[Navy Lifer]

pretty much all photos seem to be gone.

so just create a cloud link (as if I know what the heck I'm talking about) to a photo library and post that link in this thread, or start a new thread "95wagon LS7 photo dump", re-post all the photos, and put the link in this thread....no doubt there are some internet wizards here who could make this happen yesterday!

 

[Navy Lifer]

I wonder if 2 bottles,will be enough
View attachment 199926 View attachment 199927

Forgoing the lightened ring gear for now.
Keeping the full girth AAM 4.56 .

Will use the lightened set with the posi on the street if this set grumbles about a big RPM launch with new bigger slicks

looking for the weakest link in the drivetrain, eh?

that additive won't help....your "friction modifier" issues are between the rear tire and the surface under it.

It's time to change things up, anyway - when are you going to install the LT4 or LT5 with 8L90 - you could be done with this rear axle gear change crap, and all you would need to do is put on the skinnies & slicks.

8L90-E 8 Speed Transmission for LT4: 19367135 | Performance

The 8L90-E 8 speed transmission unlocks the power of the LT4 engine. New gear ratios allow for take-off power and comfortable cruising.

www.chevrolet.com

I know.....I'm real good at spending your money! Maybe start a GoFundMe???

 

[Caddylack]

looking for the weakest link in the drivetrain, eh?

that additive won't help....your "friction modifier" issues are between the rear tire and the surface under it.

It's time to change things up, anyway - when are you going to install the LT4 or LT5 with 8L90 - you could be done with this rear axle gear change crap, and all you would need to do is put on the skinnies & slicks.

8L90-E 8 Speed Transmission for LT4: 19367135 | Performance

The 8L90-E 8 speed transmission unlocks the power of the LT4 engine. New gear ratios allow for take-off power and comfortable cruising.

www.chevrolet.com

I know.....I'm real good at spending your money! Maybe start a GoFundMe???

Why no 10L90E?

 

[95wagon]

looking for the weakest link in the drivetrain, eh?

Still thinking about Nabil's records.

-1/4 mileT56
-Most parts left on starting line

Hummmm, which to choose.

 

[95wagon]

The spool just makes sense for what I am up to.
A lot of time and money in the 33 spline 8.5 Eaton ( try and buy one )

 

[Navy Lifer]

Why no 10L90E?

"Eight is Enough" - 10 speed is gilding the lily, and neither 8-speed or 10-speed is compatible with LS control system, unfortunately. Spend enough money and anything can be made to work.....

4.56 trans first gear should do just fine....and run a 3.08 rear axle ratio! Bonus lower driveshaft speed and stronger gearset. 3:08 is 40:13T & 4:56 is 41:9T - 3.08 pinion teeth are larger, 4.56 ring gear is spaced further away from diff carrier mounting flange.

Gerry has an SSR 6-speed with 2.97 or 3.01 1st gear, paired with 4.56 rear yields 13.72 start ratio (plus clutch dump)

8L90 has 4.56 first gear, pair with 3.08 rear yields 14.04 start ratio (plus torque converter - less chance of damage to driveline)

Not really worth the extra 2 gears - bigger ratio drop with the 10 speed than 8 speed from 1st to 2nd. GM Hydra-Matic 10L90 10-Speed Automatic Transmission

 

[SSandman]

Still the best LS swapped car around.

I really would have loved to have used an 8 speed. Such a difference between the 8 speed in my '19 silverado and the 6 speed in my '16 silverado and this isn't even a performance application. The trans is just always where it needs to be, the shifts happen everywhere you want them to. I've driven a lot of 6l80/6l90e cars and even great tuners can't seem to completely fix the fact that the trans sometimes doesn't seem to know what it wants to do. I actually prefer a 60e to many of the 6 speeds i've driven.

I'm still tempted to go 6l90e, but I also wouldn't be thrilled about adding that much weight to the car or the ground clearance issues it may create on a lowered car.

 

[95wagon]

Finally bought a case spreader
Cheapo Amazon one intended for a Dana so there was some modding required to properly fit the 8.5 10 bolt and 8.875 12 bolt GM diff.
Sure makes life easier.
Take VERY little effort to move things so I was careful to measure as I loaded it.
Interesting aside , the Strange spools are wider so you end up with sub .200 shim stacks preventing the " smart shim" style.
Luckily I had selective spacers in the correct range

.

 

[Fix Until Broke]

Other than the obvious answer (spread the case) what/why do you do this to a housing?

 

[95wagon]

Small dia drag slick brakes,
Drilled to access park brake adjuster
Register ring

 

[95wagon]

 

[95wagon]

Why a case spreader ?
The final assembly requires preload on the side bearings.
This means you are putting something in a space that is smaller than itself.
The factory preload is .008" on this type diff.
Some of us , depending on the use , bearing type, etcetera use even more preload.
This depending on shim type, diff location, planets aligning ,can make re&re for for final checks , final assembly a pain.
Spreading the case that .008 makes getting it in much easier.

Added bonus ,
With out the case spreader, after final assembly, if you found the lash was say .001 different than you wanted, you would leave it.
.001 not worth the trouble!
With a spreader, you would be much more apt to " pop 'er out" and make that tiny adjustment.
Does everyone need one , probably not.
I got by, only borrowing one for Dana 80s, for 45 years.

 

[sherlock9c1]

Gerry, fantastic! I just ordered that spreader, it's surprisingly affordable on Amazon. The last differential attempt I made, I messed up those thin shims for this exact reason. No more of that mess!

 

[95wagon]

Gerry, fantastic! I just ordered that spreader, it's surprisingly affordable on Amazon. The last differential attempt I made, I messed up those thin shims for this exact reason. No more of that mess!

As I noted , you will have to do some mods.
Smaller threaded holes closer inboard need to be done.
If you just made threaded adapters for the original holes, the bars will encroach the shim area preventing you from dropping shims in straight.
The pins can be nothing more than hardened bolts threaded in with their shanks bearing on the housing.
MAKE SURE to do some test runs with dial indicator reading shim face to shim face.
It takes VERY little load to spread.
I worked up to it .
Zero gauge, spread case couple thou, release, make sure gauge returns to zero.
Worked up to .009-.010 made sure the housing would return to zero.
How far can you spread it ? Whats the limit ? Don't know, not going to explore that.
If your pins are a good fit, you can mark the adjuster nut , that helps when you are pulling the gear back out .

I try to say away from the thin ones, keeping max 3 thicker but sometimes you are forced to use them.
With them, I would only use the sides smart shim.

 

[sherlock9c1]

I did a lot of thinking about why the factory carrier shims would very; it seems to me that most of the tolerance would be in the housing, not in the carrier nor the ring & pinion. Those pieces should be highly repeatable. Theoretically, the shims would be housing-specific. I did confirm this with a manufacturing engineer although not one who had worked with this specific component. What else am I missing?

 

[95wagon]

So, So many variables
I have seen housings in both directions.
Brand new replacement housing , identical shim. Brand new housing, not even close.
In my past life, I changed more housings than gears .
Production ring and pinions , all over .
Later OE stuff yes much closer, hence guys using original pinion shim, calling it a day, and getting away with it,,,,, usually!
Anything ring and pinion is going to change shim stacks.
Now throw in the adapter bearing used to fit the aftermarket posi units in the small 8.5.
GM never even used that bearing in production.
I also don't think manufacturers hold call out or tolerance as tight when they know there is an adjustment provision .

While the total L+R carrier total "usually" falls into similar , ( .24 something x 2 comes to mind ) this aftermarket spool is like .100 wide .

Side shim total governed by housing, bearings, posi.
Actual numbers , add gears, pinion bearings choice of depth, choice of lash, choice of preload.
Yeah in theroy if every design call out was bang on , every manufacturer agreed to and adhered to ,,,,,,, but come on, not in this world!!