Yukon Gear 8.75in Chrysler Axle Bearing Adjuster & Seal Kit

A classic Mopar with the Chrysler 8-3/4 rear that growls at speed and changes pitch in a sweeping turn, weeps gear oil onto the brake shoes, or clunks as the axles walk in and out has usually worn out its tapered axle bearings or the seals behind them. This is the Yukon Gear and Axle AK C8.75-OEM-COMPLETE kit, the factory-style repair: new axle bearings, inner and outer axle seals, retaining plates, and the threaded adjuster with its plate. Yukon lists it as servicing both sides, so one kit does the whole rear end.

What this kit does in a Chrysler 8.75 rear

Unlike a C-clip axle, the 8-3/4 holds each shaft in the housing with a tapered roller bearing pressed onto the axle behind a bolted retainer plate. Because a tapered bearing has to be set, not just pressed in, Chrysler put a threaded adjuster in the right-side housing end. The left axle goes in fully seated, then the adjuster on the right is turned to set axle shaft end play across both shafts. The inner seal rides in the axle tube and keeps gear oil in the housing; the outer seal keeps oil and dirt away from the bearing and the brakes. Chrysler's own 1964 feature notes describe the all-rubber inner seal used on 8-1/4 and 8-3/4 axles from that year and the end play adjustment procedure shared by the 8-1/4, 8-3/4 and Sure Grip units. This kit replaces every one of those parts at once instead of reusing a tired adjuster or a hardened seal.

Symptoms of worn 8.75 axle bearings and seals

• Growl or hum from the rear that rises with road speed and changes when you load one side in a turn
• Gear oil on the inside of the brake drum, soaked shoes, or a wet backing plate
• Clunk or knock as the axles shift side to side, a sign of too much end play or a loose adjuster
• Rough or notchy feel when the wheel is spun by hand with the drum off
• Low gear oil level with no leak at the pinion or cover

How to confirm before you buy

Jack the rear up, grab the tire top and bottom, and rock it; then push and pull on it to feel in-and-out movement. Pull the drum and look for oil on the shoes or backing plate. A bearing growl can sound a lot like ring and pinion whine, so drive it on and off the throttle: gear noise changes with load, bearing noise follows speed and cornering. If the noise is the gears, the job grows into a full setup with the Chrysler 8.75 741 master bearing kit and an 8-3/4 ring and pinion installation kit instead of axle bearings alone.

Fitment

The listing covers the Chrysler 8-3/4 inch rear axle with factory-style tapered axle bearings and a threaded end play adjuster. The 8-3/4 was used across Plymouth, Dodge and Chrysler cars from the late 1950s into the 1970s, and those cars also came with the smaller 8-1/4 and the Dana 60, which take different bearings. Count the cover bolts and check the casting on the third member before you order, and if anything was swapped over the years, send us the year, model and what is stamped on the housing so we can confirm. Shafts that have been converted to sealed ball bearings need the Yukon 8.75 sealed ball axle bearing instead. More axle parts are in our rebuild kits category.

Install notes

• Press the old bearing and retaining collar off with a proper axle bearing press setup, and press the new bearing on until it seats fully against the shoulder. Do not heat or hammer it on.
• Drive the new inner seal squarely into the axle tube and lubricate the lip so it does not run dry on first start.
• Install the left axle fully seated with its retainer nuts at the factory torque, then fit the right axle and set end play at the adjuster with a dial indicator on the axle flange, using the range in the service manual for your year.
• Fit the adjuster lock and retighten, then recheck end play; a reading out of range means another pass at the adjuster.
• Clean the backing plates and replace oil-soaked brake shoes, then refill the housing with the gear oil your rear end calls for. Sure Grip units need a friction modifier.
• If the pinion seal is weeping too, the Chrysler 8.75 crush sleeve eliminator kit is worth doing in the same weekend.

Does one kit do both rear wheels?

Yes. Yukon lists this kit as servicing both sides of the axle, with axle bearings, inner and outer axle seals, retaining plates, and the adjuster with its plate.

Will this fit an 8-1/4 or a Dana 60 Mopar rear?

No. It is built for the Chrysler 8-3/4 inch rear with factory-style tapered axle bearings. The 8-1/4 and Dana 60 use different bearings and retention. Check the housing before ordering.

Which side does the adjuster go on?

On the 8-3/4 the threaded adjuster is on the right side. The left axle is installed fully seated first, then end play for both shafts is set from the right side with a dial indicator.

Do I need a press to install the bearings?

Yes. The tapered bearing is pressed onto the axle shaft behind the retainer plate. Most owners take the shafts to a machine shop or driveline shop to press the old bearings off and the new ones on.

My rear whines on the highway. Is it the axle bearings or the gears?

Bearing noise follows road speed and changes when you turn and load one side. Gear whine changes when you go on and off the throttle. If it is the gears, plan on a full gear setup rather than axle bearings alone.