RE: [ihc] 13" clutches ...I think it is possible

["John M. Adams" <jma@xxxxxxxxxxx>]

I look back through my maintenance notes and see that both my manual
transmission and transfer case have GL-4, not GL-5. Back then - my
truck is recently back on the road after an 11 year "rest" - I had
some reason for using GL-4 in the cases, and GL-5 with an additive
in the diffs. Don't remember the details, and I don't have any product
lit saved, can't read the labels...  Anyway, my question:

To purge the transmission and transfer case of the old GL-4 gear oil,
you're suggesting I run a 15w-40 diesel oil for a while, then switch
to the Mobil-1 15w-50. Is that because you can't mix the old GL with
the synthetic Mobil-1, or just because it's a cheaper flush? In other
words, if I don't mind throwing out 6 quarts of Mobil-1 after a 2K
"rinse", can I go straight to Mobil-1 and skip the dino oil?

Also, I read this on the Mobil website:

"Mobil 1 Synthetic Gear Lubricant 75W-90 meets the most severe API
Service MT-1 and GL-5 EP gear oil service classification."

Should I therefore consider running their 75w-90 synth in my diffs -
it does say EP - and the 15w-50 in the transmission and transfer case?

Thanks, all of you... this is real helpful input I'm getting.

-John


-----Original Message-----
From: owner-ihc@domain.elided [mailto:owner-ihc@domain.elided]On Behalf Of
John Hofstetter
Sent: Sunday, November 09, 2003 7:53 PM
To: Dennis Bernth; ihc@domain.elided
Cc: jma@domain.elided
Subject: RE: [ihc] 13" clutches ...I think it is possible


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.


--
I agree with Dennis in that you couldn't do much better than the
Mobil 1 15-50 motor oil in your manual tranny.

It was Eldon McFarling of diesel engine fame that finally convinced
many of us that the old Manuals weren't gospel when they specified
gear oil in the trannies, and I maybe I've been the strongest pusher
of the Mobil 1 as a very good choice for that application, but
regardless of my prejudices in lubrication, believe me when I say
that you will be very happy with that choice.

In regard to a lifetime fill, I'd be perfectly happy to leave the
Mobil 1 in there for the life of the vehicle.

So that I avoid being found out as a hypocrite one of these days, let
me confess, I use Amsoil lubricants in all the running gear on my
Dodge diesel.  Very expensive, but they give me a lot of confidence.
I don't recommend the Amsoil to others. If asked, I suggest they use
Mobil's synthetics as I do in my Scout.

John Hofstetter
www.goldrush.com/~hofs
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.536 / Virus Database: 331 - Release Date: 11/3/03