Tranny FLuid
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From: Oregon city, OR
Year: 94
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From: North Carolina
Year: 1999
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Yes. I can find you the link if you really want. This is the personal advice from a guy that's been at Royal Purple for 18 years. It's what I use, and shifting is butter smooth.
Last edited by HCCAFan; Feb 11, 2011 at 09:40 PM.
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Year: 1995
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mines a manual so they dont shift butter smooth brand new lol im gonna have to go wit the other guy on this one
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From: North Carolina
Year: 1999
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https://www.cherokeeforum.com/f2/ax-...1-fluid-70292/
Seasoned Member
Joined: Feb 2009
Posts: 440
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From: Oregon city, OR
Year: 94
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Nov 2010
Posts: 1,275
Likes: 2
From: North Carolina
Year: 1999
Model: Cherokee
Engine: Gas
Josh,
If you had a NV3550 manual transmission – I would highly recommend the RP Synchromax fluid. This is a fully synthetic fluid having the viscosity of an atf the oil film strength of a gear oil. It is a recommended replacement for any manual transmission that specs an atf or the GM Synchromesh (or equivalent) fluid.
Since you have the AX15, this transmission used to specify a GL5 80W90 or 75W90 up to year 1995/6 I believe.
In 1997, Chrysler / Jeep changed the recommendation from a GL5 to a GL3 to avoid the issues of lower quality EP gear oil additives causing poor shifting as the phosphorus component potentially plates out on the bronze synchronizers of the transmission. An API GL-5 gear oil contains a full EP (extreme pressure) additive package typically of a sulfur / phosphorus composition. An API GL-4 also contains EP additives but in conventional mineral fluids – usually only contains 50% of a GL5 to reduce any negative effects of the additives to soft metals if the oils are run past their useful life interval or at too high a temperature. An API GL3 contains no EP additives – hence the difference. See the attached API GL listings.
An gear oil SAE 75W90 fluid in viscosity is virtually the same in fluid thickness as a crankshaft SAE 10W40. See the attached comparative viscosity grade chart.
So for you application, in an AX-15 that is not damaged, the correct fluid is an SAE 10W40 Motor Oil such as the RP SAE 10W40 part # 01140.
If – however, the synchro’s have been damaged, or you live in a very cold ambient conditions you might benefit from using the RP 10W30 or RP 5W30 Motor Oils.
Cheers,
David
If you had a NV3550 manual transmission – I would highly recommend the RP Synchromax fluid. This is a fully synthetic fluid having the viscosity of an atf the oil film strength of a gear oil. It is a recommended replacement for any manual transmission that specs an atf or the GM Synchromesh (or equivalent) fluid.
Since you have the AX15, this transmission used to specify a GL5 80W90 or 75W90 up to year 1995/6 I believe.
In 1997, Chrysler / Jeep changed the recommendation from a GL5 to a GL3 to avoid the issues of lower quality EP gear oil additives causing poor shifting as the phosphorus component potentially plates out on the bronze synchronizers of the transmission. An API GL-5 gear oil contains a full EP (extreme pressure) additive package typically of a sulfur / phosphorus composition. An API GL-4 also contains EP additives but in conventional mineral fluids – usually only contains 50% of a GL5 to reduce any negative effects of the additives to soft metals if the oils are run past their useful life interval or at too high a temperature. An API GL3 contains no EP additives – hence the difference. See the attached API GL listings.
An gear oil SAE 75W90 fluid in viscosity is virtually the same in fluid thickness as a crankshaft SAE 10W40. See the attached comparative viscosity grade chart.
So for you application, in an AX-15 that is not damaged, the correct fluid is an SAE 10W40 Motor Oil such as the RP SAE 10W40 part # 01140.
If – however, the synchro’s have been damaged, or you live in a very cold ambient conditions you might benefit from using the RP 10W30 or RP 5W30 Motor Oils.
Cheers,
David
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