Removal and rebuild of the 8.875" 12 bolt.

cdnpont · Canadian Poncho Superstar!

Removal and rebuild of the 8.875" 12 bolt.

cdnpont · Canadian Poncho Superstar!

The arms that will be going in,

Spohn, custom with Del-Sphere roto joints in the front, poly rear.

They are a thing of beauty,

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seventy2plus2 · Canadian Poncho Superstar!

You're taking the diff out, and today I was putting the diff into the chassis I'm doing.

cdnpont · Canadian Poncho Superstar!

I hope to soon be doing the same as you Clint!

Did you rebuild yourself!

Any shots?

seventy2plus2 · Canadian Poncho Superstar!

cdnpont wrote:
I hope to soon be doing the same as you Clint!
Did you rebuild yourself!
Any shots?

Didn't rebuild it, just changed all the seals and took a look at the teeth. They look ok, lets see how they do once I put a LS6 and M20 ahead of them.

cdnpont · Canadian Poncho Superstar!

Posi of course?

hawkeye5766 · Canadian Poncho Superstar!

Looking good Mark! Will be fallowing along. Did you ever find an inch lb torque wrench?

cdnpont · Canadian Poncho Superstar!

hawkeye5766 wrote:
Looking good Mark! Will be fallowing along. Did you ever find an inch lb torque wrench?

Thanks,

No wrench as of yet. They're not easy to come by. The hard part is, I had one on the last 12 bolt build. But I'd never need another ... right?

hawkeye5766 · Canadian Poncho Superstar!

cdnpont wrote:
It can be smooth when the bolts turn like new. Even the lines came undone. No rust. Drivers side needed the Vice Grip, but only just (because I wasn't willing to wait for the PB Blaster to work). But I'm sort of worried about the flex line to main chassis line.
Cracked it open and pulled the axles. They have no fingernail ridge! Did GM have silicone sealer back in 67? It seems like there is decent traces of it around the gasket. And unless the Canadian Government took the cover off "Just to check", why would this car ever had the cover off?
Will anyone ever need a set of good axles, a open 8.875, 3.08:1 R/P and carrier ?
Bolts, no rust, so nice.
Just slight wear..
Unusual really. No rust, even on the flange.

Maybe you changed the diff fluid and forgot. biggrin

-- Edited by hawkeye5766 on Friday 4th of July 2014 09:51:24 PM

cdnpont · Canadian Poncho Superstar!

It's just weird to see that clear silicone sealant. Who knows, maybe someone just had to have a look at some point. The car only had 56 or so thousand miles when got. Maybe a repair?

Removing the "Bolt of Death",

Sharp eyes will see it's a 9/16 wrench. Wrong! The bolt is 1/2"! Fitted the wrench and took the shot, lol.

Funny how big the 3.08 pinion looks,

hawkeye5766 · Canadian Poncho Superstar!

If your going from crush sleeve to shims, how do you measure pinion depth or do you just keep removing crown and shimming until pattern is right? Have never installed shims (on pinion ), have only ever used a crush sleeve.

cdnpont · Canadian Poncho Superstar!

The pinion shim between gear and inboard bearing is always subject to change, and the two (pinion depth and preload) are not related. I know it will take a bunch of times to get the main shim right according to the pattern. Took me 5 tries the last time I did one. Fit shim, press bearing on, check pattern, pull off. But this time I'm going to try a honed bearing. So I can pull it off and press it on the pinion without needing 20 tons of force. The hope being is that the old bearing might be the same as the new. But I'm worried it might not be. If that's the case, then its on and off with the new bearing as many times as I need to see a good pattern. I have a good little shop nearby that charges 10 bucks a press. It's a huge press, and he has the right collar to remove the bearing.

As far as the solid spacer, You leave the pinion seal out. Fit the pinion in with lightly lubed bearings in place, with the solid spacer and a starting shim fitted. Using the old pinion nut and lubed washer, torque to a certain value (but far from 200), then check preload. Ease up to the high torque value so as not to over tighten the bearings if you're too light on the shim. Use the same torque value each time, adjust the preload force with the spacer shim only. Get the preload right, then move to pattern. The solid spacer shim will stay the same once you have the correct preload, regardless of depth shim. The crush sleeve makes no sense to me. And I don't like to submit the bearings to 200 foot lbs to start a crush. Even getting 200 foot pounds is tough.

When you see around 20 inch pounds on the dial rotating, you're there. Seeing it is a solid spacer, only the shim need be changed to achieve the said preload. And it can be done as many times as necessary, as you are using a old metal lock nut. When doing the final button up after confirmed pattern, fit the seal and use the new nut and washer.

Patience is key here.

hawkeye5766 · Canadian Poncho Superstar!

Thanks for the info, was wondering if you had to torque pinion nut, will be saving info. Keep us posted. thx Jim

cdnpont · Canadian Poncho Superstar!

Got the unit all torn down today, I'm glad my wife Mel lets me indulge in my hobby. This was a 6 hour project.

Power washed, degreased and scrubbed, let sit wet in degreaser, rinse, soap and water, pulled through the tubes, ScotchBrite, degrease again, then to paint. Bead blasted the backing plates. Every time I want to get rid of that darned Princess Auto blaster, another job pops up! Glad I kept it.

I was soaked head to toe during the washing, but most of the thick crud came off with a fine PW jet. The fact it wasn't real crusty with rust probably helped.

Used the DupliColor high build fleet mat black, just like I used under hood (Thanks Todd!). Good paint it is, very fast. Big can, $15.00. Did the backing plates and rear, one can, good coverage. Put another diff cover on to keep the paint out of the housing during paint.

Good progress,

clean 1.jpg

Mostly surface rust, they really never painted these did they? Tons of thick runs of what I think was some kind of black paint or pitch? Some areas were like new steel. Dried it out in the hot sun, wiped off all the water, in and out. Lubed all the race faces .

The elusive "X " marking. It had another flesh coloured mark on the bottom of the center, and one white swipe on the tube, forward left. COPO confirmed.

Tube marking. EP = 2.73! I thought it would be 3.08?

One worthy hint; Resting the rear on the square brake flange will allow the rear to be rotated to each quarter for paint. It will hold solid at every quadrant without tumbling over. If you have a sawhorse with a top groove, it'll work incredibly well. If it sits on the round part of the tube, it has a mind of it's own and will tumble all over. Rest it on the square flange! I only just figured this out today. I fought the thing having it sit on the horse at the control arm slot. If I was to ever make a work jig, it would involve the flange for sure. GM probably knew this!

Clean, Painted, and a good end to a productive day.

4SPEED427 · A Poncho Legend!

You worked harder than me today...

But it likely wasn't 34 degrees there with a humidex of 40. All I did was take my wife on a date in the convertible!

Nice looking project you're doing Mark. Enjoying the pictorial.

cdnpont · Canadian Poncho Superstar!

It's not work Carl.

My yard is work, and that is promised to be done tomorrow!

4SPEED427 · A Poncho Legend!

Well, I hope our heat and humidity from today don't hit there tomorrow, or you won't do yard work, believe me.

I was on the riding mower before lunch for about 1 1/2 hours. I soaked my long sleeve shirt in the sink and then put it on before I went out to work. That's the best air conditioner in the world for hot days. Looks like you had a nice sunny day too.

Where did you buy that diff? You may have mentioned but I must have missed it. It sure is clean.

cdnpont · Canadian Poncho Superstar!

True about the wet shirt Carl, mine is always that way in the summer lol!

It's the original rear to the car. 12 Bolt 8.875 open. Soviet style 3.09 ratio with incorrect speedo ratio.

(Edit 7/15, turns out the rear is 2.73 ratio)

4SPEED427 · A Poncho Legend!

Oh, ok, I was thinking it was an extra you picked up to build.

cdnpont · Canadian Poncho Superstar!

Another late addition, Just cut the packaging open.

The new bolts I got with the Spohn control arms. Metal lock nuts, plating like I've not seen in a long time. Apparently, they could actually be, omg!...quality!

Could they actually be made in....the United States of America?

Naw... forget it. Must be China?

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4SPEED427 · A Poncho Legend!

What? Can't be. Must be a misprint.

hawkeye5766 · Canadian Poncho Superstar!

" E F G " Extra F%6$ing Good, must be USA! and on the part of wet T-shirt, hope it's not a contest Looking good Mark!

2drpost · Uber Guru

nice clean housing mark, alot nicer than the '66 ontario housing i started with...

cdnpont · Canadian Poncho Superstar!

Good save on that housing Dave. Looks nice.

I've actually heard of a guy trying to restore a 12 bolt, and the center section was actually rusted through!

cdnpont · Canadian Poncho Superstar!

So back at it, today I worked on bearings and pinion preload.

Drove in the new axle bearings and pinion outer races. Made sure the race and bearing lands were completely burr free. Did find a couple high spots at the little punch cutouts in the housing, filed them out. Cleaned the lands perfectly. A little swirl with some Scotchbrite and a wipe out with degreaser, add a touch of oil and you're good to go.

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Put a little bit of never seize on the race edges on top of a little oil. Helps start them in smooth as silk. Used a set of old races and axle bearings to start them in. Make sure you're square when starting. Go slow, don't force.

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Finish with a brass (not steel) drift until you hear that home ringing sound.

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I'm using a Ratech solid spacer and shims in place of the crush sleeve. As much as it's fussier to set the correct spacer distance, I think it's the way to go. Used a old pinion nut. A little lube on the nut to washer. No pinion seal yet in place.

I've also gone and bought another inner pinion bearing, and opened up the ID about .0015". The interference fit between the bearing and pinion shaft is just about that, .0015". The shaft measures 1.626"+ and the bearing is 1.625" Used a emery roll on an arbor. Put it in the drill press and, holding it at a slight angle, hand worked it (the inside race will self turn slowly) down to the point that (after cooling) it would just slide onto the pinion. Took about 10 minutes of grinding and checking. Washed it out afterwards. The will give me the ability to quickly change pinion shims to get the pattern. Saves the chore and potential damage of pressing it on and off 6 times! I measured the test bearing and the final bearing in the race, and they are the same height. Will press on the running bearing when satisfied with the pattern, then re-check.

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Heat the outer pinion bearing a little with a heat gun and it'll slide right over the splines and onto the shaft. Much easier that trying to tap in on while holding the pinion from falling out. Use a deadblow hammer taking it apart. Easier on the bearings.

Lube the bearings with gearlube. no grease.

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Have all the parts and tools close at hand, you'll need both hands, walking over to the bench when you start assembly isn't an option. One hand holds the pinion in, the other fits the bearing, yoke, washer and nut.

DSC_3190[1].jpg

6 tries to get it right. Started with a .036 shim stack. Worked down in .002 increments all the way to .028. .036 and .034 gave no real pinion preload.

Started feeling decent load at .030. Went to .028 and that was too high at 11 lbs. Back to .030 with 140 FT/Lbs on the nut and I'm now getting 6-8 Lbs on the scale. We'll call it good at that. Should be 20-24 inch pounds preload. Feels about right.

Used the 6" metal coffee can and a fish scale method to measure the preload. $15 scale (CTC) vs $200 for a In/Lbs dial torque wrench (if you can find one used).

6-8 pounds of steady force x 3" (1/2 the can dia.) should equate to 18 - 24 inch pounds. Used a strong piece of string. Drilled the holes in the can as such the can is centered on the yoke. Use the UJ straps with yoke bolts. Had about 5' of string wound on the can. The pen centers it on the yoke. The lower image is just an example, not the actual pull.

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Next; the carrier,

Cheers,