USA Standard Gear Open Spider Gear Set For Chrysler 8.25in / 29 Spline
A clunk from the rear when you turn into a parking spot, a click on every take-off, or a broken cross pin in a Jeep Cherokee, Grand Cherokee, Dodge Dakota, Durango or light Ram 1500 rear axle usually traces back to worn spider gears in the Chrysler 8.25 inch differential. The USA Standard Gear ZIKC8.25-S-29 is a complete open spider gear set for the 29-spline version of that axle, with every gear and washer that lives inside the carrier.
The ring gear turns the carrier, and the spider gears inside it divide that torque between the two axle shafts. Two side gears are splined to the axle shafts, and two pinion gears ride on a cross pin between them. Driving straight, the whole set turns as one piece. In a turn the pinion gears walk around the side gears so the outside wheel can turn faster than the inside one. The 8.25 is a C-clip axle, so the cross pin also acts as the stop that keeps the axle shafts from sliding inward and letting the C-clips fall out. That makes a worn or loose cross pin more than a noise problem. USA Standard lists this set with two side gears, two pinion gears, the cross pin shaft, the cross pin bolt and the spider gear thrust washers.
Pull the cover and look. With the axle jacked up and one wheel held, turn the other wheel back and forth: a lot of free play before the gears load up points at worn thrust washers and gear faces. Check the cross pin lock bolt and look for chipped teeth on the spiders. Then confirm the spline count, because this set only fits the 29-spline axle. As a rule of thumb older 8.25s are 27 spline and most built from about 1997 on are 29 spline, but count the splines on a removed shaft to be sure. Our Chrysler 8.25 problems and rebuild cost guide and spider gear failure guide walk through the diagnosis.
ZIKC8.25-S-29 fits the Chrysler 8.25 inch rear axle with an open differential and 29-spline axle shafts. The 8.25 was used under the Jeep Cherokee XJ and Grand Cherokee, Dodge Dakota, Durango and Nitro, and lighter Ram 1500 trucks, but the spline count changed during production, so match the splines and confirm the carrier is open rather than a Trac-Lok or Sure-Grip limited slip. It does not fit 27-spline axles, clutch-type limited slip carriers, or the Chrysler 9.25. Send us the year and VIN if you are unsure. More internal parts are in our hard parts category.
This is a cover-off job with the ring and pinion left in place. Drain the oil, pull the cover, remove the cross pin lock bolt and cross pin, push each axle shaft in and fish out its C-clip, then slide the shafts out far enough to rotate the old gears out of the window. Clean the carrier, oil the new thrust washers, roll the new pinion gears and side gears in together, reinstall the C-clips and shafts, then fit the new cross pin and lock bolt with thread locker. A loose cross pin will wreck the case. If the pinion bearings are also noisy, do the full 8.25 master overhaul kit at the same time. If you want traction instead of an open diff, the Dura Grip limited slip for 29-spline 8.25 replaces the whole carrier. The carrier side adjusters are not touched on a spider job, but if you do pull the carrier, the 8.25 side adjuster tool makes resetting them much easier. Seal it with a new gasket or a heavy-duty 8.25 cover and refill with 75W-90 gear oil.
| Brand | Yukon Gear & Axle |
| Part number | ZIKC8.25-S-29 |
| Fits | USA Standard Gear Open Spider Gear Set For Chrysler 8.25in / 29 Spline |
| Type | Differential Spider Gears |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. The side gears are splined for 29-spline axle shafts. A 27-spline axle needs a different spider gear set.
USA Standard lists two side gears, two pinion gears, the cross pin shaft, the cross pin bolt and the spider gear thrust washers.
No. This set is for the open 8.25 differential. Clutch-type limited slip carriers use their own internal parts.
No. Spider gears come out through the carrier window once the cross pin and C-clips are out, so the ring and pinion setup is not disturbed.
In a tight turn the spider gears are working hardest, so worn thrust washers and gear faces show up as a clunk or knock there first. A loose cross pin can cause the same noise.
75W-90 gear oil. An open differential does not need friction modifier.
