4-to-1 LoMax™ Gears

4:1 LoMax Gears

Part #2307 -- $845.00

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The LoMax gear set has been designed to achieve maximum gear strength and the lowest possible reduction ratio for the Jeep Dana 300 transfer case. For over 2 years, the LoMax gear design effort has been an independent project of JB Conversions, Inc. and bears no affiliation with any other aftermarket gear manufacturer. The LoMax design features that set it apart from others are incorporated into all areas of the gears. Tooth volute shapes and face finish, gear hub thicknesses, and manufacturing tooling & processes yield a gear set far superior to any other gears being produced for the Dana 300. The LoMax gears were designed as a complete 5-gear "set" from the very beginning. This means there were no strength-limiting tooth size restrictions forcing the new gears to mesh with smaller stock gears. As you will see in the accompanying photo comparisons, the result of this "clean slate" philosophy is a set of gears with massive, helical gear teeth with tremendous strength capacity.

Another practice commonly used in aftermarket gear production is one that we have chosen NOT to adopt. This practice involves the use of two piece gear construction. Several of the gears used in competing gear sets are manufactured using a process which calls for pressing and welding two gears together to form one piece. This two-piece process allows for a more simple manufacturing process and much cheaper gear cutting tools. The strength of a solid gear over a comparable sized two-piece gear is indisputable. All LoMax gears are cut from a single slug of alloy. The cutting tools required for this type of construction are extremely expensive however we feel the benefits are well worth the investment.

The LoMax gears are not entirely new. They have been proven through the rigors of western rockcrawling and the high throttle abuse characteristic of the Tellico area of North Carolina. The LoMax gears are compatible with both the long and short tail versions of the Dana 300. Although not required, it is highly recommended that a complete rebuild accompany the installation of the LoMax gears. Supplimental rebuild kits are available from JB Conversions, Inc.. New detent springs are also available in our optional Twin Stick Ball & Spring Kit. We have found in many cases that twin stick applications will create a tendency for disengagement of the clutch rings while under load. Often this condition is amplified with the installation of lower range gears. For this reason we recommend the use of the optional Twin Stick Ball & Spring Kit.

The track record of the LoMax gearset has been excellent. Western rockcrawling competitors use our gears as well as many of the heavy footed folks who power their rigs through the rigors of Tellico N.C. and the mud bogs of the Northeast.

When the LoMax gears were prototyped in 2000, the intended use was strictly hard core abuse. Our gears were tested in the rigs shown below. 39.5" and 44" tires accompanied with two hot small block Chevys and a hopped up AMC 401 put our gears to the test and they all passed without a flaw.


Owner: Keith at OffRoad Connection, 39.5" tires, Vortec 350, Dana 60's


Owner: John, 44" tires, 350 small block, Dana 60's


Owner: Sam, 42" tires, AMC 401 V8

ATLAS II Comparison

The LoMax gearset was designed to equal or surpass any low range gear set currently on the market. Gear teeth achieve their strength largely in part to the cross sectional shear area of the tooth. The Atlas transfer case is longer than a Dana 300 case therefore the gear teeth are made wider than the stock Dana gear teeth. Obviously a Dana 300 low range gearset can’t be made wider than stock without changing the case. HOWEVER, the LoMax design does achieve tremendous strength by increasing the tooth thickness. The LoMax gear teeth are significantly thicker than the AtlasII gear teeth.

To illustrate the differences between the AtlasII and a LoMax equipped Dana 300, check out the following photos. We disassembled an AtlasII and compared the gears to the LoMax gears. Judge for yourself.

The LoMax gear is the gray gear on the right, Atlas is on the left (Fig.1). These are the intermediate gears. The low range side of these gears are the small sides. This is the side of the intermediate that encounters maximum stress while in low range.

Gear Comparison

FIG: 1

Here is a closeup of the gears once again (Fig.2,2a). The large tooth gear on the left is one of the mating low range gears in the LoMax set.

Gear Comparison

FIG: 2

Gear Comparison

FIG: 2a

We placed one of the LoMax low range gears into the AtlasII to further illustrate the overall size of the gears (Fig.3).

Gear Comparison

FIG: 3

The increasing popularity of our LoMax gearset has allowed significant increases in production quantity. These production increases have resulted in much lower costs for raw materials and lower machining costs "per piece". The savings we have gained from these advances has allowed a tremendous drop in price to the customer.

Other gearsets on the market are available however we feel their design basis has an origin of being a "retrofit" kit therefore the strength is equal to or less than stock. When the reduction ratio of a gearset is lowered, either the tooth cross-section should increase to sustain tooth strength or the material of construction must have a higher stress limit. We have seen low gearsets with tooth profiles no larger than stock. We feel these low gear sets are weaker than stock as there is no appreciable material upgrade in the steel used for the gears themselves (we checked).

Two-piece gear construction is an accepted manufacturing method in modern gear manufacturing HOWEVER, one-piece construction is preferred when dimensional restraints allow it. As mentioned, all LoMax gears are one-piece construction to achieve maximum strength. Notice the photo comparisons below:

The LoMax gear teeth are significantly larger and stronger than the Tera Low gear. The web of the gear is also thicker than the competition. The LoMax gear is not a pressed and welded gear as is the competitor’s piece. All LoMax gears are manufactured as one-piece.

The LoMax Idler Gear is precision ground and designed with maximum tooth size and strength.

Notice the larger center-section of the LoMax gear. The LoMax idler gear is machined from solid alloy with no surface imperfections which contribute to stress concentration.

As mentioned above, no LoMax gears are formed from pressed and welded parts. The tooling required to produce the one-piece gears is expensive however the strength benefits well justify the added tooling cost.

Additional Info

Installation Instructions

Install Instructions

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