Got a question for you

on a manual transmission 1990 2wd 22re how many miles before you change your transmission gear oil 80/90 ?

 

Normal driving not required, inspect at 15,000 mile intervals or 18 months. Severe driving conditions replace 15,000 miles intervals.

 

Every 30,000 miles. Fluid can look new but normal wear and tear introduces metal particles circulating about which is hard on the bearings.

 

And use GL-4 only fluid, not GL-4/5 fluid. I highly recommend Redline mt-90. It smoothed out my notchy shifts on my trans.

 

I highly recommend Walmart house brand GL-5 and Sta-Lube GL-4. But, as you can see. you don't need any GL-4 cuz GL-5 is OK in your manual toyota transmission since at least 1985. Now my Troy-bilt roto-tiller specifies GL-4 and that's what I use. But, the rototiller is ancient. There may have been a time when the gear oils DID (past tense) contain a chemical component that would attack copper and copper alloys. But them days be gone forever. Urban legends, old wive's tales, misifnformation, etc. persist, as well as ignorance.

 

Going to have to disagree with the gl-5 supertech, yes the spec says gl4-5 but I've never experienced shifting problems untill we put in 2.5 quarts of the super tech gl-5 stuff. There are plenty of other occurances of the gl-5 not working well with the w series syncronizers which I we I'll add to. No bueno! Gl-4 MT spec lubricant...

 

I guess my transmission is a either a liar, ignorant, or believes in fairytales.
My post is based on me using both GL4 and GL5 fluids in my transmission. First change I did was with GL5 and it made the 1-2 shift very crunchy and it would grind a bit every time. Didnt do that before the fluid change. Came on here and read many posts about how GL5 can make the trans feel like that. So after less than 5000 miles, I drained the GL5 and put in the MT-90 GL4 and it smoothed out the crunchiness and grinds on the first drive.
Just because something is put in a book, doesnt mean its correct

 

eh, i don't change the fluid very often. ran whatever my first '87 had in it for about 90K miles - 7 years - (i did periodically check to make sure the level was satisfactory), then changed it using redline mt-90. haven't noticed a difference in shifting or smoothness, but i don't know what was in it when i purchased it (could have been original, as i bought it with only 97k miles on it). my second '87, however, was low on fluid, and the transmission was noisy at 241K when i purchased it. so, i changed the fluid, and immediately lost 4th gear.

presently have a marlin crawler 5-speed crated and uninstalled, sitting in the back cargo area of that 4runner awaiting the swap. i'll use mt-90 when i install it.

 

My response was inappropriate. My feeble explanation is "thinking more about the effect on the brass and copper parts", when actually the posting was an anecdote about personal experience. I had to do some research,and it seems that the differing friction handling characteristics of the two formulations likely does have an effect on the smoothness or lack thereof of shifting gears while driving. I hereby retract my post and apologize t Robert M.

 

You need a gear oil that has the additive package in it to help a manual gear box that has brass synchromesh collars in it like the R150 F has.
Royal Purple, Amsoil and Valvoline seem to pop up with the word synchromesh being key for a smooth shifting non-temperature dependent manual gear box.
I replaced the crap the PO had put in my 91 4Runner with Royal Purple 75W-140 gear oil and the cold morning notchyness disappeared before I was at the end of my street on a typical cool morning.
High speed roll-ons and doubling down shifting from 5th to 4th to 3rd was improved with freeway accelerations when passing etc.
The other big improvement was a short throw shifter kit from Marlin which came later on.
But even before that the ability to get it into first gear with straight gear oil was difficult.
So I abide by the Royal purple product and am slowly but surely putting it in the axles and t-case in my 4Runner.
The stuff still smells unappealing but it is purple in color, pours almost like water and that is kind of a bit different and kind of cool for a gear oil with additives!
As for duration and service life I would aim for 100K miles before I bother with replacing it, partly because the stuff is expensive.
This is not to be confused with the ATF alternative trade marked as Synchromax by Royal Purple.
The collars in the R150F apparently need the viscosity of a true gear oil and not a mineral oil like ATF to keep the synchromesh collars spinning at speeds needed for smooth shifts between ratio's as the collars are slid from one to the other for engagement and power transmission.

 

i made had a thread about redline when i installed a brand spanking new marlin w56b and it would shift into second. sent it back. they opened her up, said it was fine, sent it back. same problem. someone suggested the redline mt90, problem went away and never came back. its all ive used ever since.