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How to Install 3-4 1988-Up 4L60, 4L60E, and 4L65E Z Pak™
January 10, 2019

1. Use a 1988 or later input drum, identified by narrow snap ring groove and a 0.093” 3-4 snap ring.

2. Use only a 3-4 apply ring measuring 3.675” ± 0.005” inches tall, commonly referenced as a Number 7 apply ring. This stamped steel ring rests on top of the 3-4 piston. The number “7” is stamped into the part for identification. The dealer OE number is 8685043.

3. Pre-soak all friction plates in ATF fluid prior to final assembly.

4. First, install the special grooved apply plate (bottom) with the groove facing upward.

Do not attempt to install the narrow external spline friction plate, with “TOP” printed on it, into the machined groove. Set it aside until Step 6.

5. Install the friction plates, beginning with an external spline friction plate with friction material facing upward (away from the special grooved apply plate), then an internal spline friction plate with friction material facing upward, continue alternating until you have installed seven external spline friction plates and seven internal spline friction plates.

6. IMPORTANT! Install the special external spline friction plate, identified by the narrow band of friction material, with the word “TOP” facing up. This external spline plate does not look like any of the others. It is critical to install this plate last. Using it anywhere else in the pack will damage the clutch pack and void the warranty.

a. ** Install optional External spline shim to adjust clearance to 0.050” - 0.070” if necessary.

Note: Use of load release springs is optional. Use of load release springs recommended for RPM above 5000.

7. Finally, install the 0.145” pressure plate provided, followed by the factory snap ring. Clearance should be within the 0.050”-0.070” range if not see 6a above. It is recommended to check actual piston travel by placing a dial indicator on the backing plate and apply air to the third clutch feed. If clearance is measured with feeler gauges, it is important to measure in two places at the same time, 180° apart, for even loading of the pressure plate. Failure to do so may cause incorrect end play reading.

Note: See Optional Shim Installation Instruction Below

To properly install the Z Pak™ do the following:

1. Pre-soak all the frictions in ATF.

2. Make sure you are using a 1988 or later input drum. (Identified by the thin snap ring groove. Uses the 0.090” snap ring. The 0.120” snap ring will not fit in the snap ring groove.)

3. Use only the 3-4 apply ring with the number 7 stamped on it. It measures 3.675” ± 0.005” inches tall.

4. Install the grooved pressure plate with the groove facing up. (That means when the pressure plate is in the drum you can see the groove when looking down inside the drum).

5. Install the first single-sided friction plate with outside splines. – Material facing up.

6. Install the first single-sided friction plate with inside splines. – Material facing up.

7. Alternate with outside spline friction plates and inside spline friction plates till you finish with the last of the inside spline friction plates.

8. Install the plate marked “TOP” with the thin band of material facing up. (That means you should be able to read the word “TOP” when it is installed in the drum). Note: Use of load release springs is optional. Use of load release springs recommended for RPM above 5000.  a. ** Install optional External splined shim to adjust clearance to 0.050” - 0.070” if necessary.

9. Install the 0.145” pressure plate.

10. Install the factory 0.090” thick snap ring.

11. The measured clearances should be in the 0.050” – 0.070” range. “See 8a above.”

posted by: Nathan Truncone   comments: 0