[ihc] Tranny lube

[John Hofstetter <hofs@xxxxxxxxxxxx>]

At 8:27 PM -0600 11/9/03, Dennis Bernth wrote:
> The stuff Steve is talking about is probably the synthetic manual trans lube
> that the over the road trucks use. It's considered a 500,000 drain interval in
> OTR, and lifetime fill for light duty. For what you're driving, you might just
> take Mac's tip on the Mobil 1 15w-50 synthetic motor oil. More than one person
> has run that in IH manual trannies and transfer cases and been impressed with
> how much better the old gearboxes work with it in there. You need to make sure
> all of the old GL-5 type gear lube is gone first though; an easy way might be
> to drain and refill with some regular old dino 15w-40 diesel oil, run it a
> couple thousand miles, drain, then do the Mobil 1 thing.

--
Geez, I wrote a short book on this subject and nothing went out 
except the part I excerpted. Have you guys made a deal with Richard 
to condense my ramblings.

OK, here is the short version.

The IH manuals specify gear oil for the manual trannies. It took a 
bit of pushing by digesters to get some of us to heed the information 
from Eldon McFarling, diesel guru and contributor to technical info 
on the Bulletin, that the trannies and transfer cases are better 
served with 50 wt. motor oil.

I think that I was the most ardent pusher of Mobil 1 15-50 for this 
purpose, early on. However, as you can tell there are a number of 
other converts. Bottom line is that what Dennis is saying. You 
probably can't do any better for the money than the heavy duty 
synthetic motor oil.

Before I'm exposed by others as a total hypocrite, let me confess 
that I use Amsoil lubricants in all my running gear in the my Dodge 
diesel. Very expensive, but makes me feel good.  If it's almost twice 
as expensive, it must be twice as good, right?  Nah,  not a bit.

And, would I use the Mobil 1 in my Scout if I didn't think it was as 
good as any, and better than most other lubricants? Nope. By the way, 
I would, and do,  consider the Mobil 1 in the tranny to be a lifetime 
fill.  Not in my tranny, because I have an auto in which I use a 
synthetic ATF fluid.

Occasionally,I talk to guys who have a feeling that the synthetic 
lubricants aren't the best choice in traditional applications, but I 
have never seen a single documented fact to support that belief.  The 
fellow whose work I like a lot and who rebuilt my 727, believes in 
the dino products, but he is the first to admit that he has no 
evidence to support this belief.

Early on, when Mobil 1 first came out, Smoky Yunick, race mechanic 
and Popular Science contributor said that he had some misgivings 
about the synthetics being so slippery that the cylinder walls would 
drain completely dry and one might get excessive wear when starting 
up. You'd have thought he was the guy who invented Slick 50, but he 
wasn't. <g>

On my Traveall I used nothing but Mobil 1 and it had pretty 
significant  cylinder wear at 160,000 miles, when I rebuilt it.  My 
GC with 132,000 miles shows no signs of ring wear, so I think one 
possibility is that the oil has been improved significantly since its 
first introduction. The Terra with a lot of miles doesn't appear to 
need rings, but I have no real data to support its engine wear, 
except that it still runs very strong.

I know perfectly weill that none of that means much because guys 
using dino oil get in excess of 200K miles on their IH engines. So, 
who knows?

I like Dennis' suggestion on getting the old gear oil cleaned out of 
the tranny. I didn't do it that way on my transfer case, but I should 
have. Too old, too lazy.

John Hofstetter
www.goldrush.com/~hofs