Ford trac lok no friction modifier

[ntsqd]

So the Ripple Effect is in full swing.......

"It's only $25 more." yeah, well, then you need to..........

In a keeper it's an upgrade that I'd want. If I could find the budget for it. In a short term toy I doubt that I'd spend the money.

 

[jamesroney]

@ntsqd What are the possible modes that would lead to a crush sleeve becoming more compressed? These are what I can think of off the bottom of my head:
Nut loosens.
Pinion shaft bends.
Housing flexes.
Bearing bore shoulders recede.

I thought about this last night. Only one of these root causes would actually compress the crush sleeve. The other 3 remove load, and go the wrong way. The only one that squeezes the collar tighter is the elastic deformation of the pinion shaft under sustained load. And wow...it's going to be a fractional 3rd order effect? If the pinion were simply supported and cantilevered with an overhung load,the bending deflection would be a PaL^2 / 9EI calculation...but of course you have that redundant 3rd bearing...so the loads get weird. But even at half load, I still have to translate the beam deflection to an elongation. But I'm going to agree that if you managed to load your pinion enough to deflect the shaft between the bearings, and the shaft bends about the neutral axis, then the associated compression would in fact shorten the crush sleeve. Which might explain why @Yeller sees what he saw.

I gotta go.

 

[ntsqd]

I was trying to picture how slop in the stack of bearings and spacer could occur, not necessarily that the crush spacer had actually been squished further as the initial failure mode. What I do expect to happen, particularly if it isn't caught, is that once the bearings are running without the spacer being loaded (by whatever means that might happen) that now our effective shaft OD just got a whole lot smaller. So now it is easier to bend the pinion shaft, and that will eccentrically and cyclically load the spacer as the assembly rotates, which will over-compress it.

I don't really expect much from that third bearing in a 9" Run a pinion in one w/o the other bearings in place. They don't fit as tight as you would like, and that's probably necessary. Then I consider how hung out there in space that bearing is. The supporting structure around it is far from stiff or rigid.
Easier to just assume it does nothing. then whatever it does do is a bonus.

 

[jamesroney]

I was trying to picture how slop in the stack of bearings and spacer could occur, not necessarily that the crush spacer had actually been squished further as the initial failure mode. What I do expect to happen, particularly if it isn't caught, is that once the bearings are running without the spacer being loaded (by whatever means that might happen) that now our effective shaft OD just got a whole lot smaller. So now it is easier to bend the pinion shaft, and that will eccentrically and cyclically load the spacer as the assembly rotates, which will over-compress it.

I don't really expect much from that third bearing in a 9" Run a pinion in one w/o the other bearings in place. They don't fit as tight as you would like, and that's probably necessary. Then I consider how hung out there in space that bearing is. The supporting structure around it is far from stiff or rigid.
Easier to just assume it does nothing. then whatever it does do is a bonus.

Gotcha. I was going for squished, because if it goes loose...a shim / spacer would also go loose.

 

[Timmy390]

ok, take the crush collar out and do your diagnosis with it on the workbench.

How does the pinion feel on just the inner bearing? Is the pinion bent?

If you have some dyechem, you can paint the races and look for the contact pattern. I’ve used a black Sharpie in a pinch.

Hard to believe that the pinion support bores are out. But it’s possible.

So used a Sharpie as I can't locate my Prussian Blue. I've never done this on a pinion support before so there may be a dumb question coming up.

Colored both races and let them dry. Assembled the pinion without the spacer and got 20 inch pounds of preload. Spun it a few times (with the bump bump bump) and disassembled the pinion.

I have to say I'm puzzled at the results. The inner race was clean as could be. All the Sharpie black was gone but for a thin line on the edges of the race. The outer however was still black. Not pitch black but not clean at all.

I'm under the impression both bearings should have the same preload thus both races should be clean or both dirty not one of each.

Inner bearing is pressed all the way on. There isn't an oil slinger nor is there a washer between the pinion and nut (my Bronco has one as I recall). I verified the races are bottomed out as in pressed all the way in. I even took the inner out and made sure there wasn't any "crud" around the edge keeping the race from seating. It was all clean.

Tim

 

[Timmy390]

Hummmm I think have still got my 3.50 gears I took out of the Bronco. I could press the old bearing onto it and see what results I get. That should rule out the pinion as the cause? Heck I bet it has a bearing on it already.

Tim

 

[Timmy390]

Oil slinger just arrived (thanks Amazon) so I ran out and quickly installed it. The bump bump bump is gone much smoother HOWEVER.......Preload is set to 25 inch pounds and it hold for 1/2 turn then jumps to 30 inch pounds for the second half of the turn then drops back to 25, Same thing revolution after revolution. 1/2 of the circle is 25 and the other is 30.

Something is bent.......Now to find that other pinion.....

Tim

 

[ntsqd]

Someone jack the car up by it's pinion yoke or more likely, drop it onto a jack stand at the pinion yoke?

 

[Timmy390]

Found the other pinion and it already had a bearing on it. Repeated the process.....some issue. Half the turn is tighter than the other half. To me it makes no sense at all. I also noticed that if I spin it over and over and over the whole thing tightens up. I hate to send $100 on a new support but I don't see an alternative at this point. I don't have the tools to dig any deeper.

Tim

 

[Yeller]

If you can build the pinion support, you have 3/4 of the process done. All your missing is a dial indicator and a mag base to measure backlash, I’ve used calipers in a pinch. Changing the pinion support means you need to double check backlash and run a pattern to verify pinion depth. More than likely nothing will change but if it does you get to do it again.

 

[jamesroney]

I don't really expect much from that third bearing in a 9" Run a pinion in one w/o the other bearings in place. They don't fit as tight as you would like, and that's probably necessary. Then I consider how hung out there in space that bearing is. The supporting structure around it is far from stiff or rigid.
Easier to just assume it does nothing. then whatever it does do is a bonus.

Agree to disagree. But I’m gonna say that the R1535TAV cylindrical bearing is good for 7200lbs of lateral load. Coupled with the 88048 at 17,400 you get 24,600 or coupled with the Daytona at 26700…you get 33,900 lbs.
Contrast that with the Dana 60 HM803146 at 32,400 and it all seems to look like real world results.

I’m totally with you in regard to case deflection, and ring gear spread. But that little pocket bearing is embedded in the strongest part of the housing, and is very robust in compression. As long as the pinion support doesn’t eject itself out of the housing…it’s pretty stout.

 

[Timmy390]

If you can build the pinion support, you have 3/4 of the process done. All your missing is a dial indicator and a mag base to measure backlash, I’ve used calipers in a pinch. Changing the pinion support means you need to double check backlash and run a pattern to verify pinion depth. More than likely nothing will change but if it does you get to do it again.

Yup....I've setup gears in the past so got the tools. I have to do a gear setup anyway after rebuilding the TL that's fubar this pinion support issue is kind of out of left field.......Just hate to buy the new support not knowing 100% it's the issue. I'll have to dig into my stash of cash I had set aside for a new shooting bench.

Tim

 

[ntsqd]

Maybe I'm remembering the details of the case wrong, but what I recall is that the case casting surrounding the third pinion bearing gets pretty thin in one area. Looked it up, if this is typical then I recalling it correctly:

Granted in the major thrust direction is the thickest part of that bearing's support, but not quite halfway around that bearing is pretty thin and not my idea of solid structure. What makes me discount that bearing is the fit to the nose on the pinion gear. It necessarily has some slop in it, and that slop means that the pinion gets to be just a little bit of not where it should be before that bearing comes into play. Poke a pinion gear into a case without a pinion support and wobble the gear around, you'll see what I mean. It's not a lot, but it's there.

 

[Yeller]

All of the pinions I’ve seen twisted off all did so at the end of the yoke. The desert/ultra 4 guys are doing it during shock loads in whoops or other similar high speed jumping episodes typically in the rear. Going to a gearworx 10 or 35 spline pinion solves the issue lol, moves it down the line but that’s how it works

I’m sure a high powered street car could do it too but not easily. They lack the rotating mass, huge difference in a 28-30” tire vs a 40-42” tire in drivetrain abuse.

 

[ntsqd]

My thinking about why I don't really count that bearing is this: Say that there is .001" play between it and the nose of the pinion. If the pinion bearings are set correctly then there is no play in the gear. Now something loads the pinion gear head laterally. It can deflect that .001" before the bearing provides any support. How much of a bend does the pinion shaft have in it when the pinion head is deflected, and more importantly, what is that bend in the pinion shaft doing to the crush spacer?

Been thinking about the current results and I'm not coming up with a good explanation for why it's behaving like that. Curious, can you "clock" the high and low spot by rotating the bearing on the pinion shaft?
I've lost track, are these the same bearings that have been in the diff from the beginning?

 

[bmc69]

What a rabbit hole........ugh

Tim

Aren't they always??

 

[Timmy390]

OK, so got an update on this situation. I'm not focused on what got me to the place where I have the third member out......Looking forward to getting it fixed.

In a nutshell, CHINA F'd me hard.........

I've spent hours examining every possible issue. TOO many scenarios to go through. Even had a buddy come over and help and he left the shop shaking his head. A strange thing happen yesterday that left me at a total loss. I had the outer pinion bearing in my hand and was spinning it. It just fell apart......OMG how in the world right?

I continued my troubleshooting with one of the old Temken bearings I had. I got consistent results when changing my solid spacer for the old bearing. Something I wasn't getting before. Odd right?

Get a replacement bearing from parts store and started back this AM........ inconsistent readings. Tight one turn then loose. I noticed the new outer bearing was fitting the pinion shaft really tight. OK, maybe it's getting stuck and the rear bearing is pulling in more as I tighten the nut. I'm on to something now....Polish the pinion shaft and the bearing now slides on with just a small amount of resistance. With the pinion still in the vice, I slid the solid spacer on....then the outer bearing.....Hold it bearing in place and give it a spin....NO SPIN.....WTH?

The top of the bearing case on the new National brand bearings is smaller than the Temkens I took out. The solid spacer is contacting the cage and will not let the bearing spin freely. Repeated crushing/deflecting of the cage caused the first bearing to fall apart.

So for the solids spacer haters (just kidding ) you win this round. While the bearing is the issue, had I not opted for a solid this issue may never have came up.

Now what to do. Buy another brand of bearings and use the solid spacer or buy a crush sleeve. Leaning towards different brand of bearings because I'm still not sure if the pinion support is damaged (probably not) as the original issue was a "hitch" in the pinion and a speed related vibration.

Tim

 

[ntsqd]

Send me (or James as I'll guess that he'd also volunteer) the bearings and the spacer. One of us will make sure that the spacer clears the bearing cages and send them back to you. If you have a friend with a lathe, or a good local machine shop that is willing to do small jobs they can do this work pretty fast and easily.

 

[Timmy390]

Send me (or James as I'll guess that he'd also volunteer) the bearings and the spacer. One of us will make sure that the spacer clears the bearing cages and send them back to you. If you have a friend with a lathe, or a good local machine shop that is willing to do small jobs they can do this work pretty fast and easily.

Offers like this make this board the BEST tech board on the WWW. 70_Steve offered and sent me his D44 setup bearings years ago. Just send them back he says.,....This place is filled with good people.

I may take you up on that offer. I was needing to order a few maintenance thing for wife and kids car from RockAuto so I just added a set of Timken bearings/races for $30 Shipping was the same so just have to wait for them. No one in a 50 mile radius has bearings other than Duralast and National brand. I didn't check Napa. Kind of forget about them as they moved and are off the beaten path now.

If the Timkens come in and don't work......The spacer will have to be machined.

Tim

 

[Yeller]

I love the lessons going on here for all of us.

most of the spacers that I've used are directional, with no instructions.... one side toward the bearing and it rubs flip it over on the shaft and it does not rub. I'm sure that would stand out, but not everyone is looking at your parts. My guess is someone is making a cheap spacer that is not clearanced to clear the bearing.

If it wasn't a 4 hour drive, I'd hand deliver a Timken bearing for free and/or a spacer that is machined for bearing clearance.