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ring/pinion install question

BillR

Toy Jeep driver!
Location
Flagstaff, AZ
A buddy and I are in the middle of a rebuild of an HP Dana 30 for my XJ, and we've run into a question.
I have the original gears that came out of this housing. The pinion is marked "+1" on the face. On my gears to be installed, the pinion has "+3". I know that this is the distance from the standard checking distance for pinion depth. Here's the "issue"...
The older pinion that came out of the housing has a .028" thick oil slinger under the bearing. The newer gear has a .055" slinger that was mounted on. (these are used gears). We used the slinger that was on the newer gear, then added the .002" shims to the thickness that was alrteady on the older gears to get the pinion depth. The pattern is really good, but we ran out of shims before we got to the proper preload setting for the pinion nut. The old set of gears only had .054" in shims for preload. My install kit comes with .094" in total shims, and that doesn't seem to be enough. (preload is still too tight)
We've checked to make sure that the races are seated correctly, and the backlash is .006" and the pattern is great! Do we need to just keep adding shims for the pinion preload, or is the different oil slinger thickness throwing things off? Is the slinger housing-specific?
TIA!!
 
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which oil slinger? the one near the pinion, or the one near the yoke?

the one near the pinion affects depth as you've seen, and if you have a .006 backlash and great pattern, you are all set there....

now, as far as the preload is concerned, the slinger near the yoke does not affect preload since it is on the other side of the bearings......

if the old set had .054 in preload, than your new preload pack should be very close to that! so something is wrong.....

my guess is you have the shims on the wrong side of the bearing. the shims need to go on the pinion side of the bearing cone, not the yoke side.....is this the problem?

take some pictures too.
 
Beezil said:
which oil slinger? the one near the pinion, or the one near the yoke?

the one near the pinion affects depth as you've seen, and if you have a .006 backlash and great pattern, you are all set there....

now, as far as the preload is concerned, the slinger near the yoke does not affect preload since it is on the other side of the bearings......

if the old set had .054 in preload, than your new preload pack should be very close to that! so something is wrong.....

my guess is you have the shims on the wrong side of the bearing. the shims need to go on the pinion side of the bearing cone, not the yoke side.....is this the problem?

take some pictures too.
The preload shims are in the right spot. The slinger is the one directly under the pinion gear, between the gear and bearing.
I THINK I've figured it out. Please correct me if I'm wrong...
The shim pack for the original pinion depth was set using the old oil slinger. If I put a thicker oil slinger AND added shims to compensate for the difference in the markings on the face of the pinion, that would throw things off. We DID need to move a shim from one side of the carrier to the other side to get the correct backlash. This would indicate a slightly different pinion depth than what was there from the factory.
Am I on the right track?:confused:
I'm thinking that if I replaced the slinger with the one that was on the original pinion, my actual depth would be closer to the correct setting. Then I'd be able to reset the carrier to the shim arrangement that was there, and still be close to the correct backlash.
 
yeah, you are on the right track, but it does not explain why you've run out of preload shims.....

I just wanna use something as an example, and I'll use numbers that round-up for simplicity.....

lets take pinion A, it might as well be the original pinion. Assuming it is set-up exactly in spec.....if the pinion depth shim is .040 and the pinion preload shim is .060, add the two together and you get .100.....that means if you ever had to change the pinion depth of pinionA, say to .050, you can assume that the preload shim should be .050 so that both number add up to .100......because, the relationship between the two bearings should not change as long as the preload was correct from the start.

This correlation can be applied to the new pinion...ALMOST....the tolerances are pretty damn close. That's why when I do a gearset, I begin with NEW shims of the same thickness as the old ones. many times, i get lucky and nail it, other times, i'm within .010" using .005" "steps"......On shim style pinion set-ups, I will install the new pinion with new shims of the original thickness, and check for preload....I don't have to do it first, some folks wait and do preload last, but once you establish the correct preload, the relationship remians constant, so if I have to make a depth shim addition or subtraction, I simply add or subtract preload shims so both add up to the same total shim thickness.....

This is just the way i do it, but I wanted to illustrate that point to help you understand why it doesn't make sense for you to be running out of shims.....

If i read your post correctly, your depth shims are .057 and your preload had .054......So, are you saying you got lucky and the new pinion depth thickness gave you a good pattern on the new pinion? Thats cool! That happens now and again....You can assume that the new preload shims should be pretty damn close to the original thickness, provided that your new pinion has a bearing shoulder ground were it SHOULD be. If possible, measure the distance between the back of the pinion to the shoulder were the preload shims go.....measure the original pinion and the new one to see what the difference is....You should expect tight tolerances between the two. If they are identical to within .001-.002 as they should be, your preload shim pack should be pretty close to the original dimension, otherwise, I would double-check to make sure the bearings are correct and seated correctly...the race could be sitting on a booger, or possibly even a gouge from removing the old race......

Bill I hope I'm understanding your problem correctly. I apologize in advance if I've provided info so obvious it borders on insult!

not my intention
 
Beezil said:
yeah, you are on the right track, but it does not explain why you've run out of preload shims.....


If i read your post correctly, your depth shims are .057 and your preload had .054......So, are you saying you got lucky and the new pinion depth thickness gave you a good pattern on the new pinion?

I guess I really didn't get lucky on the pattern, sine we had to rearrange the carrier shims to get the correct backlash. We ran out of preload shims due to the pinion depth being off because of the wrong slinger. After confering w/the techline at Randy's, the original slinger needs to be installed. At that point, the pinion depth will be closer to correct in relation to the housing. The carrier shims should be able to be arranged at or near where they were from the factory, instead of compensating for the pinion depth being off.
FYI, we tightened the pinion nut to the correct preload before we did the pattern, but it was nowhere NEAR the correct torque spec for the nut. (200 ft# is spec!)
This is my first time helping w/a complete gear install, so please don't think your responses are too simplistic. I appreciate the assistance!
 
it still doesn't make sense to me....

since the oil slinger (sandwhiched between the pinion gear and the bearing) accounts for the pinion depth, I don't understand why you or randy says it is affecting the preload.

you said the "new" gear had a .055 thick slinger on, and you added .002 for a pinion depth shim thickness of .057 overall......once you adjusted the backlash, you said you got a great pattern. then you know the pinion depth is correct......

if you install the old slinger that measures .028, you'll have to add somewhere near .030 worth of shims to achieve the same pinion depth.......

this doesn't solve your preload problem........

Am I not understanding correctly?

maybe I'm just not seeing it.
 
I'm not sure how to explain it...
There are no shims between the gear and the slinger. The preload shims are on the rear "shoulder" of the pinion shaft, and the depth shims are mounted in the housing between the races along with another slinger.
The slinger (just behind the gear) being too thick causes the bearing to be too far back, and increases the distance that needs to be shimmed for the preload. Installing the thinner slinger would move the shoulder on the pinion, along with the preload shims, farther toward the yoke end of the housing. This would decrease the number of shims needed to "fill the gap" and get the correct preload.
(right?):confused:
 
Beezil said:
GOTYA!

SORRY....

okay, so you got the correct info from Randy....

sorry if I confused you.
I knew what it looked like in my mind. My confusion was not being able to put it in writing clearly. :anon:
Thanks again for the advice!:cool:
 
Ive rarely gotten backlash that tight, with a good pattern with USED gears. Have to find the worn spot in the gears. Anything else is too tight or the pattern is thrown off. Don't know if this would be different with 'almost new' gears, as the ones I did were pretty old.

Dan
 
it would be terribly difficult to get a good pattern with a tighter backlash on used gears, since every g-damn dana axle I've ever touched has had sloppy wide-open backlashes in upwards of .030"! I can see where yer coming from Dan.

I've been setting up R&P's so that I get a good pattern with spec backlash, but then I tighten up the backlash to around 3-4 thou......

when I installed a locker in my 44 a while back, I took a reading and it opened up to .007.....PERFECT.

I'd rather do that than to have the backlash open up beyond spec, and have the pattern fall to the topland of the tooth under high torque
 
First off always start with what came out of the housing you working on!Second you should have removed .002" worth of shims!
 
I am bringing this backup because I am in the middle of it.

I was confused that this one did not have the crush sleeve like my TJ D30. I understand that you have to set the preload with the shims, but I am confused on where the heck they go.

I have the gears installed in the axle right now awaiting the pinion preload shims. The backlash is at .007 and I have a perfect pattern.

This is what I have done, I think it is wrong, so correct me.

I set the pinion depth by adding shims between the BIG washer (which I assume is the slinger?) at the bearing. I think I have about .025 worth of shims.

After reading this post, I am thinking that those shims should have gone between the race and the bigger shim that is touching the differential?? Does this mean you have to remove the race everytime that you want to change the depth?

Next question, how am I suppose to set the pinion preload? Right now I have it about 12 in lbs with the current setup.

Tell me what I am doing wrong. FYI - there is a ARB in the middle of this.

Chip
 
iispms said:
I am bringing this backup because I am in the middle of it.

I was confused that this one did not have the crush sleeve like my TJ D30. I understand that you have to set the preload with the shims, but I am confused on where the heck they go.

I have the gears installed in the axle right now awaiting the pinion preload shims. The backlash is at .007 and I have a perfect pattern.

This is what I have done, I think it is wrong, so correct me.

I set the pinion depth by adding shims between the BIG washer (which I assume is the slinger?) at the bearing. I think I have about .025 worth of shims.

After reading this post, I am thinking that those shims should have gone between the race and the bigger shim that is touching the differential?? Does this mean you have to remove the race everytime that you want to change the depth?

Next question, how am I suppose to set the pinion preload? Right now I have it about 12 in lbs with the current setup.

Tell me what I am doing wrong. FYI - there is a ARB in the middle of this.

Chip

Anyone?
 
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