Pull Differential Cover or Use a Fluid Pump

[TheLawnRanger]

I've noticed this topic appears about every three years or so since the beginning of BITOG. Over time, the consensus swings back and forth. So I will ask our current members the question once again. When changing your differential fluid, should you pull the cover, use a fluid pump, or do you think either way is fine?

 

[Pelican]

Originally Posted by TheLawnRanger
I've noticed this topic appears about every three years or so since the beginning of BITOG. Over time, the consensus swings back and forth. So I will ask our current members the question once again. When changing your differential fluid, should you pull the cover, use a fluid pump, or do you think either way is fine?


Why not use the drain plug? Of course make sure you can undo the fill plug 1st!

If the above is not possible I'd go for the fluid pump, unless you have a leak.

 

[Lapham3]

I prefer to pull the cover with a physical check along with gear backlash. Then inspect what doesn't fully drain (the dregs) and clean it all out

 

[Imp4]

Reality is, either method will suffice.
Which way makes you feel better?

 

[double vanos]

If I feel that the suction method gets most of the oil I'll do that. But if it's questionable as to whether not I got it all, I'll pull the cover.

 

[bdcardinal]

The diff on my '14 came with drain and fill plugs on the OE cover. I changed the fluid at 5K but didn't pull the cover. I am almost at 50K and am going to do all the fluids again. I will probably pull the cover this time and clean whatever is there out.

 

[gman2304]

I had my 2005 Chevy G80 diff oil changed this week at a local shop. No drain plug so I had them pull the cover. Mine had lots of fuzz on the magnet after 206,000 miles which was the main reason I had them pull the cover, plus I just wanted to take a look, after admittedly being neglected. Mine looked good with no chipped teeth or bluing from heat.

 

[xxch4osxx]

I pull the cover so I can have a look to make sure everything looks like it should.

 

[tblt44]

Pull the cover, get all the fluid out and clean the magnet

 

[Rand]

if there isnt a nice drain plug so you can flush it out,
I'd prefer the first change to pull the cover and clean it out fully.. tons of break-in junk.

after that sucking it out is fine esp on a decent schedule (do it more than once every 100000 miles.)

 

[LotI]

I would love to pull a plug or cover on my E450 but Ford & Dana didn't give me an easy way.

No drain plug and the rear sway bar and 55 gallon fuel tank make access to the cover difficult.

I did a suction change at 30k. Maybe at 60k I'll take the time. I don't have a 12k# lift so it's crawling around on the ground.

 

[ka9mnx]

Originally Posted by Lapham3
I prefer to pull the cover with a physical check along with gear backlash. Then inspect what doesn't fully drain (the dregs) and clean it all out

^ This ^

 

[supton]

Mine doesn't have a cover so I pulled the plug. Easy that way. Supposedly the worst wear is during break-in, so I'm guessing you could do a vacuum pump and change most of the oil and it'd be just fine. Seems like many lightly used diffs are fine with huge miles and infrequent lube changes. That said, if I had a diff cover that didn't have a drain I'd be sorely tempted to order one that did, then go through the mess of draining and replacing, so as to make future oil changes easier.

 

[BrianF]

On my 2011 1500, I did one drain/fill with the cover in place and the next I pulled the cover to do an inspection. Its more of a pain with RTV though.

On my 3500, I did both. The rear diff had the cover pulled for inspection and drain. The front cover I just unbolted the bottom bolts and cracked it to drain. The AAM axles have reusable gaskets.

 

[code5coupe]

Originally Posted by double vanos
If I feel that the suction method gets most of the oil I'll do that. But if it's questionable as to whether not I got it all, I'll pull the cover.

Using suction will not get ALL the lubricant out, but is it necessary to get ALL the old lube out? Probably not.
Which method you use probably depends on which is the easiest in your particular situation.
Either way will work and sucking it out is far better than not changing it at all.

 

[Dino01]

Done both and both work fine IMO.

On my old F350 I did the suction method for front and rear and both were perfect at 250k when sold, as said most important thing is changing it, even if it's a partial change. I estimate I was able to get about 70% of the old fluid out with the suction method, good enough for me

 

[Whimsey]

Our 2017 Explorer has no drain plug and the rear diff real is close to the rear suspension, so removing the cover requires some suspension removal it appears. Ford claims their non synthetic 80W-90 is a "lifetime" fill so they don't care, it'll last most likely the 5yr/60,000 mile pt warranty, then you're on you own. At 22,000 miles I had my indie pump out what he could and replace with Amsoil Severe Gear 75W-90. Sometime in the future I'll have him do it one more time with the Amsoil then I'll call it a lifetime fill

.

Whimsey

 

[hatt]

I pulled the cover on the rear of my truck. I pumped the fluid out of the front because you can't easily get the cover off. Either way is 1000x more maintenance than the avg vehicle gets. If I suspected contamination or some other issue I'd pull the cover for sure.