Getting Ready for 915 Rebuild - It's my turn.

[arbita1]

Originally Posted by Christien

The rebuild docs I was following suggested 2nd and reverse - http://www.pelicanparts.com/MotorCity/marcesq3/TrannyRebuild.htm. I think it only matters in that you have to engage a forward gear plus reverse, so that the shaft won't turn.

That link is great. Why did I not find that before.

[arbita1]

Originally Posted by Peter Zimmermann

Matt: Are you using a manual? Which one?

I'm following the Bentley Manual.

[arbita1]

Originally Posted by Peter Zimmermann

Also, if you choose to make a tool, like the one pictured in another thread, to R&I the nut in the middle of the main shaft, be sure to look up on the Internet, or other sources, how much that tool will throw off the final install torque. The factory tool is a socket with a long tube that slides over the mainshaft, so the application of torque is true to the setting on your wrench.

CoolLX (Dom) turned me on to this link - http://www.belknaptools.com/extcalc.asp

Nice to keep on your desktop for reference.

[Peter Zimmermann]

Originally Posted by arbita1

CoolLX (Dom) turned me on to this link - http://www.belknaptools.com/extcalc.asp

Nice to keep on your desktop for reference.

Good site!

[Christien]

Originally Posted by arbita1

That link is great. Why did I not find that before.

That was one of my main resources, along with a few other threads on here. Also invaluable are the exploded parts diagrams - I printed off a spare copy and sacrificed a small binder to the tranny oil gods so I could keep it right in front of my on the workbench - indispensable, IMO.

Here are the links from my bookmarks folder:

http://www.pelicanparts.com/MotorCity/marcesq3/TrannyRebuild.htm
915 Rebuild - Overview (my tips!)
Can't Shift Into First
915 rebuild

That last one has an excellent description of the $%#%%#% detents - do NOT overlook this or you'll be dropping your engine/tranny again. I can't stress this enough - this MUST be done properly. Luckily I got it write, but Pelican is full of people finding out the hard way that they didn't. It's not at all difficult, you just have to make sure they're in the right place.

Unfortunately red-beard's page with his 901 tranny rebuild has gone AWOL. Even though it's a 901, there was still a ton of great info there, as most of it the same.

[arbita1]

Well, I'm going to use my 41mm socket that I got for the special tool which I'm going to have made.

I checked sears website, but all they have in the stores is a 12pt regular 36mm socket. Do you think I can use this? Or should I just order the 6pt impact 36mm socket and wait for it?

[arbita1]

I finally removed the nuts. The 27mm nut was so loose the only thing that was holding it on there was the roll pin. I took it off by hand. The 36mm nut I just blasted off with my impact wrench no problem. By the way, I locked the transmission in two gears.

I've disassembled the 5th/reverse gear stuff.

5th Gear - I'm not seeing anything except some wear on the synchro ring. I still have to disassemble it though.

Pete - I checked the inner surface of the 5th Gear where the needle bearing rolls and did not see any marks. It looks smooth.




The Hub that the slider sits on and bearings - I don't see any problems here.




Reverse and 5th Gear


Reverse Idler


5th/Reverse Slider



I know some of the pictures are a bit hard to see. I'll take better ones when I get a chance. All in all I'm not seeing any huge problems...however let me know where I need to look.



I removed the mid housing to expose the gear stacks. After a quick look there I didn't see anything very obvious. Just wear on the synchros. More to come as I disassemble that stuff.

Let me know if you see anything. Thanks.

[Peter Zimmermann]

Matt: Good news on 5th! The pictures are a bit fuzzy, you will have a very hard decision to make regarding the 5/R slider. I cant really see the 5 synchro, do you have a metric v. caliper that you can measure it with? I have a hunch, by the shine, that it is bad, which means, to guarantee good shifting, if you replace the 5 synchro you should also replace the 5 slider. Need a better picture of those slider teeth!

I should add that, if the inner teeth on your 5/R slider are crisp & sharp (no roll-over or spread on the tooth tips), if there is one place you can risk mating a used slider with a new synchro is 5th. All 5th gear shifting activity takes place over 50-60 mph, so you have that working in your favor. The used slider will still shave off some friction material on the new synchro ring, but that is not nearly as critical as putting a new synchro with a used slider on 1/2.

[Peter Zimmermann]

If you have not done this yet, prepare a place (I use clean pieces of cardboard) where you can lay out the various pieces in the exact order that they were removed. This is critical, because if you plan to reuse things like loose gear needle bearings/bushings, they should go back exactly the way that they came out. It does not matter when you clean them (now or during assembly) - your work area will smell better if you clean them during dis-assembly - but clean everything one piece at a time and then put them in order of removal.

[Christien]

Originally Posted by Peter Zimmermann

If you have not done this yet, prepare a place (I use clean pieces of cardboard) where you can lay out the various pieces in the exact order that they were removed. This is critical, because if you plan to reuse things like loose gear needle bearings/bushings, they should go back exactly the way that they came out. It does not matter when you clean them (now or during assembly) - your work area will smell better if you clean them during dis-assembly - but clean everything one piece at a time and then put them in order of removal.

This is really, really good advice! I laid out some newspaper (cardboard would be better) then laid out each piece in the exact order it came out in, then numbered each one sequentially. I wrote the number on the newspaper, wrapped a piece of painter's tape around each part and wrote the number on that, then took several pics of the entire setup (about 6 sq feet), and even took a video of myself picking up each part and turning it over in my hand while saying the assigned # and any inscribed serial # out loud and describing anything unusual that might help identify it. This video really helped because inevitably you'll find one piece un- or mis-labeled and out of order, and many of the pieces look very similar, so having the serial # noted, as well as any distinguishing features, was a useful backup. The whole process only took maybe 10 minutes - I just used the video function of our Canon point and shoot, then dumped them all the pics and video onto my computer for reassembly.

[arbita1]

Originally Posted by Christien

This is really, really good advice! I laid out some newspaper (cardboard would be better) then laid out each piece in the exact order it came out in, then numbered each one sequentially. I wrote the number on the newspaper, wrapped a piece of painter's tape around each part and wrote the number on that, then took several pics of the entire setup (about 6 sq feet), and even took a video of myself picking up each part and turning it over in my hand while saying the assigned # and any inscribed serial # out loud and describing anything unusual that might help identify it. This video really helped because inevitably you'll find one piece un- or mis-labeled and out of order, and many of the pieces look very similar, so having the serial # noted, as well as any distinguishing features, was a useful backup. The whole process only took maybe 10 minutes - I just used the video function of our Canon point and shoot, then dumped them all the pics and video onto my computer for reassembly.

All really good ideas. I get it...BE ORGANIZED!!!

With the 5th/Reverse Gear stuff, I got zip lock bags and basically organized it into groups (the sleeve stuff, 5th/reverse input shaft gear stuff, 5th/reverse pinion shaft gear stuff, and idler gear stuff).

The thing that I didn't think about is like Pete said...I need to put the needle bearings back the direction they were installed. I'm kind of screwed for that on the needle bearings I removed from 5th gear and reverse idler. I hope I can still reuse them since they look fine.

Moving forward...when I disassemble the input and pinion shafts, what I'm thinking of doing is taking two stainless steel poles (one for input and one for pinion shafts) that I have. As I take the part off the shaft, clean it, and then put it on the pole exactly as it should be installed. (I'll have to label the pole front and rear so I know.) But I think it will work and ensure to keep everything together.

[arbita1]

My next step is to remove the gear shafts.

The Bentley manual says to remove the input shaft leaving the 3/4th gear selector rod attached to the shaft. And to remove the output shaft leaving the 1/2 gear selector rod in the housing and disconnecting the fork from it.

However, I've seen others say not to loosen the forks from the selector rods and to leave them attached to the shafts when you remove them.

What should I do?

[Peter Zimmermann]

Originally Posted by arbita1

My next step is to remove the gear shafts.

The Bentley manual says to remove the input shaft leaving the 3/4th gear selector rod attached to the shaft. And to remove the output shaft leaving the 1/2 gear selector rod in the housing and disconnecting the fork from it.

However, I've seen others say not to loosen the forks from the selector rods and to leave them attached to the shafts when you remove them.

What should I do?

The book is your friend! You will want to learn how to adjust the shift forks during assembly (they might be wrong now), so you might as well do this deal the right way!
1. Remove 3/4 shift detent plug (the top one) and take out the spring & detent.
2. Remove bolt completely from 1/2 fork - it might help to use a large screwdriver and very gently spread the clamping part so that it will move on the shaft (this is a feel thing - do not do it unless you have to).
3. Remove the ten retaining plate nuts/washers - P/S & M/S.
4. Remove the input and pinion shafts complete with the 3/4 selector fork/rod, and the 1/2 selector fork.
5. Remove 1/2 detent plug, spring, detent and selector fork rod.
6. Use a micrometer and measure the metal shims that determine pinion depth.

Check the pinion shaft bearing race in the diff housing - is it loose?

[Christien]

The needle bearings have to go back in a certain way? Are you sure? I didn't pay any attention to them, and the sure look exactly the same one way or the other. I'm not 100% sure, but I sure didn't pay any attention to that when I reassembled and my tranny runs, turns and shifts fine. I've got 2-3000 kms on the rebuild, including a couple track days. The exploded parts diagram doesn't seem to indicate a differene, either, fwiw.

[Porsche_monkey]

Originally Posted by Christien

The needle bearings have to go back in a certain way? Are you sure?

It is 'preferred' that they go in the same way, so they 'match up' to their wear pattern. Ideally there is very little wear and it won't matter.

[arbita1]

Originally Posted by Peter Zimmermann

The book is your friend! You will want to learn how to adjust the shift forks during assembly (they might be wrong now), so you might as well do this deal the right way!
1. Remove 3/4 shift detent plug (the top one) and take out the spring & detent.
2. Remove bolt completely from 1/2 fork - it might help to use a large screwdriver and very gently spread the clamping part so that it will move on the shaft (this is a feel thing - do not do it unless you have to).
3. Remove the ten retaining plate nuts/washers - P/S & M/S.
4. Remove the input and pinion shafts complete with the 3/4 selector fork/rod, and the 1/2 selector fork.
5. Remove 1/2 detent plug, spring, detent and selector fork rod.
6. Use a micrometer and measure the metal shims that determine pinion depth.

Check the pinion shaft bearing race in the diff housing - is it loose?

Done. I have a whole bunch of pictures to upload later.

The shim depth is .015". There are three shims. What does that tell me?

I can remove the pinion shaft bearing race. What does that mean?

I want to start opening up these gears. What do I use to remove the circlip?

[coollx]

Matt,

Assuming the area of the shims surrounding where the pinion and input shafts go thru them isn't beat up or curled over, I think you just need to put them aside for now. You'll re-install them upon reassembly assuming you don't change the pinion bearing.

If you do you do a search regarding the loose pinion race you'll find a lot of discussion about it. Depending on how loose it is some solutions are very expensive. My race was a bit loose so I took the approach of using loctite bearing retainer which is supposed to be designed for this kind of problem. Some people think it won't last others think it may. I decided to try it.

As far as the circlips, there's a special tool for removing those that's not too expensive.

Dom

[Christien]

Originally Posted by coollx

As far as the circlips, there's a special tool for removing those that's not too expensive.

Dom

Yep. Go to your local hardware store and just look/ask for circlip pliers. Easy to find, and less than $10. I can't see how you'd get those buggers open without them - it's hard enough with the right tool, trying to do without would be impossible. When you finally get them open, take a very clear picture of each before you touch a thing, to make sure you get the orientation of the brake band, energizer and stop blocks right when you put them back together. Of course, if you forget to take a pic, I've got some. Here's first gear, for example. Note the relation of everything to the "C" band. That's how I worked.

[arbita1]

Here are my pictures for review:

Input and Output Shafts:



Better pictures of the the 5th/Reverse slider teeth:



5th Gear - The only think I see is some wear on the synchro. Teeth look fine. It measured according to spec.




First Gear -



Some wear on the synchro -


Teeth look worn as well -


1st/2nd Gear Slider worn teeth -

[arbita1]

Broken corner on 1st/2nd Gear Slider Hub -



2nd Gear -



Synchro and teeth wear -



3rd and 4th gears - no problems here I think


Output Shaft - looks fine


Input Shaft close up of 3rd and 4th gear teeth. I have to wait to disassemble this one until I get my "special" tool. But teeth don't look bad. Maybe just synchros.