CJ8 transmission lubrication

1982 Jeep CJ8 -- 6 cylinder, 4 speed

Transmission shifts and works well.

What should I be using as lubricant in the transmission?

The shop manual refer's me to a "Special Lubricant" (which is no
longer available). And there are references to using automatic
transmission fluid (ATF).

The Jeep dealer, when asked the question, has given me differing
answers depending upon who I happen to talk to.

It has most recently had Mobil 1 synthetic gear lube or Mobil 1
synthetic ATF -- I'm not certain which.

So what should I use:??
-- gear lube?
-- ATF?
-- some other magical lubricant?

(And if the synthetic in there now wasn't the correct choice some
time ago, what do I need to do -- if anything -- to flush prior to
getting the proper stuff in there??)

Advice, please -- and thanks as always for the help .....

Mike
Michael Pomeroy

[email protected] ([email protected]) wrote on Saturday 27 March 2004 05:11
pm:

> 1982 Jeep CJ8 -- 6 cylinder, 4 speed
>
> Transmission shifts and works well.
>
> What should I be using as lubricant in the transmission?
>
> The shop manual refer's me to a "Special Lubricant" (which is no
> longer available). And there are references to using automatic
> transmission fluid (ATF).
>
> The Jeep dealer, when asked the question, has given me differing
> answers depending upon who I happen to talk to.
>
> It has most recently had Mobil 1 synthetic gear lube or Mobil 1
> synthetic ATF -- I'm not certain which.
>
> So what should I use:??
> -- gear lube?
> -- ATF?
> -- some other magical lubricant?
>
> (And if the synthetic in there now wasn't the correct choice some
> time ago, what do I need to do -- if anything -- to flush prior to
> getting the proper stuff in there??)
>
> Advice, please -- and thanks as always for the help .....
>
> Mike
> Michael Pomeroy

Mike,

It depends on which 4-speed you have. If it's a T4, according to the Jeep
factory service manual, you should use ATF (Dexron II). If it's a T176,
you should use 85W90, API GL5.
--
Michael White "To protect people from the effects of folly is to
fill the world with fools." -Herbert Spencer, 1891

While ATF was in fact the recommended choice for some manual transmissions
for several years, ATF is no longer recommended by those manufacturers, even
if it was at one time. It was later discovered that ATF does not have
sufficient shear-strength to protect the gears, only a true gear lube does.
Some manuals, like Chilton's, still erroneously recommend ATF because they
are based on manuals from the era when ATF was still being recommended.
They tried to switch to ATF in their desire to standardize on one lubricant
suitable for both autos and manual trannies, but the experiment failed when
they figured out ATF was not protecting manual transmission gears
sufficiently.

Use a GL-3 or GL-3 gear lube with a suggested viscosity of 75W-90. Gear
lubes like Mobil-1's 75W-90 or 70W-90 are GL-5 which are not recommended for
a manual tranny, they are only suitable for differentials. Any GL-5 should
be avoided as it is harmful over the long-term to the soft yellow metals
like brass used to make gear synchronizers, though damage won't happen in
the short term. Redline's MTL is a good GL-3 gear lube that has a viscosity
of 70W-80, or if you wheel in warmer conditions, Redline's MT-90 has a
slightly higher 75W-90 viscosity.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
N6TAY, PP-ASEL
See the Geezer Jeep at
http://members.cox.net/jerrypb/

<[email protected]> wrote in message
news:[email protected]...
> 1982 Jeep CJ8 -- 6 cylinder, 4 speed
>
> Transmission shifts and works well.
>
> What should I be using as lubricant in the transmission?
>
> The shop manual refer's me to a "Special Lubricant" (which is no
> longer available). And there are references to using automatic
> transmission fluid (ATF).
>
> The Jeep dealer, when asked the question, has given me differing
> answers depending upon who I happen to talk to.
>
> It has most recently had Mobil 1 synthetic gear lube or Mobil 1
> synthetic ATF -- I'm not certain which.
>
> So what should I use:??
> -- gear lube?
> -- ATF?
> -- some other magical lubricant?
>
> (And if the synthetic in there now wasn't the correct choice some
> time ago, what do I need to do -- if anything -- to flush prior to
> getting the proper stuff in there??)
>
> Advice, please -- and thanks as always for the help .....
>
> Mike
> Michael Pomeroy

Jerry,

As always, I appreciate your advice.

I've learned to trust what you say for quite a while.

Although I haven't been specifically looking for it, I don't remember
seeing either Redline or GL-3 gear lube in local auto parts stores.
Do you have any suggestions as to who might carry this?

And, importantly, if I decide to switch now (from the Mobil1 ATF to
GL-3), can I just go ahead and put the gear lube into the transmission
with what remains of the ATF. (As I'm sure you know, the fill/drain
hole is 1/2 way up the tranny case. I siphoned out what I could this
evening but I'm sure it is not completely empty.)

Can I add GL-3, run it for a while (days or weeks or whatever) and
then do several more cycles like this until the ATF has been replaced
by the GL-3??

Mike

On Sat, 27 Mar 2004 18:04:22 -0800, "Jerry Bransford"
<[email protected]> wrote:

>While ATF was in fact the recommended choice for some manual transmissions
>for several years, ATF is no longer recommended by those manufacturers, even
>if it was at one time. It was later discovered that ATF does not have
>sufficient shear-strength to protect the gears, only a true gear lube does.
>Some manuals, like Chilton's, still erroneously recommend ATF because they
>are based on manuals from the era when ATF was still being recommended.
>They tried to switch to ATF in their desire to standardize on one lubricant
>suitable for both autos and manual trannies, but the experiment failed when
>they figured out ATF was not protecting manual transmission gears
>sufficiently.
>
>Use a GL-3 or GL-3 gear lube with a suggested viscosity of 75W-90. Gear
>lubes like Mobil-1's 75W-90 or 70W-90 are GL-5 which are not recommended for
>a manual tranny, they are only suitable for differentials. Any GL-5 should
>be avoided as it is harmful over the long-term to the soft yellow metals
>like brass used to make gear synchronizers, though damage won't happen in
>the short term. Redline's MTL is a good GL-3 gear lube that has a viscosity
>of 70W-80, or if you wheel in warmer conditions, Redline's MT-90 has a
>slightly higher 75W-90 viscosity.
>
>Jerry

Michael Pomeroy

> Although I haven't been specifically looking for it, I don't remember
seeing either Redline or GL-3 gear lube in local auto parts stores. Do you
have any suggestions as to who might carry this?>

It can be hard to find, but good speed shops often have it. You can also
try 4 Wheel Parts, or any of the Desert Rat stores. Last time I was in PHX I
packed in a good supply. BTW, Jerry's on the money, I highly recommend
Redline MTL in AX15s, etc., which are notorious cold gear clashers with
regular manual trans GL4 lube.

I've used mobil 1 in all 4 of my Jeeps 55,74,84, & 85, sence it has
been on the market, never had a problem. It has more shear strength
than any thing else.

Joe

On Sat, 27 Mar 2004 23:11:33 GMT, [email protected] wrote:

>1982 Jeep CJ8 -- 6 cylinder, 4 speed
>
>Transmission shifts and works well.
>
>What should I be using as lubricant in the transmission?
>
>The shop manual refer's me to a "Special Lubricant" (which is no
>longer available). And there are references to using automatic
>transmission fluid (ATF).
>
>The Jeep dealer, when asked the question, has given me differing
>answers depending upon who I happen to talk to.
>
>It has most recently had Mobil 1 synthetic gear lube or Mobil 1
>synthetic ATF -- I'm not certain which.
>
>So what should I use:??
>-- gear lube?
>-- ATF?
>-- some other magical lubricant?
>
>(And if the synthetic in there now wasn't the correct choice some
>time ago, what do I need to do -- if anything -- to flush prior to
>getting the proper stuff in there??)
>
>Advice, please -- and thanks as always for the help .....
>
>Mike
>Michael Pomeroy

You can buy Redline's MTL or MT-90 GL-3 gear lube at www.summitracing.com/
or www.redlineoil.com/ Summit Racing is a bit cheaper.

GL-3 (or any gear lube) is compatible with ATF so no worries about the tiny
amount of residual ATF inside your transmission after you've drained it.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
N6TAY, PP-ASEL
See the Geezer Jeep at
http://members.cox.net/jerrypb/

<[email protected]> wrote in message
news[email protected]...
> Jerry,
>
> As always, I appreciate your advice.
>
> I've learned to trust what you say for quite a while.
>
> Although I haven't been specifically looking for it, I don't remember
> seeing either Redline or GL-3 gear lube in local auto parts stores.
> Do you have any suggestions as to who might carry this?
>
> And, importantly, if I decide to switch now (from the Mobil1 ATF to
> GL-3), can I just go ahead and put the gear lube into the transmission
> with what remains of the ATF. (As I'm sure you know, the fill/drain
> hole is 1/2 way up the tranny case. I siphoned out what I could this
> evening but I'm sure it is not completely empty.)
>
> Can I add GL-3, run it for a while (days or weeks or whatever) and
> then do several more cycles like this until the ATF has been replaced
> by the GL-3??
>
> Mike
>
> On Sat, 27 Mar 2004 18:04:22 -0800, "Jerry Bransford"
> <[email protected]> wrote:
>
> >While ATF was in fact the recommended choice for some manual
transmissions
> >for several years, ATF is no longer recommended by those manufacturers,
even
> >if it was at one time. It was later discovered that ATF does not have
> >sufficient shear-strength to protect the gears, only a true gear lube
does.
> >Some manuals, like Chilton's, still erroneously recommend ATF because
they
> >are based on manuals from the era when ATF was still being recommended.
> >They tried to switch to ATF in their desire to standardize on one
lubricant
> >suitable for both autos and manual trannies, but the experiment failed
when
> >they figured out ATF was not protecting manual transmission gears
> >sufficiently.
> >
> >Use a GL-3 or GL-3 gear lube with a suggested viscosity of 75W-90. Gear
> >lubes like Mobil-1's 75W-90 or 70W-90 are GL-5 which are not recommended
for
> >a manual tranny, they are only suitable for differentials. Any GL-5
should
> >be avoided as it is harmful over the long-term to the soft yellow metals
> >like brass used to make gear synchronizers, though damage won't happen in
> >the short term. Redline's MTL is a good GL-3 gear lube that has a
viscosity
> >of 70W-80, or if you wheel in warmer conditions, Redline's MT-90 has a
> >slightly higher 75W-90 viscosity.
> >
> >Jerry
>
> Michael Pomeroy

"Joseph Myers" <[email protected]> wrote in message
news:[email protected]...
> I've used mobil 1 in all 4 of my Jeeps 55,74,84, & 85, sence it has
> been on the market, never had a problem. It has more shear strength
> than any thing else.

But your synchros would be happier if you didn't use Mobil-1 since Mobil-1
is a GL-5 gear lube and most GL-5 gear lubes, including Mobil-1's, are harsh
on the metals used to make the the synchronizers. A GL-3 or GL-4 is much
better for your synchros and transmission. Mobil-1's gear lube is GL-5
because it's intended for hypoid-cut gears like are used inside
differentials.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
N6TAY, PP-ASEL
See the Geezer Jeep at
http://members.cox.net/jerrypb/

>
> Joe
>
> On Sat, 27 Mar 2004 23:11:33 GMT, [email protected] wrote:
>
> >1982 Jeep CJ8 -- 6 cylinder, 4 speed
> >
> >Transmission shifts and works well.
> >
> >What should I be using as lubricant in the transmission?
> >
> >The shop manual refer's me to a "Special Lubricant" (which is no
> >longer available). And there are references to using automatic
> >transmission fluid (ATF).
> >
> >The Jeep dealer, when asked the question, has given me differing
> >answers depending upon who I happen to talk to.
> >
> >It has most recently had Mobil 1 synthetic gear lube or Mobil 1
> >synthetic ATF -- I'm not certain which.
> >
> >So what should I use:??
> >-- gear lube?
> >-- ATF?
> >-- some other magical lubricant?
> >
> >(And if the synthetic in there now wasn't the correct choice some
> >time ago, what do I need to do -- if anything -- to flush prior to
> >getting the proper stuff in there??)
> >
> >Advice, please -- and thanks as always for the help .....
> >
> >Mike
> >Michael Pomeroy
>

Just one comment, you will not find a 'GL-3' only lube anywhere but at
the dealer for about $17 a quart. They sell it for the AX-15's which
require a GL-3 ONLY lube. That said I have been running Mobil-1 75/90 in
my 98XJ's 5 speed for the last 160,000+ miles. I changed mainly because
the stock oil was just too cold in the winter and it took forever to be
able to shift into second, the mobil solved that problem. A lube that is
listed as GL-2, GL-3, GL-4, GL-5 is not GL-3, the GL-3 spec calls for 0
sulphur content, all the other GL's require sulphur so unles it is some
kind of a smart oil can that recognizes GL-3 trannies and witholds the
sulphur the lable is a deceptive label.
All the Asins I've run across in other cars and trucks require GL-3
also...
I don't think you can really hurt anything buy using Mobil-1, the only
thing that I've run into that did not like it was my 20yo wheel horse
lawn tractor, but boy it sure did clean it out some...

[email protected] wrote in
news[email protected]:

> Jerry,
>
> As always, I appreciate your advice.
>
> I've learned to trust what you say for quite a while.
>
> Although I haven't been specifically looking for it, I don't remember
> seeing either Redline or GL-3 gear lube in local auto parts stores.
> Do you have any suggestions as to who might carry this?
>
> And, importantly, if I decide to switch now (from the Mobil1 ATF to
> GL-3), can I just go ahead and put the gear lube into the transmission
> with what remains of the ATF. (As I'm sure you know, the fill/drain
> hole is 1/2 way up the tranny case. I siphoned out what I could this
> evening but I'm sure it is not completely empty.)
>
> Can I add GL-3, run it for a while (days or weeks or whatever) and
> then do several more cycles like this until the ATF has been replaced
> by the GL-3??
>
> Mike
>
> On Sat, 27 Mar 2004 18:04:22 -0800, "Jerry Bransford"
> <[email protected]> wrote:
>
>>While ATF was in fact the recommended choice for some manual
>>transmissions for several years, ATF is no longer recommended by those
>>manufacturers, even if it was at one time. It was later discovered
>>that ATF does not have sufficient shear-strength to protect the gears,
>>only a true gear lube does. Some manuals, like Chilton's, still
>>erroneously recommend ATF because they are based on manuals from the
>>era when ATF was still being recommended. They tried to switch to ATF
>>in their desire to standardize on one lubricant suitable for both
>>autos and manual trannies, but the experiment failed when they figured
>>out ATF was not protecting manual transmission gears sufficiently.
>>
>>Use a GL-3 or GL-3 gear lube with a suggested viscosity of 75W-90.
>>Gear lubes like Mobil-1's 75W-90 or 70W-90 are GL-5 which are not
>>recommended for a manual tranny, they are only suitable for
>>differentials. Any GL-5 should be avoided as it is harmful over the
>>long-term to the soft yellow metals like brass used to make gear
>>synchronizers, though damage won't happen in the short term.
>>Redline's MTL is a good GL-3 gear lube that has a viscosity of 70W-80,
>>or if you wheel in warmer conditions, Redline's MT-90 has a slightly
>>higher 75W-90 viscosity.
>>
>>Jerry
>
> Michael Pomeroy
>

First look closely at the bottom center of the tranny. You will find
the drain plug there. The fill plug is only for filling unless you
really like the taste of old gear oil.....

Any left isn't an issue then, they are ok to mix a bit, I asked my local
Jeep dealer about it. The commented I could run ATF, but only to do it
in the real cold 'if' I have trouble shifting. I don't so I didn't.

I am in Canada and I couldn't find any regular gear oil without the
'safe for limited slip' moniker on it. This stuff will not work for
long. My syncros went nuts with it.

So I ended up buying a semi-synthetic that didn't mention limited slips.

As Jerry mentioned , some did call for ATF, but by 85 they realized it
didn't work so they went back to calling for gear oil in the 85 and 86
owners manuals.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

[email protected] wrote:
>
> Jerry,
>
> As always, I appreciate your advice.
>
> I've learned to trust what you say for quite a while.
>
> Although I haven't been specifically looking for it, I don't remember
> seeing either Redline or GL-3 gear lube in local auto parts stores.
> Do you have any suggestions as to who might carry this?
>
> And, importantly, if I decide to switch now (from the Mobil1 ATF to
> GL-3), can I just go ahead and put the gear lube into the transmission
> with what remains of the ATF. (As I'm sure you know, the fill/drain
> hole is 1/2 way up the tranny case. I siphoned out what I could this
> evening but I'm sure it is not completely empty.)
>
> Can I add GL-3, run it for a while (days or weeks or whatever) and
> then do several more cycles like this until the ATF has been replaced
> by the GL-3??
>
> Mike
>
> On Sat, 27 Mar 2004 18:04:22 -0800, "Jerry Bransford"
> <[email protected]> wrote:
>
> >While ATF was in fact the recommended choice for some manual transmissions
> >for several years, ATF is no longer recommended by those manufacturers, even
> >if it was at one time. It was later discovered that ATF does not have
> >sufficient shear-strength to protect the gears, only a true gear lube does.
> >Some manuals, like Chilton's, still erroneously recommend ATF because they
> >are based on manuals from the era when ATF was still being recommended.
> >They tried to switch to ATF in their desire to standardize on one lubricant
> >suitable for both autos and manual trannies, but the experiment failed when
> >they figured out ATF was not protecting manual transmission gears
> >sufficiently.
> >
> >Use a GL-3 or GL-3 gear lube with a suggested viscosity of 75W-90. Gear
> >lubes like Mobil-1's 75W-90 or 70W-90 are GL-5 which are not recommended for
> >a manual tranny, they are only suitable for differentials. Any GL-5 should
> >be avoided as it is harmful over the long-term to the soft yellow metals
> >like brass used to make gear synchronizers, though damage won't happen in
> >the short term. Redline's MTL is a good GL-3 gear lube that has a viscosity
> >of 70W-80, or if you wheel in warmer conditions, Redline's MT-90 has a
> >slightly higher 75W-90 viscosity.
> >
> >Jerry
>
> Michael Pomeroy

I use ATF in my T5 because it lets me shift easily when its -30
If I lived down south then I'd use GL-3 also.

JJ
85 CJ7


On Sun, 28 Mar 2004 02:28:36 GMT, [email protected] wrote:

>Jerry,
>
>As always, I appreciate your advice.
>
>I've learned to trust what you say for quite a while.
>
>Although I haven't been specifically looking for it, I don't remember
>seeing either Redline or GL-3 gear lube in local auto parts stores.
>Do you have any suggestions as to who might carry this?
>
>And, importantly, if I decide to switch now (from the Mobil1 ATF to
>GL-3), can I just go ahead and put the gear lube into the transmission
>with what remains of the ATF. (As I'm sure you know, the fill/drain
>hole is 1/2 way up the tranny case. I siphoned out what I could this
>evening but I'm sure it is not completely empty.)
>
>Can I add GL-3, run it for a while (days or weeks or whatever) and
>then do several more cycles like this until the ATF has been replaced
>by the GL-3??
>
>Mike
>
>On Sat, 27 Mar 2004 18:04:22 -0800, "Jerry Bransford"
><[email protected]> wrote:
>
>>While ATF was in fact the recommended choice for some manual transmissions
>>for several years, ATF is no longer recommended by those manufacturers, even
>>if it was at one time. It was later discovered that ATF does not have
>>sufficient shear-strength to protect the gears, only a true gear lube does.
>>Some manuals, like Chilton's, still erroneously recommend ATF because they
>>are based on manuals from the era when ATF was still being recommended.
>>They tried to switch to ATF in their desire to standardize on one lubricant
>>suitable for both autos and manual trannies, but the experiment failed when
>>they figured out ATF was not protecting manual transmission gears
>>sufficiently.
>>
>>Use a GL-3 or GL-3 gear lube with a suggested viscosity of 75W-90. Gear
>>lubes like Mobil-1's 75W-90 or 70W-90 are GL-5 which are not recommended for
>>a manual tranny, they are only suitable for differentials. Any GL-5 should
>>be avoided as it is harmful over the long-term to the soft yellow metals
>>like brass used to make gear synchronizers, though damage won't happen in
>>the short term. Redline's MTL is a good GL-3 gear lube that has a viscosity
>>of 70W-80, or if you wheel in warmer conditions, Redline's MT-90 has a
>>slightly higher 75W-90 viscosity.
>>
>>Jerry
>
>Michael Pomeroy

Learning a lot here. As always. Thanks to all who know so much more
than I.

I live in North Florida where it is certainly warm and where I don't
have _immediate_ access to Redline. So until I can figure all this
out -- new Mobil 1 ATF went back in today. I'm inclinded to think
Mobil 1 ATF is fine; maybe Redline would be better.

Re: the comments below -- here is how Redline addresses the issue GL3
vs everything else issue on its public website http://www.redline.com
(I'm quoting here to make certain I get it accurate.) They seem to
clearly state that their MTL can be properly used in all
transmissions, no??:

" Red Line MTL is classified as a 70W80 gear lubricant satisfying the
API Service requirements of GL-3 and GL-4. MTL also satisfies motor
oil viscosities SAE 5W/10W/30, and the viscosity requirements for
ATFs. MT-90 is a 75W90 GL-4 and also satisfies motor oil viscosities
SAE 10W/15W/40. The additive chemistry used is non-corrosive, so even
though they will provide GL-4 performance, they will not corrode
synchros or bushings. Because of its low corrosivity, Red Line MTL and
MT-90 could also be used in transmissions requiring GL-1 or GL-3
lubricants. Seal compatibility is designed to be similar to
petroleum-based lubricants."

On Sun, 28 Mar 2004 07:25:49 -0600, Rich Pierson <[email protected]> wrote:

>Just one comment, you will not find a 'GL-3' only lube anywhere but at
>the dealer for about $17 a quart. They sell it for the AX-15's which
>require a GL-3 ONLY lube. That said I have been running Mobil-1 75/90 in
>my 98XJ's 5 speed for the last 160,000+ miles. I changed mainly because
>the stock oil was just too cold in the winter and it took forever to be
>able to shift into second, the mobil solved that problem. A lube that is
>listed as GL-2, GL-3, GL-4, GL-5 is not GL-3, the GL-3 spec calls for 0
>sulphur content, all the other GL's require sulphur so unles it is some
>kind of a smart oil can that recognizes GL-3 trannies and witholds the
>sulphur the lable is a deceptive label.
>All the Asins I've run across in other cars and trucks require GL-3
>also...
>I don't think you can really hurt anything buy using Mobil-1, the only
>thing that I've run into that did not like it was my 20yo wheel horse
>lawn tractor, but boy it sure did clean it out some...

>**snip **

Michael Pomeroy