Symptoms:

Direct clutch failure

Delayed 3rd

Delayed Reverse

Code 87, 730, 756, 1811

No 3rd

No Reverse

Maximum line presssure

No 4th

2nd Gear starts w/MIL on

TCC slip codes

Cause:

Wear at the direct clutch drum bore from the center support piston rings allows 3rd and Reverse clutch apply oil to exhaust.

Correction:

Sonnax direct drum sleeve kit allows the salvage of worn direct clutch drum bores, and restores the hydraulic integrity at the center support piston ring locations.

Warning:

Recommended tool kit 34838-TL is no longer in production. Check with your distributor for availability.

4L80-E, 4L85-E, TH400

Direct Drum Sleeve Kit

Part No. 34838-01K

In 4L80-E units, part can be used in either early or late-model drums.

Requires: 34838-TL (Recommended)

Wear at the direct clutch drum bore in GM TH400, 4L80-E and 4L85-E transmissions allows 3rd and Reverse apply oil to exhaust. This oil leakage can result in direct clutch failure, delayed or no 3rd/Reverse, slips in 3rd or no 4th Gear, and the various slip codes noted above. Often the direct drum bore is worn beyond the ability for new seals to restore the hydraulic integrity.

Sonnax direct drum sleeve kit 34838-01K salvages worn direct clutch drum bores and restores the hydraulic integrity at the center support piston ring locations. Machining of the direct drum is required.

Contents

Sleeve

Spring Pin