Five Torrington-style thrust bearings that replace the worn needle bearings in a GM 4L60E, 4L65E, 4L70E or 700R4 during a rebuild.
Anyone tearing down a 4L60E from a Silverado, Sierra, Tahoe, S10, Camaro or Express van, or an older 700R4, finds the same thing sooner or later: a needle thrust bearing with a cracked cage, flat spots on the race, or loose needles lying in the pan. This SBK-G12 set gives you the five Torrington-style thrust bearings that carry the axial load between the rotating members of the GM 4L60 family, so the rebuild goes back together with fresh bearings at every position instead of reused ones that have already seen a failure.
Helical planetary gears push sideways as they carry torque, and the 4L60E stacks two planetary sets, the input drum, the forward and 3-4 clutches and the output shaft end to end in the case. The thrust bearings sit between those parts so they can turn at different speeds while the whole stack is pushed fore and aft. This kit covers the stator shaft to input clutch position, the front clutch to input sun gear position, the output carrier to ring gear position, the output shaft to case position, and the reaction carrier to support position. When one of them breaks up, the stack gains endplay, gears lose their alignment, and the needles become abrasive debris that circulates through the pump and valve body.
A worn bearing cannot be tested with a scan tool. Road noise that tracks vehicle speed can also be a rear axle, a wheel bearing or a driveshaft, so rule those out first. If the pan shows bearing needles, the transmission is coming apart anyway, and this kit belongs in the parts order. Our 4L60E common problems guide walks through the hard-part failures that usually travel with bearing damage, and the overrun clutch guide helps separate clutch-related noises and coast complaints from gear train wear.
The SBK-G12 set, also sold as TBK-G12, interchanges with K77907A, 74201A and GM 8642066, 8642162, 8642215 and 24217327. It is listed for the 1982-up 700R4 and 4L60 and the 4L60E, 4L65E and 4L70E, which covers most GM rear-drive trucks, SUVs and cars through about 2012. GM changed some gear train parts over the years, and late units use a bearing at the front planetary hub where early ones used a tabbed washer, so compare each new bearing with the one it replaces before it goes in. If you are unsure which parts your unit uses, send us the year and VIN. The full range of parts is on our 4L60E parts page.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for the GM 700R4 and 4L60 from 1982 on and the 4L60E, 4L65E and 4L70E. That covers most GM rear-drive pickups, SUVs, vans and cars that used the 4L60 family.
No. Endplay is set with the selective shim on top of the input drum. Install the bearings, then measure with a dial indicator and change the shim to bring endplay into spec. Sonnax lists .005 to .036 inch for final unit endplay.
If the transmission came apart because of a hard-part failure or there was metal in the pan, replace them. A bearing that has run in debris can look fine and still have damaged needles or races.
Inspect the planetary carriers, sun shell and reaction shell. Most rebuilders replace the clutches, seals, filter and gaskets at the same time and refill with Dexron VI.
Lay out the old bearings in the order they came out and note which side faced forward. Install each new bearing the same way. A bearing installed backward will not ride on its race correctly and will fail quickly.
