I like it short and simple But what about xcases? -4 or -5?

 

Either is fine, non-synchromesh, and non-hypoid gears, so nothing special:
- http://www.4crawler.com/4x4/4R_TechInfo.shtml#Fluids

 

well I put in GL-4 /GL-5 mobil 1 synthetic oil in the tranny and I can say that the shifting was worse than before I changed it. Eventually 2nd gear was grinding nearly everytime I shifted. I put in Redline MT-90 and literally overnight, I was able to shift smoothly every single time. Bottom line is just cus it says GL-4 and GL-5 applications, that doesnt mean it will work well with it....If the tranny needs GL-4 dont use a multi-application oil. Go with straight GL-4 ONLY... just thougth I would share my little real world test results...

 

Make sure you run a GL-4 in the manual transmission.

I have Amsoil Synthetic 75w90 GL-5 "Long Life" Gear Lube in my transfer case, and front/rear diffs. I put Amsoil 75w90 GL-4 Manual Transmission and Transaxle Fluid into my manual transmission (I had it special ordered into my local parts store). Everything works great - and it shifts fine. The specific manual transmission fluid I just mentioned is just a bit on the thinner side as far as viscoscities go at operating temperature and in the morning than your typical striaght 75w90 gear lube so it'll shift a bit easier and flow well, and it doesn't have the extreme pressure additive that you'll find in GL-5 Gear lubes so you shouldn't have any problems with it, period.

 

Great thread to revive guys! I have castrol syntec 75W-90 Gl4-5 in mine right now and 3-4 synchro grinds way to much and it sure does seem sluggish but i thought it was just my imagination. I figured since the manual calls for gl4 or 5 i was safe with either... had no idea gl5 could cause problems such as this... Might in the next week switch to a gl4 only gear lube and compare!

 

Strange tho that toyota would specify a gl4 or gl5 gear oil tho?

 

Hmmm....I guess those fellas (some of them, enyway) selling their synth products will tell you anything sometimes. May be that they don't really know, either.

Well, other than the shifting sluggishness, is my transmission in any danger of synchro wear until I can summon the cash to change the oil out? I mean, do I need to address this right now?

 

Depends on how much "grind" into gear your experiencing. I think longhungsilver's got a point. If Toyota states, and they do, GL-4 or GL-5 in thier manual transmissions you should be able to blame them for damages , right? I should add that my experience has been GL-4 makes a difference, esp. when it's chilly outside.

 

Well when I went to the store all they had was 80w-90 so that made my decision easy. I'm going to run the cheap dino stuff for 500 miles or so on this rebuit 3rd then I'll switch to the $6 a quart good stuff.

 

None right now, unless I'm being careless and driving like Mario Andretti....which is not very often. The grinding I was having downshifting from 3rd to 2nd and sometimes shifting to reverse has disappeared with the new shifter seat bushing. And that was a little while back. Now, it's just the shifting is a bit sticky...trouble going into gears, but not always and only slightly. Still, I don't like it and makes me nervous like I will grind or something.

Yeah, we could blame Toyota all we'd like, but how far would that go..lol? This settles it, though. I've been reading far too many Yoter-heads say GL-4 is the way to go for buttery shifting. I'll just have to do it as soon as I can....(prays no syncro harm will be incurred until then ).

On second thought, I might go ahead and just drain the M1, save it for the t-case/diffs and just get some inexpensive dino to put in the tranny for now. Good idea? (ovrrdrive...your post spurred this idea..thanks)

 

Well I picked up some amsoil 75w-90 synthetic GL4 today.. 4 quarts for 50bucks.. Im hoping to change the fluid in my tranny tmorow.. Thisll be my third change since i got the truck (just over a month ago...and hopefully my last for a while!!)..

I originally ran castrol syntec gl5 with lucas oil additive and it was way to thick and hard to shift... so i ran just the castrol on its own and have had it that way for a while and it still seems stiff and slow then i read this post and it all makes sence so time for gl4 as i do not wish damage to my old tranny!!

Thanks for the info guys i hope not to find brass bits in my oil pan lol ill let u know

 

Boy, did I have trouble trying to find any GL-4 today. I went to Auto Zone and O'Reilly and I might as well been asking for tea at the beer pub. Imagine the looks! All anyone had was the multi-app. stuff....GL-4/5. Hmmm....suppose I'll try NAPA tomorrow. Where are you all getting yours locally? And what brands?

BTW, I asked earlier how can one tell (aside from obvious bits of brass) that the synchros are breaking down? Would there be a certain hue to the gear oil? When I drained the tranny a little while back to service my clutch, the M1 looked clean and normal to me....aside from being a bit dark for having been in since last summer.

Also, I would describe the feeling when I shift that of being a bit "chunky" when it goes into gear. Those of you that are using GL-4, does that happen for you?

 

In my search this was the only gear oil thread with any technical information in it so it was a logical one to bump.

Btw I saw the same thing you did at Autozone as far as multigrade oils. I did see one brand though that was gl4 but I can't remember which it was.

Btw I know the look you're talking about too. I don't care what store it is, if you walk in and request a grade of any kind of oil the guys behind the counter don't know what the hell you're talking about.

 

Last night at O'Reilly, a fellow came in to get something and overheard my request for the oil. He began spouting off something about GL-4 being uncommon and how synthetics are different from dinos. Too bad he was in big hurry to leave or I would have superglued his feet to the floor. He'd been building race cars for a long time and works in a shop, and he seemed to have some really good info. That fish got away..

Well, if you happen to have a sudden light hit you let me know what brand that was, if you will. I am going to call NAPA, but their hours are limited to when they are open. Regardless, atleast there I can talk to someone who's more informed....usually. The only looks I get from them is when they don't have something in stock for metric size and what not. I joined bobistheoilguy a few years ago, so I'm going to do some reviewing on what I read about synthetics, oil grades, etc. I just need to get really clear on this because I thought I was covered on component compatibility issues. The last thing I need is to redo a tranny any time soon.

So, any comments from GL-4 converts?

 

The Toyota manual transmissions can use either GL-4 or GL-5 oil, per the specs listed in the Owner's Manual. That means they won't be "eaten up" if you use GL-5 oil in them. But they will (and do) work better with GL-4 oil. I've run both in mine and for sure GL-4 is better than GL-5 (conventional or synthetic) and now all I run is GL-4. I've also done the same in my VW, and am currently running conventional GL-5 while I break in some new gears in the transaxle. Shortly will be draining that and putting in GL-4 (Redline MTL).

I think StaLube makes a conventional GL-4 oil, but I prefer the synthetics for their longer life and lower operating temps.

 

I think I put GL 5 mobil 1 in my 5spd. Maybe that is why the 1st gear syncro died.... oops. After the mobil 1 change over, the truck popped out of 1st on an increasing frequency till it never even held. I put in a new shifter bushing, and that did not help.

I think I am hosed

 

Thanks for clarifying that for me. Now, I'm not concerned anymore. GL-5's all I'd been using for several years. It's probably about time to change my oil anyway with all the hauling I do. So, a Redline order will be in the works for me soon.

Thanks again.

Now, the "chunkiness" I was asking about.....is that just normal or is that related to the gear lube?

 

Depends on what is causing the "chunkiness". If it is lack of synchronization making the gears clunk into mesh, then GL-4 might help. If something else is worn out and causing that, then it may still do it. Only two ways to tell, try some GL-4 oil and if it goes away, it was the oil, otherwise need to tear the tranny down if is is a major problem (or just live with it).

 

Well I would describe my tranny using gl5 as chunky as well... I just put in amsoil (bitch to find) gl-4 synthetic and i have to say it dechunkified it (not a word i know).. its much smoother...maybe not redline smooth but smooth enough. Its well worth the swap over and as my gl5 oil was only 3 weeks used i put it in the old containers and am saving it for the front diff or transfer case down the line.

 

I initially put Amsoil in my transmission (and diffs) about 2 years ago. My transmission did not like the Amsoil. It shifted worse with the Amsoil than with the original dino oil.

I drained the Amsoil and put in Redline MT-90 and it much improved the shift compared to the Amsoil and too some degree, the dino. It's not perfect, but it's pretty good.