10 pinnon lsd body core cracked

[gt14rider 764]

 Hi all, working on my 73 no name, took differential apart and found the body core cracked, A to Z doesn't seem to0 have one , any other sources for one.      pn # 7200,   transmission 5089

[ebinmaine 67,553]

I'd have a GOOD welder repair that one.  

File the hole. Back in it goes. 

[19richie66 17,508]

Let me check tomorrow. I believe I may have one. 

[gt14rider 764]

Thanks richie, 

[19richie66 17,508]

3 minutes ago, gt14rider said:

Thanks richie, 

1-1/8” axles correct?

[gt14rider 764]

Yes sir.

[ri702bill 8,327]

Hmmm... that looks like a Powdered Metal part - most likely cannot be successfully welded to restore its original integrity and long term function....

Bill

[ebinmaine 67,553]

52 minutes ago, 19richie66 said:

1-1/8” axles correct?

All the ten pinions were Richie 

[19richie66 17,508]

1 hour ago, ebinmaine said:

All the ten pinions were Richie 

Learn something new every day  

[oliver2-44 9,756]

4 hours ago, ri702bill said:

Hmmm... that looks like a Powdered Metal part - most likely cannot be successfully welded to restore its original integrity and long term function....

Bill

Considering that a 70’s vintage tractor, wouldn’t powdered metal be fairly exotic/expensive for a tractor back at that time.

 

@gt14rider Just an FYI. There was a thread on here not long ago with a very similar failure. So maybe a common failure when that transmission is worked hard or bearings west.  Like you, I believed he replaced it. 

[ri702bill 8,327]

@oliver2-44 - that part is an excellent candidate to be formed from powdered metal - every feature is a thru shape and the thickness is consistant. PM parts are strong - but brittle and do not tolerate flexing at all. I suspect the flexing became the issue - well beyond the factory WH warranty !

Where I worked last we designed Automotive OEM Actuators that used a lot of PM internal components - perfect for gears and dificult to fabricate shapes....

Bill

[gt14rider 764]

2019, I had both body cores cracked on my gt14

[WHX?? 48,823]

13 hours ago, ri702bill said:

Hmmm... that looks like a Powdered Metal part 

Care to skool me on powdered metal Bill? 

[OoPEZoO 525]

It's pretty amazing what can be done with powdered metals these days.  I work for a power tool company and we use PM for all sorts of things.....mainly internal drive gears in the transmissions and such.  The process is pretty neat, think about it like this........take metal in a powdered form, fill a mold, shake it to remove voids, seal the mold, and then put it in a pressure cooker for X amount of time/temp until the powder forms a solid metal part.  Many of those parts are then heat treated after the process for added strength.  Like was mentioned above, PM parts are very hard, but also brittle.  If they do fail, cracks like in the above pics are a normal failure mode for thin areas.......as are chunks breaking off of gears.  Overall, they are very durable and cost effective.  Especially with oddball shaped parts that are "easy" to mold but would be a complete nightmare to machine......plus no waste chips all over the floor

[ri702bill 8,327]

Jim - the short version is that the metal powder is blended with a binder - pressed into dies that have the desired shape. The die is overfilled approx 15% - the cover to the die is added and the die closed with approx 50 to 100 tons of force. The die is opened, the "green" part removed in its delicate state and placed with others like it in a high temp oven to "melt" the binder agent to bond all the metal particles. Sometimes with PM leadscrews they get copper infused - a copper "pill" is placed atop the part, it melts into and thruout the part to add lubricity.

PM parts have no grain structure unlike extruded, machined, or forged parts - that is why they are brittle. So much for the short version...

There are several Yt tutorial videos out there on the PM process....

Edited January 11, 2023 by ri702bill

[Handy Don 12,233]

9 hours ago, oliver2-44 said:

 

@gt14rider Just an FYI. There was a thread on here not long ago with a very similar failure. So maybe a common failure when that transmission is worked hard or bearings west.  Like you, I believed he replaced it. 

The unique feature of the 10-pinion differentials is that their pinions do not rotate on shafts or on forged-in pivots--they are loose in the body core. The LSD spring and other internal forces drive the pinions to rub against the walls of the core and the resulting friction provides the “limited slip” function.

It makes sense to me that such a break in the core at that narrow section could come from excessive “outward” force on the pinions from:

- a sudden shock load on the differential

- a foreign object getting wedged between the pinion and the core

- worn pinions exerting asymmetric loading on the core

[ri702bill 8,327]

12 minutes ago, Handy Don said:

- a foreign object

Shades of Saturday WWF Wrestling... !! 

[Handy Don 12,233]

1 hour ago, ri702bill said:

Shades of Saturday WWF Wrestling... !! 

Ok, I’m dense and don’t know anything about WWF wrestling  so I don’t get this at all! (PM me the explanation?)

[19richie66 17,508]

I do not have this. I thought I did but everything I have is 8 pinion. Sorry bud.

[stevasaurus 22,760]

Speaking of 8 pinion, if you can not find that piece, you could go 8 pinion differential.  That would still be 1 1/8" axles.  There is a Service Bulletin that tells you what you need to make the change.  Just a thought.  Also, it would get you running while you search for the Limited Slip part(s).  

[ebinmaine 67,553]

3 minutes ago, stevasaurus said:

Speaking of 8 pinion, if you can not find that piece, you could go 8 pinion differential.  That would still be 1 1/8" axles.  There is a Service Bulletin that tells you what you need to make the change.  Just a thought.  Also, it would get you running while you search for the Limited Slip part(s).  

 

I'm thinking the eight pinion versus ten pinion is a direct bolt in replacement to one another?

 

[pfrederi 17,741]

9 minutes ago, ebinmaine said:

 

I'm thinking the eight pinion versus ten pinion is a direct bolt in replacement to one another?

 

 Depends on which style mushroom gear you have.  Two piece is OK one piece will not work

[ebinmaine 67,553]

3 minutes ago, pfrederi said:

 Depends on which style mushroom gear you have.  Two piece is OK one piece will not work

How about hydros?

[stevasaurus 22,760]

That is why you look at the service bulletin.  2 piece mushroom gear, 8 pinion differential with axles are needed.  8 pinion axles are the same length, 10 pinion axles are not the same length.  The parts replace said parts in your 10 pinion transmission or get a whole different 8 pinion transmission and bolt that in.  

Edited January 11, 2023 by stevasaurus

[stevasaurus 22,760]

Hydros don't matter here and are off topic.  

On the other hand, a 10 pinion holder piece from a hydro is probably the same as the manual trans as far as part number.  

Edited January 12, 2023 by stevasaurus