TH400 Master Rebuild Kit 1965-98, new and ready to install. Fits the TH400. Ships fast from the USA.
This is the TH400 kit for builders who want more than stock paper in the clutch packs. It pairs a complete Alto professional overhaul kit with Alto Red Eagle frictions and Kolene-treated steel plates, and it fits Turbo 400s from 1965 on, from big-block muscle cars and Chevy and GMC trucks to motorhomes and street-strip builds. If your 400 slips and flares under load, burns up its direct clutch, or is coming out of a car that now makes more power than it did, this kit renews every friction surface and seal in one order.
Bands, bushings, a filter and a modulator are not part of this kit, so measure and inspect those during teardown and order what you need.
Alto builds Red Eagle lining with a dual saturation process, first in phenolic resin and then in a silicate, which gives it a high friction coefficient and better heat resistance than standard paper. In a TH400 that means the forward, direct and intermediate clutches lock up faster and spend less time slipping on each shift, so they make less heat. The steels are Kolene treated, a salt bath nitriding process that Alto says raises wear and fatigue resistance and helps the plates resist hot spots and warping. Together they suit a 400 that sees towing, high stall converters or a lot of throttle.
Low fluid, a leaking modulator or a misadjusted kickdown switch can mimic worn clutches, so rule those out and do a line pressure test. The TH400 valve body testing guide shows how to separate a valve body fault from a clutch failure. If budget is the deciding factor, our TH400 rebuild cost breakdown shows where the money goes in a typical job.
The kit is made for TH400 units from 1965 onward and covers GM cars, light and medium duty trucks, vans and motorhomes that use the Turbo 400. Clutch counts differ between car, truck and racing builds, and some performance drums take extra plates, so count your packs at teardown against the kit before you start, and send us the year, vehicle and VIN if you want us to check first. All of our parts for this transmission are on the TH400 page.
If the forward or direct drum shows heat damage, replace it with a TH400 clutch drum rather than resurfacing it, and check the TH400 sprag clutch for rollover. The TH400 wear points guide covers the hard-part upgrades worth making on a high-power build.
| Fits | TH400 1965-98 |
| Part type | Master 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.
No. It contains the Red Eagle frictions, Kolene steels and the full Alto overhaul kit of gaskets and seals. Bands, bushings, filter and modulator are bought separately after you inspect the old parts.
Red Eagle is Alto's go-to material for performance use, but it works in a street-driven TH400 as long as clutch clearances are set correctly. It shortens lock-up time and reduces heat in the clutch packs.
It is made for 1965-on TH400 units. Heavy-duty units can use different clutch counts, so count your packs at teardown or send us the year, vehicle and VIN first.
They are steel reaction plates treated in a salt bath nitriding process. The treatment hardens the surface so the plates resist wear, hot spots and warping better than untreated steels.
Dexron ATF. Plan on about 10 to 11 quarts for a dry unit with an empty converter, plus whatever the cooler and lines hold, then set the level hot on the dipstick.
