27-spline 1330 slip yoke (2-3-12051X) with a 5-134X U-joint for GM 4L60E, 700R4 and TH350 driveshafts - replaces a worn or grooved yoke.
A tail seal on a 4L60E that starts weeping again a few weeks after you replaced it is almost never a bad seal. It is the yoke. When the polished hub on the front of the driveshaft gets grooved, pitted or rusted, the new seal lip rides on a damaged surface and the leak comes right back. This kit pairs a new 27-spline slip yoke with 1330 series ears (cross-reference 2-3-12051X) and a 5-134X combination U-joint, so a two-wheel-drive Camaro, Firebird, S10, Astro or full-size GM with a 4L60E, 700R4 or TH350 can go back together with a fresh sealing surface and a fresh joint in one order.
On a rear-wheel-drive 4L60E the output shaft ends inside the extension housing. The slip yoke slides over that shaft on 27 splines and becomes the front of the driveshaft. Its long hub does three things: it transfers every pound of torque to the rear axle, it rides in the extension housing bushing to keep the back of the output shaft centered, and it gives the rear seal something smooth to seal against. Because the axle moves up and down with the suspension, the driveshaft changes length, and the yoke slides in and out on the splines to absorb that change. Fluid in the extension housing keeps those splines lubricated, which is why a leak here is ATF and not grease.
This yoke has 1330 ears: 3.625 in. between the ears with a 1.062 in. cap bore. Many GM driveshafts use a smaller 1310 joint at the shaft end, so the included 5-134X is a combination joint with 1.062 in. caps on both axes, a 3.219 in. span on one side to fit a 1310 driveshaft and a 3.625 in. span on the other to fit this yoke.
Pull the driveshaft and look at the hub under good light. If you can catch a fingernail on a groove, or you see a dull band where the seal rides, the yoke is done. Rock the yoke on the output shaft and check the joint for notchy or loose caps. A clunk on engagement can also come from inside the transmission, so rule that out too: the forward sprag and overrun circuit both affect how a 4L60E engages, and our 4L60E common problems guide covers what internal clunks and slips look like so you do not chase the wrong part.
This yoke fits the 27-spline output used on the GM 4L60E and 4L60 as well as the 700R4, TH350 and 200-4R, plus T5, T10, T56, M20 and M21 manual boxes with the same spline. Overall length is 6.760 in. from the U-joint centerline to the end of the splines, and the seal surface is 1.502 in. in diameter. GM used different driveshaft lengths and joint sizes across years and body styles, so measure the old yoke and count its splines before ordering, or send us the year and VIN and we will check it. If your driveshaft already uses 1350 joints, the 4L60E 1350 series slip yoke is the matching part. Four-wheel-drive trucks with a transfer case and 4L80E or TH400 boxes use different yokes. Browse every part for this transmission on the 4L60E parts page.
Mark the driveshaft to the pinion flange before removal so it goes back in the same orientation, and plug the extension housing if the rear of the vehicle sits low. Install a new rear seal with the new yoke every time. Press the 5-134X into the yoke and driveshaft with a vise or joint press, seat the snap rings fully and confirm the joint swings freely without binding. Coat the hub with clean ATF before sliding it in so the seal does not run dry on startup. With the vehicle at ride height, check that the yoke has slip travel left and does not bottom against the housing. Top off with Dexron VI and check for leaks after a test drive. If the tail leak came from a transmission that is also slipping, our 4L60E S10 problems guide and the 4L60E master rebuild kit are the next stops.
| Slip yoke | 1330 series, cross-ref 2-3-12051X / 2312051X |
| U-joint | 5-134X, 1310 to 1330 combination |
| Yoke length (U-joint centerline to spline end) | 6.760 in. |
| Ear spacing / bearing cap bore | 3.625 in. / 1.062 in. |
| Hub (seal surface) diameter | 1.502 in. |
| Fits | GM 4L60E, 4L60, 700R4, TH350, 200-4R, T56, T5, T10, M20, M21 (27-spline output) |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. On a four-wheel-drive 4L60E the transmission bolts to a transfer case, and the rear driveshaft yoke goes on the transfer case output instead. This yoke is for two-wheel-drive applications and manual-transmission swaps with the 27-spline output.
The yoke has 1330 ears, but many GM driveshafts carry 1310 size at the tube end. The 5-134X has 1.062 in. caps all around with a 3.219 in. span on one axis and 3.625 in. on the other, so it connects the 1310 driveshaft to the 1330 yoke.
Measure the old yoke: a 1330 has 3.625 in. between the ears and 1.062 in. cap bores. A 1350 has larger 1.188 in. caps. Match what your driveshaft uses or what you are upgrading to.
Always replace the rear seal with a new yoke. If the old yoke wobbled in the housing or the bushing shows wear, replace the bushing as well, or the new seal will wear unevenly.
The 4L60E specifies Dexron VI. Check the level hot on level ground and top off any fluid lost while the driveshaft was out.
