4L80E Shift Kit 1991-2013, new and ready to install. Fits the 4L80E. Ships fast from the USA.
If your 4L80E or 4L85E keeps cooking the direct clutch, gives a soft, slipping 2-3 shift under a load, or throws gear ratio and solenoid performance codes, this is the kit built for that problem. It is a new TransGo 4L80E-HD2 reprogramming kit (TransGo T34169E) for 1991 to 2013 General Motors vehicles with the 4L80E or 4L85E: Chevrolet and GMC 2500 and 3500 pickups, Suburban 2500, Express and Savana vans, Hummer H1 and swap builds.
The direct clutch handles third gear, stays on in fourth, and also applies in Reverse. TransGo calls the third gear clutch the weak spot of this transmission. The HD2 kit attacks it two ways. First, a laminated triple separator plate dual feeds the direct clutch, which TransGo says triples its torque capacity, and it does it without dismantling the transmission. Second, it recalibrates the valve body, pump and internal parts to work with a higher line pressure curve, so clutches apply firmly instead of slipping.
The kit also fixes the boost valve. A worn boost valve and bushing can cause low pressure, which brings soft 2-3 shifts and direct clutch failure, or runaway boost pressure, which can crack the case and break the direct drum and piston. HD2 replaces it with a hardened, wide land boost valve and bushing and adds an EPC boost relief valve system as a safety limit.
A reprogramming kit corrects hydraulic weak points, but it does not fix a failed solenoid, harness or sensor. Codes such as P0751 or P0756 can come from a bad shift solenoid or a pass-through connector, so test those first with our 4L80E shift solenoid diagnosis guide. Check the pressure control solenoid and line pressure too; the 4L80E harsh shift causes guide walks through it. If the direct clutch has already burned, the kit belongs in an overhaul, not as a band-aid on a slipping unit.
TransGo lists the HD2 for 1991 to 2013 GM vehicles with the 4L80E and 4L85E. That covers both early and late valve bodies, but the 4L80E did change over those years (valve body castings, pressure control solenoids and accumulator parts), so read the TransGo instructions for your exact year before drilling or swapping any part. If you want a milder kit, compare the TransGo SK 4L80E shift kit. For anything else for this transmission, browse the 4L80E collection.
| Fits | 4L80E 1991-2013 |
| Part type | Shift Kit |
| Condition | New |
| Brand | TransGo |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. TransGo lists the 4L80E-HD2 for 1991 to 2013 GM vehicles with either the 4L80E or the 4L85E.
Not for the main reprogramming. TransGo says the triple separator plate dual feeds the direct clutch without dismantling the transmission. The return springs and snap rings in the kit are for when the unit is apart.
It raises line pressure and firms shifts for durability. It is aimed at towing, work and higher power use, so expect firmer shifts than stock.
Only if the cause is hydraulic. TransGo lists P0756 among the codes the kit helps, but a failed shift solenoid or harness sets the same code, so test those first.
A tired pressure control solenoid, the valve body and pan gaskets, and, if the direct clutch is burned, a full set of frictions and steels.
Dexron VI ATF, checked hot.
