M1009 Differential Goes Boom

[porkysplace]

]Um, so it made 35 years, got rebuilt and died under a year later.

But okay, didnt know GM invited the gov lock

Oh right, they did not... Eaton corp did... of course gov lok is a made up name for the Eaton "automatic differential lock"

So you can see how I would be confused when you blame GM for something Eaton made...

I mean please explain to me how this is a GM design issue when it is a Eaton designed part... I mean honest... I aint an axle expert...

Right there is most likely the answer 35 years of metal fatigue and when it got freshened up it stressed the fatigued metal . With a junk design to start with.

 

[Recovry4x4]

As far as I know, GM requested it. It was installed by GM. Eaton didn't magically have one that fit. Like any other manufacturer, GM didn't make every single part. It was likely made to their specs.

We are splitting hairs here. That's like blaming the gasoline company for the square body tank issues. After all, the tank didn't burn anyone up.

Look at the history of the gov bomb. It has a colorful past. You are certainly entitled to your own opinion but not your own facts. Gov bombs explode. I'm not implying guilt to either side but since they have a history of history of breakage, why not consider it.

 

[cucvrus]

I really don't understand condemning the Eaton rear axle. It is still in every new truck I buy. My 2019 Silverado Trail Boss has the Eaton locker rear in it. I never had any trouble with any of them. I stand by my statement everything has a breaking point. And 30+ years of wear and use has taken its toll ion the original design. Throw a few home brewed repairs into the mix and things go even worse from that point. I still think it is a great rear axle and like I said I have several in use and still functioning. It is not a 14 bolt but it is still a good design and works as designed. Good Luck. Everything can and will break eventually.

 

[carter262]

I appreciate the feed back and advice. I looked into changing the axles out for come thing larger and decided that I did not want to go through the trouble of all the work that is involved. This is my daily driver and don't abuse it so I really feel the original axles should serve me well. Plus I need to get it back together quickly so I can get back on the road.

That being said when I have it rebuilt I don't want to but a Gov-Lok back in it. I think I am going with a Detroit Locker. I'm no expert but do know they have a good reputation and are a lot better than the original locker that came in the M1009.

So my questions so I can get this ball rolling.

Is the 10 bolt in a M1009 a 28 or 30 spline?
Is that the only thing I need to worry about for fit in the M1009?

 

[carter262]

I ended up having it rebuilt with a Detroit TrueTrac Locker; GM 8.5 28 spline. The part number is 912A556.

The rear master overhaul kit was a Yukon part number was ZKGM8.5.

Thanks for the help.

 

[Chaski]

That truetrac is a neat unit. Should be very street friendly since it is a torque biasing differential and not a locker. That is what I have in my daily driver pickup.