41TE Assembly, Pt. II

"Urambo Tauro" (urambotauro) 04/03/2017 at 18:00 • Filed to: 41TE, Automatic Transmission, Rebuild, Blog

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Now that the rear planetary carrier is installed, we can start building up the core of the transmission. Let’s start stacking clutches!

Here’s where we left off. The front planetary carrier will slide over and around this rear planetary, but first, we’re going to install the clutch-packs.

The friction plates have been soaking in ATF (+4) and can now be stacked with their steel plates. This is the LOW/REVERSE clutch pack.

Steel, friction, steel, friction, steel, friction... The steels have teeth on the outside that lock against the inside of the case. The frictions have inner teeth that will engage the front planetary.

One more steel plate, then a span-ring goes around its circumference. One more friction, then this thick steel plate (called the pressure plate) gets locked down with another snap-ring.

These two snap-rings hold the pressure plate in place. When it receives fluid pressure, the low/reverse piston underneath this clutch-pack will press upward against the pressure plate, clamping the frictions and steels together in between, locking the front planetary carrier to the case.

Now we add another stack. These alternating steels and frictions make up the 2-4 clutch pack.

LEFT: Here is the 2-4 clutch piston, sliding into its housing, all cleaned up with fresh ATF and inner/outer seals. RIGHT: the piston seated in its housing must get lined up with this return spring.

Return spring goes in first, then the piston in the housing. Another snap-ring must go atop here to lock the piston housing against the case.

So between those two clutch-packs is the pressure plate, which stays stationary. The low/reverse piston presses its clutch against the pressure plate from below, and the 2-4 piston pushes from up top.

(Eh, “top” and “bottom” are relative terms here. I have this transmission mounted on a stand with the bellhousing facing up. But once it’s back in the vehicle, these are going to be sideways motions.)

So now we take this rear sun gear (after cleaning it, of course) and place the flat roller bearing around the snout. The bearing is all greased up with petroleum jelly, which makes a great assembly lube for transmissions.

The sun gear goes into the center of the rear planetary, bearing facing down. Note the open end of the 2-4 piston housing’s snap-ring is inside the large “lug” at the top of the case. This helps keep the snap-ring from breaking.

We didn’t take the front planetary apart during disassembly, but briefly removing this snap-ring makes cleaning easier

The clean front planetary gets another flat roller bearing on its underside. The jelly keeps it stuck in place while it’s flipped upside down

The front planetary now goes down inbetween the rear planetary and the clutch packs. Hmmm... that’s not quite far enough

The front planetary’s teeth are at the bottom (or rear, I guess I should say), and they must pass by the 2-4 clutch and engage with the L/R clutch. So we wiggle the planetary back and forth to line up the teeth and work it deeper into the case.

There, that’s better. All settled in place ...I think. We’ll have to see how the next component stack up to be sure that everything’s seated properly.

Now for the front sun gear assembly and its thrust washer. The lower teeth here engage the 2-4 clutch frictions. The upper teeth will connect to the input drum. And underneath, the’s a sun gear that meshes with the front planetary.

And here’s the sun gear assembly all nestled down into place

Next: the input drum! !!!error: Indecipherable SUB-paragraph formatting!!!

Noah - Now with more boost. > Urambo Tauro 04/03/2017 at 18:39

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Wild! I’ve actually never looked at pix of transmission guts before. That looks SO scary haha

Urambo Tauro > Noah - Now with more boost. 04/03/2017 at 19:36

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That’s why these posts are coming in bite-sized pieces! The whole thing would be just too overwhelming, I think.