Okay fellas ive read around and ive read everywere gl4 gear oil in my w56 ive looked around cant find any gl4 75w90 and i have found some gl4 85w90 at my local napa auto store in a gallon its stalube like 35$. Would it be okay to use that or does anybody suggest something different? I live in Alabama so not to cold i mean it is winter time but the coldest its been is thirtys coldest it could get to would be 20s but once r twice a winter. So how bout some opinions?

 

I don't think it would hurt to run it, it's good your going for gl4 in the tranny rather than gl5. I can't get any around here either. I had to order Redline MT-90 through amazon.com. It dosen't take too long to get. MT-90 is about the best you will find.

 

Yea I've heard about the redline but I can't find it on amazon unless I have to buy a full case of quarts or gallons. I'm liking the stalube because it's right here n good price I jus wanna make sure the heavier weight won't damage anything.

 

Google the MT-90 and you'll find places that sell it by the quart. Summit Racing comes to mind.

 

Here in Pa I run 85W140 year round now on the cold windy days around zero the trans does take a few minutes to warm up.

It is parked inside at night so no big deal

 

That is what I use.

 

Well i looked into ordering amsoil synthetic 75w90 gl4 from there website it would look to be about 75 bucks before shipping for enough oil to do the trans and tcase, 102 $ if i order some 80w90 for the front diff and a pump to pump the oil up. I dont need to change the rear diff a leaking pinion seal made sure i changed that fluid.

 

I've run the Sta-Lube GL4 oil in my W56. My take is any GL4 oil will work better than any GL5 oil in the transmission. MT-90 does work better, but the 85W90 is fine. You could check Redline's dealer list and see if there are any local shops that carry it, or try Summit Racing.

 

Could you tell any difference in the 85w90 harder to shift or anything, yea i just looked at the redline sight and no dealers within 50 miles lol. Ill check out summit and see what their price is.

 

It is a little more sluggish shifting on cold mornings for the first mile or so until it heats up.

 

Hmmm so you think the warmer climate here in the south I'd be okay? I figure at least it'd be better than the way old oil in my trans

 

this was a PITA when I was doing my vehicles, I finally found some 75w-90 but it was a chore. everything wants 85w-90 or 85w140 it seems, nobody carries any selection/amount of 75w.

I put 50% or more lucas HD oil stabilizer in everything, front diff is 100%, rear diff is 75% (I think). love it to death, it sticks like no other. cut's down on the amount of gear oil I need I guess is my point here....

i would bet that as long as you changed it at the recommended service intervals, you will be light years ahead of most folks anyway as far as longevity, regardless of the specific weight oil

 

Yea at least changing it would be ahead of not. Ive had the truck for almost a year and all ive done is check and fill jus a lil bit, so i have no idea when or if its been changed. Maybe after christmas i can pick up a gallon of the stalube, still wanting to hear any ideas so keep um coming and thanks for all the replies so far!!!

 

As long as you are OK with it being a little sluggish shifting for the first mile or so on cold mornings. Still shifts fine, but don't expect to speed shift up and down through the gears for a few minutes. Pretty much any weight gear oil will be like that, I found even MT-90 you can feel it for the first few shifts. With the very thin MTL oil, I have not felt the oil thicken at all, at least down to around freezing, which is about all the colder it gets here. But in the W56, I found the MTL to be pretty noisy compared to the MT-90.

 

I switched to redline. Mine doesnt pop out of fifth as much. third to second isnt grindy anymore, and second to first isnt as grinding anymore..... Just thought i would pass that on.

 

Hmm so any oil will be sluggish, right now I don't have any trans noises or grinding a lil chatter noise while cruising in fifth and grind going in reverse every now and then think an oil change could free that up?

I'm still gonna check summit when I get the chance because everyone seems to enjoy the results of the mt90

 

I've run the Sta-Lube GL-4 85w-90 that you're talking about for years in my R151F, and it's just like he says. Not as noticeable in the summer, pretty bad in the dead of winter here in Oregon. GL-5 75w-90 in my tranny is definitely much better in terms of shift quality while cold.

 

similar to motor oil, the first number is the viscosity cold, the second number is the viscosity when at expected operating temps. So the lower the first number, the easier it would be to shift cold. I think the GL rating is just as important, learned this today:

GL 4 contains up to 4 percent additives, GL 5 has up to 6.5 I believe. additives are "anti-scuffing" compounds I guess... mo' slippery

like I said and others said on here already, changing it often is more important but as in most cases, stay as close as you can to FSM and you will be fine.

all that said, I still love my lucas oil stabilizer and I have no idea what that does to the cold vs. hot viscosities but I think it works awesome.

 

i too am a lucas oil guy i think that stuff does wonders. use 1 quart in every oil change. it helped reduce my dry starts and it seemed to quiet the notorious head tick the 4cylinders have.

 

The odd time I've used Lucas as well! A couple of weeks ago I listened to a call in show where the guest taught automotive at a local technical college for many years. He's pretty sharp and one caller asked him about aftermarket additives. Lucas was one of the additives that was mentioned, he said that some of these additives such as fuel stabilizers do help, but when it comes to oil he asked an expert. The expert he asked was a chemical engineer that worked in the petroleum industry, his expertise was lubricants. The reply that he got was that the blending of lubricants is done under precise conditions, adding additives and expecting them to blend with your lubricant is like baking a cake where you forget to add the eggs and trying to add the eggs after the cake comes out of the oven.
Food for thought! (no pun intended)