Rear Diff Change Ques

[Digital Man]

Ok, so I'm at my usual oil change place (been going to this place for 10years) and he says my rear diff fluid is very dirty. I'm runnin 22,000mi and never had it changed. I say "ok, how long?" He said "15mins." I say, "You know, for tranny things, I'm going to go to the dealer because I am still under warranty." He said, "Ok, cool." So i go to my dealer and I say, "I need a rear diff flush". He says "Come tomorrow, I need two hours." I say "Whaaa?" My oil change guy said 15mins" He says, "That's fine, then go to him. I remove the pan, clean inside, dry, change the oil, and put on a new seal. I need 2 hours." I said, "Ok, I'll call you and book an appointment."

So my question is, should I go for the full autopsy of the rear diff? Or the quicky lube job? I assume one is going to be sizable more costly then the other.

Suggestions?

[RF Overlord]

So my question is, should I go for the full autopsy of the rear diff? Or the quicky lube job? Neither. Do it yourself in less than an hour. It's almost as easy as changing the motor oil.

Ford now recommends 75W-140 synthetic for the Marauder differential...2 quarts of that and a new gasket will cost about $30...the quick-e-lube would most likely install 80W-90 dino. If DIY isn't an option, then either go to the dealer, or find a real mechanic who will do the job right.

[Motorhead350]

yup couldn't have said it better myself

[RoyLPita]

Why should this be done at such a soon time? According to the owner's and shop manual, Police and taxi vehicles (ours could apply with the limitied slip differential) should be changed is at 100k or if the axle has been submerged in deep water. If you are still in base warranty, have the dealer check this out.

[Breadfan]

I woudln't expect it to get "dirty" per say, but I suppose extreme conditions could cause heat and breakdown of the fluid. It could varnish and that could be bad for the traction-lok clutches...

Would be interested to see more insight on when or if differential fluid should be changed.

On that note, I just had mine changed at 25,000 miles thanks to a 4.10 upgrade. ;)

[RF Overlord]

I suppose extreme conditions could cause heat and breakdown of the fluid. Perhaps this is why Ford includes 75W-140 synthetic, along with a diff tag stating to use that fluid, in the axle TSB kits...?

[Marauderjack]

When did Ford go to 75W140 Synthetic recommendation?? :confused:

My owner's manual says 80W90 "Premium Axle Lube" with 4 ounces of friction modifier!! :bows:

I like the idea of the synthetic and higher "Hot" viscosity but most folks here said they didn't think the synthetics offered any advantage?? :confused:

I was going to change mine this week with 85W90 but will wait and see what y'all have to say!! :argue:

Talk to me!! :help:

Marauderjack :D

[thePunisher]

there is no need to change the fluid at 22,000 mi. that is rediculous. the fluid looks dirty because it is a traction lok diff and when the clutches wear they make the fluid merky...this is normal. i wouldnt even peek at the fluid till 50,000 and even thats too soon....

[thePunisher]

definitely use the 75-140. that fluid is great...even the GM guys use it...its pricy though.....

[RF Overlord]

When did Ford go to 75W140 Synthetic recommendation??
My owner's manual says 80W90 "Premium Axle Lube" with 4 ounces of friction modifier!!jack:

Indeed, that's what the owner's manual says, but when I had the axle TSB done, I noticed they installed a tag that said "75W-140 Synth Oil Only". I asked the dealer tech about it and he told me that's what Ford supplies with the kits (they do a lot of CVPIs for the local police departments).

[Mike M]

Ok, so I'm at my usual oil change place (been going to this place for 10years) and he says my rear diff fluid is very dirty. I'm runnin 22,000mi and never had it changed. I say "ok, how long?" He said "15mins." I say, "You know, for tranny things, I'm going to go to the dealer because I am still under warranty." He said, "Ok, cool." So i go to my dealer and I say, "I need a rear diff flush". He says "Come tomorrow, I need two hours." I say "Whaaa?" My oil change guy said 15mins" He says, "That's fine, then go to him. I remove the pan, clean inside, dry, change the oil, and put on a new seal. I need 2 hours." I said, "Ok, I'll call you and book an appointment."

So my question is, should I go for the full autopsy of the rear diff? Or the quicky lube job? I assume one is going to be sizable more costly then the other.

Suggestions?


Most likely the lube shop will stick a hose in it and suck out the oil and put in the new with a pump system. Not terrible but not complete.

[Blackened300a]

Ok, so I'm at my usual oil change place (been going to this place for 10years) and he says my rear diff fluid is very dirty. I'm runnin 22,000mi and never had it changed. I say "ok, how long?" He said "15mins." I say, "You know, for tranny things, I'm going to go to the dealer because I am still under warranty." He said, "Ok, cool." So i go to my dealer and I say, "I need a rear diff flush". He says "Come tomorrow, I need two hours." I say "Whaaa?" My oil change guy said 15mins" He says, "That's fine, then go to him. I remove the pan, clean inside, dry, change the oil, and put on a new seal. I need 2 hours." I said, "Ok, I'll call you and book an appointment."

So my question is, should I go for the full autopsy of the rear diff? Or the quicky lube job? I assume one is going to be sizable more costly then the other.

Suggestions?Gear oil Can go at least 75k Miles without a change. I think this is another Shop trying to take advantage.
I took my Ex GF's 2002 Honda Accord to get a oil change, She had 16k miles at the time. The Yo-yo then tells me that She Should have her Transmission fluid changed at the cost of $65! I got mad and said no way! This car can go almost 100k miles without a fluid change, I suggest you knock off trying to rip me off or there will be a issue here. He Insisted that the fluid has to be changed! I pulled out the manual and showed him that according to Honda. The Interval between transmission fluid Changes are 120k miles or 8yrs! He Got Real Quiet, Walked in a corner and had another Mechanic drive the car out.
I would check your manual and show it to them. It seems like they are trying to make a few extra bucks at your expense and since you brought it to the dealer and asked them to change the fluid, Who are they to turn down a almost $100 job.

[RF Overlord]

Gear oil Can go at least 75k Miles without a change. I would check your manual and show it to them.With all due respect, in many cases, now more than ever, manufacturers like to proclaim that their cars are "maintenance free". "Lubed-for-life" is another bit of hype they like to spout, and I don't believe most of it...no, transmission fluid is NOT good for 50,000 miles in these cars...etc. Changing the rear end lube is inexpensive and easy, so it shouldn't be a problem to do, even if it isn't strictly necessary. Go for it...

[Mike M]

When you change it use Mobil synthetic for the rear. I did it at 30k
I changed my Trans with FULL synthetic at 28k

[metroplex]

75W-140 is for heavy load/shock applications as well as high temperature applications. It will decrease driveline efficiency just a tad though. I have never had a rear end fail/leak/blow up because of synthetic 75W-90.

Friction Modifier can break down over time. I have known people that never changed the gear oil and the differential runs fine.

[Marauderjack]

Just ordered Red Line 75W140 for $9.33 a quart delivered from Summit!! Local thieves wanted $15.95 a quart for 75W140 but only $7.95 for 85W90...What's up with that?? :argue:

It says the rear holds 4.75 pints but I think 2 quarts pretty well takes care of it?? :confused:

Marauderjack :D

[RF Overlord]

It says the rear holds 4.75 pints but I think 2 quarts pretty well takes care of it??Um, 2 quarts isn't going to be quite enough...I hope you ordered 3.

[Marauderjack]

I actually ordered 6 quarts.....Gonna do my Cobra also!! :banana2:

Marauderjack :D