The Jeep & IH Dana Spicer 300 is a phenomenally good transfer case on the trail and street. Professional level rebuild work is possible for the conscientious shade tree rebuilder.
We offer nearly all parts at the component level, and our master rebuild kit, which includes the most thorough collection of parts offered anywhere.
For 1980 Short Output Jeep D300
For 1981-1986 Long Output Jeep D300
For 1980 IH Scout D300
Our master rebuild kit has been assembled for our customer's rebuilds as well as our own. It is the most complete kit we've seen anywhere and features all bearings, seals, gaskets, O-rings, fork inserts, output yoke nuts & washers, shims & small parts - everything required to bring your 300 to peak strength and tune. We use only premium (Timken®, BCA®, Nachi®, Torrington® and Koyo®) bearings. Our exclusive intermediate shafts are made at Novak from a triple-alloy gear steel and case-hardened to exceptional hardness and are the strongest and hardest shafts available. They also feature o-ring grooves at both ends, assuring a better seal than factory; extra o-rings are also included.
If you're unsure of whether you've got the 1980, short output style 300, or the 1981- , long output style 300, read our Knowledge Base article, here.
All kits include all the bearings, seals, gaskets, shims, small parts, intermediate shaft, and comprehensive rebuild guide.
This kit fits all Jeep Dana 300 Transfer cases and IH Dana 300 transfer cases as specified above.
These kits are a reduced version of our Master Kits. They contain the specially hardened intermediate shaft, O-rings, thrust washers, bearings, and snap ring.
This extended capacity, billet bottom pan is the answer to a few Dana transfer case dilemmas. Its rigid construction replaces the thin, warped factory pans virtually assuring a drip-free seal and adds rigidity to the transfer case. The pan is made of corrosion resistant 6061 aluminum and then anodized clear for further protection.
Two designs are available for the Dana 300:
Included are the stainless socket head button cap screws, drain plug, and sealing washer.
There's not a better gaskets and seals kit available. This one makes it possible to have a Dana 300 and a drip-free garage floor. The pan gasket itself (usually the most problematic) is cut from a rubber-cork compound.
There's not a better gaskets and seals kit available. This one makes it possible to have a Dana 300 and a drip-free garage floor.
The Dana 300 is a very strong transfer case in stock form. However as power levels or loads go up, you start to find the weak links in any chain. After a good solid rebuild with our center pin, the next place to look to upgrade is the output shaft. That is the “fuse” in a D300. We carry two 32 spline heavy duty output assemblies for the Dana 300. With our 300RX you also get a much shorter assembly.
The factory output shafts are strong, but 26 splines just doesn't cut it for Jeeps seeing greater strains due to tire size, terrain difficulty, Jeep weight and power.
We are proud to offer the ultimate rear output assembly for the D300 transfer case, our own 300RX
This kit comes largely pre-assembled and includes the 32 spline output shaft, tailhousing, opposed tapered roller bearings and cups, seal, drive flange, drive flange nut, reluctor ring, breather fitting, port plug, shims, and pilot bearing. The speed sensor is not included and available separately below to meet your applications needs.
Highlights of the 300RX:
The 300RX is compatible with all versions of the D300 1980-1986 including the 1980 short and IH. It works with all known gearsets and adaptations in standard or flipped configuration with dual breather ports to accommodate either orientation. Because of the extreme short length, it will only accommodate an electronic speed signal. 3 pulse (stock later model Jeep) or 40 pulse (standard late GM) reluctor options are available. If no sensor is ordered, that port will come with a plug where the sensor would go.
If you do not require the Novak super short drive shaft, or on a budget, we've partnered with TeraFlex to provide a quality solution for you. The HD300S still allows you to retain your factory speedometer. This kit however will not fit any Jeep Dana 300 transfer case made in 1980, or any scout Dana 300 transfer cases. The TeraFlex Low300 heavy duty output kit replaces the stock output shaft of the Dana 300 transfer case (1981-86) with a heavy-duty output shaft. The new shaft is better suited for high-torque and high-stress situations because it is thicker and stronger. It is great when combined with the Low300 gear set because of its additional strength.
Chrysler/Jeep, three-wire square wave, generally used with the 3 pulse wheel
GM, two-wire sine wave, generally used with the 40 pulse wheel
The most common factory (1981-1986) version of the Dana 300 (left) vs. the Novak 300RX version, making for the shortest Dana 300 on the planet.
For comparison, the following measurements are from the rear face of the transfer case to the center of the universal joint:
Installation is straightforward, requiring the removal of the original factory tailhousing assembly. Prerequisite to this is the removal of the intermediate shaft assembly and front input shaft assembly. The endplay of the shaft bearings is already pre-set, simplifying reassembly by the installer.
The dual pattern flange will accept most any of the 1300 series joints in either a single u-joint or CV /Double-Cardan. Driveshaft length and connection will need to be changed. The following mating flanges are some of the more common types.
This version of the HD output will work on 1981-1986 D300 models. It will not fit 1980 or IH versions. Supplied with a 1310 CV style yoke and otherwise mirrors the stock length and speedometer compatibility while adding a substantial strength improvement.
The factory shaft input splines were roll forged, and not as precisely as can be achieved with rotational shaper cutting. As a result, factory splines seem to wear down excessively. Novak's 23 spline input shaft is a precision, hardened replacement for factory 23 spline shafts when used with the SR4, T4, T5 transmissions or in certain conversion applications. Because of the extended input splines of this shaft, they are not compatible with the T176 transmission.
Upgrading the factory 2.6:1 gearset to 4:1 creates a 35% deeper crawl ratio. We recommend the Tera LOW300 set.
IH 6 Spline Manual Transmission Version
IH 23 Spline Automatic Transmission Version
The TeraLow 300 gearset will change your 1980-1986 Jeep Dana 300's low range ratio from the 2.6:1 to 4:1. This kit is fairly easy to install. There are no drive shaft changes, or special shift linkage required. It comes complete with all necessary gaskets and seals. A new shift rail with increased detent pockets help prevent it from popping out of gear when using "2 Low" in twin stick applications. Special poppet spring shims for adjustment are also included.
The IH Scout transfer cases will require some internal case grinding. Instructions are included.
Most all of the parts for the Dana 300, including gears, shafts, etc. are available new and affordably so. Our parts ordering module is provided below.
It is very common for our customers to do top-level rebuild work, using good methods and by following our included instruction guide. We suggest the rebuilder have access to a set of snap ring pliers, and a small arbor press, in addition to standard shop tools. A detailed rebuild guide is included with the master rebuild kits.