Looking for a GL4 Specific. Amsoil or Redline

Status
Not open for further replies.
C

CruzNlife1

Joined
Nov 17, 2007
Messages
58
Location
Palm Beach FLORIDA
My trans calls for GL4 (manaul, toyota tacoma 4x4) I've been using GL4/GL5 Royal Purple in is since I've had it. COLD SHIFTING SUCKS. Even in cooler florida mornings 60-70's it shifts horrible in the morning. Anyways, doing some reading, a specific GL4 fluid should be better for this transmission. Looking at Redline MT-90 or Amsoil GL4 MTF Both are 75-90 I believe and thats EXACTLY what my manual calls for. 75-90 GL4

Which is better and how much better are they than a GL4/GL5 ?? I just want it to last a long time. I drive 100 or so miles a day and plan to drive this truck forever
 
Actually you want this Amsoil MTG 75W-90 GL-4 (not MTF) anyhow it is labeled as a GL-4 only, because it's not to be used in GL-5 differentials. GL-4 specific fluids are typically better for manual trannies because they have the correct FM's and lower EP/AW additive levels.

But are sure your shifting is not a viscosity issue rather than an EP/AW additive level issue? What is the cold temp viscosity of that RP you are using? It just may be on the heavy side.
 
Originally Posted By: CruzNlife1
My trans calls for GL4 (manaul, toyota tacoma 4x4) I've been using GL4/GL5 Royal Purple in is since I've had it. COLD SHIFTING SUCKS. Even in cooler florida mornings 60-70's it shifts horrible in the morning. Anyways, doing some reading, a specific GL4 fluid should be better for this transmission. Looking at Redline MT-90 or Amsoil GL4 MTF Both are 75-90 I believe and thats EXACTLY what my manual calls for. 75-90 GL4

Which is better and how much better are they than a GL4/GL5 ?? I just want it to last a long time. I drive 100 or so miles a day and plan to drive this truck forever


Describe your cold shifting. Do you get any grinds/gear crunches? I tried RP Max Gear 75W90 a long time ago and it was the worst shifting gear oil I ever used. My guess is that it`s so thick it won`t allow proper synchro engagement. I`m trying to get some opinions on the thinnest gear oils anyone has had any experience with. I get some saying that too thin an oil will create better quality shifts,but are bad for the bearings. But,I`d think gear grinds would be the worst possible thing on the tranny internals.
 
Cold shifting as in, pull out of my driveway, clutch and put some serious honest effort in getting it into 2nd or third. So fed up I usually just yank it into second. About 15 minutes of driving, it shifts Perfectly. It feels like the clutch isnt disengaging but it is, it's just hard to physically shift it. No grinds no noises, and it started when I put the Royal Purple in.. I want to try a GL4. Which would be better though or are they going to be similar ?? I can get both over the counter locally. Thanks
 
Haven't tried Amsoil, but Redline MT-90 made a big improvement in my Mazda. No more 1-2 protest/grind and all other gears feel more cooperative.
 
I have the amsoil pablo recommended to you. I have not put it in yet as I am waiting to get 15-20K on the car then switch over. Other corolla owners have experienced much smoother shifting with the amsoil mtg. will let you know in a couple of months how mine is
 
Haven't tried Amsoil, but Redline MT-90 made a big improvement in my Toyota. Smooth, no slow downs between 1/2.....a HUGE improvement over the GL5 that was OEM fill.
 
Is there a reason the GL5 75W90 Mobil1 synthetic couldn't work? Mine specs GL4 too, but it's hard to find in a synthetic, and the thing runs better than ever on the M1 Syn GL5. Goes into reverse much easier than with the brew I had before, too. This is an AccentGT 5 speed, but only has 50,000 (mostly road) miles..
 
GL5 that is also GL4 approved will work. The problem is that the extra additives in GL5 can interfere with the synchronizers ability to do their job well.
 
Will GL5 do physical harm to the tranny internals,or just give bad shifting quality? I emailed Mobil one time and they said not to use their gear oils in any manual trannies.
 
If you get a grind when shifting, then damage is being done! I once had a old timer tell me that one grind of a gear takes a hundred good shifts to smooth it back out.

I would use GL-4 products only. You might even want to try mineral GL-4 75-90.
 
Quote:
Will GL5 do physical harm to the tranny internals,or just give bad shifting quality? I emailed Mobil one time and they said not to use their gear oils in any manual trannies.

GL-5 gear oils tend to have friction modifiers which are not good for the synchros. If your manual transmission calls for GL-4/GL-5, either use GL-4 or get a GL-5 that does not contain the friction modifier (Redline 75w-90NS & Amsoil Long-Life 75w-90 FGR are two examples).

From what I have gathered, use GL-4 in manual transmissions, unless otherwise stated by the manufacturer, and use GL-5 in differentials.
 
Saw this on another forum, I include it here to see if someone can confirm or debunk.

"It uses Brass Synchros and so a GL-4 is called for...

If the Boxster uses hard metal synchros, there's no problem at all, but I've never been inside one and so cannot say for sure. But, GL-5 has been reported repeatedly to have attacked soft metal parts. GL-4 does not."
 
Anybody have any pictures of synchros that dissolved due to GL-5? Didn't think so!

You guys are scared about nothing. GL-4 has plenty of sulfur in it as well, and the sulfur only becomes corrosive at temperatures over 250 degrees F. How many of you get your transmissions that hot?
LOL.gif


- Scott
 
Just as you found get either the Amsoil or Redline and you will be happy.

I used Redline MTL in a trans that spec'd 75W-90 per Redline Rec and it was fantastic. Use the online Amsoil Guide or all up Redline and ask what they recommend and get one or the other and all will be well.
 
Is that typical putrid smell of rear differential gear lubes the sulfer that`s being smelled? If so,then you`re right about the GL4 gear lubes containing a bit of sulfer. My Nissan MTF has that same smell,but very faint.........nothing like the RP Max Gear GL4/GL5 that I have in the rear diffy.

After I try my 2 quart Nissan 75W85 MTF/1 quart ATF (recommended by a few Zcar.com members),the next fill will be RL MTL (as recommended by several Twinturbo.net members)if the MTF/ATF mixture doesn`t give me improved shifts,but I`m keeping my fingers crossed it will.
 
I've changed mt lubes before, and was sorry I did. They were worse when I was done. My last change was on a new 2000 Civic that had a balky tranny that I wasn't happy with. I installed Redline MTL. That did wonders. I was very happy with it, and would recommend it.
 
Quote:
the sulfur only becomes corrosive at temperatures over 250 degrees F. How many of you get your transmissions that hot?

Individual contact points can easily reach that temperature.
 
Originally Posted By: aquariuscsm
Will GL5 do physical harm to the tranny internals,or just give bad shifting quality? I emailed Mobil one time and they said not to use their gear oils in any manual trannies.


GL5 is corrosive to the "yellow metals" in your man. trans.
 
Status
Not open for further replies.

Similar threads

Yuk
What's better in the extreme cold than Amsoil Severe Gear 75W-90?
2
Replies
25
Views
2K
CarbonSteel
H
Fluids for 2016 Mustang GT
Replies
11
Views
580
pzev
MolaKule
  • Locked
Updated List of MTF's (both GL-4 and GL-5)
2
Replies
35
Views
10K
Ruturaj
OM605
Oil for an old Mercedes manual tranny
Replies
16
Views
1K
OM605
1 SX
GL4 MT synthetic transmission fluid for Forte Coupe 6 speed. Can i use GL5? + other questions.
2 3
Replies
51
Views
7K
MolaKule
Back
Top