Adjusting Pinion Preload on a Dana 30
Jennifer’s Jeep Cherokee has been riding a bit rough lately. It has had a growl and a vibration at speed. We tried swapping drive shafts and rotating the tires but the noise and vibration was still there.
A close inspection showed some play in the pinion shaft in the front axle. I knew form the experience with my Jeep that this could cause a vibration.
She really did not want to spend a lot of money fixing up this gear set since she will be installing a set of 4.11s in the next few weeks. She needed just a temporary fix to get by.
I looked in the factory shop manual for the preload adjustment procedure and it mentioned a crush sleeve. I thought that I could just crush the sleeve a bit more and take out the slop. I put a big pipe on my pull handle and cranked on the nut. The nut turned but the end play stayed the same.
A bit more research made me realize that there is no crush sleeve in a XJ Dana 30. I am not sure which front axle the shop manual was referring to. But, I was sure I had succeeded in stripping the nut.
When I later pulled the nut, sure enough, the threads of the nut were nicely embedded in the pinion. I was glad the nut stripped and not the pinion. It took a few minutes with a pick, but I was able to clean the threads.
To adjust the pinion preload, I began by removing the wheels and tires. Next I removed the brakes and the center axle nuts. I could have left the axles in the hubs but it was easier to handle them separately. I used my sacrificial bolts to separate the hubs from the knuckles.
I then removed the hubs and axle shafts. I then separated the tie rod on the driver side and let it hang down out of the way. I then removed the cover and drained the fluid.
I removed the carrier bearing cap bolts and after noting he marks, carefully removed the caps. I was getting ready to set up the spreader on the case to remove the carrier when Jennifer who was removing the drive shaft tapped on the pinion. The whole carrier fell out almost on my foot! So much for needing a spreader. I guess all the bearings are pretty worn. The carrier as well as bearing s will be replaced when the new gears are installed so I just reused all the parts anyway.
With the drive shaft out of the way, I removed the pinion nut. Sure enough it was stripped. With the yoke off, I tapped the pinion out the front. I pried out the seal and collected he slinger, bearing and shims.
I set the pinion back in place and removed a .010 shim. It was still too loose. I pulled another shim and it was still too loose. With .030 shim gone it felt about right. With any less shim, it was way too tight, so I settled on a shim pack and put it al back together.
I made sure it all felt OK with the axles back in before I installed a new pinion seal. The seal and the gear oil were the only expenses for this job. I used an old pinion nut from a spare axle behind the barn.
I used black silicone for the front cover seal and left the tie rod off until Jennifer had refilled the housing with gear oil before putting it back in place.
A quick test drive showed much less vibration and the dragging growling feeling was gone. Hopefully the bearings will last a few more weeks.
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