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.0295 and the pattern in post #13 is .031. I think I'm gonna try .032-33 so the drive doesn't have that hard line at the bottom. The drive is farther up the heel though.
I finally got to test drive it last night. Went on a short trip to heat cycle the gears and it's pretty noisy overall. I'm getting a considerable amount of gear whine at low speeds that sounds like a jet engine. It gets a little quieter as the speed increases but it's still there. I thought the pattern was good but maybe it needs to be reset. Backlash at 8. Pinion is at 15 inch lbs of rotating torque with the solid spacer. Whole rear has about 15 miles on it.
Yukon aluminum center, through bolt
Aluminum daytona support
Motive 3.89 gears orange box
Wavetrac
35 spline axles
I know 9s are supposed to be noisier but I'm not sure by how much. My poly trans, poly ta, and rod end panhard definitely aren't helping. I can tolerate loud if it's strong. Does this pattern look good?
You mentioned this has a Yukon aluminum center, did you build the center section yourself?
__________________ ATI ProCharger and Moser Sales 260 672-2076
Yes. I've built a few 10 bolts with success but this is my first 9". This one was a lot trickier.
I pulled the third member out yesterday to check everything out. Backlash was right where I left it at 8-9 and the wear pattern mimicked the first contact pattern I posted (.0295 shim stack).
Out of curiosity, I moved the pinion out farther than post #13 to see what kind of pattern I'd get. Shim stack was a .0325" and backlash was 7-8.
Looks like crap on both sides. I took the shims back to what I had in post #13 (.031") and ran this with backlash at 7-8. Sorry, my pictures aren't very good.
Pretty much what I already posted before. I also took the pinion bearing preload down to 9-10 inch/lbs of rotating torque from the 15-16 it was at before.
I slapped the whole thing back together with 8~ inch/lbs of preload on the carrier and put it back in the car. I also made a shim to go between the TA and the cast TA mount (what I thought was clunking previously). I took some 18 gauge steel from the hardware store (measured out to .055" with my caliper) and stuck it between the two parts after some grinding. Fit is nice and tight now.
My observations... Airplane noise isn't as loud as it was previously. I'm guessing that was from too much torque on the pinion bearing. There's still a little bit of gear whine on decel but it's lower in speed now. It's nowhere near as deafening as it was before. Definitely liveable.
Now here's what's going to drive me up a wall... the clunk is still there. It's very apparent when playing with the gas in 3rd/4th gear or when starting from a stop. I thought I was getting a clunk from the UMI TA being loose on the Moser TA mount. My shim should have fixed that but it's still there. Backlash is at 7-8 so that's not it. I HIGHLY doubt it loosened up (I preloaded the carrier bearings and triple checked the BL after torquing it). I noticed there was some play between the Moser axles and the Wavetrac when assembling. Could this be it? I'll try to rig something up to test it.
Edit: Just saw you have a wavetrac, I don't know if the following info applies to that.
What kind of posi unit do you have? Is it a helical gear Truetrac type? If so the clunking is normal noise when the helical gears go from their unloaded state to being wedged into the pockets. My S-Trac makes noise at every stop light when I put the shifter in first, I'm sure the rotating inertia of the trans in neutral is suddenly transfered to the output shaft (clutch disengaged), the driveshaft moves a bit and the posi gears clunk into their pockets. When selecting first from idling in neutral if you hold the clutch depressed for about 2-3 times longer than normal and then put the shifter in first there is no noise as by then the trans internals have stopped spinning on their own.
The Wavetrac is typically very quiet without exhibiting any clucking noises. If this was a Moser center section I would have to quickly pack it up and send it back to get it sorted out. Hopefully you get it worked out. Bob
__________________ ATI ProCharger and Moser Sales 260 672-2076
Edit: Just saw you have a wavetrac, I don't know if the following info applies to that.
What kind of posi unit do you have? Is it a helical gear Truetrac type? If so the clunking is normal noise when the helical gears go from their unloaded state to being wedged into the pockets. My S-Trac makes noise at every stop light when I put the shifter in first, I'm sure the rotating inertia of the trans in neutral is suddenly transfered to the output shaft (clutch disengaged), the driveshaft moves a bit and the posi gears clunk into their pockets. When selecting first from idling in neutral if you hold the clutch depressed for about 2-3 times longer than normal and then put the shifter in first there is no noise as by then the trans internals have stopped spinning on their own.
That's EXACTLY what I'm experiencing. I thought it could be attributed to weak clutch hydraulics (put in a new clutch with the 9") or the input shaft dragging on the pilot bushing. It's a little hard to shift but I think that could be because the clutch isn't even broken in yet with about 45 miles on it (same for the rear). I bought new clutch hydraulics just in case but the old ones only have about 15k on them. Engagement seems in the right place on the pedal, I just think it needs to wear in. If not I've got another master/slave NIB just in case.
I also get the clunk from the rear of the car when I push the clutch in quickly while accelerating. It's so annoying to me that I might pull the center out a second time and make sure my backlash is the same and nothing shifted.
When I was building the center I noticed you could shake the Wavetrac a little bit and hear what sounded like a tiny part shifting around inside. so maybe the noise is loose gears loading? It didn't seem solid like a clutch posi but this is the first worm gear diff I've had so I wasn't sure what to expect.
I can make the noise on demand...
car in reverse
back up a few feet
come to a stop
put car in neutral
release clutch so input shaft/countershaft spins with motor
push clutch in
go to put in 1st gear and CLUNK
Like you said, if I wait a few seconds after pushing the clutch in it's silent.
Even if it was a dragging clutch, the clunk really shouldn't be that severe.
I took a rotor off on one side, put the car in 1st gear, and rotated the axle clockwise until I was sure the worm gears in the Wavetrac were turning (takes a considerably more force). That way the pinion, driveshaft and trans were all locked together. If I were to rotate the axle counter clockwise with enough torque then the pinion would become unlocked and rotate slightly. There's still preload on the carrier and pinion that I can feel and I can assure you that the pinion DID NOT shift at all during this video.
It takes varying levels of torque to rotate/play with the axle. I'm guessing the first level of play where I can jiggle the axle lightly with my fingertips is play in the axle splines or the Wavetrac gears loading. The second level is what I'm guessing is the backlash. I have to apply a little more pressure with my thumbs to turn the carrier because of the preload. If I were to rotate the axle farther than this point I'd end up turning the worm gears or rotating the pinion gear.
Not really sure what to compare this to or if it's causing the clunk. I'm going to go play with my old 10 bolt to compare... although it's seen better days.
For your TA mount issue, looks like the center tube welded to the rear is the issue as the upper and lower mounts have the same number of washers. Maybe just grind the center mount tube some then you can get rid of the washers on the other two mounts.
Other than ring and pinion backlash the only other place I can think of for the thunking is the axle spline fit in the Wavetrac. Do you remember how tight the fit of the axles in the posi unit was? I consider the thunking I described above as normal for my S-Trac.
I know that the M6 doesn't work good with a Detroit Locker because of the play in the Locker, maybe the Wavetrac exhibits some of the same traits with a M6.
I do remember the axles being a little loose in the diff but I don't remember how much. There's nothing I can do about it now because I have this event next week. When I get back I'll tear back into the rear and take a closer look. I can't live with the amount of clunking I have now.
The TA wouldn't sit flush unless my grinding was really precise.
I spent all of this money and nothing is going my way.
I definitely feel your pain as you've bought all the top shelf stuff. You could always sell the whole thing and buy something from Strange Engineering.
The shimming you've done with washers is a workable fix. If they bother you then you could shorten the center mount. From your pictures it appears the center mount is too long by the thickness of two washers. If you tighten a worm screw clamp on the mount where you want to make the cut it will serve as a guide to make the cut square. A hack saw or cutoff wheel would work, have a tap handy to clean up the threads in the mount.
No way I can bail out now, I've got almost $3k wrapped up in this rear and it has to work. I'm willing to do some grinding for the TA mount and sway bar but I can't tolerate this clunk. If I find out that it's the axles or diff then the manufacturers will be taking care of it. I can't afford this.
I got the car up to 50 and the howl is there. I don't think the contact pattern was getting any better than what I had. Maybe the Motives were duds. Now I'm wishing I went with the Yukons.
So it's been years since I started the thread, but I can still say that this rear is a steaming pile. Replying to this for reference incase someone else has similar issues.
Found out why the TA mount was so crooked, check the pic below. I'm guessing the mounting tubes are supposed to be 90* to the plane that exists at the axle centerline and is parallel to the third member flange. They're off by about 4 degrees.
I measured 0.265" worth of washers stacked up on under one side of the TA mount. The distance between the 2 left bolts of the TA mount to the single right bolt along the axle axis is 3.5". A quick trig calculation tells me that the washers shifted the TA alignment 4.33 degrees, effectively cancelling out the **** poor fabrication work done by Moser.
I called Moser back in 2014 when I was originally having issues with this thing and they basically said 'all of our rears are made in the same jig, our production system is perfect, blah blah blah get bent kid.'
I also pulled apart the rear last year to get to the bottom of the clunking. I found that the Moser axles were in fact very loose in the Wavetrac splines. The internal parts of the Wavetrac itself had 0 play as far as I could tell. There seems to be a tolerance issue between Moser's 35 spline axles and Autotech's which could be anything from OD, spline pitch, shape, etc. Autotech was super helpful on the phone and offered to inspect the carrier. Moser's techs once again told me their axles are perfect and to go pound sand which was perfectly in character. Their axle measured close to the 1.5" spec they gave me, but something is awry beyond a simple OD measurement and I don't have the tools to figure it out. Oh well.
TLDR: Take your money and run far, far away from Moser.
Bracket doesn't sit flush like it should but it's bolted down tight. This is less than ideal and I'll need a permanent solution.
The permanent solution is to sell that rear end and buy a MWC fab 9 and never look back. That's a total joke that you are going thru this for all the money spent
So it's been years since I started the thread, but I can still say that this rear is a steaming pile. Replying to this for reference incase someone else has similar issues.
Found out why the TA mount was so crooked, check the pic below. I'm guessing the mounting tubes are supposed to be 90* to the plane that exists at the axle centerline and is parallel to the third member flange. They're off by about 4 degrees.
I measured 0.265" worth of washers stacked up on under one side of the TA mount. The distance between the 2 left bolts of the TA mount to the single right bolt along the axle axis is 3.5". A quick trig calculation tells me that the washers shifted the TA alignment 4.33 degrees, effectively cancelling out the **** poor fabrication work done by Moser.
I called Moser back in 2014 when I was originally having issues with this thing and they basically said 'all of our rears are made in the same jig, our production system is perfect, blah blah blah get bent kid.'
t/
I also pulled apart the rear last year to get to the bottom of the clunking. I found that the Moser axles were in fact very loose in the Wavetrac splines. The internal parts of the Wavetrac itself had 0 play as far as I could tell. There seems to be a tolerance issue between Moser's 35 spline axles and Autotech's which could be anything from OD, spline pitch, shape, etc. Autotech was super helpful on the phone and offered to inspect the carrier. Moser's techs once again told me their axles are perfect and to go pound sand which was perfectly in character. Their axle measured close to the 1.5" spec they gave me, but something is awry beyond a simple OD measurement and I don't have the tools to figure it out. Oh well.
TLDR: Take your money and run far, far away from Moser.
Damn i read your entire thread , i just retake a project from years ago, trying to find a solution for issues like yours , i run into the Torque arm mount problem but mine was not as bad as yours (i fix that grinding), i also got a problem with the strut mounts as they are tilted down (fixed with an adapter so i dont redo welds),
as for the clunking have you figure out the solution? im now on that boat
Damn i read your entire thread , i just retake a project from years ago, trying to find a solution for issues like yours , i run into the Torque arm mount problem but mine was not as bad as yours (i fix that grinding), i also got a problem with the strut mounts as they are tilted down (fixed with an adapter so i dont redo welds),
as for the clunking have you figure out the solution? im now on that boat
Unfortunately, the only real solution to the clunking is to try different axles and pray that the fit is tighter in the carrier. I don't know if that's even doable being that I have tapered axle bearings, unsure if Strange, QP, MW, and other axles would even fit properly. I'll probably dump the rear for something else in the future. Not in the cards at the moment though.
05-07-2014, 01:45 PM
