1975 14bff carrier?

[gone huntin]

What type of locking unit would this be? What type of lubricant does it require? Asking for a friend that just aquired this truck.

 

[Eric M.]

You'll need to know what locker is in it (assuming from your post is isn't an open dif.) and then you can determine the type of gear oil you need.


Eric M.

 

[gone huntin]

From pics. I've seen on ebay, it's a gov-lock.

 

[K5MONSTERCHEV]

Well no matter what posi, 80-90w and limited slip fluid, friction modifier, whatever.

 

[gone huntin]

There is a TSB from GM saying NOT to use a friction modifier in the rear diff. containing a G80 in 10 bolts like in my 'burb. It states that using the friction modifier will cause pre-mature wear.

 

[Blazer1970]

There is a TSB from GM saying NOT to use a friction modifier in the rear diff. containing a G80 in 10 bolts like in my 'burb. It states that using the friction modifier will cause pre-mature wear.

That is correct. Gov-locks DO NOT use limited slip additive.

 

[K5MONSTERCHEV]

That is correct. Gov-locks DO NOT use limited slip additive.

Since when? Where did you learn this?

 

[Blazer1970]

Since when? Where did you learn this?

Since Eaton started making them in the mid '70s.


Here is a quote from a post on the diesel page where someone e-mailed Eaton for info on this:

oneton,
You were right. I did email Eaton to get their recommendation on oil type and maintenance schedule. Here is their reply:
"The newer GM trucks use synthetic oil that is considered lube for life in most cases. Depending on the year /make of your truck the GM manual may require you to change the lube after 500 miles of aggressive towing , as this condition works the axle (generates heat) the hardest. After initial towing the axle temperatures will no longer peak, and the new synthetic lube will last a long time.

You should stay with the lube GM recommends as other lubes, especially synthetics may cause G80 to lose capability. Some of these oils reduce the friction characteristics of the G80 clutch packs, increasing the slip between clutch discs, which will prevent the axle from locking. Never use friction modifier (additives) in combination with the G80 as they also increase slip between the discs."

John

 

[gone huntin]

Then he should use regular 80w90 in it then? That's what I was thinking, but I wanted to hear it from someone else too. I went to look it up in my ALL-DATA, but it only goes back to '82.

 

[K5MONSTERCHEV]

Since Eaton started making them in the mid '70s.


Here is a quote from a post on the diesel page where someone e-mailed Eaton for info on this:

Ahh, well there not that great anyway.