Gear lube question

The specification for GL-3 was set in mid 1930's.

The specification for GL-5 was set in 1960.

For 1962, it would have been GL-4, or lesser, potentially.

GM did not fully adopt GL-5 until the mid-1970's, and first in heavy truck axles.

 

The original lubricant specification for an AX-15 was GL-3.

Later it was GL-4.

 

Apparently GM didn't seem to think the API grade was important enough that their customers should know anything about it.

 

We usually carry a few parts (points, etc-gasp-ignition modules) when going on a long drive in something old. If GL4 isn’t as easy to find as GL5 on the road, carry an extra gallon in the trunk, bed, etc.

Hopefully we just carry it around, put it on the shelf when home.

 

When was the last time anyone needed gear oil on the road that didn't involve a major breakdown ?

 

Some of these posts remind me of cold calling on prospects, where when you ask them if they're having any issues they tell you No, everything is fine. Then you walk through the shop and see hydraulic pumps or engines or differentials, etc in the s**** metal bin; and if you ask them what about these they just shrug their shoulders, "eh, they just wore out". Yeah, right. Or, "it was the driver", which actually is pretty believable, drivers and equipment operators can sure tear stuff up. The point is, it's never their maintenance practices that results in failures, it's always somebody else's fault. Yep, never saw an oil related failure, and that transmission over there in the junk pile, that was the driver's fault....

 

Besides, I thought you were supposed to be able to drive manual shift transmissions hard. I thought you were supposed to be able to downshift them. I thought you were supposed to be able to stab the throttle and dump the clutch. WTF??? All you see around here is posts about how "real hot rods have 3 pedals"; like everyone is a real bad ***; now you see all these posts that appears like everyone drives their car around like it's a cream puff. Which is it?

 

If you're gonna drive a car hard, don't put a T5 in it.

 

I’ve been enjoying this discussion on the nuances of lubricants, very educational for those of us who are used to just reading the requirements in the various manuals and the info on the packaging.
If I may ask without derailing this thread, what do we use now days for a lubricant in the old ‘55-‘64 Chevy Positraction rear ends?

 

I would use a GL-5 oil that says something about limited slip on the label, and if it chatters, try some additive.

Or...bust out those two quart cans of GM rear end oil I have, they're probably 40 years old. Or use GL-3 or 4 oil (if I could find any!) and put in some of the old GM additive I have, which everyone said not to use because it's well past it's due date.

Keep in mind that my recommendations are worthless, because I just do whatever works, I don't follow the rules.

 

Right now it’s working fine with 50 year old lube, maybe I should leave well enough alone. I just thought it might be time to service it.

 

I'm in a similar situation with a non-posi rearend in my 62 Corvette. It looks like it's never been worked on, the oil level is OK, it has the usual seeping at the pinion. My plan is to pull the axles and center out, and replace the pinion seal and crush sleeve, and the (sealed) wheel bearings. Then put it back together and fill it with GL-5 gear oil.

It's possible I'll buy an aftermarket posi unit for it, too....

 

Back in the day one of my Mopar factory service manuals said to run ATF in their 4 gear ******s unless there was objectionable gear rattle whatever that means,,, then drain and use 80/90W gear oil...Myself I always used gear oil in stick cars....More Sulphur the better....Prevents galling the gears...

 

Personally, not myself. It was mentioned several posts back about the possibility though of a major breakdown and not being able to find it.

 

I've had to buy gear oil at a gas station....

 

The original spec for Fuller transmissions was mineral oil. The leasing company I worked for went to 50 W synthetic at Fuller's recommendation in the 80's. Synthetic gear oil in the differentials.

 

I’ve only been through a few rearends, only “posi” was a late/mid ‘60’s GMC Dana44, but I don’t recall any br***/white metal in it. So I’d think GL5 should work in a rear end for older vehicles without issues?

 

I’m a renegade like Squirrel,,( Jim ),,,,I use what I need to get the job done .
I’ve used gear oil for years and years,,,,,never changed it because of a needed service date .
Unless it gets contaminated with water or debris of some kind EP gear oil lasts almost indefinitely .

And I feel that 50 wt motor oil will definitely let the gears wear out well before their true service life .
But,,,then again,,,,this is a throw away society now,,,,the T5 s are a fine example .
I know there are instances where a lighter weight lube is needed,,,,,,extremely cold temperatures are a fine example .
Chrysler recommended ATF in their A833 ,,,,in very cold climates.

Tommy

 

Many transfer cases spec ATF as well, may be because they are not in constant use? More useless non-relevant information added

 

Like Jim said if you close to 400 pds of torque even in light 2500 pound ride that hooks .

 

Right. That's why trucks get over a million miles before overhaul....

 

Ihc hytran fluid

 

They do ?

Tommy

 

Absolutely, especially in line haul applications. Vocational applications are different. The diesel engine manufacturers actually supply overhaul intervals depending on service type. We routinely see road tractors with a million plus. I have a customer whose Mom and Dad pull for FedEx and they traded their Volvo recently with 2.5 million on it without major engine work.

 

That's actually not too bad of a suggestion, it is a GL-4 spec fluid, but the viscosity is a little light for a high temp climate. Might be just fine for upper mid-west area; not so good for the south west.

 

The guys who worked on my trucks until I got one that was fully electronic were much older than me, 30 years or more. I went by their experience. I figured they knew more than me, and never had any problems doing what they told me. When the trucks got too complicated, I started using truck and engine dealers.
I never lost a transmission or rear end to a lubrication problem. I did lose two different engines, following the makers oil recommendations and change intervals.

 

Just don't power shift 3rd gear(middle of cluster), you should be fine then.

 

I enjoy these educational threads, as my job doesn’t provide any mental stimulation whatsoever. My thoughts boil down to, do you want, or have room for, 2 different half empty bottles of gear lube in your garage? Or, is it just easier to choose 1? For the record, I used GL4 in the Muncie and GL5 in the posi on my last car. Was it necessary? Probably not, but I have room for the bottles.

 

Hi Andy ,

So you are saying that a road tractor with 50 Wt motor oil in the transmission will be just fine to go after a million miles ?
No transmission wear ?

Now I understand a FedEx truck road tractor,,,or UPS ,,,,,,carrier over the road .
Are those trailers routinely loaded to the max weight ,,,,,no ,,,,they can only haul what they can fit inside the trailer .

What about a steel hauler,,,that is usually at the max allowed,,,,or more,,,,,,usually more ?
Or a tractor that hauls heavy equipment ?

Im ***uming that the rear differential get regular motor oil as well ?

Tommy

 

I can’t speak for road tractors, but my dad ran bottom dumps and transfers, always 80k loaded. BDs made 12-15 round trips a day, about 1/2 that with the transfer. 80/95 in the rears and transmission (13 speed) and Dello 400 10/40 in the engines ( big cam ***mins).
He never had a chance to wear out the Transfer before he retired, but with the BDs, 7/8 seasons each engine (no wet weather work for BDs, that’s when he ran the Transfer) we replaced the 13speed once in the BD.
Not comparing lubes, but based on experience I’d say it would be easy for a road tractor that may not shift for hours, ie “aim and drive” to easily make a million miles, especially with all the electronic fuel controls, etc.