5L40E Sprag Clutch, used and ready to install. Fits the 5L40E. Ships fast from the USA.
If your BMW or Cadillac with the GM-built 5L40E five-speed pulls away like it is in second, slips or bangs on takeoff, or rolls in Drive with no first gear at all, the low sprag is the part to look at. This listing is a used low sprag (the inner roller clutch the 5L40E uses for first gear) supplied together with the low/reverse clutch assembly it works beside. The unit carries BMW part number 24407504300 and the reference number 134577, and it came out of a BMW application. It is sold as-is from a running take-out, so you get a complete, matched assembly instead of a loose sprag.
The 5L40E uses one Ravigneaux planetary set, nine clutch packs and four mechanical one-way clutches: the forward sprag, the intermediate sprag, the 2nd clutch sprag and the low sprag. The low sprag sits behind the center support and holds the planetary carrier against rotation in first gear when you are driving forward. Because it is a one-way device, it simply freewheels when the transmission shifts to second, which is what gives the 1-2 shift its clean, no-overlap feel.
The low sprag only holds under drive load. When you coast in first or select a manual low range, the TCM applies the low/reverse clutch instead to give engine braking, and the same clutch is applied in Reverse along with the reverse lockout circuit. Check ball number 8 in the valve body directs either low/reverse fluid or reverse lockout fluid into that clutch. That is why the sprag and the low/reverse clutch are serviced as a pair: they share the same space and splines, and the sprag race engages the low/reverse plates on assembly.
The ATSG manual for the 5L40-E is clear that the low sprag cannot be taken apart. Its retainer is crimped in place, and if anything inside is worn the factory service part is the complete assembly. A used complete assembly is the practical repair.
A sprag that slips in first only, while manual first and Reverse are fine, points away from the pump and pressure control. Check fluid level and condition first, then read our transmission slipping diagnosis guide to separate a mechanical slip from a pressure problem, and the flare versus slip guide if you only feel it during the shift. On the bench, hold the hub and turn the outer race: ATSG specifies the low sprag outer race should freewheel counter-clockwise and lock clockwise. If it locks both ways, turns both ways, or feels rough, the assembly is done.
This assembly fits the 5L40E family, the five-speed GM unit BMW calls the A5S 360R. It was used in BMW 3 Series cars from the 1999 model year and later spread to other BMW models and to GM cars such as the Cadillac CTS. The 4L40E four-speed version uses a different planetary carrier, so do not mix parts between the two. GM car versions and late updates can differ in details, so compare the spline count, race diameter and photo against your old part, or send us your year, model and VIN and we will check it. More parts for this family are on the 5L40E and 5L50E parts page.
| Fits | 5L40E |
| Part type | Sprag Clutch |
| Condition | Used |
| Brand | GM |
| Ships | From the USA |
| Warranty | 1-year |
It is the low sprag (inner roller clutch) together with the low/reverse clutch assembly it works with, removed as a matched used unit. It carries BMW part number 24407504300 and reference 134577.
No. The ATSG 5L40-E manual notes the low sprag has a crimped retainer and cannot be taken apart. If it is worn, it is replaced as a complete assembly.
That pattern fits a slipping low sprag well. In manual first the low/reverse clutch holds the carrier, so it can mask a failed sprag. Confirm fluid level and pressure first, then bench test the sprag rotation.
Do not assume it will. The 4L40E four-speed shares the case but uses a different planetary carrier and leaves out the 2nd clutch parts, so match your old part before installing.
If the old sprag broke up, plan on an overhaul kit, a new filter and pan gasket, and a cooler flush. Debris from a failed sprag will damage the replacement if it is left in the unit.
Yes. After any internal repair, clear codes and run an adaptive relearn or reset the TCM adaptives with a scan tool so the shifts settle in correctly.
