TH700R4 to Dana 300 - 0.75" thick plus Rotation Plate
Kit Components
Kit #10-1001 -- $575.00 $460.00 ON SALE!
NOTES:
- ADAPTER THICKNESS - 0.75" BILLET ALUMINUM
- INCORPORATES A 0.75" BILLET ROTATION PLATE
- PROVIDES 4-POSITION CLOCKING OF THE DANA 300
- KIT INCLUDES A 1-PIECE, ALLOY MAINSHAFT FOR THE TH700R4
- GRADE 8 - 12 POINT BOLTS ARE SUPPLIED IN THIS KIT
- A NEW INPUT GEAR IS SUPPLIED FOR THE DANA 300
Assembled views
Installed photo
Features which set our adapter apart from others are reflected in the quality of the machine work exhibited in the kit components. The rotation plate and adapter are machined from solid blocks of T6061 aluminum. Each component is 0.750" thick. A new output shaft for the TH700R4 is supplied in the kit along with a new 23 spline input gear for the Dana 300.
The adapter plate is milled to exact tolerances with large radius corners and a thick mounting foot. We do not suggest the use of the stock transmission support mounting face found on the bottom side of the transmission tailhousing. Using this stock transmission support mount creates substantial stress in the tailhousing of the TH700R4 by allowing the entire weight of the transfer case to be "cantilevered" from the four 10mm bolts in the TH700R4 tailhousing. This is a common break point on TH350's and TH700R4's. Stripped threads and cracks in the tail section of the case are not uncommon. Our solution to this problem is to provide a strong mounting base machined into the overall part. This "foot" mount allows all of the vertical weight load of the transfer case to be transferred through the adapter, onto the rubber or urethane mount therefore removing the load from the rear of the transmission case.
Adapter
The rotation plate supplied in the kit provides 4 optional mounting positions for the Dana 300. This feature allows for better ground clearance and the use of flat skid plates. Read more about the design benefits of this rotation plate here.
Photo of cutaway
Driveshaft clearance is a critical element when using this kit. The oil pan on the 700R4 does not allow as much clearance as the TH350. Vehicles using wide front axles and having the front differential yoke farther from center than stock will be better candidates for this kit than a Jeep CJ with a stock front axle and a mild lift. Taller lifts, coil-over springs, and wide front ends are much more conducive to a narrow adapter such as this. When using a Dana 300 with a TH350 or TH700R4, it is best to build the driveshaft with a smaller OD and a heavy wall thickness. Oil pan modifications can be made to the TH700R4 to allow for more driveshaft clearance.
Layout of TH700R4 and Dana 300 with 1-1/4" driveshaft
Layout of TH700R4 and Dana 300 with 1-1/4" driveshaft
This kit also provides a new input gear for your Dana 300. Our new input gear has 23 splines cut to match perfectly with the new TH700R4 output shaft. Oil seals are used in the adapter plate and the rotation plate to guard against leaks.
Spline Engagement:
Our adapters are designed to be short in length however we do not sacrifice spline engagement in any case. In fact, our main goal is strength over length and as you can see in the photo, our new mainshaft allows for a full 1.5" of engaged spline.
Close up of the new input gear with seals against surface
FRICTION WELDING is a common practice used in manufacturing processes for "hybrid" mainshafts found in transfer case adapter kits. Low production costs are among the incentives for using the friction welding process. Our company does NOT use this process. We only produce new, 1-piece mainshafts with our adapter kits. Notice the results printed in the destructive testing section of this site. Our shaft yields a torsional strength value more than twice the amount found in a welded shaft.
Worm gear comparison
Installation Tips:
The stock Dana 300 input gear must be replaced with the new input gear supplied in the kit. This is an extremely easy task to perform. View the instructions for this task here.
A small portion of the gusset shown in the photo must be removed to allow for clearance of the nut. This modification does not weaken the case.
Gusset area marked for removal
The two studs in the front face of the Dana 300 should be removed. A tight bolt clearance can be noted near the governor cap on the side of the TH700R4 and TH350. We supply a 3/8"x3/4" 12-point bolt for use at this point however you may choose to use a short stud and nut. If you choose to use the bolt provided in the kit, it will be necessary to tighten this bolt as the transfer case is pulled toward the adapter during mounting.
Short bolt in place.