Setting up used gears: factory Dana 35 shims too loose and advice reading patterns

[Yasha]

Hiya all, I'll spare background story and get straight to the point. Setting up a Dana 35 axle with used gears I pulled from a junker with 100k miles, to swap in place of my 3.07s. I've put in new pinion bearings and seal, set the pinion to 15 in-lbs preload, made some setup bearings, dropped the carrier in with the original shims (.141", .145")... it just drops right into place??!! Before putting on bearing caps, I can stick a 22 thou feeler gauge between the carrier bearing race and shim on either side. It's so loose. After installing bearing caps and torquing to 57 ft-lbs, the shims are still loose and can be wiggled / rotated when poked with an awl. I assume to expect a very tight fit, so I've ordered a Yukon gear shim pack.... but anyone see this before?

For what it might be worth, here are the patterns I have ran already... I did coast, then drive, and during drive a faint second pattern was made on the coast side. But looking at the original coast pattern alone (and even drive side), it looks like pinion depth is OK, now need to get proper shims to jam the carrier in place and set backlash right (measuring .006" but those loose shims are unacceptable to me)

Figure it's worth showing pics of my front Dana 30 pattern too. I set 20-25 in-lbs preload on the front Dana 30 pinion, seeing backlash .0093"... Coast side looks like pinion is alittle too far away, I'm thinking a little re-shimming of the carrier to reduce the backlash, which will also bring the carrier closer to the pinion, is all I need.

On the plus side while I wait for advice and also for my shims to arrive in the mail, I have longer to decide if I'm going with 3.25" or 4" lift.... but looking to be back on the road again soon. I think when I first pulled these axles some folks advised me to just run them... I decided they had to be totally cleaned and all bearings replaced... I'm a little uncertain whether I'm obsessing over nothing or not, as these aren't new gears. Except for that Dana 30 shim problem .That's messed up for sure. Maybe I lost some shims somehow... I don't think it was easy to pull the carrier... I doubt that though.

 

[Rickyd]

Yep, tighten up the carrier and start over with the pattern. It's no surprise the new carrier doesn't fit perfect.

 

[Yasha]

Yep, tighten up the carrier and start over with the pattern. It's no surprise the new carrier doesn't fit perfect.

Same carrier, only changing bearings, that's what shook me I even mic'd the bearings, they're within a thou of the originals. If anything I'd expect a tighter fit from new bearings + races. Got new shims coming today anyway we'll take it from there.

 

[Rickyd]

Same carrier, only changing bearings, that's what shook me I even mic'd the bearings, they're within a thou of the originals. If anything I'd expect a tighter fit from new bearings + races. Got new shims coming today anyway we'll take it from there.

You are taking gears(and carrier?) from one axle and putting it in another right? Housing tolerance would explain that.

What ratio? You don't want to put 3.73 on a 3.07 carrier if I remember right. I assumed the donor carrier would also be moving over.

 

[Yasha]

You are taking gears(and carrier?) from one axle and putting it in another right? Housing tolerance would explain that.

What ratio? You don't want to put 3.73 on a 3.07 carrier if I remember right. I assumed the donor carrier would also be moving over.

Oh, I'm sleep deprived lately, maybe didn't make sense. I have a complete axle I tore down just to paint and replace the bearings + seals. You're right, there are 2 carrier sizes, I don't remember the cutoff point but I remember the price for a complete used 4.10 axle was less than just the larger carrier so decision made for me there.

Anyway got the thing re-shimmed. 0 side end play, carrier backlash .004". Not sure what to make of this patter. I ran coast side first, 3-4 teeth 3 times around the ring, and get this two part imprint (showing pattern imprint and ghost on clean teeth)

Now for drive side, this one was clearer, I think pinion depth looks OK based on this (cautiously, because this is a gear with 100k miles on it)

Not sure what to make of coast side.

 

[Rickyd]

Maybe open up the backlash to start.how does the pinion gear look?

@hosejockey61 @Blackjack ?

 

[Blackjack]

Ok with used gears patterns are rarely pretty. Do not chang your pinion depth from where it was. Ideally you do not want to change the backlash either.

Lack of preload on Dana 35s is not uncommon. You will want to increase preload by increasing shim thickness on the shim opposite of the ring gear and if the backlash doesn’t go out of sight run it.

 

[Yasha]

Here are pictures of the pinion for reference as asked. Could not get coast side in focus but tried. I will increase the backlash a little and add preload, see if pattern happens to change, and in either case, with backlash in spec .005-.008" I will run it.

@Blackjack I did not change pinion depth however didn't know anything about axles when I tore this down a couple years back so didn't measure original backlash. I appreciate your input. Lesson learned next time I do this run pattern and measure backlash before teardown...

 

[Blackjack]

Since the gears are used I would not try to get below .008 for backlash. .010--.012 would be better most likely as that is probably where it was.

 

[Yasha]

Here we go, I got .011" backlash now, pattern remains unchanged, everything feels smooth. Feels a little loose compared to .008", I can hear the slight clink of contact break/make when reversing directions, but I trust the judgement of those who have done this before better than me who has 3 axles waiting to be built and 0 historically done.

A little unclear from camera angle. First image (two part pattern print) is drive side, second (burger) is coast side. Both within boundaries of the tooth, so even if ugly, contact patch is within alignment.

By the way, worst time to have to ask this question... anyone recognize this part and where it might have come from on a Dana 35 or Dana 30? It looks like an oil slinger but I don't remember seeing it behind the pinion on either axle (I do have a much larger OD shim/slinger on the Dana 30 I haven't finished setting up carrier on yet). It's .030" thick. Reading up, seems it might be somewhere near the pinion nut on the Dana 30, not used to set pinion depth, and may not be something I need to worry about... but I'm not sure.