Quaife LSD Installation in R180 - With Questions About Installation Also

[Patcon]

Most vehicles and equipment in the US have had metric fasteners for a long time. To change to metric would be quite expensive for the US. We have a very large road system and it would be complicated for the construction industry too. Probably not the best use of money right now since we already have a ton of debt

[Captain Obvious]

11 hours ago, inline6 said:

To make matters worse, I measured my shim's thickness today while off of the pinion shaft, and it is only 1.260

Yeah, I think the first order of business is to definitively figure out exactly what thickness you need to get correct lash. After that, you can figure out how to achieve that task.

As for the question about grinding the new washer... I was going to suggest exactly that. Assuming the new washer is thicker than what you really need, then knocking the thickness of that one down to what you need would be my first choice.

Only thing that would make that plan questionable would be if there were some sort of case hardening on the shim. You should be able to tell once it arrives. It's not yet even guaranteed that it will arrive though, is it?

[inline6]

5 hours ago, dutchzcarguy said:

Let me just say:  ....... I'm going a bit crazy......  I will NEVER understand what the americans have with those inches, 1/4 1/8  3/32  pfff... (sigh)

Why not mm it's metric it's simple!! 

What do you mean with:

it's only 1.260 thick  ... to me that's A LOT more than 0.140 ????   and.. " means inches.. Right?? 

Oops - yes, I entered the wrong number there.  The washer is .126" not .140" thick.  I fixed it in my post above. 

When I was in grade school, we were taught the metric system because we were taught also that America would be transitioning over the next couple of decades.  That did not happen, however.  

I found a comment from a machinist friend of mine about the metric system to be interesting.  He said that the tolerances typically used for machining (thousandths of an inch) did not have a good equivalent in the metric system.  

Consider:

 

So, when working with tolerances of thousandths or "tenths" (.0001") for machined parts, how well does the metric system work?  

[Jeff Berk]

Your machinist's comment about tolerances might explain why when I tinker around at a machine shop at the university, I'm forced to convert all my projects to inches from metric.

This thread has convinced me NOT to pull out the pinion on my LSD upgrade. All this trouble just to get the right shim is not worth it. 

[dutchzcarguy]

16 hours ago, inline6 said:

I found a comment from a machinist friend of mine about the metric system to be interesting.  He said that the tolerances typically used for machining (thousandths of an inch) did not have a good equivalent in the metric system.  

Hihi.. It has ALL to do with what you are used to..  I worked with studer revox studio equipment, audio machinery worth sometimes over a million Swiss Franks..

For example, and i said it before .. I was in the factory in Switserland, they make capstan axles* on 1/1000 of a mm!  After they made them on some special lath they are stored for a year! Then they get measured on a special bench and if they are out of tolerance they get scrapped!  That's SWISS engineering!

I've seen there recorders for studios they where expensive, well over 1 million swiss Franks.. Also mixers that were over 4 meters wide.. (13 feet).

 

Capstan axles = are those axles in a taperecorder or other tape machine like a cassetterecorder that give the speed to the tape.. (Also the pinchroller pushes the tape against this axle.)

[jonbill]

[inline6]

The pinion shim was not in the shipment I received.  Instead, they cancelled that part and sent me the rest of the order, a few carrier side flange shims.  

Since the shim I took out only measured .126" thick (possibly part number 383535200), I again looked at the shim part numbers that showed as still available (yellow highlight below):

  

The 3.63 (0.1420) is the one I ordered before and was/is on national backorder.  So, I ordered the other two in yellow highlight yesterday, and found out today that they plan to ship them in about 4 days - they are available! 

Now, we just have to see if either of those will work to bring my backlash into spec.  The difference between what I took out (.126") and the thinner of the two I will receive (.1382") is .0122" or 12 thousandths plus 2 "tenths" or two tenths of a thousandth.  There are lots of different shim thicknesses in the chart between these two, which makes me think a little change in shim size goes a long way toward changing the mesh of the pinion and ring gears.  But, we'll just have to wait and see.   

Edited January 9 by inline6

[Captain Obvious]

11 hours ago, inline6 said:

There are lots of different shim thicknesses in the chart between these two, which makes me think a little change in shim size goes a long way toward changing the mesh of the pinion and ring gears.

That would be my assumption as well. Little bit here makes a large change there.

If your measurements are correct, I think you are going to bind with a 12 thousandth thicker shim in there. Did you ever use some thing shim material to try to figure out what thickness (total) you really need?

[inline6]

That shim stock is still in my Amazon cart.  My thought is that instead of binding, the pinion will move closer to the crown gear, possibly so much so, that the tooth contact moves past the center of the crown wheel, but not too far.  And maybe, I end up with an amount of backlash that is acceptable?  My original wear pattern looks too far forward on the crown gear to me...  Depending on what happens with the thinner of these two new shims, I can proceed with the buying the shim stock, and seeing what size I actually need, and then possibly modify one of these thicker washers to that spec.  Thoughts?

[Captain Obvious]

My thoughts? I agree.

Having not been through this exercise myself, I'm not sure of all the effects of changing the pinion position like that. Maybe you'll get lucky and end up exactly where you need to be. And if not, you'll have a better handle on the effect(s) of the change.

 

[Patcon]

My only concern about moving the contact pattern is noise. I have read that moving to a new contact pattern in a worn in R&P can cause excessive noise and/or whine.

Otherwise I agree with your plan overall

[Yarb]

My two cents here, @inline6 You have spent a lot of money and time on building the LSD. What would the cost factor be to take it to a specialist and have them dial it in versus the risk factor moving forward. I applaud you for the effort and research trying to find the parts to dial it in. I realize companies that specialize in this area are hard to find. I’m rooting for you friend, this is a tough one.