489 gear pattern setup results - #2 Final Round ( I hope)

[dvw]

After messing with my failed Dana, I made a lot of inquiries. Strange, Moser, Racers and a couple of gear shops. For sure eveyone I talked to said to increase backlash. The harder you hit the gear, The tighter it pulls the teeth together. Exactly opposite of what most of us would think.
Doug

 

[Cranky]

I used a 3/8“ somewhat anemic battery impact to run down the pinion nut to pull the front bearing on and snug up the nut, and only with the carrier out while I centered the yoke. I dont think it has enough ummphh to do much to anything. Beyond that I went to a torque wrench. Finally got the pinion preload to 28 in-lbs which was a little higher than I was shooting for but with .0005” less shim it was still a little low so I quit there. It stayed stable and smooth to 170 ft lbs on the nut. Fortunately the pattern looked the same - maybe a bit cleaner as the extra drag helped produce a cleaner imprint in the gear paste.

Cranky my shims seemed to fit fine but I guess they are all rough stamped out anymore. I couldn’t a stable measurement on any of them with my caliper as they seemed to have a sheared, distorted edge from the stamping. I had to file the ID & OD edges on all of them and then sand their faces with emory cloth on a flat surface with an aluminum block. After that they would measure uniformly around their radius with a caliper and I could figure out what I was doing.

If you have distorted edges on your shims may mean they don't fit the radius and then you need to get different shims. Dr. Diff has them and it sucks that we have to deal with that crap but with so much stuff coming from China......well, just have to deal with it. Using a bit of grease to get the over sized ID shims to stay in place might be an option when you assemble the parts.

 

[Cranky]

After messing with my failed Dana, I made a lot of inquiries. Strange, Moser, Racers and a couple of gear shops. For sure eveyone I talked to said to increase backlash. The harder you hit the gear, The tighter it pulls the teeth together. Exactly opposite of what most of us would think.
Doug

Is that for racing or.....?

 

[AR67GTX]

If you have distorted edges on your shims may mean they don't fit the radius and then you need to get different shims. Dr. Diff has them and it sucks that we have to deal with that crap but with so much stuff coming from China......well, just have to deal with it. Using a bit of grease to get the over sized ID shims to stay in place might be an option when you assemble the parts.

They were manufactured and delivered this way. I didn’t see any distortion in any after use in any of the trial set ups. I bought shim kits specific for the 489 pinion and for a solid spacer and they fit well. Worse thing was a sparse selection of shim thicknesses in the kits. Even after buying 2 sets of pinion depth shims I had to file and sand some down in thickness to get to a specific shim pack thickness for the pinion head.

 

[AR67GTX]

Well, not quite as good of results as I hoped for. Coast side seems quiet but still got some whine on drive going through the 45 - 50 range and quiet above that. Sort of makes sense in that the drive side pattern was not bad when I got it back from the shop - made noise then and still does. Coast side pattern from the shop was funky as I think DVW put it. Fixed that and now coast side seems OK noise-wise as a result. I doubt I can do much more without a 4th set of gears yet, if then.

 

[steve340]

Can you live with it?
I probably would it seems you have done a good job. It may settle down a little with use I would wait for a bit and monitor it.

 

[AR67GTX]

Probably will try to live with it. I have a box of foam noise insulation and a new Legendary interior on order. My plan will be to apply it under the package tray board, on the board behind the seat back and to the floor pan under the rear seat and up the axle rise to just below the top. Then also apply it under the rear seat side panels since the areas over the wheel wells duct trunk noise into the rear seat quarter panel area. That may help a little but I don’t think a lot. At least it’s over a fairly narrow range - seems to be quiet once over 50 mph.

 

[dvw]

Is that for racing or.....?

Increased backlash was recomended for high load applications.
Doug

 

[hunt2elk]

Probably will try to live with it. I have a box of foam noise insulation and a new Legendary interior on order. My plan will be to apply it under the package tray board, on the board behind the seat back and to the floor pan under the rear seat and up the axle rise to just below the top. Then also apply it under the rear seat side panels since the areas over the wheel wells duct trunk noise into the rear seat quarter panel area. That may help a little but I don’t think a lot. At least it’s over a fairly narrow range - seems to be quiet once over 50 mph.

You sure did try your best to get those gears to quite down, and learned a whole lot in the process. I went through the exact same thing several years ago. Bought a set of gears from Cass and set them up. They howled right away. Put 5 miles on them going around the block before calling him. He told me I could try to change the shims, but in his opinion, once they are run and make noise, there is no fix. He was right. I got it slightly better, but couldn't live with the noise.

 

[oldkimmer]

Here is the next to final pattern on my D60. It still needed.010 thicker pinion shim to get it into the middle where I wanted it. Sorry I don’t have pics when we got it done. Somehow deleted those pics. Kim