Working on my ruckstell. How much noise should I hear when I turn the drive shaft. Its not much but some. I have taken it apart three times and can't get it quiet. I have shimmed ring gear .010 and.015 I have .015 clearance now and using prussion blue the contact is perfect. The first time the pinion wasn't deep enough fixed that and it helped, but still a little pulsing noise. The ring and pinion are new, axle housings straight, I just can't get it totally quiet. I searched the forum and it seems like this is a very common problem but it never really ever seems to get solved, I bet I've got 15 hours trying to figure this out.
Been there - Fought That !!
If the ring and pinion are new to each other, it will take some time for them to get acquainted.
If you are using a modern lubricant (especially a synthetic) it will be a little more noisy than with 600 wt oil.
Time heals all - give it some time to break in.
Synthetic gear oil is a poor choice for antiquated differentials and transmissions. Synthetic oil tends to be less viscuous and does not "climb" gear sets as a conventional lubricant does. This is all fine and well for equipment that has been designed with synthetic oils in mind. However it can spell early doom for old technology that depends on old style lubricants that climb the gear sets.
A friend of mine builds four speed Ford "Top Loader" T&C transmissions for a living. He recommends the customer use conventional gear lube because he has seen first hand the rapid wear and early failure caused by synthetic lubricants.
I run 250wt Amsoil synthetic in mine. I guess someone should tell it that it should should be noisy and wear out faster. Seems to be running just fine all this time. By the way...it doesn't leak either.
Your gear lash is fine. The Prussian blue shows good contact. Your housings are straight. Personally I'd button it up and run it. Only then can you tell if the noise is unacceptable.
If so, inquire further. I once tore apart a rear end and adjusted it over twenty times and it never quieted down. Turns out the pumpkin had been sprung.
Use SAE 120 in a Ruckstell. 600W is too thick to get into all the gears. 600 is fine for standard Ford.
Well I did just put it together and in. A little more background in case it helps, when assembled on the bench half the housing with the driveshaft in and supported, totally quiet, perfect. Put the other side on and snugged it starts to get a little noisier. So I just gave up and put it in as suggested, well it is quiet in the car so far. I put about 10 miles on it with a mid way stop to check. I hear only a very slight whine, hardly noticable, up through the tourque tube, but I have my floorboard off. I am running the 85W-120W weight regular oil in it for now. So thanks everyone for the suggestions and help.