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Rear Diff Oil

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Old Aug 22, 2017 | 06:09 PM
  #1  
ligito's Avatar
ligito
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From: Oregon
Rear Diff Oil

'99 F250 SD 3.73 posi.
How difficult is it to change diff oil and add modifier?

What is the process?
 
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Old Aug 22, 2017 | 07:35 PM
  #2  
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Mike189677
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It's not too bad but man that stuff stinks I just changed mine and added the ford finned aluminum cover pretty much all the fluids off the shelf has the modifier in it already except for the ford fluid so far no chatter from the lsd in mine you need 75w-140 synthic fluid for the rear. I would also recommend getting a fluid pump to pump the fluid form the bottle into the diff or atleast clamp a piece of clear tubing to the end of the nozzle on the bottle just squuezing out of the bottle into the diff is a pain in the you know what since the nozzle is really short but that pump is like 5 or 6 bucks well spent in my opinion.
 
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Old Aug 22, 2017 | 08:01 PM
  #3  
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mattymax
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Pretty simple. Go on YouTube. There are a ton of videos on it.
I took the cover off my 08' to get it nice and clean for refill. I defiantly agree that a cheap hand pump is money wel spent. I use it when I change my transfer case fluid too

matt
 
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Old Aug 23, 2017 | 05:53 AM
  #4  
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Chuck's First Ford
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From: very South Texas
I was going to say.. You-Tube.. must be 100 of them for this job.

the smell is the hardest part.... second is WASHING up yourself.

if you get any of the used gear lube on your clothes.. put them in the trash.. as wife will kill you IF that smell gets in her washing machine.
 
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Old Aug 23, 2017 | 07:47 AM
  #5  
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Thanks for the help.
The driveline shop wants many bucks for this job,
 
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Old Aug 23, 2017 | 02:00 PM
  #6  
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R&T Babich
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From: Thousand Oaks, CA
As mentioned earlier, now is a good time to upgrade to the '99 Ford aluminum diff cover ($65 ebay), since you have to remove the cover anyway.
I used a Lube Locker Ford Sterling gasket ($22 Amazon) which is reusable.
Also, you can add a 1/8" NPT drain plug in this cover to make it somewhat easier to drain the fluid.
 
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