4L80e pump question

Joined
Feb 21, 2022
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South Texas
I’m new here. Howdy All. I am normally Glagulator @ dieselplace, yeah, 6.5td.
Mainly need to ask a question about 4L80 pump gear clearances.
I have been researching 4L80’s on a number of sites over the years and see that @clinebarger seems to be a goto on them, and anyone else who may help.
So here goes.
I have a pump that has the O.D. clearance of the large gear of .004” to the stator. The gears have about .0020” to .0025” to the top surface and are the same height. The problem is there seems to be a lot of slop in the inner gear. I measured .024” to .026” between an inner gear tooth and the “divider” while pressing the gear tight to the other side.
I have not been able to find any useful info on this.
I have 3 pumps all about 200k miles from running trucks and all are almost exactly the same. Is this normal?
I am building it stock with a few of the recommended fixes to be dependable, no hot rodding, no heavy towing.
Also on the same pump, large front bushing that the TC rides on appears to be galled on one side and worn through the grey coating to the bronze on the other third. The TC is OEM and the snout also looks well worn.
This tranny is a Mr. Goodwrench special and appears to have been on the 95 6.5td Burb for most of it’s life. I say special because the overdrive planet was missing 1 washer on 2 of the gears, they were never there. I’m rebuilding it because it was leaking fluid all over and then the fluid did not look good, not real bad but not clear, and the high mileage. Pan was amazingly clean, just a little of the usual black stuff and very minor glitter.
Any help would be greatly appreciated.
 
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Do a search 4l80e build.
Pretty sure that is one of those parts that always get replaced in a rebuild.
 
Joined
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The problem is there seems to be a lot of slop in the inner gear. I measured .024” to .026” between an inner gear tooth and the “divider” while pressing the gear tight to the other side.
I have not been able to find any useful info on this.

There is no published specification for this, But careful inspection of the Leading Edge of the Crescent is a must.....You can usually catch a nail on the edge if it's worn, But a visual inspection for scoring is also needed.

Wear (if any) will be between the 2 arrows, New gears are highly recommended.

F5xqX6T.jpg
 

Glagulator

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That is exactly what I am seeing. I can see that the pump gear in that image is much tighter.

The contact areas on my gear teeth look perfect, as if new, kind of surprising.

The OEM gears must have some kind of surface treatment, the dark grey color. Are the OEM gears available?

I have not been able to find any. Are there any aftermarket pump bodies and gears you would use?

I have 4 of these trannys I am rebuilding for my collection of diesel Burbs and figure I will need these parts on all of them.

Thanks so much for the responses.
 
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GM part# 24243327 which is a Pump Body & Gears, Will work on ALL 4L80E units!

The above photo is a good used Pump Body with CK Performance coated gears.

Good used parts/cores are drying up, Forcing me to tear-down a unit before I even give quotes.
 

Glagulator

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Feb 21, 2022
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South Texas
Thanks for that. I was able to find a new OEM pump with gears at a reasonable price, military surplus, and a brand new valve body. VB has a damaged shift solenoid. I see shift solenoids with old GM #’s (10478148) and have a brown plastic end instead of the newer white ends. Any problem using those?
Is there a difference or Is it GM up to their part number game?
 
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IIRC the gears were run through a black oxide process in production for corrosion resistance and a break in coating. Very thin, typically one micron.
 

Glagulator

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Feb 21, 2022
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South Texas
There was very little difference in clearance between the new pump and the used one.
I have another question -
How important is the front to rear planet clearance?
Sonnax say's it should be around .01" and I'm getting about .03".
If so are there selectives available?
Thanks for the help
 
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