What would be the benefit?

no, but it would be the same as painting the oil valley on your block. prevent build up of sediment in the porus surface, and make it easier to clean when it comes time. there is a special paint for doing it.

It's supposed to let the oil drain back down faster/easier... As long as you have enough gear oil in there I don't think it would make a difference.

If you don't use the right paint and it starts flaking off, who wants paint floating around in the gear oil anyway...I'm sure it would get mixed in, but I don't think it would be good for bearings, etc.

I think it's pointless because there is no significant benefit to it. Unless you were racing at highspeeds, but still. I've never heard of a rearend failing or wearing out prematurely because the friction between the oil and the housing was limiting the flow of oil. Plus, the surface of the housing will have a layer of oil that clings to it and the rest of the oil will flow of that layer. This is called Lagmuire Theory, if that's how it's spelled.

I think it's pointless because there is no significant benefit to it. Unless you were racing at highspeeds, but still. I've never heard of a rearend failing or wearing out prematurely because the friction between the oil and the housing was limiting the flow of oil. Plus, the surface of the housing will have a layer of oil that clings to it and the rest of the oil will flow of that layer. This is called Lagmuire Theory, if that's how it's spelled.

Thats what I figured. I wasn't going to do it, but someone was trying to tell me that it was VITAL!!

someone was trying to tell me that it was VITAL!!

That's probably why all the OEMs did it.

Hit that person with a croquet mallet.:shaking:

That's probably why all the OEMs did it.

Hit that person with a croquet mallet.:shaking:

That made me laugh.:cool2:

That's probably why all the OEMs did it.

Hit that person with a croquet mallet.:shaking:



be sure to stand on their balls, hit them in the head and see if you can knock his shoes off.

Thats what I figured. I wasn't going to do it, but someone was trying to tell me that it was VITAL!!

People say that crap because they want your money and a good laugh when they get it. I think it's hilarious of what people think up these days which are absolutely ridiculous.:shaking:

OEM did coat the inside of difs.
late 70s and 80s Danas have a black coating inside

A solution in search of a problem.

OEM did coat the inside of difs.
late 70s and 80s Danas have a black coating inside
Might have been a protectant from rust while the axle was being built?

OEM did coat the inside of difs.
late 70s and 80s Danas have a black coating inside

Really? That's news to me. My '78 Dodge D60, as well as the 3-4 Dana 60 and 70 axles I've popped open at the JY, did not have this coating.:confused:

My Rockwell T221 transfer case was painted blue on the outside and was red inside. It didn't help too much, seemed to leak grease and chew up bearings just fine.

I painted the inside of my d60 with bbq grill paint - duno why - it looked pretty. 18 months later it hasnt degraded at all, but I dont see any benefits.

OEM did coat the inside of difs.
late 70s and 80s Danas have a black coating inside
my 1973 dodge dana 70 has a nice factory coat of black paint on every non-machined surface inside the pumpkin. im sure it does some good or dana wouldnt have wasted time/$ painting it.

OEM did coat the inside of difs.
late 70s and 80s Danas have a black coating inside

I've built 12 axles, GM, Ford, Jeep, and Toyota and have never seen this. If you really want to paint the inside, you need to have it acid tanked well to get the oil out of the pores of the metal. Pointless and a waste of time IMO :shaking:

I've seen several Dana axles painted black on the inside, and most, if not all of the bigger axles I've worked on were painted on the inside. They are easier to clean up after a teardown.

Gus

Yup, the Dana axles that I have worked on were painted on the inside of the housing. You have to clean them up good or you would not notice it.