Tech Tip: Kia 4WD Mode Inoperative On the 2000 Sportage, the four-wheel-drive mode may become inoperative (diagnosed either during or after replacing the knuckles and hub seals) due to insufficient vacuum being applied to the hubs. In some cases, moisture has entered the vacuum system and vacuum lines have become corroded, plugged or ­developed a leak. Corrective Action: Verify that w More

Tech Tip: Honda Drivetrain Noise/Judder from Rear of Vehicle If a customer with a 2003 and later Pilot or 2006 and later Ridgeline complains of a noise and judder from the rear of the vehicle when turning, the VTM-4 differential fluid could likely be contaminated by clutch wear, condensation or both. This causes the VTM-4 differential clutches to make noise and to judder when turning. More

Tech Tip: An Economical And Effective Way To Refinish A Seal-Worn Shaft Grooves from shaft wear can allow oil to leak out, which can result in bearing damage and failure. More

Tech Tip: A/T, M/T Crossmember Service Precautions When performing service work or installing an accessory short-throw shifter on any Subaru vehicle, it’s extremely important that the transmission is supported properly when removing or reinstalling the cross member. If not, damage to the bolts and/or threads will occur. Service Tips: 1. Support the transmission using a transmission jack, regardl More

Diagnosing Mercedes-Benz Low Range Light Flashes, Code P1831 If you receive customer reports in the affected model vehicles of the low range light flashing rapidly (18 times) after vehicle start with fault code P1831 (positioner motor, position sensor or power supply is faulty) in transfer case ECU, do not replace the transfer case motor. More

Honda Tech Tip: Rear Differential Moan or Groan On 2002-'07 CR-Vs with 4WD, a moaning or groaning noise may come from the rear differential when making a sharp or tight turn at low speeds. This condition may be caused due to contamination in the rear differential fluid. More

Nissan Tech Tip: Chirp Noise on 2-3 Upshift If a 1999-2000 Quest or Altima exhibits a “chirp” noise as the automatic transmission shifts from 2nd to 3rd gear, particularly when accelerating the vehicle with only 1/8 throttle applied, the noise may be coming from the high clutch assembly during operation. This noise can be eliminated by adding two bottles (200 cc each, 400 cc total) of Automatic Transmission Fluid Treatment... More

Tech Feature: Mass Airflow Sensors Are Critical In Today's Engine Management Systems In addition to providing an exact measurement of airflow into the engine, airflow sensor inputs can be used to provide a load-sensing input to the powertrain control module (PCM) to help control the shift points and shift quality of an automatic transmission. More

Tech Tip: Chrysler Intrepid Won't Shift, DTCs Set Automatic overdrive transmission goes into second gear (limp-in mode) and will not shift, and trouble codes for the transmission solenoid pack are stored in memory. More

Tech Tip: Put a Damper on Booming Astro Van Harmonic with Rear Axle Parts Some 1995-2004 Chevrolet Astro Van and GMC Safari owners may complain about a "boom" noise inside the vehicle while driving at speeds between 60-65 mph. This condition is most noticeable from behind the driver's seat. The noise may result from an engine-firing harmonic, which becomes noticeable at torque converter clutch (TCC) lock-up. A new rear leaf spring damper kit (one per spring) has been developed... More