M-35 starting from a stop around town, notice
rpm vs mph when in 5th, it's like another gear.

M-35 from a stop to 65 mph at full throttle.
Are you looking for a way to have more speed from your truck? For years people have talked about ways to gain more top end. Larger tires have been the most often used way but this affects all gearing and is harder on the clutch and brakes. The solution came to me a few years ago after reading some spec sheets on the civilian version of the Spicer 3053. The civilian version, usually a 3153, came behind a gas motor which turned much higher rpms. Because of this, the transmission had more reduction in the lower gears. To achieve any top end, it then needed to have more teeth on the 5th counter shaft gear and fewer on the 5th main shaft gear, in effect an overdrive, just as the 3053 has. So it occurred to me that if only this gear set was put in a military transmission, this would result in more overdrive there. Now it would have been very convenient to just buy some gears for the Spicer 3153, but they are so old that even used parts no longer exist. While it is possible to produce several ratios, .69 has been shown to be the best ratio for the M-35 as it will accommodate stock 9.00x20 and 11.00x20 tire sizes and works well with the popular 14.5R20.

The .69 sets can also be used in repowered M-37 vehicles, (it is quite common to use a 4BT and the 3053 transmission), and M-35 based vehicles that have been shortened. The main shafts being modified are new Spicer shafts, your second gear needs to be modified to match the newer production with oil passages (see picture) that allow for much better lubrication. 5th gear is also mounted on needle bearings as well as 2nd for increased reliability.

The .69 overdrive kit will include gasket set, a new main shaft, needle bearings, syncro hub for 2/3 syncro, 5th gear and sleeve for needle bearings on main shaft, and 5th counter shaft gear. New syncro hubs and bearings are available at an additional low cost, should you need them.

Pricing: It is my goal to offer this to people as economicaly as possibly, but there are considerable costs involved. The complete set of parts will cost $1344.

Price includes unlimited technical support. If you can remove the transmission from your truck, you can install this kit, it does not require any special tools other than a bearing puller and access to a small press.

(Click on photos for larger view)

Kit Contents

Test truck at highway speeds
$1344.00 and free shipping
Pricing Policy

Click here or on image above to purchase a 0-70mph speedometer for your M35-series truck
Truck Requirements
How to take the transmission apart
How to put the transmission back together
Charts: View the MPH for each transmission gear
How to modify your 2nd Gear
Photos of the changes to your transmission

Page last updated 07-03-2014
Tom Bauer (410) 549-6649 Email Waterloo Specialties