Frequently Asked Questions

Q. What are the noises I hear from my differential?

A. There are several different types of noises and indicators of differential problems. Here are a few of the most common.

• A constant rumbling noise on acceleration and deceleration usually means that the pinion bearings are bad.
• A whirring noise at lower speeds most likely indicates a bad carrier bearing or axle shaft.
• A howling or whining sound, typically at a certain range of speed, can be a worn out ring and pinion.
• A banging or clunking noise while driving straight usually means a broken ring gear or pinion tooth/teeth.
• A banging or clunking noise when making a turn would indicate broken spider gears and/or carrier case.
• A vibration would most likely not indicate a differential problem but could be a bad u-joint or out of balance driveline.
• Inspect all seal areas periodically for any leakage. There is a pinion seal at the end of the driveline. There are axle seals out by the wheels which can be inspected by removing the brake drums or rotors in most cases. Also, check around the cover or third member for any oil leaks.

Q. How much is it going to cost to repair my differential?

A. Each repair will vary somewhat depending on the extent of damage. Rebuild with new bearings & seals using same ring & pinion: 4 to 6 hrs. Install ring & pinion, and bearings and seals if needed: 5 to 7 hrs. Install limited slip or locker, without removing pinion: 3 to 4 hrs.

The following is a list of variations or exceptions to the above rule which could make the job more difficult, or easier, and require an adjustment to the cost:

Rear-end is brought in out of the vehicle: Subtract 1.5 hrs. Three quarter and one ton trucks: Add 1 hrs. General Motors independent front suspension: Add 3 to 4 hrs. Late model independent front suspension (excl GM): Add 1 to 4 hrs. Two-piece tapered axles: Add 1.5 hrs. Motor homes or large Box Vans that do not fit on common lift: Add 4 to 8 hrs.

Q. What kind of warranty do I get on my parts and/or labor?

A. Any shop that is familiar with rear ends will probably have some limitations to their warranty. Some of the common warranty restrictions that we use in our shop are: Mini and mid-size trucks (Jeeps®, Ford Rangers with 7.5" diff, Toyota trucks) with tires taller than 31"; half ton trucks with tires taller than 33"; three quarter and one ton trucks with tires taller than 35"; trucks used for towing have a shorter than standard warranty; and vehicles used for competition or racing are not warranted. These may seem like extreme limitations, but they are sometimes necessary to protect the shop from people (like myself) who abuse their vehicles on or off road.

Q. Why did I lose power when I put different tires on my vehicle?

A. Any time you change tire sizes you ultimately change the drive ratio to the wheels of your car, truck, van, Jeep, or SUV. The loss of power can be corrected by simply changing the ratio to accommodate the tire change. Check out our On-line Calculators to compare the best gear ratio for your vehicle. Click here to link to Calculators

Q. What are the torque specifications for my Ring Gear Bolts and Main Carrier Cap Bolts?

A. Each differential torque specifications vary depending on nut or bolt size. You can obtain the specifications for your differential from our extremely detailed Installation Instructions provided by Yukon Gear. You MUST have Adobe Acrobat to open the .pdf file. Click here to open and/or print the Yukon Installation Instructions, which we helped write.

Q. Do I need to break in my new ring and pinion gear?

A. Yes! All new ring and pinions should be broken in to avoid over heating or over loading and burning up. We recommend a specific break-in procedure that has worked for our own service shop over the past fifteen years. First, NO towing, heavy loads, or hard acceleration for the initial 500 miles. Next, for the first 100 miles you should drive 15-20 mile increments under 60mph and then let the differential set and cool for at least 15-20 minutes. At the 500 mile mark you should have the differential oil changed. This removes all the loose shavings from the new gear and phosphorus material from the oil. Small price to pay to prolong the life of your differential. Also, after 500 miles you can start towing or carrying heavy loads. We recommend that for the first 45 towing miles you drive in 15 mile increments again due to the fact this is the first real load the gear will see and as the ring gear flexes there will be contact on new portions of the ring gear and pinion gear teeth.

Q. How do I calibrate my speedometer?

A. There are several different ways of correcting your speedometer depending on what kind of vehicle you have. For mechanical speedometers you can change the drive or driven gear in the transmission or transfer case if the correct tooth count is available. If there is not a drive/driven gear available then you can install a calibration gear box between the cable and the drive/driven gear. If your vehicle is equipped with an electronic speedometer you may need to purchase an aftermarket calibration programmer or take your vehicle to a dealer/speedometer shop and have it calibrated.