"Notchy" manual transmission after gear oil change

1999 Tacoma 2wd base 5 lug w59 mtm. 250k miles

I recently drained my transmission and refilled with Redline MT-90 GL4

$28 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 as recommended by a few post I saw here. Ever since then it's been harder to get into gear, noticeably first, and reverse is absolutely awful. It feels like I am hitting a wall partially into first gear on about half of my shifts. On reverse I can hardly ever get into it first try, it used to be 50/50. Now I have to double clutch, go into first, sometimes 5th, and only then will it let me, sometimes it still doesn't and I have to repeat.

It was filled all the way up to the fill plug, exactly 2.7qts like the manual and hanes book calls for.

I did more looking online on separate forums and found other people with tacomas reporting the same thing with redline mt90. They said they switched to amsoil and it shifts fine now so I think I will try that. Don't really feel to great about draining brand new $60 worth of gear oil out but can't stand the poor shifting.

Just wanted to know what you guys think or if anyone has had a similar experience. Thanks

 

Look into motocraft

$35 xt-m5-qs full synthetic manual transmission fluid - 1 quart , black

xt-m5-qs. It's a beloved choice in multiple automotive circles. Some people call it unicorn tears. I used it in my 3rd gen and it worked well (wasn't having any issues prior to using it). It HAS remedied shifting issues in other vehicles of mine though.

 

Yep, that's what I used, loved it, then the last drain and re-fill I couldn't find it, had to go with the Redline, it was a little rougher at first but does OK now. I still liked the Furd stuff mo-betta though.

 

How did it shift prior to the change?

A few months ago, I drained the original oil from my '96 and replaced with MT-90. It shifted perfectly on the 25 year old oil, but I figured that it was about time for new stuff. After replacement, I notice a slight bit of notchiness when the oil is cold, but that goes away once warm. My truck has less than half the miles as yours though.

 

The Motorcraft XT-M5-QS made an immediate difference when I changed to it.

Rock Auto had the best price.

https://www.rockauto.com/en/parts/motorcraft,XTM5QS,transmission+fluid,13630

 

The W59 in mine shifts great with redline MT90

 

It shifted just fine. Once in a great while it would be a little difficult to get into first but not even close to how bad it is now.

Looking like I will switch to the motorcraft

$35 xt-m5-qs full synthetic manual transmission fluid - 1 quart , black

xt-m5-qs based on what was said above.

I'll report back with results.

 

Please do. I have redline mt90 in mine and first and reverse are bad enough that I keep thinking I need to rebuild the trans. I switched out as soon as I bought the truck so I don’t know what it was like before. Would be interested to know your results.

 

Definitely interested in what you find.

 

Maybe check your shift lever bushings. Made a big improvement on mine. The big one was totally gone though.

 

+1 on all the shift bushings. Mine looked relatively good and I still have a huge improvement in shift feel.

 

So I just refilled it with

$35 XT-M5-QS Full Synthetic Manual Transmission Fluid - 1 Quart , black

XT-M5-QS and drove around for 30 minutes. It's easier to shift into 1st and 2nd now, and far easier to shift into reverse. It's also considerably easier to downshift which is great. The synchros work much better/faster than before.

Overall the low speed shifting is improved a lot and isn't nearly as notchy/stiff, no more muscling it into gear. Glad I switched.

 

I’ve been using

$35 XT-M5-QS Full Synthetic Manual Transmission Fluid - 1 Quart , black

XT-M5-QS for quite some time and my experience has been the same, and I came from using Redline MT-90.

 

Well thanks for the update. Sounds like it’s about time for me to make a switch and see what it does for me too. Much appreciated feedback!

 

Damn wish I knew about that, just put in mt90 a few months ago..

 

If you have the same issues I described at the top then definitely give it a shot. Pretty easy to do especially since you've done it before.

 

Me too. Bummer. At least for me it's not too bad.