Parts for the
T90 Transmission

Name: O-ring, 1/16 fractional width
Brand: Novak
SKU: 9452K59
Price: 0.07 USD
Availability: OutOfStock

Shop individual T90 parts on the exploded diagramClick any number on the diagram to find that part · 48 parts available online

The T90 is as much a tradition as it is a transmission for classic Jeep people. It is a legendary gearbox and surprisingly tough. However, a couple of the T90's kinks are a bit legendary themselves. We carry what it takes to iron them out and make lasting improvements.

After 40 years of rebuilding these transmissions, we've assembled the most complete master rebuild kits available anywhere.

A T90 that pops out of second gear, has excessive noise, leakage and looseness in operation can be repaired and solved.

The Master Rebuild Kit

Kit T90MR-J, master rebuild, T90 transmission, Jeep, 1945-1971, includes Novak extra-hardened counter shaft

Product Details

Right Stuff Gasket Maker Liqui Moly SAE 85W-90 GL-4 Gear Oil, 1 qt 4 qt fill

Version:

We provide a curated selection of parts, including our specially hardened cluster idler shaft which will provide far longer service and quieter operation, as well as a sealed input bearing and plug method, which can eliminate leaks when used in conjunction with the factory felt seal, which is superior to the conventional method of using the felt seal alone.

Our master rebuild kits have been assembled for our customer's rebuilds as well as the hundreds of rebuilds we do at Novak. It is the most complete kit we've seen anywhere and features all the consumable and wear item components. Cut-rate "BK" basic kits seen on the market don't hold a candle to the Novak kits' quality and completeness.

These rebuild kits set the industry standard for reliability, using only premium bearings and seals from proven manufacturers like Timken, JTEKT, Nachi, CR Seals, and more. No single brand makes every part we require, so we hand-select each component to ensure unrivaled performance and longevity.

T90 Rebuild Kit Compatibility (International / Scout T90)

Our T90MR-J master rebuild kit fits the vast majority of T90 transmissions (roughly 90%). Some International / Scout T90 variants use a few parts that differ from common Jeep T90 specifications. If you have an IH T90, verify the items below before ordering.

Synchronizer keys (struts/dogs/pawls) width: Our keys measure approximately 0.221" wide. If your keys are a different width, the synchronizer assembly may not function correctly with our keys.
2nd gear helical direction: Compare your 2nd gear helix direction to the gear shown in this photo: T90 top view photo . If your helix direction does not match the photo, our included 2nd gear will not interchange. In that case, select T90MR-X2 (the kit without 2nd gear).
Input shaft needle rollers (input-to-mainshaft) diameter: In rare cases, IH units use larger needle rollers inside the input gear where it couples to the mainshaft. Our needle rollers measure approximately 0.217" diameter.

If your transmission matches the specifications above, the rest of the kit components will apply. If one of these items differs, the kit will still cover the transmission except for the components that measure differently. If you’re unsure, contact us and we’ll help you identify your version before you order.

Novak kits include:

World class deep ball roller (sealed version for the input) and needle bearings
New second gear
Premium seal with best sealing forms and materials
Thick, strong gaskets
Precision brass synchro (blocker) rings
Top cover rebuild components: plugs, poppet springs, balls, interlocks, etc
New synchronizer struts and springs
Idler shafts retaining plate
Cluster / counter shaft spacer
Fastening hardware; bolts & washers
Instructions, based on our own in-house rebuilds
Access to Novak's T90 rebuild techs if you have rebuild questions

Rebuild Requirements

It is very common for our customers to do top-level rebuild work, using good methods and by following our instruction guide.

We suggest the rebuilder have access to a set of snap ring pliers and pullers in addition to a standard tool set.

T90 Exploded Parts Diagram

Click a number on the diagram to find that part, or search the list. 48 of the 72 parts listed can be ordered online — for anything else call 877-602-1500.

Red callouts on the diagram are in the master rebuild kit. The sealed front bearing is supplied but not pictured.

Pinch or use + to zoom

Available onlineCall to order / not sold separately

Front bearing to case retaining ring
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Input shaft to bearing retaining ring
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Front input bearing, sealed
#643721-S Sealed T90 Front Input Ball Bearing w/ Retaining Ring Groove
In master rebuild kit
$34.95
Front input bearing
#643721 T90/Early NP435/T150/SM420 35-Spline Output Ball Bearing w/ Retaining Ring Groove
$29.95
Front input bearing slinger
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Input shaft, T90A — 18-tooth, short
#640428 T90A Input Shaft, 18 Tooth (Short)
$86.25
Input shaft, T90C — 16-tooth, short
#643246 T90C Input Shaft, 16 Tooth (Short, 9-1/8" OAL)
$113.50
Input shaft, T90J — 18-tooth, 11.5" long
#906203 T90J Input Shaft, 18 Tooth (11.5" Long)
$160.25
Input to mainshaft needle rollers
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Synchronizer ring, 3rd
#640397 T90J/T90A/T90C/T86 Synchronizer Ring, S30T (0.358" Wide Slots)
In master rebuild kit
$11.95
2nd/3rd hub to mainshaft retaining ring
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Synchronizer spring, 2nd/3rd
#640394 T90 2nd-3rd Synchronizer Spring
In master rebuild kit
$2.49
Synchronizer keys, 2nd/3rd
#640395 T90 2nd/3rd Synchronizer Key (3 Req’d)
In master rebuild kit
3 required
$1.20
Synchronizer keys & springs kit, 2nd/3rd
#T90-K T90 2nd/3rd Synchronizer Keys & Springs Kit
$10.95
Synchronizer hub, 2nd/3rd (assembly with slider)
#640391 Assembly, synchronizer, 2nd – 3rd, T90 transmission, Includes the hub and slider
Call to order
Synchronizer spring, 2nd/3rd
#640394 T90 2nd-3rd Synchronizer Spring
In master rebuild kit
$2.49
Sliding clutch, 2nd/3rd (assembly with hub)
#640391 Assembly, synchronizer, 2nd – 3rd, T90 transmission, Includes the hub and slider
Call to order
Synchronizer ring, 2nd
#640397 T90J/T90A/T90C/T86 Synchronizer Ring, S30T (0.358" Wide Slots)
In master rebuild kit
$11.95
2nd gear (Jeep)
#906197 T90 2nd Gear, 30-R22T (Jeep)
In master rebuild kit
$82.50
Mainshaft
#640390 T90 Main Shaft
$112.00
1st/reverse sliding gear
#906199 T90 1st-Reverse Sliding Gear, S29-S10T
$80.50
Mainshaft to rear bearing spacer
#643621 T90 Transmission Mainshaft Bearing Spacer
$11.95
Rear bearing retainer / adapter
#644552 T90 Rear Output Bearing Retainer (3-5/32")
$29.95
Rear output bearing
#6307N Ball Bearing 6307N, Snap Ring Groove, 80mm x 35mm x 21mm (T150/T90/T86 Rear)
In master rebuild kit
$22.95
Transfer case input gear washer, 7/8"
#A1410 Flat Washer, 7/8", Dana 18/20
In master rebuild kit
$4.00
Transfer case input gear nut, nylock
#940970 Jeep/Dana Mainshaft Nut, Nylock (7/8"-16)
In master rebuild kit
$4.79
Cluster gear front thrust washer
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Cluster gear, T90A/T90J
#906200 T90A/T90J Cluster Gear, L33-26-19-S14T
L33-26-19-S14T
$255.00
Cluster gear, T90C
#643702 T90C Cluster Gear, L35-26-19-S14T
L35-26-19-S14T
$280.00
Needle bearing spacer washers
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Cluster shaft spacer tube, slotted
#802414 Countershaft Spacer Tube, Slotted, T90
In master rebuild kit
$4.99
Cluster shaft needle rollers
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Cluster gear rear thrust washer
#T90A-CSTW T90 Rear Cluster Thrust Washer
In master rebuild kit
$3.99
Case to cluster gear thrust washer
#922607 T90 Small Parts Kit
In master rebuild kit
Only sold in the T90 small parts kit
$41.95
Cluster (counter) shaft — ultra-hardened
#640412-N T90/T86 Counter Idler Shaft (Ultra-Hardened)
In master rebuild kitNovak upgrade
$84.00
Countershaft kit — ultra-hardened
#640412-NK T90/T86 Countershaft Kit (Ultra-Hardened)
Novak upgrade
$88.00
Reverse & cluster shaft retaining plate
#937459 T90 Reverse Idler Shaft Retaining Plate
In master rebuild kit
$1.60
Reverse idler gear with bushing
#640417 T90 Reverse Idler Gear (Incl. Bushing)
$61.75
Reverse idler shaft
#640420 T90 Reverse Idler Shaft
Call to order
Top cover shift rail port plug
No longer available
Not sold separately
Shift rail poppet spring
#A966 Dana 18/ Dana 20 Shifter Poppet Springs
In master rebuild kit
$4.24
Shift rail poppet ball
#38G25 Detent Poppet Ball, 0.375"
In master rebuild kit
$0.89
Top cover bolt
In master rebuild kit
Comes in the master rebuild kit
Top cover lock washer
#91102A030 Washer, lock, split, 5/16, zinc plated
In master rebuild kit
Call to order
Top cover (control housing)
Not sold separately
Shift rail interlock
Not sold separately
Front bearing retainer bolt
In master rebuild kit
Comes in the master rebuild kit
Front input bearing retainer (to 4-cyl engines)
#640422 Jeep T90 Front Input Bearing Retainer to I4 Engines
$37.95
Front input seal (Jeep)
#11111 Input Oil Seal, T86/T14/T15/T150/SR4/T176
In master rebuild kit
$12.95
Front input seal, T90A/T90C
#640422RS T90A/T90C Input Oil Seal
$11.95
Front input seal (IH Scout)
#12364 Seal, oil, front input, IH T19, IH T90 and IH NP435 transmissions
$18.95
Front bearing retainer gasket
#923301 T90 Transmission Gasket Set
In master rebuild kit
Sold in the T90 gasket set
$8.78
Shifter cane spring
Not sold separately
Top cover gasket
#923301 T90 Transmission Gasket Set
In master rebuild kit
Sold in the T90 gasket set
$8.78
Oil collector bolt
In master rebuild kit
Comes in the master rebuild kit
Oil collector
Not sold separately
Drain plug
Not sold separately
Transmission case
Not sold separately
Fill plug
Not sold separately
Rear gasket, to transfer case
#8187 Dana 18 Front Face Gasket, 3-5/32" Bore, 1941-1971, T90
In master rebuild kit
$4.34
Shift fork, 2nd/3rd
Not sold separately
Shift fork to rail pin
#937870 Pin, shift fork, T90 transmission
In master rebuild kit
Call to order
Shift rail, 2nd/3rd
Not sold separately
Shift rail, 1st/reverse
Not sold separately
Shift fork, 1st/reverse
Not sold separately
Shift fork to rail pin
#937870 Pin, shift fork, T90 transmission
In master rebuild kit
Call to order
Side-shift shaft oil seal (side-shift versions)
#640383 T90 Side Shift Shaft Oil Seal
$13.95
Shifter cane
Not sold separately

Also for the T90 — not pictured

Small parts kit
#922607 T90 Small Parts Kit
In master rebuild kit
$41.95
Gasket set & front seal
#923301 T90 Transmission Gasket Set
In master rebuild kit
$8.78
Tapered oil-port plugs
#6448K89 Plug, tapered, EPDM, 11/32”, T90 oil port
In master rebuild kit
Call to order
O-rings
#9452K59 O-ring, 1/16 fractional width
In master rebuild kit
Call to order

For IH Scout T90 parts, contact us and we'll help you determine which rebuild kit or parts will be appropriate.

Parts for the
T90 Transmission

The Master Rebuild Kit

Product Details