Retail Price: $505.87
The 700R automatic transmission adapter to the Jeep New Process 231 is 1.50" in length. The adapter material is 356 T6 heat treated aluminum alloy and has a provision for a transmission mount. The adapter kit includes an adapter housing, new 700R4 output shaft, upgraded NP231 (23 spline) input gear, bearing, snap rings, o-ring, seal, gasket, fastening hardware and adapter instructions.
The adapter assembly will fit the Jeep NP231 transfer case with a 21spline input shaft. Introduced in 1988, the Jeep NP231 is a part-time transfer case became the standard for XJ and YJ models. It was also used in six cylinder ZJ models through 1995. Chain driven with a 2.72:1 low range, it's reliable even with more than stock horsepower applied.
This kit is designed for exclusive use with our new main shaft that fits the 700R-4 / 4L60 manufactured thru 1996. The overall case length of the transmission is 23.375", has a non-removable bell housing, and a 4 bolt square rear case. Late model 4L60E automatics will have a removable bell housing and a 6 bolt hex pattern rear case. The late model automatic will require an additional Advance Adapter to work with this kit (50-0405).
Engine conversions for off-road vehicles are popular with both old & new models. We have been involved with engine and transmission conversions for more than 30 years and are not surprised when we see a new vehicle with less than 10,000 miles having an engine swapped. Since you are venturing out beyond the boundary of the corner gas station and local repair shop, you should be aware that off-road driving is quite different than street driving. Once you pull onto a dirt road, your vehicle must be capable of returning you and your passengers back to civilization. The best, single reason for an off-road 4WD engine conversion is reliability. If your 4WD cannot deliver this, then you're in serious trouble. Make sure that when making a change on your off-road vehicle it is done with the best equipment and design available. Don't short change your conversion for components that will give you less reliability.
There will always be situations where more power would be nice such as when towing a trailer, turning those big new tires, or falling short from the top of a hill. A common mistake of many off-road drivers is overpowering the existing drivetrain. If additional power is required and the stock transmission specifications and rear axle torque rating have been exceeded, then you might be required to use a stronger substitute. Jeeps have been equipped with several types and sizes of engines. In order to assist you, we have listed the various stock engines that were used throughout these years.
150 CID 4 Cylinder Engine TBI (1987-02)
148 CID 4 Cylinder Engine (2.4) (2003-05)
258/4.2L CID Straight 6 Cylinder (1972-90)
4.0L Straight 6 Cylinder (1991-05)
2.8L V6 Engine (Cherokees) (1984-86) GM
2.5L V6 Engine 151 CID (XJ) (1984-00) GM
4.0L Engine (XJ) (1987-01)
2.4L & 3.7L Engine (KJ) (2002-05)
Select a motor which best fits the use of your vehicle. We manufacture motor mounts, bellhousing adapters, headers, and transfer case adapters for Chevy, Chevy Gen III V8's, Ford, Dodge & Dodge Hemi, Buick V6 & some AMC motors. Within these range of motors, every practical need can be met.
Many people become overly concerned about moving the transmission, resulting in driveshaft modifications. The value of a good engine location requiring driveshaft modifications will far exceed the expenses of an installation requiring special cooling due to poor engine location.
We design most transfer case adapters to eliminate driveshaft modifications (whenever possible). This normally pertains to the newer type Jeeps with the longer wheel base. In order to position your new engine, it is usually mandatory that the original engine mounts be removed from the chassis. When placing the new motor into the chassis, several factors determine the best possible location.
A. Firewall Clearance: Allow adequate clearance between the distributor & firewall. Be sure that the distributor can be removed easily. Make sure the engine can be worked on without having to remove it from the vehicle.
B. Front Axle Clearance: Check the oil pan and harmonic balancer for axle housing clearance. Double check the suspension clearance if bottoming out. Location of the motor mounts will require some vehicles to relocate their front axle snubber.
C. Hood Clearance: When the air cleaner is in position, will the hood still close? On certain applications, special low profile air cleaners or a 1â€ body lift may be required .
D. Driveshaft Clearance & Angularity: The front driveshaft should have sufficient clearance to pass the bellhousing and starter. On vehicles 1987 & newer, the drivetrain may have to be offset towards the passenger side or centered in the frame rails. Make sure that the driveshaft's do not bottom out when the suspension is collapsed. The angle of the rear driveshaft is very critical, and compensation can be made by either axle shims or lowering the transfer case.
E. Radiator Clearances: Proper spacing and centering of the fan with the radiator is necessary for optimum cooling. If you are having a problem in this area, an alternative is an electric cooling fan. These fans are popular for engine conversions, since they can be mounted on the front or backside of the radiator and don't require engine placement considerations when using an engine-driven fan.
F. Exhaust Manifold/Header Clearance: If headers are planned for the vehicle, it is best to purchase them before the installation of the engine. Although we make headers for several different applications, a perfect fit can never be guaranteed. When locating the engine, have the headers or stock manifolds in place and check the following for clearances: firewall, brake & clutch pedals through travel, steering box or linkage, body & frame, heater/defroster, and battery. When placing the engine into position, be sure and have your engine exhaust system mounted on the engine. This ensures all proper clearances are maintained.
I. Oil Filters: Oil filters can be a real problem especially on Ford conversions. The filter on Ford engines is locate up front on the driver's side, and this can interfere with the stock steering or suspension components. If additional clearance is needed, we suggest a remote oil filter. We offer remote oil filter kits for most engines.
J. Motor Mount Installation: The motor mounts we manufacture are designed for specific applications, along with some universal applications. Some are a bolt-in style, while others require welding. The universal mounts are designed to fit a variety of frame widths. The channels that extend to the block are slotted, allowing a choice of engine placement.
â€œLâ€ brackets on weld-in mounts should be welded entirely around the perimeter. All welding should be done by a certified welder. When using a double donut design mount, make sure that the donuts properly index to the â€œLâ€ bracket and the bolts are properly tightened. Mount bolts should be checked periodically.
Once the engine has been selected, you will now need engine mounts. We offer several combinations that will fit Ford, Chevy, Dodge, and Buick blocks. On most Ford and Chevy applications, we standardize our mounts by using a special dual rubber donut, locked together with special hardened bolts. This combination offers a positive means of securing the engine for the most severe off-road conditions.
Most of our mounts are universal and can be adjusted to accommodate the best possible engine location, while others are very specific and offer no alternate for changes. Our universal Chevy and Ford side mounts are the most popular style for Jeep engine conversions. The mounts are furnished so that they can be either welded or bolted into position, and are fully adjustable so that the engine can be offset.
The universal mounts are now available in two styles; one for the Jeep universals, and one for the wider framed vehicles that will fit up to 30.500" frames. We also offer a saddle-type mount for Chevy engine conversions that works well for vehicles with frames from 25" to 30". In the Buick V6 category, we also offer a universal Buick V6 engine mount that utilizes our double donut design and is fully adjustable, similar to the Chevy and Ford engine mounts.
In conjunction with all engine mounts, you will need to use a rear cross member mount. This is usually the same mount with a new location adjusted to the new engine position. Two mounting points are all that is ever required with most installations. This will allow for plenty of engine flexibility and will eliminate transmission and engine vibrations.
We have been doing engine conversions for over 40 years . We've learned the hard way to count only on top-quality & proven design installations. Our mounts are secured with a 5/8â€ diameter bolt between the engine brace and frame bracket. No rubber vulcanization failure will let you down. To assure that you have the premier engine mounts that we offer, make sure our name is on the box. Do not accept look-a-like takeoffs. We are the â€œ4-Wheel Drive Expertsâ€ and have the quality to prove it. 4.3 INTO YJ 5 SPEED
K. YJ Steering Shaft and Mounting upgrades: The stock steering shaft normally does not present any clearance issues with new engines. We have found that as these Jeep get older, the stock steering shaft does develop end play. We now carry heavy duty replacement steering shafts for Jeep YJ's. Jeep's original steering shaft assembly was not designed for the added stress of body lifts and oversize tires. We carry the Bergeson's replacement assemblies which have a telescoping shaft with two precision needle bearing u-joints. The steering assembly is easy to install with common hand tools. Once installed, you will experience much tighter and more responsive steering.
P/N 716871 YJ STEERING SHAFT POWER & MANUAL BOXES
Steer your Jeep YJ easy without interference. This new mounting plate moves the YJ steering box 1â€ forward, increasing the clearance between the tie rod and drag link. This provides more clearance making it less likely to have steering bind. This mounting plate is made with 1/2â€ steel for strength and reliability. P/N 716855
Universal Motor Mounts Jeep YJs: The universal mounts we manufacture are a high quality mounting system. The â€œLâ€ brackets in these kits are made out of 3/8â€ material and designed to handle any style of driving. These universal mounts allow for lateral and vertical placement in the frame rail to maximize you drivetrain fit. The installation of these mounts will require the removal of you stock engine mounts.
Chevy V6 & V8:
P/N 713001-S - 1987-1996 Jeep YJ Chevy V8 motor mounts
P/N 713005 - 1987-1996 Jeep YJ Chevy V8 LT1 motor mounts
P/N 713088 - 1987-1996 Jeep YJ Chevy V8 Gen III & LS1 motor mounts
P/N 713006 - 1987-1996 Jeep YJ Ford small block V8 motor mounts
P/N 713011 - 1987-1996 Jeep YJ Buick V6 motor mounts
Dodge V8 & Hemi:
P/N 713095 - 1987-1996 Jeep YJ Dodge V8 (318/360) motor mounts
P/N 713097 - 1987-1996 Jeep YJ Dodge Hemi motor mounts
1987 to 1996 Jeep YJs: We offer a bolt-in saddle motor mount for the Chevy engines. This mount is designed to replace both the stock 4 & 6 cylinder Jeep engines, and is designed around a stock oil pan. If you are using an aftermarket oil pan, the maximum depth in the front is 3-5/8". This motor mount will not work with LT1 or 383 Stroker motors.
We have designed this mount to position your new engine in the best location possible. Driveshaft modifications may be necessary depending on your application. This mount will allow 1-1/4" of overall adjustment from front to rear. The stock Jeep motor mounts need to be completely removed from the frame before installing the new saddle mount. An electric fuel pump is required for ALL applications.
P/N 713087 - Chevy V8 to Jeep YJ (bolt in mount)
1997 to 2005 Jeep TJs: We now offer motor mounts for Chevy and Mopar engines. The mounts are designed to replace both the stock 4 & 6 cylinder Jeep engines and also work on both stock and lifted TJs; however, a 1â€ body lift is recommended on most applications and required on Gen. III engine installation.
P/N 713090 - Chevy V8 to Jeep TJ 4 cyl. replacement (bolt in mount)
P/N 713091 - Chevy V8 to Jeep TJ 6 cyl. replacement (welding is required)
P/N 713092 - Gen. III V8 to Jeep TJ 4 cyl. & 6 cyl. replacement (welding is required) JEEP TJ 5.3 GEN 3
P/N 713093 - Gen. III V8 to Jeep TJ 4 cyl. & 6 cyl. with AC replacement (welding and frame mods. required)
Dodge V8 & Hemi:
P/N 713094 - Dodge 318 to Jeep TJ 4 cyl. & 6 cyl. repl. (welding is required)
P/N 713098 - Dodge Hemi to Jeep TJ 4 cyl. & 6 cyl. repl. (welding is required)
P/N 713096 - 4.3 V6 to Jeep TJ 4 cyl. & 6 cyl. replacement (welding is required)
Advance Adapters â€œOff Roadâ€ Mounts: We carry an â€œOff Roadâ€ series motor mounts for the hard core 4-wheel enthusiast. These mounts are a weld-in design that use a horizontal neoprene isolator. These mounts are designed to handle the abuse of the roughest type of trail
P/N 713206 - Jeep YJ & TJ Stock Rubber Mount Replacement
Jeep Cherokee XJ Mounts: We manufacture motor mounts for installing a Chevy V6 or V8. Our mounts require the original motor mounts to be removed from the frame rails. The engine mounts will set the Chevy engines at a height that will provide minimum hood clearance. Engines equipped with throttle body fuel injection, will need to modify the air cleaner.
A suspension lift is mandatory in order to have the proper suspension clearance. Failure to use a suspension lift will not provide the proper engine clearance which will cause both engine and suspension damage. The engine mounts are designed for a direct bolt in conversion. The stabilizer assembly on the driver's side will need to be reinstalled to the new engine mounts.
P/N 713109 - Jeep Cherokee to Chevy V8 mounts
P/N 713117 - Jeep Cherokee to Chevy V6 mounts
In 1987 Jeep began the gradual introduction of the New Process 231 transfer case. The Np231 was initially introduced in Cherokees, followed shortly thereafter into the Wrangler. Jeep enthusiasts initially received the transfer case with mixed opinions. Many jeepers hoping for the grand old days of the gear driven Dana 300 were obviously a little disappointed. Skeptics aside, the medium duty NP231 proved itself reliable and capable for most applications. The transfer case is by no means perfect, but coupled with aftermarket upgrades; the NP231 transfer case meets the expectations of most jeep consumers.
Identification and Features
The chain driven NP231 was offered with a driver side front driveshaft shaft assembly only. The rear output shaft offer a centered slip yoke design. The slip yoke feature caused the transfer case to be somewhat long at 21.5”. The Np231 continued to utilize the round circular six bolt pattern as seen on the previous NP207 and Dana 300 transfer cases. The Np231 case was a die cast aluminum 2 piece design. The standard 231 weighs approximately 70 lbs.
One of the easiest ways to identify the NP231 is the metal tag located on the back of the transfer case. This red and silver tag offers some valuable information concerning the transfer case. This tag indicates from top to bottom: the model type, production build #, date, and lastly 2:72; identifying the standard low range for the Np231.
The input shafts were available in either 21 or 23 splines. These inputs were further offered with a short or long design. These variations were determined by year, engine size, and transmission options. The chart below gives a general breakdown of not only length and spline count but also includes a pitch difference found on the internal planetary gear portion of the various input shafts.
The NP231 operates as 4 basic functions: 2H, 4H, N and 4 low. Since the transfer case is a chain driven design, a true twin stick is not functionally available. There are internal aftermarket kits available which allows for a 2wd rear low only function.
The speedometer feature of the NP231 can be broken down by three different styles. The speedometer was always located in the rear nose cone of the NP231. The 1987-1991 used a standard mechanical drive which basically turned a cable. In 1992, The Np231 featured a similar mechanical drive however the spinning gear was converted to a digital square wave signal. The interchangeable plastic gears were the same as previous mechanical units. These replaceable gears allow the consumer to quickly and easily recalibrate their speedometer when doing common tire and ring and pinion changes. The TJ introduced a similar vehicle speed sensor (VSS) however the speedometer drive used a new shorter gear assembly.
Strength and Upgrades
The NP231 has long been the topic of many campfire debates as well as internet forum arguments. There has been much discussion as to the strength of this transfer case. In some corners, the transfer case has been proven durable and dependable; capable of handling V8 power, larger tires and moderate off-roading. For others, they view the transfer case as problematic with questionable manufacturing design choices. Both ranges of opinions hold some validity. Luckily with the support of the aftermarket, numerous fixes and upgrades are available. These include wider chains, heavy duty planetaries, low range gears, and fixed yoke kits. The most common upgrade to the NP231 by far is the “fixed yoke kit” also known as an SYE (slip yoke eliminator). More information can be found here PNNP231-SYE concerning the NP231 fixed yoke kit.
These upgrades eliminate certain pitfalls and clearly strengthen the transfer case. For some off roaders, the cost of upgrades with limited results just doesn’t fill the void compared to a gear driven transfer case. The consumer should heavily weigh his driving style, build choices, and most importantly: his options. We have seen many Wrangler owners who have installed numerous upgrades including lower gearing to the tune of $1600-$1800 only to replace the transfer case. Aftermarket transfer cases such as the Atlas have brought back dependable gear driven options to the market.
GM 700R4 & 4L60 Transmissions
The 700R4 Automatic Overdrive Transmission was GM’s answer to the American consumer’s desire for better fuel economy. First introduced in 1982, the 700R4 was met with wide fanfare as the ideal transmission. The transmission featured an impressive 30% overdrive while also offering a low first gear of 3.06. The improved fuel economy added with a low off-road first gear made this transmission an immediately popular choice for conversions.
The 700R4 was basically designed to replace the retired TH350 transmission. The 700R4 was used in rear wheel drive passenger vehicles, S-series trucks, Blazers, ½ ton pickups and even a few ¾ ton trucks. The transmission was offered with the standard V8 90° bolt pattern which also included the 4.3 V6. A smaller 60° bolt pattern was also available for some smaller V6. Engines like the 2.8. The bolt pattern on the rear of the transmission was the same 4-bolt pattern as the TH350 but used metric bolts. The transmission always used a 27 spline output shaft. The 4wd output shaft protruded out of the transmission with a stick out length of 2.75". This stick out was approximately 2" longer than the TH350. 700R STOCK 4X4 700R-4L60 shafts
Another unique feature to the 700R4 was the lock up torque converter. This feature essentially locked up the torque converter to create a direct mechanical connection similar to a manual clutch transmission. By locking the converter at highway speeds the slip of the converter was eliminated. The results were lower RPMs and significant loss of generated heat. Although the 700R4 is not an "electronically" controlled transmission, this feature was controlled by a PCM. We offer a lock up kit under Part # 23-700R which can be used with carbureted engines or applications outside of the GM engine family. The 700R4 also uses a TV cable (or Throttle Valve) to control the shift points and line pressure. It is critical that special attention be used during the adjustment of the T.V. cable. Although GM should be credited with the introduction of such a revolutionary transmission, the transmission did suffer from a few glitches. GM persevered with the development of the 700R4, and to their credit, the transmission received all of the necessary upgrades by 1987. Something else to consider in researching and selecting a 700R4 is the wide aftermarket support available. Automotive aftermarket manufacturers have had over 25 years to master and perfect this transmission. The availability of better clutch packs, shafts and building techniques has allowed this transmission to reach several strength levels. The 700R4 can now be built around the consumer’s needs, which spread a wide spectrum from conservative highway vehicles to extreme completive racing and rock crawling vehicles.
In 1990, GM decided to code and rename their transmissions, the 700R4 is best described as a 4 speed, longitude transmission rated for vehicles around 6000 lbs. It was this information that was used to change its name to 4L60; therefore, a 700R4 and 4L60 are the same transmission. Later the transmission would become electronically controlled and the name was changed to 4L60E.
In 1990, GM decided to code and renamed their transmissions, the 700R4 is best described as a 4 speed, longitude transmission rated for vehicles around 6000 lbs. It was this information that was used to change its name to 4L60; therefore, a 700R4 and 4L60 are the same transmission. Later the transmission would become electronically controlled and the name was changed to 4L60E.
Forward Speeds .... 4
Dates Produced .... 1982 - 1990
Manufacturer .... General Motors
Case Length .... 23.375
Bellhousing Length ... Integral
Over All Length .... 23.375
Case Material ... Aluminum
Output Shaft Spline .... 27
1st Gear Ratio .... 3.06
2nd Gear Ratio .... 1.63
3rd Gear Ratio .... 1.00
4th Gear Ratio .... .690
Reverse Gear Ratio .... 2.29
Transmission Weight .... 175lbs