Royal Purple vs RL 75W-140 gear oil

[OiledMustangGT]

Ford 8.8, LSD (track-lock), manual tranny....I HAVE to run 75W-140 due to warranty BS..so I cant run the 75W-90 like most of you guys suggest.
Which oil (or other alternative brand?) will be better for my application..it is a toss up for me and both run about $7-8/quart

RL:

quote:

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75W140NS
Gear Oil
Recommended for manual transmissions and non-limited-slip transaxles that recommend 90 WT oils. Can be used in racing limited-slip units to increase lockup and reduce wheel spin. Street-driven rear-wheel drive cars should use regular Red Line 75W90 or 80W140.

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Royal Purple:

quote:

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75W-140
Max-Gear® is recommended for use in truck and automotive front or rear differentials, manual transmissions and lower gear units of marine engines that specify use of an API GL-5 or GL-4 fluid.

Max-Gear® is an ultra-tough, high performance, GL-5 automotive gear oil designed to provide maximum protection to heavily loaded gears while maximizing power output throughout the drive train. It outperforms other GL-5 gear oils because it combines the highest quality synthetic oils with Royal Purple's proprietary Synslide® additive technology.

Max-Gear® makes gears run smoother, quieter, cooler and longer without overhauls.

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[Titanium_Alloy]

Hi,

I'm pretty sure that you won't see any difference in everyday driving between these 2 gear oils. I would personally go with Redline, although I'm sure that RP would work just as fine. Redline, if I'm not mistaken, is also cheaper like $7 compared to RP's $9-10 per quart. Mobil 1 75W-140 is also a great choice, but at $16.99/quart (year ago used to be $6.99 just as 75W-90) in a local stores I would pass it in favor of RL. Hope this helps.

Regards,

 

[Bio-T]

I just changed the rear diff in my 01 Ford F-250 and the tag on the cover specifies 75W140 Full Synthetic Only. So I ordered a case of Royal Purple 75W140 for both my 01 and 95 Ford F250 also. On my 01 I did not have to add any Limited Slip additive as it already had it in the Royal Purple Gear Lube. After 300 miles on it, no chatter and runs good. My 95 does not have LS.

What is ironic, I just came in from changing both lower units on my 60 HP Johnson and my 90 HP Suzuki boat engines. Tommorow I am going to do my Mercury 200HP EFI. I am using Royal Purple 75W90 in all 3 boat engine lower units. Now I need to order a case. I am going to yearly changes now using the Royal Purple instead of semi-annual when using another brand.

 

[Michael SR]

quote:

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Originally posted by Titanium_Alloy:
Mobil 1 75W-140 is also a great choice, but at $16.99/quart (year ago used to be $6.99 just as 75W-90)

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i was surprised to see on their website that they made a 75W140, since i never saw any in the stores. but $17/qt? how is it better?

-michael

 

[sbc350gearhead]

I am currently using the RP max-gear 75w90, and it works very well. I have no reservations recommending the max-gear........although I am sure that redline will serve your purpose as well. In all honesty, go with the one that is cheapest, and I am sure that you will be happy.

 

[Bror Jace]

Just like no one makes a terrible SL oil, I'm sure you'll have no trouble with either of these gear oils.

It might come down to price and/or availability to decide between them.

Having trouble finding both of those? I'd also consider Amsoil.

--- Bror Jace

 

[OiledMustangGT]

yup, i currently run 85W-140 (or whatever it is) RP max gear in my jeep which I have been happy with. I never tried the RL, but heard it was good. The guy at the parts store told me to use Lucas Gear oil

How long can I run the RP or RL lubes in an axle w/ mostly city driving and occasional (1-2 times a week) hard shifting

 

[Titanium_Alloy]

quote:

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Originally posted by Michael SR:
i was surprised to see on their website that they made a 75W140, since i never saw any in the stores. but $17/qt? how is it better?

-michael

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I didn't mean to say that M1 would work much better than RL. I just mentioned that it might be just as good. For some reason physical properties of M1 75W-140 look significantly better than 75W-90. I suspect that Mobil's 75W-90 contains too much of "additive carrier oil" probably group I or II. Taking into consideration physical properties of other gear oils and making rough estimation among them I assume (but don't know for sure) that such carrier oil accounts for about 30% (possibly even more) in Mobil 1 75W-90 gear oil. I believe that in 75W-140 they probably either reduced it significantly or eliminated it altogether. That's why they managed to achieve better physical properties of 75W-140 (thus making it better oil) compared to 75W-90. High price of 75W-140 is another reason to support my assumption. On the side note: I use M1 75W-90 and have absolutely no complains and very pleased with its performance.

Regards,

 

[tdi-rick]

Is Castrol SAF-XA available over there ?

It is a full synthetic, 75w-140 LSD diff oil.
I'd link you to the Aussie Castrol site, but they've dumbed it down in the last few weeks, and dropped the PDS's in PDF format.

I have a PDS on file, any one know how to cut and paste from a PDF file ?

75w-140 GL-4,5,6 (obsolete)
25 cSt @ 100*C
186 cSt @ 40*C
Pour point -54*C
Flash point 220*C

It's a little cheaper here than RL.

Rick.

 

[dkcase]

quote:

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Originally posted by OiledMustangGT:
Ford 8.8, LSD (track-lock),

RL:

quote:

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75W140NS
Gear Oil
Recommended for manual transmissions and non-limited-slip transaxles that recommend 90 WT oils. Can be used in racing limited-slip units to increase lockup and reduce wheel spin. Street-driven rear-wheel drive cars should use regular Red Line 75W90 or 80W140.

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You have said you have a limited-slip, but you then quoted RedLine on their lube for non-limited-slip.

Their 75W140NS would not be appropriate for your limited-slip.

 

[OiledMustangGT]

nope, never even knew castrol made gear oil

I'll probably go with Royal Purple, since that is the easiest to get my hands on.

quote:

---

Originally posted by tdi-rick:
Is Castrol SAF-XA available over there ?

It is a full synthetic, 75w-140 LSD diff oil.
I'd link you to the Aussie Castrol site, but they've dumbed it down in the last few weeks, and dropped the PDS's in PDF format.

I have a PDS on file, any one know how to cut and paste from a PDF file ?

75w-140 GL-4,5,6 (obsolete)
25 cSt @ 100*C
186 cSt @ 40*C
Pour point -54*C
Flash point 220*C

It's a little cheaper here than RL.

Rick.

---

 

[JohnBrowning]

Well I am running Max gear right now. I chose it due to time and availability. It has turned out to be a good product. I would have taken Redline in a heart beat if it had been in stock! Redline is cheaper and I like it better. Redline has proven itself to me in a number of HD applications while RP MaxGear is a young upstart in my eyes. I do not think you would ever be able to tell the difference in this application. I can not see paying more for RP!

Globaly Redline gear lubes have earned a lot of respect!!