Dana Ring and Pinion Hardness

[UKZR1]

Hi guys I need to know what the hardness of a Dana R/P is spec'd to be or at least where I can find out.

I know you are going to ask why so here's a quick explaination.

I opted for 410's at the start of the year. Marc supplied me with the Dana R+P, bearings, seals, shims etc. I was going to do the install my self but opted to get a specialist here in the UK to do it. The diff lasted 120 miles and failed. I returned it to the specialist to be told the ring had not been properly hardened.

In order to make Le Mans this year I had to buy another diff from the US the week before we were due to leave. I lost my core charge on this new diff because the old one had been ground inside for ring clearence?!?!

Since my return from LeMans my failed diff has been at Nottingham university's mechanical engineering department undergoing tests by a fellow vette owner.

The average hardness of the R+P is 60-62 rockwell. Suspected reason for failure was incorrect pinion depth - it was 11 thou too deep. From what gears, bearing races are normally hardened to, this is an expected figure but it would be nice to know Dana's actual figures.

thanks

[Aurora40]

sorry I can't help, and sorry about the gears. But did the installer tell you how exactly they get "properly" hardened?

[UKZR1]

installer didnt tell me anything - don't think he knew much;)

[Jagdpanzer]

Sorry, your "specialist" must have rally botched the set up for it to have failed so quickly. Even if the tooth surface hardness was off the gear set should have lasted much longer than 120 miles, provided it was properly set up to begin with.

[Kevin]

botched install

[A26B]

installer didnt tell me anything - don't think he knew much;)

I think the installer is the problem, not the hardness of the gears. Sounds like he's trying to shift the blame. 4.10 gears sometimes require a little clearancing in the differential housing, but nothing that affects the integrity of the housing.

Sounds like you bought a differential with the gears already installed the second time around. Sorry about your troubles, but shoddy work seems to be rampant these days. I'm dealing with some of that myself. A real pisser!

If you ever need any engine gaskets or seals, just let me know. I'm making them now, price is reasonable, quality excellent, all die cut.

Good luck!!

[UKZR1]

botched install

yes it was. Pinion depth was 11 thou to deep - thats miles in this application. Hardness has now been tested and was ok, reading what we expected but it would be nice to know Dana's spec is. some other items which didn't cause the failure but are an indication the quality of work was the fact bores were not cleaned before the bearings were pressed in