pushes through the hole with the drill quill. Such as easy test. Drill through, slap the 62mm bearing on the bottom, and push it through the hole to see how it fits. You know immediately if its the right size or not.

Since I was starting with a 57ish mm hole drilled with my 2.25" Forstner bit, I couldn't use my 56mm bearing as the pilot. I got a chance to use my fancy new rotating center finder thingy, or Coax if you want to picky.... Dang that worked slick. Got the needle to quiver inside of 1 division on the dial indicator, then swapped to the mandrel, drilled the new 62mm hole.

To test how close to center I was, I initially set the boring bar to just a bit larger than the initial hole I had indicated from, and drilled half way down, leaving a step. I then inspected it visually all the way around to see if the step width stayed consistent to test concentrical-y-ness. I can not tell the difference from one side or the other. Seems just fine to me.

Next thing up is to actually put a 56mm bearing on the mandrel and drill out a test 4 speed housing and see it the hole ends up in the right place.

I also did a thing. To help me check if my holes are the right size, and if the new 62mm hole is in the right place, I figured there was nothing better than using a real C type front bearing housing for comparison. Turns out the C type I took apart has a busted bell housing that was previously patched with epoxy and fiberglass cloth, so there was no way I would ever use it again, so.....

There you go. Now I have a nice easy to handle and measure, C bearing / shift rod plate. Easy to measure the thickness variations, size of the 16mm shift hole (a 5/8 bit is going to be SO close. 0.630 vs 0.625. The rod is very close to 16mm, so a 5/8 hole will need just a tad of honing to make it work. Steve talks about this same problem here http://zhome.com/ZCMnL/tech/240SX5spd/Transmission2.htm

"but later had to ream the hole slightly larger myself with an adjustable reamer because it was too tight"

Dollars to donuts the machinist used a 5/8 bit....

I could pony up and learn about reaming now....

 

62mm_TestFit.mp4

 

 

Edited January 1, 2020 by zKars

[zKars]

Well, the first real 62mm hole in a real 4 speed housing has been bored. The bearing fit is a nice tap-in, just like the Stock C type hole, and the location is as perfect as close as I can measure. There is exactly 4mm between the two bores.  

One slight issue that may lead me to use the coax indicator instead of the pilot bearing for centering. Maybe. This time, when you first move the bearing up/down into the 56mm hole with the quill and start moving the table X/Y to get the bearing to slide nice and evenly in the hole, there is quite a bit of X/Y motion possible with the bearing still passing through. You have to listen very carefully to get the least drag noise, and to get the minimum quill effort. This is not slop between the bearing and hole, or bearing on the mandrel, this is the table motion deflecting the casting on its plywood base I suppose. It’s pretty easy to get close. I drilled the hole, it worked out fine, BUT there is a clue that I was not perfectly centered.

The bearing stays engaged with the old 56 mm hole until you are about 75% of the way through, then the bearing pops out the bottom, and is no longer supporting the quill location. At that moment, you can see a mark around the circumference of the bore. It’s tiny, I can’t feel it with my fingernail, but I can see it. So the bearing was not dead center to start with. Maybe its just a remnant of the motion induced when the bearing left the bore.

Oh so close. 

Measuring the 4mm space between the two bores is tricky. My caliper is too long. 
So I set my micrometer to 4mm. You can’t measure that thickness with two curving walls, so it’s resting on top. 

I need to make a 4mm gap gauge of some type.

This is a 4mm drill bit. Parallax is a bitch.... picture is not perfect. 

This is the 62mm bearing in place.

 

Edited January 1, 2020 by zKars

[Captain Obvious]

Nice work. Some input below:

16 hours ago, zKars said:

One slight issue that may lead me to use the coax indicator instead of the pilot bearing for centering. Maybe. This time, when you first move the bearing up/down into the 56mm hole with the quill and start moving the table X/Y to get the bearing to slide nice and evenly in the hole, there is quite a bit of X/Y motion possible with the bearing still passing through.

I need to make a 4mm gap gauge of some type.

There is play in the spindle bearings, there is play in the feed leadscrews, and once you start putting forces on stuff, everything bends and flexes and squirms. Even steel. That's why it's all really "made of rubber". You're pushing a hardened bearing shell with rounded corners into a hole. The rest of the system will squirm around to make it fit when you start putting pressure on it.

Best thing you could do would be to use the co-ax to indicate the center of the original hole and then lock down both the X and Y travel leadscrews (I'm assuming you have gib lock screws on those?) before you start the boring operation.

And I know you can't do this because of the set-up, but the less you have the spindle sticking out below the head, the better. The more it sticks out, the flimsier it gets.

About that 4mm distance measurement of the wall thickness... That's not what's really important. What you really care about is that the center-line of the two shafts are in the right locations. I know you're interpolating that using the resultant wall thickness, but of course it would be better to measure the centers of the holes. Also, of course, if you get the new hole in the exact same center as the original smaller hole, you don't even have to measure it. You'll be spot on.   

[zKars]

All great feedback, thanks. Yes the 4mm measurement isn’t the be all and end all tell tail of your success, correct initial centering in the existing hole is your best defence.

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, rather than using the X/Y adjusters with all the above mentioned rubber play in everything. 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. 

Maybe I need to get some good precision DRO X/Y readout on the table so I can accurately locate the center of both holes then compute if the distance is close enough to 71mm before AND after the hole is enlarged. 

[Captain Obvious]

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...

[zKars]

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.

 

[Captain Obvious]

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?   

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

[zKars]

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!!!!    

Edited January 22, 2020 by zKars

[grannyknot]

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.

[zKars]

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.

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. 

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.