What Rear Differential and Manual Transmission Oil Do I Need?

butt I don't have sex with my truck, only in my truck

 

@flyboy718 I change them at 30k. Sometimes less if I know I'm going to be busy. Sometimes a little more like now. I'm a little over 40k right now and the shifting is getting notchy. It smooths right out with the fluid change. At 30k I don't really notice the shifting until I put new fluid in and it's so much nicer.

 

you should be fine with the 80w90_ I got a 2004 Tundra that ran on

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 for over 200k miles worth of towing heavy loads; a car trailer and lots of cars going anywhere from 100-2000miles each time for over 8 years before my dad ended up totaling the truck; slid on ice and slam into a guard rail. No problems whatsoever; just keep maintenance on the fluid; change it out every 50-60k miles and you should be fine; in fact you can probably go longer, just check the fluid condition every 30k miles. Remove fill plug and check; if its dark change it.

In fact my brother in law's mom owns a 1992 Toyota Previa that has never changed geared fluid at all for 400k miles; it was awful when we went to replace it. Smell really bad and the gear fluid was a dark as dark can be; lots of metal shavings and such; inspected the gears and no major problems at all. Put new fluid in it and it drove much smoother; that van is still driving today, now nearing 600k miles and trouble free.

Point is; you don't gotta worry that much about gear fluid; run what Toyota says to run or go with any fluid of choice because I bet they all will do their job. You just have to keep up on maintenance; change them when needed and your good to go. The only time I've ever seen differential problems is with low fluid or no fluid; or abuse.

 

Another vote for Redline.

Made a bigger difference to me over Valvoline on my 6SPD.
Most manufacturers have web sites with application guides.
Pick your poison and get their recommendation. Each is different because of additives.

I'd do yourself a favor and read these before you make a choice. There are good reasons there are two.

MT-75/90GL4 -Transmission

75/90GL5 - Differentials

 

I recently just replaced all the fluids in my truck at 50,000km. Like you I was wondering about the same thing regarding the trans fluid. After tons of research, Gl-5 is safe for our trucks, however even talking with the local service manager about the fluid, he said a "Gl-5 should....be safe", but if in doubt use a Gl-4. I ended up running Royal Purple

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 synthetic, which states on the bottle that its a Gl4/5 and also states its safe/designed for use in transmissions and any soft yellow metals. Truck now shifts a little smoother than before. Im sure other oils would be fine, but good for reassurance to know the oil is safe for the tranny

As for the diffs and transfer case, I ran Shell Spirax synthetic 75w-90 (states to be used for axles/driveline), shell makes other variants of their oils which are specifically meant for transmissions.

Royal purple is 20$ a quart (CAD), similiar to redline and the shell oil is 13$/quart.

 

Don't mean to hi jack the thread, but what diff fluid are people using with an air locker? I have read a few things as to not wanting anything with a friction reducer in it.

 

I'm going to run

$33 Ford XT-M5-QS Full Synthetic Manual Transmission Fluid - 1 Quart , black

Ford XT-M5-QS in my 6MT on the next oil change. I did my MT with Redline MT90 at 18k miles. I'm at 35k now and it's starting to get a little grumpy on cool mornings.

 

Any brand in the required viscosity range will function. Don't worry much about the GL4 vs GL5 business and synchros - Toyota has been specifying GL5 as an acceptable type for Taco manual tranmissions since 1996. However, shift feel is subjective. Redline MT-90 gotten positive reviews from more people. How much better it is vs a "mainstream" brand synthetic 75W90 will probably vary from person to person.

Yep.

 

+1 to ALL of this. FWIW, my "mainstream" brand is Amsoil. Their Severe Gear

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 is the "one size fits all" gear oil for ALL our vehicles, which greatly simplifies what to buy/stock in the garage.

Synthetic works as well (some would say better) than conventional oil in just about every application of which I can think.

 

Headed to my local race shop to pick up the Redline MT-90 for the manual transmission but they don't carry the 75W-140 that I would like to use for my rear diff; they do have the

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 for the rear diff though. I am going to run to my local O'Reilly's to pick up Royal Purple 75W-140 for my rear differential.

 

Well $h!t. something always freakin happens. I got three quarts of Redline. I go to Autozone to get the little handpump. I start pumping into my transmission and the freakin chinese crap pump leaks like freakin crazy. I must have lost a half a bottle! I still need more to top it off after pumping probably 2 1/2 bottles in and the other 1/2 bottle is on the ground! I have no place open right now to get Redline! Can I mix something else with this Redline or am I screwed?

 

Going to wait and get a bottle or two of Redline to top it off with tomorrow and just take the wife's Rav4 to work

 

Day 3: Rav4 is surprisingly nice. Gonna trade in my Taco! Goodbye TW!
Day 4: What's the biggest tire you can fit on a Rav4 without trimming?

 

No way! I looked like a pansy getting out of it at the gym last night. I don't normally start my workouts at the benchpress but I I went straight to it and racked 225.

 

Another for Red line MT90.

Just replaced my trans fluid with it on my new to me 09 with 75k. Looks like the owner never changed any of the oil besides engine.

I went ahead with new oil in the rear/front diff and transfer case. Drives great and I like the peace of mind.

The Red line made shifting a tad more notchy. Precise is the word, and smooth..

 

Well, a happy ending. I got it topped off last night and it only took another half quart. I am loving the Redline!

 

I'm looking at a $423.43 order from Red Line right now. This includes every fluid in the truck besides coolant and windshield wiper fluid. Got some WaterWetter for s**ts-and-giggles. Also some SI-1 Fuel System Cleaner and CV-2 Moly Grease. Going to flush my transmission (A/T), brake fluid and power steering fluid as well as change the oil in engine, diffs, and transfer case.