T9 Gear Oil to Use

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alexob53
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T9 Gear Oil to Use

Post by alexob53 » Sat Feb 04, 2017 2:12 pm

Morning everyone,

My T9 recently started making whirring noises in lower gears when cold, check the fluid level and it is pretty low, I can't even feel it through the fill hole. That being said, I will suck out what is left and fill it with "other" stuff. I just need a clear answer to what this "other" stuff should be. I have a few different options picked out so far, let me know which one you would recommend or if there is a different one you have had success with! Thanks!

Chrysler 4874459 - GL4 75w-85, $25, this is the rebranded Motorcraft oil used originally
Royal Purple Max Gear 74w-90, $21, this is RP's recommended replacement for things requiring the oil listed above
Motorcraft XT-M5-QS, $21.50, this is what some people have recommended, originally used for a focus and MX-5
Redline MT90 GL4 75w-90, $16, I have heard a lot of people using this but yesterday heard an ill review about it foaming up in the gearbox

Anyways, let me know if these or anything else is the obvious choice. It will mostly be normal driving with occasional track use. Thanks!
88 Merkur XR4Ti manual
90 Chrysler TC by Maserati 16V
00 Mazda MX-5 Miata LS 5-speed
01 Dodge Ram 2500 5.9 Cummins 5-speed
08 Smart Fortwo
08 BMW 135i Cabriolet

my8950
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Re: T9 Gear Oil to Use

Post by my8950 » Sat Feb 04, 2017 6:43 pm

Redline MTL

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Matt01
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Re: T9 Gear Oil to Use

Post by Matt01 » Sun Feb 05, 2017 11:34 am

I think I used straight 80w90 in there with a Prolab manual tranny additive. It quited down my T9 if I remember correctly.
Technically I think I should do another oil change, the oil in there was disgusting.

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merkurdriver
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Re: T9 Gear Oil to Use

Post by merkurdriver » Mon Feb 06, 2017 9:51 am

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alexob53
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Re: T9 Gear Oil to Use

Post by alexob53 » Mon Feb 06, 2017 11:36 pm

I ended up going with Red Line GL4 75W-90. It is significantly cheaper and I have seen many threads that indicate putting Red Line in has quieted down the T9. I will report as to whether or not this improves the whirring noises I have been hearing, and thanks for all the replies!
88 Merkur XR4Ti manual
90 Chrysler TC by Maserati 16V
00 Mazda MX-5 Miata LS 5-speed
01 Dodge Ram 2500 5.9 Cummins 5-speed
08 Smart Fortwo
08 BMW 135i Cabriolet

espacef1fan
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Re: T9 Gear Oil to Use

Post by espacef1fan » Wed Feb 22, 2017 11:24 pm

I run max gear. Bonus feature is its less stinky than most gear oils.
Adam Escott
Dothan, AL
89 XR with Outcast Body in red
Duratec build in progress(need cams and stand-alone)

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Mike McCreight
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Re: T9 Gear Oil to Use

Post by Mike McCreight » Thu Feb 23, 2017 8:54 am

Gear oil will make it very unhappy in cold temperatures.
I run it in my summer car.
It's not a hobby, it's an obsession!

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