TH400 Banner Rebuild Kit 1965-98, new and ready to install. Fits the TH400. Ships fast from the USA.
A Turbo 400 that slips on the 1-2 shift, takes a beat to grab Drive or Reverse, smells burnt on the dipstick or drips from more than one seal usually needs the same thing: new frictions and a full reseal. This Alto banner rebuild kit is listed for the TH400 from 1965 through 1998, which covers the big-block cars, Chevy and GMC C/K pickups, G-series vans and motorhomes, and the 3L80 trucks of the late 1980s. It is the middle ground between a gasket-and-seal overhaul kit and a master kit with steels, bands and bushings.
A banner kit pairs the overhaul set (paper and metal gaskets, the pan gasket, clutch piston lip seals, O-rings, sealing rings and metal-clad seals) with a new set of friction plates in the same box. In a TH400 those frictions live in three packs: the forward clutch that applies in every forward gear, the direct clutch that applies in third and Reverse, and the intermediate clutch that holds for second. The two bands and the roller clutch round out the hold devices, but most high-mileage failures come down to burnt or glazed frictions and hardened piston seals that leak apply pressure. Replacing both together restores clutch capacity and sealing in one teardown. The frictions in this kit are Alto's red high-energy material, a popular choice for street builds that see towing or extra power.
Check level and condition with the engine running, then drop the pan. Lining material and black sludge mean burnt frictions; brass flakes point at bushings; steel glitter means hard-part damage the kit alone will not fix. A line pressure test with a gauge separates a leaking circuit from a worn pump or sticking valve, and our TH400 common problems and fixes guide walks through those checks. If the unit whines with engine rpm and loses engagement only when hot, read the TH400 pump failure guide first, because new frictions will not survive a tired pump.
This kit is listed for the TH400 and 3L80 from 1965 through 1998. The basic clutch and seal layout stayed the same across those years, but early 1965-1967 switch-pitch units and some truck applications use different pump and stator parts, and drum stack-ups vary with how many frictions a builder runs. Count the frictions in your forward, direct and intermediate packs at teardown and compare them to the kit before you start. If you are unsure which TH400 you have, send us the year, vehicle and VIN or the ID plate code and we will check it. Every early and late part is on the TH400 parts page.
If the direct drum is cracked or the bushing is worn, add a TH400 clutch drum, and a TH400 shift kit firms the shifts so the new frictions spend less time slipping. Our TH400 rebuild wear points guide lists the hard parts to inspect while the case is open, and the TH400 rebuild cost guide shows where a banner kit fits in the budget.
| Fits | TH400 1965-98 |
| Part type | Banner Rebuild Kit |
| Condition | New |
| Brand | Alto |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
A banner kit is the overhaul gasket and seal set plus new frictions. A master kit usually adds steels, bands, bushings, a filter and sometimes a modulator. If your steels, bands and bushings measure good, a banner kit covers the parts that actually wore out for less money.
Yes. GM renamed the TH400 the 3L80 for 1987, and the kit is listed through 1998. Count the frictions in each pack against the kit at teardown, since heavy-duty and modified units can run different stack-ups.
This listing is a banner kit, so plan on reusing good steels and bands and buying a filter separately. Replace any steel that is blued, warped or glazed rather than putting it back against new frictions.
Use a current licensed DEXRON automatic transmission fluid. A rebuilt unit with an empty converter takes far more than a pan refill, so add fluid in stages and set the final level on the dipstick at operating temperature.
Not always. Hot-only slipping and late engagement often come from a worn pump or pressure regulator bore. Pressure test the unit hot before the rebuild and repair the pump at the same time if it falls below spec.
