Master overhaul kit for the Jeep T90 three-speed manual, with the bearings, thrust washers and small parts you replace on a full teardown.
A T90 that whines in every gear, grinds going into second, or jumps out of gear on the overrun is telling you its bearings and blocking rings are done. This Crown Automotive T90-MASKIT master overhaul kit is built for the Warner T90 three-speed behind the four-cylinder CJ-2A, CJ-3A, CJ-3B, CJ-5 and CJ-6, and it puts the bearings, seals, gaskets, blocking rings and small parts for a full teardown in one box.
The T90 was the standard three-speed in Jeeps from 1946 to 1971. Novak describes it as a top-loading, cast-iron box with a six-bolt top cover, synchronized second and third gears, and spur-cut first and reverse. Power comes in on the input gear, drives the cluster (countershaft) gear in the bottom of the case, and goes back up to the mainshaft through whichever gear the shift forks have locked. Every one of those shafts rides on bearings, and second and third rely on brass blocking rings to match speeds before the sliding sleeve engages.
Decades of use wear the bearings, open up end play on the mainshaft and cluster, and round off the blocking ring teeth. The gears themselves usually survive; the parts in this kit are what actually fail.
Start with the clutch: drag from a worn clutch or a bad pilot bushing can feel like a synchro problem. Check the oil level, then with the engine idling in neutral listen for noise with the pedal up and down. A whine that stops when the pedal is down is the input bearing or the cluster spinning. Jumping out of gear under decel points to worn blocking rings, shift detent springs or excess end play. If you are weighing a rebuild against a swap, our manual vs automatic repair cost guide lays out what a manual rebuild really costs.
The kit is listed for Jeeps from 1945-1971 with the T90, including CJ-2A, CJ-3A, CJ-3B, CJ-5 and CJ-6, with other references naming the CJ, SJ and J-Series. The T90 came in more than one version: the four-cylinder T90A1 (1946-1962) and T90C (1963-1971) share a 15/16 x 10 spline input, while the T90J used behind six-cylinder trucks has a longer 1-1/8 x 10 spline input and a different front seal. It does not fit the T86, which looks similar but uses helical first and reverse gears, or the T14, T15, T18 or T176. Pull the top cover and confirm what you have, or send us your Jeep year and serial number and we will check before it ships.
Mock up the gear stack dry before you commit the countershaft so you only assemble it once.
| Manufacturer part number | |
| Brand | |
| Transmission | |
| Fitment | |
| Warranty | |
| Shipping weight |
It is listed as including bearings, seals, gaskets, blocking rings and small parts for the T90. Lay the contents out against your teardown before assembly so you know what is new and what you are reusing.
The T90 was the standard three-speed in 1946-1971 Jeeps, including the CJ-2A, CJ-3A, CJ-3B, CJ-5 and CJ-6, plus some utility trucks, wagons and J-Series trucks. It was paired with the Dana 18 transfer case.
No. The T86 looks like a T90 but uses helical first and reverse gears, and the T14, T15, T18 and T176 are different transmissions. This kit is for the T90 only.
Worn blocking rings, weak shift detent springs and excess mainshaft or cluster end play are the usual causes. New bearings, thrust washers and blocking rings restore the clearances that keep the sleeve engaged.
Novak recommends a conventional mineral or para-synthetic gear oil rather than a full synthetic for the T90. Fill until it reaches the bottom of the fill plug hole.
