Flushing differential before refilling?

firefox · Jun 5, 2011

What is the best stuff to flush a differential with that has not had its oil changed in over 10 years?
Also, can I do this procedure without popping the cover, or is that not a good idea.
Any coments are welcome, and I did try to search for stuff, but came up empty.
Doesn't mean there is nothing there.
Bruce

shootiniron · Jun 5, 2011

How about diesel fuel.

frodobaggins · Jun 5, 2011

I would empty a little bit out, add a few cups of diesel, then drive it around the yard for a few minutes and drain.

firefox · Jun 5, 2011

Thank you very much! That's what I was hoping the solution was.
Bruce

zout · Jun 5, 2011

You could also use the SEAFOAM products to add to the oil and drive it around.

It would be their engine flush product.

73m819 · Jun 5, 2011

I would run the truck down the road, get the rears up to operating temp. then drain about a 1/3, add deisel or seafoam, then run it back down the road a bit to get a good mix and cleaning, as long as you are NOT loading the rears will not hurt them, then drain while at op. temp. also, make sure the drain plug is MAGNETIC, if not replace with one

Robo McDuff · Jun 5, 2011

I am going to change drive-train oils also this month.

Should you warm up the differential oil first by normal driving, then add the diesel? I would not want to run around with diesel in there too long, but draining oil that is not warm does not sound like a good idea either.

Is just getting it to normal operating temp not enough to flush out the stuff properly, maybe put an air gun in the fill opening?

73m819 · Jun 5, 2011

just operating temp is good, don't think the air will help, after draining, stick a flex magnet in to see what you can fine, fines are normal, chunks are not

jwaller · Jun 5, 2011

you blow air into the fill port and you just might blow out your seals, that would not be good at all.

Robo McDuff · Jun 5, 2011

I have the truck sitting on clogs. How long should I run it there in second or whatever gear to get things up to operating temp, with the engine running at around 1500 rpm (or should that be higher)?

frodobaggins · Jun 5, 2011

Robo McDuff said:
I have the truck sitting on clogs. How long should I run it there in second or whatever gear to get things up to operating temp, with the engine running at around 1500 rpm (or should that be higher)?

5 minutes or so.

m139h2otruck · Jun 6, 2011

We found that with the older M139 truck, the gear oil looked and acted like tar (needed a pick to break it up so it would drain), so we drained it, added new oil, ran it for a while and drained it again. Second time, still looked like tar but now seems OK. Oil from Sam's or TSC is cheap enough so change it a couple of times to make sure.

Robo McDuff · Jun 6, 2011

FB, thanks.

m139h2otruck said:
We found that with the older M139 truck, the gear oil looked and acted like tar (needed a pick to break it up so it would drain), so we drained it, added new oil, ran it for a while and drained it again. Second time, still looked like tar but now seems OK. Oil from Sam's or TSC is cheap enough so change it a couple of times to make sure.

With good quality spec gear oil here costing around $ 36/gallon and needing around 8 gallons for one total change, I prefer the solution of adding a bit of diesel and try it that way.

Next question: does the residue of diesel-oil mix staying behind in the housing harms the fresh oil in any way or are the amounts too small to be a bother.

73m819 · Jun 6, 2011

Let drain REAL good, what is left will be to small to worry about

Robo McDuff · Jun 6, 2011

Thanks. Presumably I should do the same for the transfer case and transmission oils?

While we are at it, I am replacing the hydraulic steering oil and steering gearbox oil as well, both with W10 oil conform specs. Any special flushing recommended here?

kastein · Jun 8, 2011

Mine came out pitch black... no noticeable chunks, did have some metal flakes in it though. Magnets looked like chia pets. I considered cleaning them out with diesel but wasn't sure if it would harm the seals so I just filled er back up, it's got to be better than it was before at least.

Flushing differential before refilling?

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firefox

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shootiniron

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zout

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73m819

Rock = older than dirt , GA. MAFIA , Dirty

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m139h2otruck

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Robo McDuff

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73m819

Rock = older than dirt , GA. MAFIA , Dirty

Robo McDuff

In memorial Ron - 73M819

kastein

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