Adding moly in the tranny
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MolaKule
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I am not too familiar with the Patrol tranny but assume it is a manual (stickshift) transmission.
Secondly, you didn't state what type of moly you were considering.
Moly is one FM you don't want in a manual tranny OR automatic.
AS to the XW140, it might be too thick.
I would stick with a GL4/5 rated 75W90 assuming that is what is specified.
Secondly, you didn't state what type of moly you were considering.
Moly is one FM you don't want in a manual tranny OR automatic.
AS to the XW140, it might be too thick.
I would stick with a GL4/5 rated 75W90 assuming that is what is specified.
Thanks for the reply MolaKule,
The additive in question is Mr. Moly Gear treatment and the Nissan Patrol has a antiquated 3 speed manual with 2 and 3rd gear synchs.
The regular 80W-90 oil thins out rapidly under hard driving specially in the summers and most vehicles including some SUVs made in India are getting the 80W-140 oil as OEM fill.
The additive in question is Mr. Moly Gear treatment and the Nissan Patrol has a antiquated 3 speed manual with 2 and 3rd gear synchs.
The regular 80W-90 oil thins out rapidly under hard driving specially in the summers and most vehicles including some SUVs made in India are getting the 80W-140 oil as OEM fill.
I remember your first post about this truck.
Exactly what is breaking in the trans? Is it bearings, gears? Why do you think a thicker oil will prevent future problems?
Exactly what is breaking in the trans? Is it bearings, gears? Why do you think a thicker oil will prevent future problems?
Chris,
Luckily this tranny has lasted over 50,000Km which is way better than the previous average of 10,000Km. The main shaft would virtualy grind itself to death, the other components remained within tolerances. Regular GL-4 based SAE 90 oil would thin out within 5000-6000Km and then you could start smelling it as it would vapors would escape from the breather. Using a SAE 140 oil solved this problem to an extent that I dont have tranny failiures anymore but still have to change the oil frequently. Also using a thicker oil means very slow shifts with double de-clutching a must and the pain of switching back to SAE 90 oil in the 0c winters here.
One of the reasons I wanted to use moly as well as multi grade 80W-140 oil. The only fear is that Moly has disulphide which could lead to premature wearing out of the brass sync rings although even the EP oils I am using contain sulphur.
Luckily this tranny has lasted over 50,000Km which is way better than the previous average of 10,000Km. The main shaft would virtualy grind itself to death, the other components remained within tolerances. Regular GL-4 based SAE 90 oil would thin out within 5000-6000Km and then you could start smelling it as it would vapors would escape from the breather. Using a SAE 140 oil solved this problem to an extent that I dont have tranny failiures anymore but still have to change the oil frequently. Also using a thicker oil means very slow shifts with double de-clutching a must and the pain of switching back to SAE 90 oil in the 0c winters here.
One of the reasons I wanted to use moly as well as multi grade 80W-140 oil. The only fear is that Moly has disulphide which could lead to premature wearing out of the brass sync rings although even the EP oils I am using contain sulphur.
MolaKule
Staff member
Do you mean the mainshaft and/or mainshaft bearings are destroying themselves? Is the mainshaft bearing of brass/bronze or are they roller/ball bearing-type.
Is the clutch in alignment, as in centered concentrically to the input (mainshaft)? If not, you are going to get some additional radial thrust than designed for (loads perpendicular to the centerline of the mainshaft), and the mainshaft will fail quicker.
If your vehicle never sees much cold weather, try an HDEO motor oil (preferably synthetic) of 15W40 or 5W50 or something similar. In other words, try an HDEO oil that is 40 weight and above, before you go to a 75W140. Maybe even a 20W40 or 20W50 if they have it over there.
[ June 25, 2004, 05:03 PM: Message edited by: MolaKule ]
Is the clutch in alignment, as in centered concentrically to the input (mainshaft)? If not, you are going to get some additional radial thrust than designed for (loads perpendicular to the centerline of the mainshaft), and the mainshaft will fail quicker.
If your vehicle never sees much cold weather, try an HDEO motor oil (preferably synthetic) of 15W40 or 5W50 or something similar. In other words, try an HDEO oil that is 40 weight and above, before you go to a 75W140. Maybe even a 20W40 or 20W50 if they have it over there.
[ June 25, 2004, 05:03 PM: Message edited by: MolaKule ]
Let me get this straight,
If I were to put a regular engine oil in a gear box already under severe strain, dont I risk the shearing of gears and other components?
One of the reasons I am keen to put Moly in the transmission is due ot its extremely high sheer strength. The only better option would be to put Mobil-I synthetic gear oil but that is not available here. The Castrol ST 80W-90 I use currently also contains moly but in a limited quantity.
I have had the clutch alignment checked thoroughly. The main shaft gears wear themselves out. The bearings are roller type and the syncs are brass.
If I were to put a regular engine oil in a gear box already under severe strain, dont I risk the shearing of gears and other components?
One of the reasons I am keen to put Moly in the transmission is due ot its extremely high sheer strength. The only better option would be to put Mobil-I synthetic gear oil but that is not available here. The Castrol ST 80W-90 I use currently also contains moly but in a limited quantity.
I have had the clutch alignment checked thoroughly. The main shaft gears wear themselves out. The bearings are roller type and the syncs are brass.
MolaKule
Staff member
OOOKAY!
I went to the Mr. Moly site and nothing in the lit for Gear Aide said it was safe for brass synchronizers nor did it have the correct friction modifiers for stick transmissions. Gear Aide has a viscosity of about 9 cSt (ISO 68 by my charts) which is equivalent to a SAE 20 weight motor oil.
Your problem (theorizing from afar) sounds as if the spur gears in the transmission weren't heat treated to a sufficient hardness (faulty metallurgical design), or weren't designed with a large enough diameter or width to take the full engine torque/abuse.
Once the spur gear teeth become worn or a few teeth become broken, vibration sets up and wears the mainshaft and bearings.
A 20W50 HDEO motor oil has the same viscosity range (approx. 20 cSt) as an 80W to high 90W gear oil, bordering on the SAE 140 gear weight. In addition, an HDEO diesel 20W50 engine oil has approx. the same level of EP and AW adds as do a 80W140 gear oil, with the exception of less sulfur. Most gears oils of 80140 have a viscosity of approx. 26-27 cSt and contain a lot of sulfur.
An alternative is to find an All fleet HDEO 50 or 20W50 weight (preferably) engine oil and mix it about 50/50 with the 80W140 gear lube in order to increase film thincknees between gear teeth.
My problem with running a straight 80W140 is the hard shifting associated with the straight 80W140 gear lube is that you might ruin the cones and blocking rings. The HDEO oil's calcium and magnesium can serve as friction modifiers for the sychro's.
But I still don't recommend 0.5 um suspended MoS2 in a manual tranny.
[ June 26, 2004, 01:09 PM: Message edited by: MolaKule ]
I went to the Mr. Moly site and nothing in the lit for Gear Aide said it was safe for brass synchronizers nor did it have the correct friction modifiers for stick transmissions. Gear Aide has a viscosity of about 9 cSt (ISO 68 by my charts) which is equivalent to a SAE 20 weight motor oil.
Your problem (theorizing from afar) sounds as if the spur gears in the transmission weren't heat treated to a sufficient hardness (faulty metallurgical design), or weren't designed with a large enough diameter or width to take the full engine torque/abuse.
Once the spur gear teeth become worn or a few teeth become broken, vibration sets up and wears the mainshaft and bearings.
A 20W50 HDEO motor oil has the same viscosity range (approx. 20 cSt) as an 80W to high 90W gear oil, bordering on the SAE 140 gear weight. In addition, an HDEO diesel 20W50 engine oil has approx. the same level of EP and AW adds as do a 80W140 gear oil, with the exception of less sulfur. Most gears oils of 80140 have a viscosity of approx. 26-27 cSt and contain a lot of sulfur.
An alternative is to find an All fleet HDEO 50 or 20W50 weight (preferably) engine oil and mix it about 50/50 with the 80W140 gear lube in order to increase film thincknees between gear teeth.
My problem with running a straight 80W140 is the hard shifting associated with the straight 80W140 gear lube is that you might ruin the cones and blocking rings. The HDEO oil's calcium and magnesium can serve as friction modifiers for the sychro's.
But I still don't recommend 0.5 um suspended MoS2 in a manual tranny.
[ June 26, 2004, 01:09 PM: Message edited by: MolaKule ]
Molakule,
Very good advice and observation, the diameter issue is where you have got it right. The main shaft had to get a modified thicker spline to match with the Hino engine's flywheel, the earlier Nissan gasoline engine had thinner spline, apart from that no other mods were done to any other components in the gear box.
I wont use the gear treatment as per your advice which is appreciate very much and thank you for that.
All the HDEO oils here are standard 15W-40 weights and that includeds Delo 400 and Delvac MX, I can get Mobil-I Super Synth at 15W-50, would that be good enough.
Very good advice and observation, the diameter issue is where you have got it right. The main shaft had to get a modified thicker spline to match with the Hino engine's flywheel, the earlier Nissan gasoline engine had thinner spline, apart from that no other mods were done to any other components in the gear box.
I wont use the gear treatment as per your advice which is appreciate very much and thank you for that.
All the HDEO oils here are standard 15W-40 weights and that includeds Delo 400 and Delvac MX, I can get Mobil-I Super Synth at 15W-50, would that be good enough.
MolaKule
Staff member
If you can obtain the Mobil 1 15W50, that would be even better, IMO.
MolaKule
Staff member
Because the MoS2 powdered moly will coat-up the synchro surfaces and embed itself in sintered metal parts. You do not want that to happen.
The MoDTC moly is what is used in egine oils and is completly oil soluble. While MoDTC is a friction modifier, it is not the kind of friction modifier you want in a car or light truck tranny.
There are other friction modifiers designed specifically for and work better better in manual transmissions.
The MoDTC moly is what is used in egine oils and is completly oil soluble. While MoDTC is a friction modifier, it is not the kind of friction modifier you want in a car or light truck tranny.
There are other friction modifiers designed specifically for and work better better in manual transmissions.
What are these friction modifiers you're speaking about Molakule?
MolaKule
Staff member
The new organic friction modifiers.
(This thread exemplifies what is or can be the best about the Web!)
((Except that MolaKule actually resides in a Himalayan mountain cave)).
((Except that MolaKule actually resides in a Himalayan mountain cave)).
MolaKule
Staff member
Any name/brands? What is this stuff? I thought Moly is also used in an organic compound so in this form it should work no?
MolaKule
Staff member
Recall there are two major types of moly additives, the powdered MoS2 which in a suspension in gear oil, and the soluble MoDTC, an organo-metallic compound.
As far as I know, the non-metallic organic friction modifiers are not available to the general public. You need professional tribo-chemical training to determine proper treatment rates for any lubricant additive.
I know for sure Schaeffer's #132 has them and some proprietary fluids I have developed.
As far as I know, the non-metallic organic friction modifiers are not available to the general public. You need professional tribo-chemical training to determine proper treatment rates for any lubricant additive.
I know for sure Schaeffer's #132 has them and some proprietary fluids I have developed.
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