Broadcasting this periodically: If someone has used 87-88 LSD unit in good condition for sale (part number 92833205220), I'm interested in buying it.

 

PING! f someone has used 87-88 LSD unit in good condition for sale (part number 92833205220), I'm interested in buying it.

 

 

Let me know what you get. Right now, the most pressing need is for an '87-89 LSD unit.

 

At what measured surface hardness are steel gears usually the toughest in terms of their ability to hold load? 400 Brinell?

 

 

You know the transmission came with a limited slip, right?

 

 

I think Brinell is just the 'ball test'. It can be used on a wide variety of materials. I've mainly seen it used on lead (cast bullets).

 

 

I read about that and it turns out these gears should be tested using the Vickers or Knoop tests.

"For instance when hardness is checked on a mounted tooth sample, it is typically checked by taking a microhardness traverse. The microhardness is taken either by Knoop, a method using a 500- or 1000-gram load, or sometimes Vickers, using a kg load. Yet nearly all drawings specify surface and core hardness in values of Rockwell "C", a method which uses a 150 kg load. For this reason, a conversion must be made from either the Knoop number or the Vickers number to determine whether the part met the specified Rockwell number. Conversion is not simply a mathematical relationship. Since the structure and cold working properties vary for different materials and hardnesses, The 150kg load used for a Rockwell "C" check is inappropriate to check the hardness close to the surface or elsewhere in the case. This is because the size of the indention made by the 150 kg load homogenize the conditions over a large area. This can mask local deficiencies."

 

Greg has a Rockwell hardness tester on a stable table at the shop, but I've never seen him use it on a gear. Not sure which sets of indenters he has nor which sets of hardness scales it can be set up to measure.

 

 

 

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