Goddammit - another 4l60 build
#121
TECH Addict
Could be getting a cross leak between the pump halves. There could be a small amount of leakage from the 3-4 clutch checkball in the input drum, but that wouldn't leak into forward clutch circuit. Could be some mismatched pump parts, like wrong stator support. I didn't go back and reread the thread again, but didn't you use parts from a few different transmissions?
#122
TECH Enthusiast
Thread Starter
They were both 13 vane pumps, one from 2001, the other from 2004.
Both pumps have the same outer half casting number: 24201073.
The inner pump halves: 24206611*, and 24204705
Since they both had the same outer half, I doubt that is the issue.
The input shaft for both of those years is the same, as well, so I'm at a loss for where the leak is coming from.
*This is the one I'm using, by the way.
Last edited by dixiebandit69; 10-03-2022 at 08:15 PM. Reason: grammar
#123
TECH Addict
There was a thread on here years ago where the wrong stator support was installed in a pump and that trans was doing all kinds of stupid stuff. The problem was not discovered until after it was installed, so don't know how it would have air checked.
#124
TECH Enthusiast
Thread Starter
I did press the input shaft out, but there's pretty much no way you can get that wrong with the double spline.
#126
TECH Enthusiast
Thread Starter
#128
TECH Enthusiast
Thread Starter
UPDATE: I had a friend with a very successful transmission shop check out the input drum/ pump assembly, and he gave it his seal of approval; he said that once there was fluid in the system, any leakage would be negligible, and the clutches were applying well.
What he DIDN'T like was the clearance on the 3-4 clutches: .056", near the outer limits of what is allowable.
He said that this would work, but it's not ideal, and negates any advantages of the kolene steels.
I've tried mixing the backing plates, but they both measure out the same, as do the old steels (.090").
Do y'all recommend a thicker backing plate, thicker steels, or both? I figured .030" should be a good clearance.
What he DIDN'T like was the clearance on the 3-4 clutches: .056", near the outer limits of what is allowable.
He said that this would work, but it's not ideal, and negates any advantages of the kolene steels.
I've tried mixing the backing plates, but they both measure out the same, as do the old steels (.090").
Do y'all recommend a thicker backing plate, thicker steels, or both? I figured .030" should be a good clearance.
#129
TECH Addict
I use a combination of different thickness frictions and different thickness steels to reach the targeted clearance. Finding the right combination takes a few extra clutches and steels that may or may not be used.
#131
TECH Enthusiast
Thread Starter
Okay guys, I got the whole 3-4 clutch clearance figured out after much trial and error, and mixing and matching of different clutches, steels, and backing plates.
3-4 clearance is now .035".
Next question: Which 1-2 accumulator piston/ spring assembly should I use? I've got two of them, with noticeable differences.
Would there be any advantages to mixing the spring packs up with the housings?
3-4 clearance is now .035".
Next question: Which 1-2 accumulator piston/ spring assembly should I use? I've got two of them, with noticeable differences.
Would there be any advantages to mixing the spring packs up with the housings?
#132
TECH Enthusiast
Either one will work, just don't mix the springs up between the housings. 2nd design springs in a 3rd design housing break. The 24219937 is the 3rd design
The following users liked this post:
bbond105 (12-05-2022)
#133
TECH Junkie
If you want a Softer 1-2 Up-Shift:
-Use the Newer Housing with the Springs in the Housing, and Piston on the Separator Plate.
If you want a Firmer Shift:
-Use the Older Housing, and the Springs on the Separator Plate.
-Use the Newer Housing with the Springs in the Housing, and Piston on the Separator Plate.
If you want a Firmer Shift:
-Use the Older Housing, and the Springs on the Separator Plate.
The following 2 users liked this post by vorteciroc:
bbond105 (12-05-2022), dixiebandit69 (12-05-2022)
#134
TECH Enthusiast
Thread Starter
Now onto the separator plate holes.
Just as a refresher, I'm using:
- Corvette servo
- Wide band, .070" clearance
- .035" 3-4 clutch clearance
- .490" boost valve
-3-2 shift valves blocked
-Smaller Trailblazer I-6 torque converter
This is what I'm planning to do, unless someone talks me out of it.
#136
TECH Junkie
@dixiebandit69
With your Build Specs (especially the Corvette Intermediate Servo and that Torque Converter):
-I prefer to start out with a 0.0700" 2nd Feed (Letter "B") on my Plate-Diagram (then a 0.0760" next if needed before a 0.0820").
-I prefer to start with at least 0.1100" for the 3rd Feed (Letter "A").
-I prefer that the 3rd Exhaust match 3rd Feed (Letter "C" for this).
You mentioned (in the 1st Post) that you wanted a faster Reverse engagement...
At least go 0.0930" for Reverse Input Feed and Low-Reverse (Number "8" and Letter "D").
Last edited by vorteciroc; 12-06-2022 at 06:20 AM.
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bbond105 (12-05-2022)
#138
TECH Enthusiast
Thread Starter
Can you elaborate, please? For the record, this isn't the actual plate that I'm going to use; it's one of the old ones.
So tentatively, this is how it looks:
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bbond105 (12-07-2022)
#139
TECH Junkie
I normally would leave the Reverse Input Feed and Low-reverse Feed alone, just as is.
The Two-Way Check-Ball Capsule with the Check-Ball removed is just fine.
I ONLY mentioned those two Feed Hole sizes because you mentioned Reverse engagement in the 1st Post.
The Two-Way Check-Ball Capsule with the Check-Ball removed is just fine.
I ONLY mentioned those two Feed Hole sizes because you mentioned Reverse engagement in the 1st Post.
The following users liked this post:
bbond105 (12-06-2022)