Pinion on its way out?

[Scotty4]

Since I’ve owned Betsy she has had a good vibration/noise from the drivetrain. Since my speedo still doesn’t work (cable may be bound) I can’t tell at which speed she gets bad but can assume I’m around 50-55. If I let off the gas it gets slightly better but not great. I replaced the washers and and added some red loctite on the nuts from the Tcase (BW1345) and the rear diff (Code C9 10.25 Full Float LSD). There is minimal axial end play and not sure how much they should rotate?

The rear was pretty loose to start and has stayed tight since I played with it. Should I check the front diff too? I can feel it in my feet when driving. Is there also any diff oil recommended for each? I know everyone has a preference but there must be something out there to help.

 

[u2slow]

For the diffs, there should not be any perceptible play in/out or side-side/up-down. Backlash tends to increase with age/miles. The older short-pinion 10.25's often sees yoke/spline wear, so the yoke actually turns further than the backlash (if that makes sense) i.e. the yoke moves, but the nut and pinion gear may not move with it. Don't overtighten the crush sleeve on used bearings.

What you feel in your feet may be the driveshaft itself, or an axle ujoint. Drivetrain noises tend to echo/vibrate through everything. I will often remove a driveshaft for a test drive to try and isolate noises/problems.

 

[Scotty4]

I will often remove a driveshaft for a test drive to try and isolate noises/problems.

You drive around FWD? It is the terrible two piece drive shaft. Center bearing and rubber bushing around it look okay. Going to assume the mileage is up there pretty high on everything. 5 digits tough to tell, especially with the Odometer not rolling, shows 81,631 but that could be a 1 or 2 in front of it. PO didn't know. Hell, it could be upwards of 300,000 now.

 

[u2slow]

I was mostly thinking the front shaft, but have removed a rear as a test for the same reason. Even if it just to run it in gear on jack-stands.

In my experience, a shot support bearing sounds like somebody dragging chains across a concrete floor, or angry birds. Bad ujoints tends to vibrate more the harder you stomp on it.

 

[Scotty4]

Might get some Ujoints for it then and see where that gets me. Better to get greasable or sealed?

 

[u2slow]

Better to get greasable or sealed?

Folks have strong opinions on this.

I often use $10 ujoints so long as they're greasable. And I grease regularly.

 

[chillman88]

Might get some Ujoints for it then and see where that gets me. Better to get greasable or sealed?

In my opinion it comes down to being honest with yourself. Are you actually going to grease them regularly or are you going to forget like I do.

I think good greasable joints that are regularly greased would be best. Sure sealed joints are supposed to be slightly stronger, but I think you'd have to beat on your truck pretty hard to notice.

 

[Scotty4]

Folks have strong opinions on this.

I often use $10 ujoints so long as they're greasable. And I grease regularly.

In my opinion it comes down to being honest with yourself. Are you actually going to grease them regularly or are you going to forget like I do.

I think good greasable joints that are regularly greased would be best. Sure sealed joints are supposed to be slightly stronger, but I think you'd have to beat on your truck pretty hard to notice.

Well that settles it then. I climb under there once a week to get dirty and hit my head on stuff so will just grease them as needed.

 

[MtnHaul]

I had an 85 F150 that dropped a pinion bearing and you could feel a chunk and grind though the driveline.

I recently replaced all my driveline u-joints with Spicer and greaseable was the only option. through Spicer(Although I do have non greaseable in the D60 up front). One thing to watch out for: I bought 2 u-joints fom a quality local auto parts supplier and then bought one from O'crappy's and even though the boxes all said Spicer and the same part number the one from Oreilly was made in China and the others were not. Typical blankety-blanking blank bullony and stuff.

 

[u2slow]

I One thing to watch out for: I bought 2 u-joints fom a quality local auto parts supplier and then bought one from O'crappy's and even though the boxes all said Spicer and the same part number the one from Oreilly was made in China and the others were not. Typical blankety-blanking blank bullony and stuff.

All the big brands are having their stuff made in China. (Spicer, Cummins, Moog, etc.) The domestic production is likely old stock.

The $10 ujoints I touched on.... are GMB brand. No long-term testing yet, but the greaseable super-strength 1410 ones I got are made in Japan.

 

[CDX825]

I agree with avoiding the chinese U joints. Moog is all china crap now.

 

[chillman88]

Moog is all china crap now.

Yep, last set of upper balljoints I put in the Chevy lasted about a year. Bought the NAPA premiums and stopped even considering Moog after that.

When I replace stuff for my 4x4 swap I'm going Spicer for anything I can.

 

[snicklas]

XRF is a good option also. That’s what I buy if available.

 

[david85]

If the pinion nut on your differential came loose, there is a procedure to correctly tighten it. But as others have mentioned, there should be no play in the bearing. Some slack in the gear teeth is ok, but new gears typically only have 0.0001" when set up correctly.

Having said all that, vibrations usually come from the drive shaft and loose U-joints.

 

[Scotty4]

If the pinion nut on your differential came loose, there is a procedure to correctly tighten it. But as others have mentioned, there should be no play in the bearing. Some slack in the gear teeth is ok, but new gears typically only have 0.0001" when set up correctly.

Having said all that, vibrations usually come from the drive shaft and loose U-joints.

Best I can describe the sound on the line here is as I get up to speed she gives me a few wob wob wob wrrrrrrrr and it gets louder as I get up in the speed. Maybe about 5 seconds of silence then another wob wob wob wrrrrrrrrrrrrrrr wob wob wrrrrr then I let off the go juice and she quiets down but it’s still there. You smell what I’m putting down?