Want to bet on my luck? (atf to "save" transmission)

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Feb 16, 2008
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Ohio
So, new-to-me 2005 silverado (Quadrasteer) has been a problem child.
2005 1500 5.3 4x4 4L60E 189k

Initial test drive indicated no issues but recently there has started to be a fairly big flare in the 2-3 shift and on the highway in 4th any application of throttle had a big flare (500 rpm) before the rpms would drop back down.

Quick did a filter drop and half fluid replacement to see if it may help, still a flare and almost worse 4th gear behavior. Old fluid was dark with barely a semblance of red. Pan was dirty but not excessively so. No burnt smell.

I know a rebuild is highly likely but I'm interested to hear your wager on if this can be covered up for a while with a max life full change, corvette servo, boost valve, and a reset on the adaptives.
 
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I've had 4L60e's be worlds better after a fluid change, but known mild use on them, and you don't know the history here. Did you use Dex III here as it was designed around? Another thing that can help is trying to take care of hardened seals which may be contributing to low line pressure. I had fantastic results last year doing this on a Honda with similar symptoms.

I added ~6 ozs of Chemtool B12 and drove it a few hours cumulatively, lots of shifting. Flushed it out and replaced with Lubegard ATF (ester base to keep seals conditioned). It went from acting like yours to acting like new, and still is nine months later. If I used a different ATF, I would have added a bottle of Lubegard Red additive to achieve the same purpose. I would try something simple like this before I then started looking into removing/cleaning/changing solenoids or o-rings inthe valve body. If you address the pressure problems in time, you don't need an expensive rebuild in most cases.
 
Fluid was inexpensive Dex3

A few more thoughts came to mind.
Engine/transmission split is very wet. I was expecting a rear main leak but fluid color is impossible to discern. It could however be transmission fluid.

I could not tell you the fluid level before the pan drop. It is currently a bit low however. I had expected it was because the trans was not up to temp (5 mile drive) but perhaps that is contributing as it appears these are sensitive to fluid levels.
 
Now I can bet among the 4 posts.

I bet $20 -even money- on Oro_O's suggestion being successful.

skyactiv's suggestion is a good 2 to 1 odds bet if useful improvement constitutes success.

The absence of burnt smell can fend off Linctex's prediction.

Lube maint would've preserved this transmission.
 
Originally Posted by Snoman002
I was expecting a rear main leak but fluid color is impossible to discern. It could however be transmission fluid.


1) It may sound unpalatable, but you can taste it and tell the difference.
wink.gif


2) It also could be from above. I have an SUV (non GM) that keeps that area damp, but it's from rear cam seals above I know for certain and not the rear main or transmission input seals (I had the transmission out and verified).

Try swapping in more dex III, some Lubegard red, and then check the fill level properly with it running. May take care of the problem.
 
Interesting there are no comments on the mechanical aspects. I somewhat expected the added holding power of the corvette servo to be mentioned, same with upping the line pressure with the boost valve.

That said, using type F, interesting suggestion. Better or worse then a stop slip?
 
If the 2-4 Band is coming off too soon, Before the 3-4 Clutches can come on.....A "Vette" Servo will help with that as it takes more 3rd clutch accumulation to knock the Band off.
The stock .472" Boost Valve is adequate for what a stock 5.3L puts out & Boost Valve/Boost Sleeve wear isn't common.

But, To be honest.....Sound like the 3-4 Clutch is about done & nothing short of a rebuild will rectify that.
 
Easy enough to test....Unpin the Yellow wire out of the MAF connector, Let the PCM set P0101 & all the line pressure calculations will work off the MAP sensor values (Speed Density)

Unpinning the signal circuit is very easy with an Awl, You don't want to simply unplug the MAF as the IAT is built in.
 
Use two bottles of lubegard red. Drain out the necessary fluid and double dose it. It helped tremendously in my 05 impala when I had it. That thing practically thumped like a bucking bronco into third. It was the only thing that worked. It shifted smooth when I sold it.
 
I have the same setup, minus the quadrasteer. Mine is 2005 Z71 with 85,000 miles. I changed out the servo to the vette unit and it is almost like adding a shift kit. No lag or slippage, just quicker, firm shifts. 189,000 is a lot of miles on one of these 4L60 trannys, some last forever and some don't make it to 100,000. It shouldn't be a crap shoot to get a good one. As always JMHO.
 
Originally Posted by clinebarger
If the 2-4 Band is coming off too soon, Before the 3-4 Clutches can come on.....A "Vette" Servo will help with that as it takes more 3rd clutch accumulation to knock the Band off.
The stock .472" Boost Valve is adequate for what a stock 5.3L puts out & Boost Valve/Boost Sleeve wear isn't common.

But, To be honest.....Sound like the 3-4 Clutch is about done & nothing short of a rebuild will rectify that.



At 190k I can hardly complain about it needing a rebuild, just hope I can delay until next year.

Thanks for the advice


I see you rebuild them yourself. Any reason a reasonably competent home mechanic shouldn't attempt a rebuild? Any advice on a rebuild kit?
 
It's a bit of work to get the unit out of the truck, but it's not rocket science to rebuild.
Cleanliness and attention to detail plus a good manual should get you there.

The 4L60 is one of the most common units out there.
Rockauto has re-mans for 1100 bucks and there are a lot of other sources.
If the engine and chassis are still solid, I'd say this is one major repair that is worth it.
 
Originally Posted by Snoman002
Originally Posted by clinebarger
If the 2-4 Band is coming off too soon, Before the 3-4 Clutches can come on.....A "Vette" Servo will help with that as it takes more 3rd clutch accumulation to knock the Band off.
The stock .472" Boost Valve is adequate for what a stock 5.3L puts out & Boost Valve/Boost Sleeve wear isn't common.

But, To be honest.....Sound like the 3-4 Clutch is about done & nothing short of a rebuild will rectify that.



At 190k I can hardly complain about it needing a rebuild, just hope I can delay until next year.

Thanks for the advice


I see you rebuild them yourself. Any reason a reasonably competent home mechanic shouldn't attempt a rebuild? Any advice on a rebuild kit?



Buying all the correct tools can cost quite a bit. Expanding & Resizing the PTFE sealing rings on the Turbine Shaft almost requires the right tools! Bushing Drivers are also needed along with spring compressing tools for the Input Drum, Reverse Input Drum & Lo/Reverse Piston. Though you could likely get away with leaving the Lo/Reverse Piston in the case as your unit hasn't produced metal debris (Yet).

Probably get away without replacing the Stator Support PTFE sealing rings, But you'll need to keep them sized while the pump is out..,,,,Clean the Stator with some alcohol & wrap the ring with electrical tape. Another option is to replace them with Scarf-Cut 700R4 rings.

You'll need a "siphon blow gun", @ 2 gallons of new/clean Solvent, Feeler gauges, Dial Indicator w/ a Magnetic Base, Various Snap-Ring pliers, Cut-off wheel & die grinder, And a torque wrench that's accurate down to 8 ft ibs.

Oh & a Lip Wizard for the Piston Lip Seals!!


I'll walk you through this if you want.
 
Cline Barger,

Thank you for the advice. If the time comes I will be in contact, and I appreciate the offer. I don't think the job is beyond my capabilites but like you mention the tooling will be a concern. My garage is reasonably stocked but not towards this.

Thanks for the advice everyone!
 
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