GM 10 Bolt (Boiled?)

[Defiant]

Recently on a hunting trip, after climbing up through some rocky terrain I noticed that the rear diff oil was boiling when I got out of the truck? Is that really possible? What might cause this?


89 K5 350 TBI
700R4/NP208\
33/12.5's BF Goodrich TA
10Bolt GM w/Auburn Posi

 

[dremu]

Recently on a hunting trip, after climbing up through some rocky terrain I noticed that the rear diff oil was boiling when I got out of the truck? Is that really possible? What might cause this?


89 K5 350 TBI
700R4/NP208\
33/12.5's BF Goodrich TA
10Bolt GM w/Auburn Posi

Well, all fluid will *eventually* turn into a gas, given enough heat.

I would imagine, however, that you were burning water out of the gear oil, as I believe the boiling point of water would be less than that of gear oil.

In any event, Karnak The Invincible foresees you pulling the diff cover and looking inside.

-- A

 

[pauly383]

They do get hot with hard use . I run synthetic so the temps are down , and after wheeling my diff is still hot to the touch .

Get in the habit of changing that fluid out , its the most neglected part of the typical vehicle with a salisbury axle .

 

[dyeager535]

My question is, how did you notice it was boiling?

 

[Defiant]

Reply - How

I could actually hear it gurgling/boiling when I walk around the truck just after I stopped! I was shocked! I suspect 'maybe' the clutches in the posi were slipping? Looking into getting a 'new' auburn posi. This one is about 12yrs old with lots of hard use.

 

[vortec]

i've seen them smoke (not mine), but never heard one boil before. sounds like way too much friction in there.

are you sure you weren't just hearing gasses through the vent tube?

 

[Hogback Fabrication]

Put your hand on the diff.

If you can't hold your hand on it then its too hot.

 

[dyeager535]

Reason I ask is because I had a vent line clogged on my front, and fluid was bubbling out around the front cover, which made it look like it was boiling.

Check that your vent line is clear though.

 

[70jimmy]

Check that your vent line is clear though.[/quote]


My first thought also

 

[habitatxskate]

its just easier to replace the breather IMO, that and you know there are no leaks or anything..

 

[dyeager535]

Replace the breather? You mean the cap?

At some point if it was uncapped, a wasp could have built a nest in the line or the fitting in the axle (what happened to mine when it sat out before I installed it) so the fitting still needs checked out.