Which gear oil to use?
09-18-2008, 11:10 AM
#1
3rd Gear Member
Thread Starter
Join Date: Sep 2007
Location: Sacramento, CA
Posts: 734
Which gear oil to use?
So this weekend I am switching to 4.10s. Which gear oil weight should I put in? I am just going to get royal purple. Its like 10 dollars a quart I think. I need to buy 3 and put 2.5 in right? Also it doesnt need friction modifier does it?
09-18-2008, 11:17 AM
#2
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09-18-2008, 11:45 AM
#3
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Location: Harrisburg PA
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The weight is: 75W140. Yes get 3 quarts.
I put the Motorcraft Synthetic in and it did require Friction Modifier. I purchased from the Dealer and cussed them out all the way home, the criminals charged me $22 per quart. Wont do that again.
I put the Motorcraft Synthetic in and it did require Friction Modifier. I purchased from the Dealer and cussed them out all the way home, the criminals charged me $22 per quart. Wont do that again.
09-18-2008, 04:05 PM
#5
2nd Gear Member
Join Date: Aug 2006
Location: CT
Posts: 159
Oh, but I guess you mean when you swap in a new gear set. Yeah, makes sense. Your supposed to change the oil after break-in period so why put the expensive stuff in...
Last edited by doctorstrobe; 09-18-2008 at 04:07 PM. Reason: I'm stupid.
09-18-2008, 04:29 PM
#6
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Join Date: Nov 2006
Location: NJ
Posts: 825
When I went 3.73's, my shop put in 2 qts Royal Purple 75/140 synthetic, and 1 bottle of Ford friction modifier. ($13.95 each for the RP, and $4.95 for the Ford FM)
Are you really supposed to use 3 qts??? Now I'm concerned, I had the swap done back in June, I've put on 3,500 miles since then, and now I'm noticing a slight noise on accel & decel at about 60 mph!!! I'm getting a little pissed...I also remember him not using the gear install kit, unless he had one laying around and didn't charge me! (Doubt it)
Are you really supposed to use 3 qts??? Now I'm concerned, I had the swap done back in June, I've put on 3,500 miles since then, and now I'm noticing a slight noise on accel & decel at about 60 mph!!! I'm getting a little pissed...I also remember him not using the gear install kit, unless he had one laying around and didn't charge me! (Doubt it)
Last edited by JimsGT; 09-18-2008 at 04:36 PM.
09-18-2008, 04:34 PM
#7
Cut & Paste Expert
Join Date: May 2007
Location: NW Arkansas
Posts: 13,322
Synthetic diff lube like factory and friction modifer.
S197 8.8 SPECS
Seems to me that I read a TSB about filling it all the way up to
the fill hole until it starts coming back out instead of the original
1" below the fill hole recommendation.
S197 8.8 SPECS
Seems to me that I read a TSB about filling it all the way up to
the fill hole until it starts coming back out instead of the original
1" below the fill hole recommendation.
Last edited by 157dB; 09-19-2008 at 09:42 AM.
09-18-2008, 04:44 PM
#8
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Join Date: May 2007
Location: Utah
Posts: 1,249
My installer used Royal Purple that had the friction modifier in too. But my clutch packs still moaned during slow turns. So I waited...broke the gears in by just driving around like granny..went through a few heat cycles and good to go. Drove for another 2 weeks, getting in a good wear pattern, then off to the dealer for new clutch pack and new gear oil, all under warranty. Worked out kinda sweet.
09-18-2008, 04:47 PM
#9
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Join Date: Sep 2007
Location: Sacramento, CA
Posts: 734
The royal purple stuff has friction modifier in it. I think I am going to be running 85w140 or whatever it is. My friend is running that too cause he talked to ford and they said unless you are in a cold area you can run a higher weight. I am not sure if this all sounds right... what do you guys think?
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