BlackDuk98

iTrader: (34)

Hi. Recently I purchased a used Moser 9” w/ Detroit Truetrac, 31 spline axles, nodular iron Strange center section and new unused Power Transfer parts 4.33 gears. The rear had 2000 miles on it, but whoever put it together never cleaned the housing or knew what they were doing, so all the bearing needed to be replaced. I set everything up 2 times and checked backlash on 4 points (every 90 deg) and it would come out dead on at every point. Checked the contact pattern and saw that I needed to change the shims, so I tried the third time. Now, I will set the backlash to .008, spin the pinion around a bunch of times each way to make sure that everything is seated, then check it at the three other corners and nothing would be the same. Readings would show something like this:

Bold numbers on the left are for the four points on the ring gear that I checked at. Each time I would check the backlash, is the vertical row of numbers. I tried to do this many times is hopes that I could possibly find a pattern.

3rd Rebuild

1 - .009, .011
2 - .009, .010
3 - .011, .007
4 - .010, .007

4th Rebuild

1 - .007, .009, .010, .007, .009
2 - .007, .009, .010, .007, .008
3 - .009, .011, .009, .007, .011
4 - .009, .011, .007, .010, .012

5th Rebuild

1 - .009, .011, .011, .009
2 - .009, .012, .011, .009
3 - .012, .012, .009, .011
4 - .012, .012, .010, .013

Last rebuild before I put it in a box and tossed it in a corner

1 - .007, .005, .008, .007, .005, .009, .007, .005
2 - .007, .005, .008, .007, .005, .009, .007, .005
3 - .009, .005, .008, .009, .005, .008, .008, .005
4 - .008, .006, .009, .008, .005, .010, .007, .006

Nothing stays consistent at each of the four points no matter how many times I check it. Here are the stats on what I have:
Runout on ring gear - .0008
Preload on pinion bearings and support w/ oil seal – 23 inch lbs
Pinion nut torque – 175 ftlbs
Solid pinion spacer - .455 inches
All brand new bearings are being used.
Brand new gears

The info I have read told me to tighten the adjuster nuts till they touch the races of the carrier bearings, while leaving some backlash. Tighten the main caps to 75 ft lbs to seat them, then loosen them and tighten them to 25 ft lbs so you can turn the adjusting nuts. Then move the carrier till there is 0 backlash (Richmond says that I can substitute .001 - .002 as a “0”) Then lock the left adjusting nut, and measure backlash as you turn the right adjusting nut until you get the desired number. This way you get the backlash, and the carrier bearing preload done at the same time. After this step, you then re-torque the main caps to 75 ft lbs. Every turn of the adjusting nuts was made on a “tightening” motion as described in a shop manual.

After turning the pinion and ring gear many times in both directions, I would re-check the backlash, and it would be different at each of the four points, then I would do nothing different but go back to the first spot that I checked, and re-check it. This time I would get a whole new number. I have checked that there are no chips or high spots on the case where the pinion support contacts the case, and checked the pinion support. I tore the whole pinion support apart, and made sure that all the races were pressed in good and not crooked. Checked the ring gear and carrier runout, re cleaned all the brand new bearings thinking that there could be dirt causing these fucked up readings. Every damn thing checks out perfect. There are no nicks on the teeth either. Everything ran smooth the first 2 times I rebuilt it. After that, my luck ran out, and I have spent way too many hours working on this. I have done nothing different for every time I have rebuilt this. Anyone have any ideas on what my problem could be? I don’t want to spend another $100+ on 4 bearings and races.

Any info is greatly appreciated.

BlackDuk98

iTrader: (34)

Well, today was another day of dissapointment. I put the dial indicator on the back of the ring gear, and spun the pinion around to see if the weird backlash changes would show up on the ring gear (push or pull). The damn indicator only budged the .0008 that it would spin w/out the pinion in the housing. So no problem there.

Then I checked case spread while I did the steps that I talked about in the previous post. Using this technique (backlash and carrier preload at same time) making backlash .009, the case would spread .019. Same number I got the first 2 rebuilds that came out perfect. Then I spun the pinion around back and forth like the book says to make sure the races are seated, and the case spread moved down to .016. After I continued to spin it back and forth many more times, when I would switch from turning right to left, the case spread would move about .001 each time. Then it wouldn't move at all when I did the same. who knows.

Looking at the pinion, the very top had a slight wear pattern about half way around. This would be from pressure on the bearing in the case. I'm not sure if this was there when I purchased it or not. These gears were never run in a car (thats what I was told) and if they were, it looks like around the block at most. But on the same side the wear pattern shows up, the edges of the pinion teeth are worn shiny, and the side that has no wear at the top, has nothing smoothed on the edges of the teeth.

This woud leave me to believe that the pinion is messed up, or the pinion support is messed up. Looking through the oil hole on the pinion support, the solid shim is definately up against the bearing as it should be, so it shouldn't be crooked

So if that is true, did I possible get lucky the first 2 builds? But really, I couldn't if I have built it 7 more times and every time the problem comes up. I am just totally lost on what to do. I have looked everywhere for info, and nothing. And judging by the number of replies here, not many people have come across this either. So, I am at a complete standstill

BlackDuk98

iTrader: (34)

I messed around a little more with it today, and decided to investigate the pinion gear rub spots. I set the dial indicator up on the pinion support and took 3 reading. Above the rub are, the shiny area, then the spot under it.

Indicator reading from top to bottom: .003, .0025, .002, so the damn thing wobbles for sure.



As I checked closer to the teeth, the pinion became straiter. But I have the dilema of:



1) The pinion is bad / tweaked

2) pinion support is bent

3) something wrong with the bearings

4) center section is tweaked



But none of that should be the problem if I got perfect readings the first 2 times I set it up. I think I have officially ran out of things to check



Someone has got to have an idea of what I should do next. I don't.

madclown

iTrader: (4)

I wish I could help, sounds like you might need to try a diff. set of gears....

waynehartwig

Sorry, I didn't read the whole thing as I have to leave, but you should be able to turn the adjusters with the caps tight.

What I do is put anti sieze on the threads. Tighten the caps snug, smak with hammer and that will usually line up the threads perfect. Then you can put the adjusters in and do your setups....

I _never_ put the adjusters in before the caps are snug. That will ruin the threads and cause them to be crooked, which can cause the run out your having.

BlackDuk98

iTrader: (34)

Threads look brand new. Nothing messed up at all. I see no way that you can just put the caps and races w/out the Adjusting nuts. Otherwise the races move around. The adjusting nuts help keep the races against the bearings when you add the caps. I've been going by the Ford book which wants you to have the adjusters in there.... I will give it a try and see what happens.

thanks for the help

mark jr.

waynehartwig

I've done thousands of gear setups - I'm building/blue printing a full race setup right now for a guys drag car in CA. You CAN put the carrier in and caps on before screwing the side adjusters in. Unless you don't have the proper tools to hold the dropout level when doing so, then yes, they won't stay in. My tool of choice is a tranny stand - it holds the trans by the bell housing and in turn also holds the drop outs by their respective bolt holes.

waynehartwig

Just read the whole thing...

On mine, I put 150 ftlbs on the side adjusters until I get the proper backlash. 150 ftlbs is roughly 15 inlbs of preload.

I will tighten both sides up until my backlash is a little wide and ALWAYS make my last tighten adjustment using the LEFT adjuster. If I am too narrow, I'll back off the left, then tighten the right a bit, then tighten the LEFT. If I'm too wide, I'll back off the left, back off the right just a bit, then tighten the LEFT. No matter what, my last adjustment is always on the left and it's tightening to 150 ftlbs.

I do it this way because..
1 - the pinion will ALWAYS push the ring gear that way to open up the backlash.
2 - to make sure there are no gaps between the adjuster and bearing and that the bearing is always seated squarely.

I run heavy carrier preload to preload the case and minimize/eliminate pinion deflection. If the case isn't preloaded when a load is applied to it, then it will deflect to a point that the case allows and then stop - that might be too much and cause a gear failure. If the case is already preloaded, this is slim to none.

All of my diffs that I do go out with a 12 month warranty - even this 1,000 hp blue printed one that I will ship out on Monday. The only thing that will void the warranty is abuse - failure to break in the gears correctly, not changing the fluid timely, etc. Abuse is not the same as use. With thousands of installs, I can count the number of failures on my two hands. Most of my gear setup failures are from a busted head off the pinion or carrier failure, and not teeth missing. Teeth missing is typically caused by pinion deflection or pinion being setup too deep.

BlackDuk98

iTrader: (34)

Reading the paragraph that I highlighted in bold, If I backed off the left adjuster. backlash would increase. If I back off the right adjuster, backlash would decrease. What you have written would cause an opposite affect. I will try making sure that I add 15 inch lbs to the already 23 inch lbs of the pinion. What I have to hold the center is pictured above, A vice and 2 paint cans . I know the threads aren't messed up because if that was the case, carrier runout would change and not stay at the consistant .0008. I know that I have had it up to 150 ft lbs preload because my final inch lb readout would be around 38 inch lbs. I will try this again tomorrow. What are your thoughts on the pinion / support?

Threads are mint. I can torque the caps to 40 ft lbs, and if I take the preload off the carrier, I can tighten / loosen the adjuster w/ 2 fingers and no effort.

thanks for your time

mark jr.

waynehartwig

I've had to get creative, too... My first dropout that I did was a Toyota 8" and I did it on the floor standing on bars and whatnot so that I could get leverage and hold the damn thing in place. The second one was in the tranny jig

I just reread what I wrote and yes, you are correct it is backwards, but you get the idea. The final, last time I tighten anything, is done with the left adjuster - from there, I put my wrench down. That assures the ring gear is pushed up against the pinion and everything is seated. If for some reason the right adjuster wasn't, then backlash would decrease, not open up and deflect. That's my point.

When I'm setting them up, pinion depth, I don't install the o ring until after I'm done and everythign is loctited in place. maybe you have the o ring in place and it's not letting the pinion support sit flush? I also use three bolts, staggered and snugged up while checking depth. I've found one/two aren't enough to make sure it's flush and tight.

And on the preload, you can't assume that because you have 38" on the pinion that you have 22" on the carrier, assuming you have 16" on the pinion by itself. Different gear ratios give different readings. Lower ratios (4.86) will take more carrier preload to show up on the pinion than higher (3.10) ratios will. Make sense? I actually use a torque wrench set at 150 ftlbs - then I know it's tight

BlackDuk98

iTrader: (34)

The o ring isn't binding. It's a square type o ring so it doesn't bulge as much. When I mount the pinion support each time, I use all 5 bolts and torque them opposite like you do a wheel. At 35 ft lbs since The support is an aluminum one. I will have to customize my spanner wrench for the adjusting nuts so that I can use a torque wrench on it. I set everything up again last night and the problem came back. I drove to Summit today and purchased a set of Richmond 4.11's and set the pinion up. I started taking readings of the pinion movement and the same .003 difference would show up. Then I messed around w/ different spacers to get the correct preload (it is at 21 inch lbs now, but torqued to 200 ft lbs on the pinion nut.) Re checked it again, and now the pinion will move, but less than .001. 1 full revolution, and the indicator will go back to 0. Before, it would take 2 turns to go back to 0. I wasn't sure if the bearing could have a high spot somewhere that would cause this. I also picked up a new pinion support just in case that was the problem. So far it isn't, so hopefully I don't need it and I can get my $$ back. Tomorrow I have to finish stoning the ring gear and get it mounted and then follow your steps and see what happens. I really hope it's corrected. That support alone cost me over $120. What sixe pinion shims do you usually start your builds with? I was told .018. Thanks for all the help and hopefully I can report back good news tomorrow.

waynehartwig

Tis definately a wierd one! Bad bearings maybe?

You can try using a 4wd hub socket as a spanner wrench IIRC a D44 fits it perfect.

I typically start out with a .016, but I like mine to set up a little on the deep side.

BlackDuk98

iTrader: (34)

Well, I was very hopeful. That lasted a whole 5 minutes. Problem is still there and I am so frustrated it isn't even funny. I have never had something on a car kick my *** so bad. I shouldn't even be aloud to own a car. I have spent more $$ than if I ordered the damn thing brand new, assembled, and shipped to my door. I just can't diagnose my problem. I guess I am going to throw more $$ at it monday and buy another new set of bearings for the pinion. After that, it's the support. I have learned my lesson on this. I am buying new components built by professionals. Not by me. Any other opinions? I have used the info from a Ford manual, Strange, and the info that you provided, always w/ the same results. I will post up the instructions I have been using in hopes that someone will see something that may cause thiis problem.

So I would do it this way, the book way, and the way previously posted, and set backlash to .009. Then I would spin the pinion around a few times to make sure that everything is seated (as instructed by the Ford manual) and then recheck backlash. I would go down to .007. Check is in 4 points and and the reading would be- .007, .007, .008, .008. Which looked pretty damn good. Then checking the same points again, readings would be .008, .008, .011, .009. Then change again, and again, and again. So right now, I am not going to think about it. Possibly get new bearings tomorrow unless anyone else knows of something I can check. Right now, I am getting me some beer and relaxing before I punch a wall...

waynehartwig

I would never do it the 'Strange way'. Too much opportunity for things to move, because of my reasons above.

Are you sure you are holding the pinion still when checking backlash? Obviously if the pinion moves it will change the backlash readings...

Otherwise I'm at a loss as well. I can't see it/touch it to see why it's doing what it's doing.

I highly doubt the pinion support is bad. Bearings are possible.

BlackDuk98

iTrader: (34)

I have tried the Ford manual way, Strange way, and your way, all with the same outcome. Your way makes the most sense because there really is no chance of anything moving. I was paranoid about putting 150 ft lbs on the side adjusters, but once I did it, I could tell it was a safe way to do things. When doing it the Strange way, there really isn't any preload on the carrier bearings. All I can say is that it's a whole hell of a lot bettr than when I purchased it. Backlash was from .004-.006, the pinion support shim was only .006, and there was only 2 in lbs of preload on the pinion support.

I have ruled out the pinion support, and the bearings are brand new, and the .001 wobble at the top of the pinion stays consistant. I have removed the bearings and moved them around, stoned the backs of them etc. I rebuilt it tonight the way you outlined. Backlash ranges from .006-.00925, which is in spec. Spec if .004 variation. So everything is in spec, but I still don't like it. I guess I am just going to have to run it and see what happens. I just wish I knew why it changed from being dead perfect backlash at every spot, the going haywire

thanks for all the help, I greatly appriciate it.

mark jr.

waynehartwig

You're welcome.

Did you ever just bolt up the carrier and check it for runout without the ring gear on it?

.006-.009 is ok to run, but I'd open it up some more as it might come up being noisy and run hot. I'd do .010-.013" instead. Unless, of course, your gear manufacture is recommending .008" as the setup number.

BlackDuk98

iTrader: (34)

Yeah, that was the very first reading that I ever took on it. It has been a long time so i'm not 100% sure what it was, but I think it was just under .001. Then w/ the ring gear, the worst reading that I got was .002. I moved it around in a bunch of places to get a final ring gear runout of .0009.

I purchased Richmond gears and they have .010 etched in for recommended backlash. They reccomend .012-.014 runout for circle track cars. I figured that they wanted .010 as a reccomended "limit". That is why I was trying to keep it at .010 and under. As long as bumping it up is ok for running mostly on the road, then I have no problem doing that...

waynehartwig

.012-.014 is a lot of runout....

BlackDuk98

iTrader: (34)

Yeah, that is what they reccomended for circle track cars. I posted this question on Yellowbullet also and got a few suggestions. I had a very nice final pattern and the final pinion depth was .008, and backlash was .007-.010. So after I got that, I got my paint pen and marked everything so I knew their exact placement. Tore it down and re-did it. No matter what I do, I cannot get it back to .007-.010. So right now, I have it finally assembled and finished. I have the backlash at .008-.011.

thanks

mark jr.