Archive for the ‘Differential Product News’ Category

Jasper Engines & Transmissions, the nation’s leader in remanufactured drivetrain products, is offering complete remanufactured GM front axle actuator assemblies for 4WD and AWD late model SUVs.

These actuator assemblies fit the following vehicles:

  • 2002-2009 Chevy Trailblazer
  • 2002-2008 GMC Envoy
  • 2002-2003 Oldsmobile Bravada
  • 2004-2007 Buick Rainier
  • 2003-2007 Isuzu Ascender

“These assemblies cannot be purchased new from the dealership, only the parts can be purchased separately,” says Wayne Mehringer, JASPER Differential Division Manager.

The 4WD actuator assembly includes a new electric shift motor installed on the housing, two side gears that spline into the left and right axle shafts, along with a shift fork and collar that shifts the vehicle into, and out of, four-wheel drive. The AWD actuator has a metal plate covering the electric shift motor mount. Internally, the assembly uses a coupler gear which connects both left and right axle shafts together, making the vehicle all-wheel drive.

JASPER uses a synthetic grease in their remanufactured actuators in place of the standard lithium-style complex grease. “The synthetic grease has better lubricant flow, especially in cold conditions,” says Mehringer.

In addition, one major complaint from vehicle owners is a squealing, or squalling, noise coming from the actuator. Mehringer says the problem occurs when dry seals rub against the axle shaft. “These seals, if not pre-lubricated, will cause that condition when the shaft is turning. Here at JASPER, all axle shaft seals are pre-lubricated during assembly.”

For more information on the remanufactured rear axle assemblies and differentials of Jasper Engines & Transmissions, please call 1-800-827-7455.


The Differential Division of Jasper Engines & Transmissions tackles the job of remanufacturing the Jeep Grand Cherokee independent front suspension differential from model years 2005 and up.

Prior to 2005, Dana Corporation was the main source of drivetrain components in many Jeep products. In 2005, Jeep made a design change from a solid front axle to an independent front suspension.

“Jeep uses two hefty snap rings to adjust carrier bearing pre-load and backlash”, says Wayne Mehringer, JASPER Differential Division Manager. The snap ring in Figure 1 measured .174 thick! It requires a modified pair of retaining ring pliers to keep the ring compressed for installation. “A pinion depth shim located under the pinion bearing cup is also much thicker than the ones used in previous applications, said Mehringer.” The shim in Figure 2 measured .213 thick.

In order to properly adjust this version of the Jeep Grand Cherokee front differential, JASPER keeps in stock 98 different-sized snap rings and 75 different-sized pinion depth shims. Each component varies in thickness in .001 increments. “JASPER must keep these components in stock to properly set these units to original equipment specifications,” added Mehringer.

So when a Grand Cherokee comes to your shop needing an independent front suspension differential, give JASPER a call. Each differential is covered by JASPER’s 3-Year/100,000 mile nationwide transferable parts and labor warranty. Full warranty disclosure is available on our website or upon request.

For more information on the JASPER line of quality remanufactured products, call 1-800-827-7455.


Exceeding Expectations With Quality

Jasper Engines & Transmissions prides itself on using quality parts and components. For the remanufacture of axles, American Axle & Manufacturing (AAM) is a key supplier for authentic original equipment parts that include a variety of gears and axle components. In today’s business environment, selecting suppliers depends on a number of critical criteria. AAM provides solutions to many remanufacturers’ performance concerns, including: Cost, Durability, Quietness and Reliability. AAM utilizes advanced manufacturing techniques to exceed the normal performance parameters expected by OEMs.

One such process is a two-cut versus five-cut manufacturing process used for ring and pinion gear sets. Ring and pinion sets are often the cause for vibration, noise and durability problems in axles. A new technology developed by AAM can produce ring and pinion sets that are stronger, more durable and more quiet at a market-competitive cost.

A two-cut process uses no machining oil, compared to conventional gear cutting, making it more environmentally friendly. The two-cut process produces a better performing gear that reduces noise and vibration and increases durability. It improves the tightness of tolerances, therefore allowing fortighter backlash specifications.

AAM cuts ring gears and pinions in one operation, thereby reducing costs. In the manufacturing process, the two components are lapped together after hardening, producing a quiet gear set. Tooth height is measured from root of the gear to the crown. The two-cut tooth is the same height at the toe of the gear, as it is at the heel. This creates a natural “bias” condition, where the pattern shows up slanted when the pattern is rolled with a gear marking compound. This pattern will show more gear mating and less backlash than a conventional five-cut gear.

AAM gear sets are subject to precision shot peening to extend their life. In this process, spherical shot is bombarded to the root of the gear teeth, resulting in comprehensive stresses to combat fatigue loading. Shot peening increases the durability and reliability of the parts.

JASPER chooses to use AAM components for its axle remanufacturing, because AAM provides the same part quality found in the original vehicle products. JASPER and AAM are working hard to provide you, the installing technician, with high-quality products at market-competitive pricing.


JASPER Donates Differentials for BUV Manufacturing


Jasper Engines & Transmissions will donate ten remanufactured differentials to the Institute for Affordable Transportation (IAT) for use in their Basic Utility Vehicles (BUV).

The ten GM 7.5″ rear end differentials include drum brakes, axle shafts, an emergency brake cable, and lubricant.

Headquartered in Indianapolis, Indiana, the IAT is a not-for-profit public charity devoted to improving the lives of people in developing nations by providing simple, low-cost vehicles.

The BUV is a three-wheeled vehicle that is powered by a 10hp gas or diesel engine and uses common off-the-shelf automotive parts. It’s top speed is 20 mph; can carry up to 1,200 pounds, and has the capability to power water pumps, mills, compressors and other external machinery.

“IAT utilizes JASPER because they have high quality remanufactured differentials

and axles,” says IAT Director Will Austin. “I had heard JASPER President Doug Bawel give a speech in Indianapolis and really liked his heart for work, family and the Lord.”

The BUV has many applications and can be tailored to meet specific community needs for people in developing nations. The BUV allows for faster water delivery to remote villages, for quickened access to medical care, and for the safe transport of people and goods through rugged terrain. The most common uses include a delivery truck, school bus, water/food transporter, and an ambulance.











Catastrophic damage to GM aluminum front housings is being researched by the Differential Division at Jasper Engines & Transmissions.  Many of the cores from 2002-2006 GMC Trailblazer and Chevrolet Equinox SUVs are sent to JASPER with either cracked housings or holes blown out the side
(see figure 1).

“Several things could come into play with these premature failures,” says Wayne Mehringer, JASPER Differential Division Manager. One such issue is failure of the outer pinion bearing. “The bearings in these units are very small and cannot stand any sideward or abnormal pressure,” says Mehringer.
Another issue could involve the transfer case. “Problems either with a viscous coupler, or the internal gearing, can put extreme pressure on the drivetrain,” says Mehringer. “This extreme pressure can make the outer pinion bearing heat up and fail.”

Issues with tire circumference can also cause differential housing failure, especially with all-wheel drive vehicles. “If one of the tires on the vehicle measures larger, or smaller, than the other three, this puts extreme pressure on the outer pinion bearing,” says Mehringer. “The bearing will eventually heat up and come through the side of the housing.

During the remanufacturing process, JASPER utilizes a retaining compound to help keep the outer pinion bearing from spinning within the aluminum housing (see figure 2). “JASPER will also use new ring and pinion gear sets, pinion bearings, differential case bearings, axle shaft bearings, a collapsible spacer, thrust washers, pinion seal and axle shaft seals,” added Mehringer.