Manual transmission fluid change.

Merry Christmas everybody!

I went and changed the fluid transmission fluid in my 98 today. I filled it with 75w90 gear oil, but I forgot to check and make sure it was Gly-4. It’s Gly-5 instead.

So I need to drain this and replace it with Gly-4 right away?
I completely forgot to check that, as I had to hit up several stores to even find the correct weight fluid.

Thanks y'all!

 

Not 'right away'.

Maybe your next oil change.

GL4 is better for the syncro life. GL5 is more corrosive to those.

 

I've only run GL-4 in manual boxes and transfer cases for decades.
GL-5 for the differentials.

I'd swap it out, it's really not that much $ in the big picture, but could potentially damage the yellow metals in the manual box.

Cheers

 

Highly recommend using Redline MT-90!

 

...and yet Toyota themselves ok's GL-5 for manuals. But yeah, who are they and their engineers with fancy degrees and years of experience when we have a guy on youtube, right?

 

GL5 is fine, most dealers run GL5 for manuals, only recently has the wave of GL4 caught on. There's thousands of Toyotas out there with GL5 in the gearbox.

GL4 is ideal, but there's no reason to dump out the new fluid you put in.

Leave it, change it in a year or so, get some value out of the oil, unless it really bothers you.

 

I am glad I read this thread, I was going to swap out my transmission fluid today. It’s got about 80,000 miles on it so I figured it was about time.

 

I’ll probably have to order the GL4 fluid- it seems like the only thing I’ve found in stores is GL5.

I appreciate the replies!

 

Ditto, man that stuff is good,

 

Forget Redline MT90 and go with Motorcraft

$33 XTM5QS Ford Genuine Ford Fluid XT-M5-QS Full Synthetic Manual Transmission Fluid - 1 Quart , black

XTM5QS instead. Costs more, but it’s worth it.

 

I used MT-90 when I changed fluid last year. It's OK, but it seems that shifts are slightly less smooth than before the change. Old lube was likely original to the truck. I figured at 25 years and 115K miles it was due, though what came out looked darn good.

I've heard good things about this lube and will probably use it next time.

 

Yep, the motorcraft stuff was the best I used also,, but I couldn't find it last time, in fact everything I read was they no longer made it. So I went with the MT 90, but the motorcraft shifted the smoothest to me.

 

How much MT90 will my '03 5-speed require?

What fluid and volume for my differential?

 

Rear diff takes 2.7L of 75W-90 (or three of these bottles). Don't fuss too much about GL4 vs GL5 for the differential - from what I understand regular gear oil changes have a bigger impact than the difference between the specs for the diff, at least.

 

Using AMSoil gl-4 here for the past 8 months
I will be intrested to see how it handles the subfreezing temps to come
Whatever the Toyota dealershop had used over the decades was ALWAYS super stiffie in the cold bitter mornings until the gears warmed up

 

Thank you. And the front differential requires 1.5 liter of the same oil. Correct?

 

For real! seems like no one carries GL4... I used top end Amsoil last time I did mine because it was all I could find.

 

https://adventuretaco.com/front-diff-oil-change-not-an-ideal-situation/

Highly recommend.

There are a number of dual-rated full synthetic gear oils (GL4/GL5) that don't have the additives that will mess with your synchros, from what I've read.