Build thread - 3.08 to 3.42 front and rear gear change

5StarCustmSolutns said:

I'm sure yours will be perfect!

Actually that might be a bad thing to say....or for someone to read. Some rear end patterns simply cant be made to be perfect on drive and coast. Backlash can be right in the dead center of the range and a pattern can be incredible on drive and buried down at the bottom of the toe on coast. And that really just one of ___(a number I'm not awake enough to calculate yet) different scenarios. Please correct me if Im wrong but perfect would be all 4 within spec and producing an acceptable pattern..... Then sending it. Not full send yet, just a confident send!

That's what I did anyways... It worked... It took me 3months to find the moxie to do it......Then a couple hours later it was done.
The Trutrac (and I guess my right foot) will cause the inside rear tire to start chirping when rolling hard onto the pedal while coming off an apex...
But! Right before I headed out to the garage for go time, I had a talk in the mirror and told myself that we weren't going to play shaving hairs today. We were going into the garage for: 16in lb +- 4 0.008 thou +- 4 and 75% or more of each gear tooth in the middle half, horizontally and vertically, of the tooth it was meshing with.
Probably could've hit send on my first pattern check? But I gave it a miniscule squeak of a turn and hit send

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If this was your pattern, what would you do?

swathdiver said:

If this was your pattern, what would you do?

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Sorry James... Had long week...

Both are a hair on the toe which, if I remember correctly would want ring gear moved away from pinion... But I'd be willing to wager that by the time you got to the next bolt hole on the adjuster, you'd be too far out the other way?? It's really close to, if not in that marginal window I mentioned last week where you can't get it any better!?!!?

My OCD official answer:
- Clean it all up
- Move the adjuster one bolt hole like mentioned above and pattern it again, just to be sure
- If better, I'd Send it! (prob won't be, but I would have to know)

If it's worse:
- Clean it up again and put it back to this setting
- Pattern one more time
- If it was the same as this pattern with everything torqued down, I would take a punch and with moderate force, attempt to tap the dial back in the direction it just came from, even with it all torqued down! And not tap it hard enough to damage the retainer clip but just to see if I could gain a 0.0001's?

And whether I did or not....I'd put it back together and go FULL SEND!

NOTE: I answered this before reading anything else, other than this question. Just to be fair... So if Im wrong I'll learn from it and come back better )

[ In an absolutely perfect world I would want to back the Pinion out about 0.000001 and move ring to left/driver about 0.00001.....But them ain't options here in the real world ]

FULL SEND

swathdiver said:

If this was your pattern, what would you do?

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There were no other replies to read anyway lol

Im a little of the belief that the ring and pin may be the hardest metals in the the entire vehicle!?!? I've now seen 3 pinions do a miniature pulverization to the concrete they landed on when knocked loose without so much as a scratch on Pinion??\

Woo hoo! Not a drop overnight, LubeLocker worked. Also pounded flange straight in a couple spots.

Well project is pretty close to done. So far here's all I've done.

- Replaced rear end with 14-bolt, 9.5" SF, 3.42 axle. Replacement unit had less than 100k.
- Re-used all my rear brake components (except p-brake, used those from new axle), kept everything intact without opening up any lines.
- Replaced front diff with AABR, 3.42 unit. Replacement unit had less than 150k.
- New spicer u-joints in rear driveshaft
- New front diff came with the driver's side mount attached. Swapped that over since it was in better shape than my original.
- Replaced evap charcoal canister with new GM unit.
- Replaced radiator with Denso unit that has accommodations for oil cooler lines.
- Added new oil cooler line set (this would have been very difficult with the front diff installed.)
- New driver's side GM OEM motor mount (also much easier with the front diff out)
- Replaced both heater hoses and lower rad hose. The heater hose with the Y is the upgraded Dorman unit with a metal Y-connector.
- Replaced heater hose t-connectors at firewall. I originally ordered Dormans from RA - I did not see the GM ones there. A couple days later, I discovered the GM ones on Amazon, so I ordered those. Well, as of today, I only had the black GM one, the white one has not been delivered (I hate UPS). So I have the black outboard one as GM, but the inboard white one is Dorman. I guess it will be an experiment to see if the Dorman one holds up.
- Changed oil with Costco synthetic 5w-30. Bigger delco filter. (PF62, I think?)

Got most everything buttoned up today. Filled up with DexCool coolant and got the engine started. Not seeing any leaks. Still working on bleeding brakes. I have a Holt vacuum bleeder kit that is run by my air compressor. I was having no luck getting it to pull out any fluid. BUT.... as I was frustrated and going in for the night, I saw a big ol black washer on the floor. It's the washer that goes in the main cap of the big can. So I think it was pulling air through there, and not my bleeder hose! Try again tomorrow.

One thing I'm concerned about. I'm getting Stabilitrak, Traction Control, and ABS lights on the dash with key on and with engine running. It's got to be the wheel speed sensors at the wheel ends of the rear axle housing, right? Those are the only things I messed with that can affect those systems, I think. They are both installed, they are my originals, I just kept them connected during the swap and installed them in the new axle. Will I need new ones? Maybe just clear the codes with my Tech 2? It is still up in the air with all four wheels off.

Rockauto shows the same part for a tahoe and escalade, so I guess they should be the same sensor. ?

Is your master cylinder level low?

any codes?

DaveO9 said:

One thing I'm concerned about. I'm getting Stabilitrak, Traction Control, and ABS lights on the dash with key on and with engine running. It's got to be the wheel speed sensors at the wheel ends of the rear axle housing, right? Those are the only things I messed with that can affect those systems, I think. They are both installed, they are my originals, I just kept them connected during the swap and installed them in the new axle. Will I need new ones? Maybe just clear the codes with my Tech 2? It is still up in the air with all four wheels off.

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Did you transfer the old sensors into the new axle? Was there any point when they were disconnected that you turned the key on?

swathdiver said:

Did you transfer the old sensors into the new axle? Was there any point when they were disconnected that you turned the key on?

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Yes old sensors are in new axle. I was trying to remember if I had ever turned key on with them not installed. I don’t think so but possible.

DaveO9 said:

Yes old sensors are in new axle. I was trying to remember if I had ever turned key on with them not installed. I don’t think so but possible.

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How's the battery? Mine was throwing a code for a rear wheel speed sensor the other day but it turned out to be a bad battery.

Got it resolved! Nice and simple - pass side rear sensor was unplugged! Must have happened at some during rear end changeover. Good thing it doesn’t seem to have any problems. Been driving around all day, no issues or warnings.

It was throwing a C0050 code - circuit issue on rear pass sensor. Chased the wire up on top of frame, found the unplugged connector.