John, Bob et al,
Well, I inspected the pin, and both sides are dead smooth and mic out right at .565" +/- .001", so I'm just going to try and find a new bearing set and reinstall it. I do see the service manual calls for fibrous grease, that's the same thing I use in wheel bearings for drum brakes so I have it on hand. I counted the pins again, this time out of the bearings, and came up with the same thing, 31 on one side, 30 on the other. Sounds like 31 is the magic number.
If running without a needle, it has probably destroyed the hardened surface they roll on , on the pin. This polished surface is critical to needle bearings as there is no hardened inner race like a ball bearing . It is also possible even probable at some point in the distant past some dirt got in, causing one needle to jam and then skid, grinding it up. That ground up metal dust would get into all the rest of it and score the pin surface too. Once you have caps off inspect pin for mirror finish, same look on both sides. Possibly measure with micrometer or look for scratches or surface damage .
Most rebuild kits include a new pin, housing , pads and caps for this reason. The new pin MUST be centered to ideally less than .001 on a press fit or it vibrates . best done by machine shop… and then checked till perfect . The needle housings also wear on the sides that slide in housing, again causing vibration, and the little pads at the ends. Also worn places form like dents in outer housing where they sit most of the time . Any looseness leads to vibration.
Be forewarned there are two sizes of these , not sure when or why, but smaller one than on our 300 is very common , probably Mopar for Plymouth or Dodge like 30’s to mid fifties. That caused me a lot of grief, had 5 wrong ones on shelf . . Housing is bigger and pin longer . you might need the whole kit, as failure in needles is in fact how u joints do fail…Sounds like this one was on the way, maybe due to torn boot.
Front wheel bearing grease has fibers dispersed in it….might be better with non fibrous grease like clean front end grease..or see FSM?? Not sure which one, but one year has a lot of info on checking this. They had vibration issues.
Thank you for the feedback on the needle count, your suggestion makes perfect sense to me. The thing that is odd to me, and the reason I asked about the needle count, is that the bearing side with 31 needles feels just fine but the bearing with 30 needles seams stiff, doesn't turn easily, and does not readily slide off the pin as it should. I suspect the missing needle has somehow caused this. At this point, I'm going to try and find new bearings and install them before I put it all back together. I will count the needles in the new bearings before I install them, and post what I find.
I have some drive shaft bearing kits out in the warehouse
I could dig one out and count needles
but let me use my noggin and say the answer is likely 31.
Although I have changed a buncha boots and done the bearings
I have never counted needles. I know both cups should be
crammed full of needles such that a cup with a
full set of needles will have no space for another needle.
I bet your cup with 30 needles has room for #31 needle
your cup with 31 has no room for #32 needle......if you
follow my foggy early morning English.
It would be hard to imagine one cup full at 30 needles while the other side
If you need one needle bearing, let me know. I am
pretty sure I have a spare from which I draw needles
to replace ones I have lost.
Great boots from Mark Sherman. I am so glad he supplies them.
My guess on your high temp grease is it is more than required but won't
hurt anything. Grease requirements for a wheel bearing should be
way above anything required by a needle bearing.
------ Original Message ------
Sent: 4/1/2017 3:36:14 PM
Subject: [Chrysler300] 300G ball and trunnion boot replacement
I am in the process of replacing my deteriorated boot on the front of my 300G driveshaft with a replacement from Mark Sherman (thanks Mark). I've got the new boot in fine through the housing, but I am concerned about the needle bearings. I've counted both sides, and it appears I have 31 needles in one side and 30 in the other. Anyone out there know the correct number of needles that should be in there? also, is it OK to use hi-temp wheel bearing grease for lube?