Rear Diff. What gear oil ??
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Rear Diff. What gear oil ??
So, my Ex is at a driveline shop having new pinion, and carrier bearings put in. There is a tag on the rear diff. that says 140 synth only. (or something close to that)
Anyway, the shop says the never use synthetic.. Should I go buy some OEM or Royal purple, and bring it to them? or just let them do what they do??
What are you guys using?
Thanks
Anyway, the shop says the never use synthetic.. Should I go buy some OEM or Royal purple, and bring it to them? or just let them do what they do??
What are you guys using?
Thanks
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From: N. IL
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Senior User
Joined: Oct 2003
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I use synth. 75w140 from NAPA.
https://www.ford-trucks.com/forums/1...d-changes.html
https://www.ford-trucks.com/forums/1...d-changes.html
Super Moderator
Joined: May 2004
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From: Central Coast of CA
There's absolutely nothing wrong with using Synth. That's what Royal Purple is.
Stewart
Lead Driver
Joined: Nov 2012
Posts: 8,304
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From: Salem, VA
I went full synthetic and my rear end flew off while I was on the highway and hit a bus full of orphan nuns. Oh wait, that never happened! I used Synthetic and it has worked great ever since. No reason not to, just don't go cheap 
Tuned
Joined: Nov 2012
Posts: 307
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From: Gainesville, FL
I use the following AMSOil products:
AMSOil Severe Gear (front) SVGQT 75W 90 Syn
AMSOil Severe Gear (rear) SVOQT 75W140 Syn
AMSOil Slip Lock Additive ADATB both front and rear
AMSOil Severe Gear (front) SVGQT 75W 90 Syn
AMSOil Severe Gear (rear) SVOQT 75W140 Syn
AMSOil Slip Lock Additive ADATB both front and rear
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Mountain Pass
Joined: Apr 2014
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From: Tempe
FWIW I'm an aerospace engineer and there's absolutely no place that synthetic oil is not better than conventional oil.
Jay
Jay
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Post Fiend
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From: Bonita Springs FL
Why would the tag specifically call for synthetic oil if you're never supposed to use it? I would never let that shop touch my truck again if that's their automotive education level.
- Another satisfied royal purple user with no issues.
- Another satisfied royal purple user with no issues.
Lead Driver
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From: Kent Station, WA
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