Transfer case lube

[plexx]

I want to change the fluid in my transfer case on a 2001 toyota 4runner w/auto. transmission. The owners manual calls for a API GL-4 or GL-5 75w90 gear oil. Now the question, I will be using Redline but i am not sure if I should use the 75-90 (gl-5) gear oil, or the MT-90 (gl-4).Any comments?

[ March 08, 2003, 07:37 AM: Message edited by: plexx ]

 

[joee12]

Go with the 75W90 GL-5!! -Joe

 

[Bror Jace]

Is the Red Line GL-5 non corrosive?

--- Bror Jace

 

[TooSlick]

Go with the GL-5 stuff if they give you a choice, since it will have a more robust additive package.

Bror,

I haven't seen any GL-5, MT-1 rated synthetic gear lube that is corrosive. I've been running the Amsoil GL4/GL5 stuff in VW transaxles for over 20 years and never had a problem. I honestly think Redline is simply wrong about this issue.

 

[unDummy]

It isn't a Redline issue.

 

[Mech]

Ok I have heard from several different places that GL-5 rated lube will attack the brass synchro rings in a manual transmission. Is this true? I am planning on changing my transmission fluid, transfer case, front+rear diffs. I was thinking about running redline. I mainly use my truck for going to and from work, but I hit the trails a good bit to get to those rarely fished lakes and to go hunting. It is a 95 Tacoma with a 3.0 v6 and a 5 spd. I can check on the factory recommendations if anyone wants to know them, but I would think that the current range of synthetics should work very well it in. I just want to get the maximum out of this truck. I have no idea how long it has been since the current fluids were changed being as I have only had the truck for 1.5 weeks now. Ok so what i'm asking is what would be the best brands/weights/ratings to get the best bang for my buck without being a cheapo?

 

[Mech]

Ok ignore that I read down a little better and found the answers I was looking for. I am thinking Redline MT-90 in the transmission and transfer case. I am leaning towards a syn 75W90 but haven't decided what brand yet. I have never changed these before on any vehicle, how long should I expect it to take and what will I need gasket sets for?

 

[Rick]

I'm using Redline Lightweight shockproof gear oil. Has the weight of an SAE 30 but works like a 75W-140 I find it runs well. Just thought Id let you know.

 

[Bror Jace]

Mech, I think MT-90 is a 75W90 ... but you might want to check Red Line's site to be sure.

Yes, the GL-5 corrosion issue might be a bit over-done. The sulfur compounds in the oil react with the steel to form their barrier protection. The slight corrosion isn't an issue in rear-ends with MASSIVE gears (tractor trailers). In general this isn't too bad in most lighter applications until moisture builds up over time and the corrosive effects become more severe. So, if you change your fluids regularly, it shouldn't be a problem.

But then again, if you find a non-corrosive fluid, why not use it and bypass the chance entirely? This is especially true if you know the fluid is not going to be changed for another year or two.

--- Bror Jace

 

[Bror Jace]

Oops, as far as the job goes, it is usually fairly easy and straight-forward ... but I only worked on older American iron, not Toyotas.

Not sure if they recommend using a new replacement gasket IF you have to pull the cover. somethies these things don't survive the operation. Some folks like to use RTV in a tube instead of replacement factory gaskets. Easy to procure, cheaper, etc ...

Just not sure about your application.

I'd splurge and get the $15-20 manual ... Haynes? They are at least a little helpful in giving you an idea of what is involved with some repair projects.

--- Bror Jace

 

[plexx]

Ok, I spoke to a rep. at Redline and I was told that Mt-90 is a 75w90 gear oil that is made to improve the shifting charachteristics of a manual transmission. No it does not have the sulfer additives in it "E.P", but their regular 75w90 should provide better protection in a transfer case since they don't get shifted all that much anyway, so I am going to go with the regular 75w90.Mech; on the Toyota's, it is very easy to change the fluids, everything has a drain and fill plug but you should replace the gaskets which are made out of a soft metal.

[ March 11, 2003, 09:02 PM: Message edited by: plexx ]

 

[Jimbo]

A transfer case does not have hypoid gears like drive axles, so it does not need EP additives. However, it also does not have "yellow metal" sychronizers that could be harmed. For simplicity, go with the same lube in the t-case that you use in the front and rear axles.

BTW, the Borg Warner t-case in my Ford uses ATF.

 

[TooSlick]

Mech,

Toyota is nice enough to provide drain plugs on their diffs and transfer case, so you don't need to replace any gaskets. The plugs have pipe threads so you really don't need to use a sealant either. I suppose you could use some locktite if you were really AR about it.

I'd run MT-90 in the transmission and the GL-5 rated , 75w-90 Redline stuff in the diffs and transfer case. I've run the Amsoil 75w-90 (which is GL-4/GL-5 rated) in my Tacoma transmission for the last 8 years and it works just fine. If you run a GL-5 in a transmission/transaxle application, you want to make sure it is also MT-1 rated. The MT-1 test measures the effect of the lube on "yellow metals" at elevated temps.

TooSlick