4L80E Clutch Drum 1991, new and ready to install. Fits the 4L80E. Ships fast from the USA.
If your Chevy or GMC 2500 or 3500 pickup, Suburban 2500, Express or Savana van slips or will not pull in any forward gear but still backs up, the forward clutch drum is high on the list. This listing is a new ACDelco forward clutch drum with the ring gear already attached, GM part number 19125985, boxed and never installed. It is the starting-year part for the 1991 4L80E, and the listing states it works in all 4L80E units from 1991 on.
The 4L80E is a Turbo 400 gear train with an overdrive section bolted in front of it. The ring gear on the nose of this drum is the output member of that overdrive planetary, so everything that comes out of the overdrive unit turns the forward drum. Inside the drum, the forward clutch pack and its piston lock the drum to the main shaft whenever the selector is in a forward range. Reverse uses the direct clutch and the low/reverse band instead, which is why a forward drum problem usually leaves Reverse working.
Because the ring gear is part of this assembly, overdrive section failures can take it out too. Transmission Digest describes the overdrive roller clutch living inside the overrun clutch housing, and when those rollers come apart the debris can chip the planetary and damage the forward drum ring gear.
Start with fluid level and condition, then check line pressure in Drive and Reverse with a gauge. Normal pressure in both ranges with slip only in forward points mechanical, not hydraulic. Low pressure everywhere sends you back to the pump, filter and pressure control circuit instead. Our 4L80E common problems guide walks through splitting a complaint into hydraulic, electrical and mechanical causes, and the Silverado 2500 problems guide covers the overdrive roller clutch failure that so often damages this ring gear. Once the unit is apart, look for heat discoloration, cracks around the spline area and worn teeth before deciding to replace the drum.
This drum is listed for the 4L80E from 1991 forward, the full 1991 to 2009 run of GM 2500 and 3500 pickups, Suburban 2500, Express and Savana vans and Hummer H1, and the listing also names the 4L85E. Internal parts did change over the years, including the forward piston style, so match the part number 19125985 or compare your old drum side by side before installing. If you are not sure, send us your year and VIN and we will check it. You can see every 4L80E part we carry on the 4L80E collection page.
| Fits | 4L80E 1991 |
| Part type | Clutch Drum |
| Condition | New |
| Brand | ACDelco |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is the forward clutch drum with the ring gear attached, GM 19125985. The direct drum is a separate part that applies in 3rd, 4th and Reverse.
The listing states it works in all 4L80E units from 1991 on, and it also names the 4L85E. Compare your old drum or send your year and VIN and we will confirm it.
No. It is the drum and ring gear. Plan on new forward clutch plates, piston seals and sealing rings at the same time.
That pattern points at the forward clutch circuit. Check fluid and line pressure first; if pressure is normal, the forward clutch pack, piston seals or the drum itself are the usual suspects.
Use Dexron VI ATF, which is GM's current fluid for the 4L80E, and check the level hot in Park after the rebuild.
