Pumping out the Rear Diff, not removing the cover.

[KilgoreBass]

Originally Posted By: Bluestream
If it only gets 2K miles per year, it wil have rusted away long before you have any problems with the diff.


yeah, I'm trying to avoid that though, and keep my "Home Depot run" truck as long as possible. Despite being very solid mechanically, and a mint interior, book value makes it not even worth the cost of a paint job, so I may get hold of few spray cans and do a hack job on the body where the paint is getting thin. I am the lucky owner of that garbage "primer-less paint GM experimented with in the early 90s, it isn't rusting yet, but the paint is kind of "evaporating away", even with no salt on the roads in TX.

(recommendations welcome on a good spray can paint, GM black)

I'm changing many of the fluids more as a PM program from possible degradation over time than being worn out from use. But my guess is the nasty smelling diff gear oil would last many decades with no problems....I'm not pulling trailers or anything like that....

when I get around to painting the diff cover, I'll pull it off and give things a look over....

PS: still wondering, has anyone pulled a rear diff cover to change factory fill after 10-30K miles and actually OBSERVED something out of the ordinary that they would have missed if they only had a drain plug for the service? Not looking for opinions, just real-life experiences from the pros.

 

[KilgoreBass]

Originally Posted By: Jim Allen
If there wasn't a magnet and I had drain plugs, I see no point in pulling the cover. If there was a magnet, then at least that first time. After than maybe every other or every third time.


I don't think there is a magnet in this rear end, I have never seen a reference to one in the literature I have on it.

Someone suggested adding one if needed. Is it safe to just add a un-mounted magnet to the interior of a differential? With the gear oil being kind of thick, I would hate to think what would happen if there was enough fluid friction and turbulence to move the magnet if its grip was overcome! Not like its the flat bottom of a transmission pan.

PS: how about a magnetic plug, or putting a strong magnet on the exterior, like at the bottom of the cover? Safer, no?

 

[JakeR22]

Originally Posted By: KilgoreBass
Originally Posted By: Bluestream
If it only gets 2K miles per year, it wil have rusted away long before you have any problems with the diff.


yeah, I'm trying to avoid that though, and keep my "Home Depot run" truck as long as possible. Despite being very solid mechanically, and a mint interior, book value makes it not even worth the cost of a paint job, so I may get hold of few spray cans and do a hack job on the body where the paint is getting thin. I am the lucky owner of that garbage "primer-less paint GM experimented with in the early 90s, it isn't rusting yet, but the paint is kind of "evaporating away", even with no salt on the roads in TX.

(recommendations welcome on a good spray can paint, GM black)

I'm changing many of the fluids more as a PM program from possible degradation over time than being worn out from use. But my guess is the nasty smelling diff gear oil would last many decades with no problems....I'm not pulling trailers or anything like that....

when I get around to painting the diff cover, I'll pull it off and give things a look over....

PS: still wondering, has anyone pulled a rear diff cover to change factory fill after 10-30K miles and actually OBSERVED something out of the ordinary that they would have missed if they only had a drain plug for the service? Not looking for opinions, just real-life experiences from the pros.


Take it to Maaco and get their cheapo $250 paint job. I did this on my little work truck, and it's held up great for going on 5 years now, and it sits outside year round.

 

[artificialist]

Originally Posted By: TallPaul
If only they built cars right there would be a drain plug at the very bottom. Then all you would need is a flushing oil to clean her out. How about a flushing oil on a mini power washer, something the consistency of say MMO.

Yeah, I have a suction pump got at a garage sale, use for power steering mostly. Don't think I had it for the rear end syphon. I noticed that it is much harder to suction cold PS fluid than hot. Interesting as it's not especially thick to begin with.

Up until recently, every Toyota and Nissan I ever saw used the setup you mentioned.

 

[wgtoys]

The suction method is better than nothing, but actually opening the thing up and cleaning out the accumulated residue is better.

 

[wgtoys]

(recommendations welcome on a good spray can paint, GM black)

Valspar Tractor & Implement paint as is sold at our local Tractor Supply Company store is my favorite rattle can paint these days.

 

[MolaKule]

Quote:
PS: still wondering, has anyone pulled a rear diff cover to change factory fill after 10-30K miles and actually OBSERVED something out of the ordinary that they would have missed if they only had a drain plug for the service? Not looking for opinions, just real-life experiences from the pros.


Yes, every vehicle I have had, except for one, had metal particles and paste in the bottom of the carrier.

The exception has been my '08 Trailblazer, 5.3L. I had the cover pulled and installed a synthetic 75W110. There was no wear particles or paste whatsoever. No glistening metal particles in the sunlight.

Yes, my Nissans have fill and drain plugs everywhere. Why the domestics don't do it is beyond me.

 

[Jim Allen]

Originally Posted By: KilgoreBass


PS: still wondering, has anyone pulled a rear diff cover to change factory fill after 10-30K miles and actually OBSERVED something out of the ordinary that they would have missed if they only had a drain plug for the service? Not looking for opinions, just real-life experiences from the pros.


Every axle I've had or worked on did to some degree. I drained the gear oil on my newest truck, an '05 F-150HD, at 9K. It had a magnet that was very fuzzy. I installed a Mag-Hytec cover, which has a magnetic dipstick, and it also got a little fuzzy withing a week. I checked it about every 1K miles for a while and had to clean off minor fuzz a couple of times, but I last checked a few weeks ago at 18K and it was clea (to the nacked eye anyway).

I say again, however, that a good drain plug will get the majority of the wear materials, almost as well as removing the cover, where a suction gun will leave a lot.

 

[Bill in Utah]

My Chevy 1/2 ton rear ends both had a drain plug. Moms 2002 has one too.

I'm not too concerned with not getting the fuzz off the magnet when I change out the fluid. When I get to it I will but to me the FLUID change is much more important.

I've serviced a few vehicles that have gone many many miles without any fluid change and they have TONS of miles on the factory fill and after changing the fluid, continue to go down the road just fine.

With the "fuzz" still in there!

Originally Posted By: Jim Allen

I say again, however, that a good drain plug will get the majority of the wear materials, almost as well as removing the cover, where a suction gun will leave a lot.


I disagree. A good unit will get most of it and in some cases MORE of the fluid than a drain plug will.

Taking the cover off will get the last ounce. Like it matters that the last "little" bit of fluid you got with a rag mixed in with the new is going to matter.

Take care, Bill

 

[SuperDave456]

I changed the rear diff fluid on my Wife's Nissan Xterra around 50,000 miles. We had only been married a few months. She had had it 5 years. She dosent tow, go off roading or anything like that. Does mainly city, and some highway, but I wanted to change it out.

The unit is welded together with a drain and fill plug. The drain plug is magnetic, and it had some serious fuzz on it.

I refilled with Valvoline 80w90 Durablend and a little bottle of Amsoil Slip Lock, just in case. I could barely notice a difference.

I still need to do the front. I have all the stuff, but since we bought a house I havent gotten to it. Besides, I think actually getting to the front drain and fill plugs might be something a little more difficult than just removing the spare tire.
And if the front is anything like the rear it will have a large magnet, and the fluid will still be pretty good.

 

[mechtech2]

If a rear end had a drain plug like a manual trans or transaxle, we would not take the cover off, unless it was leaking.

 

[bluestream]

Originally Posted By: MolaKule


Yes, my Nissans have fill and drain plugs everywhere. Why the domestics don't do it is beyond me.


It's because they are short sighted. They can save a dollar per vehicle, and maybe make more short-term money and get the stock price up. They are known for not looking at the long term and the bigger picture. Hopefully that will change. My BMW has fill/drain plugs everywhere...

 

[MolaKule]

BTW, a magnet on the outside of the case will do nothing, because the magnetic field cannot penetrate the casing.

 

[KilgoreBass]

Originally Posted By: MolaKule
BTW, a magnet on the outside of the case will do nothing, because the magnetic field cannot penetrate the casing.


I have to disagree with that in principle. Although the force will be attenuated to a good extent, a magnetic field will penetrate metal, even ferrous metal. (OK, for ferrous metal it really magnetizes the material, but same thing in effect, since the effect is stronger close to the magnet).

Therefore, a strong magnet on something like the thinner cover would exert an attraction on the other side, magnetizing the steel, and creating a secondary field. Doesn't matter if the primary field actually penetrates, the force will be felt indirectly.

If this wasn't true, oil filter wrap-around magnets wouldn't do a thing either, and I have seen pictures on this site proving they do trap particles to the inside of the filter can.

PS: obviously, the thinner the metal the magnet is on, the better. I know a diff cover is thicker than a filter can, but a strong magnet should be able to catch some "fuzzies". BTW, one great source of really high flux magnets are old or crashed hard drives, the voice coil magnets are very powerful.

OK, that's my contribution to this site as an EE!!!

 

[joel95ex]

I use a liquivac....it is online, but i found it at Tractor Supply Co. which is like a ranch store.

 

[Bill in Utah]

Used mine today to change the brake fluid in Moms 2002 Silverado.

Boy it was OVERDUE!

Very ugly and glad that it is done.

Took almost 2 quarts of DOT3 fluid but it was done right!

Having the extractor really makes the job so easy.

No REASON for me to wait so long on her truck....

Bill

 

[MolaKule]

If you put a magnent inside a filter this it should work. http://www.oilfiltermagnets.com/ but I wouldn't recommend it.

A wrap-around filter magnet is esstntially a toroidal magnet in which the magnetic field is mostly contained within the radial axis of the magnet.

You will only magnetize a small area of a filter with external magnets, since most of the magnetic field lines will follow the path of of the surface of the iron or sheet metal.

The best way to catch ferrous particles is with magnetic drain and fill plugs or an internal magnet mounted as low as possible. Many gear assemblies come with a magnet cemented to the bottom of the pan.

 

[beanoil]

Changed the diff fluid in my F250 last summer. The truck had 110,000 miles on it. Used RP 75-140, and a Fel-Pro gasket. Really not hard at all, and while RTV may work fine, the Fel-Pro was easy, and hasn't lost a drop. Literally, maybe a 30 minute job, no harder than an oil change. One recommendation.. always verify you can get the fill plug out before taking anything apart.