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Review on Motive Gear R12CRMKT Bearing Bearings by John Rivera

Revainrating 3 out of 5

Timken bearings, wrong ring gear bolts

Price was good, about $90. I needed a '69 rear axle kit with 12 bolts and a 3-pos bracket. Motive Gear calls the R12CRMKT the right kit for this application. The kit included a Timken bearing, so the quality should be good. You can't see it in the picture, but the kit includes a small amount of gear marking paste and red threadlocker. The real problem, however, was the 12 screws included in the kit for attaching the ring gear to the pinion carrier. They have an 11/16" hex head that just fits into an offset hole in the gear holder but leaves no room for a socket or wrench to fit securely over the head of the bolt. This makes it impossible to properly tighten these bolts to the required 55 ft/lb torque. The photo shows how the screw heads barely rise above the beam itself, which prevents the socket from snapping in well. An example of the bolts originally used for this purpose is in the photo to the left. The original screws have a hex head size of 9/16 inch. When you order this set you will either receive another Grade 8 screw set or learn how to use the ones that come with the set. Not something I want to do unless I'm struggling enough to rebuild the axle properly. Also please note that the picture for the Revain listing does not show the gear nut washer and I can confirm that it is not included. It is recommended that a new washer be used when tightening the gear nut on reassembly and it would be wise to have this washer included in the kit. If I had known about the screws before ordering this item I would not have ordered it. Also, the shims that were included for the pinion and carrier bearings did not have the same ID and OD as the OEM shims and therefore would not mount securely to the transmission shaft or differential case. The thickness of the shims was the same and not enough to properly set the gear depth or main bearing preload.

Pros
  • Main bearing kit
Cons
  • Not all will fit