Lower Viscosity Oil in Gearbox - Pros and cons?

tsk1979 · 21st April 2011, 15:01

MY Safari has the problem of hard shifts when engine is cold. ITs more pronounced in winters, and this problem has been there forever.
I was wondering whether shifting to a thinner oil, like Power steering oil will solve this problem.
Moreover, I am worried about potential issues.
For example, gearbox oil has 130 degrees boil resistance, definitely power steering oil may lose lubrication properties much early.

Then there is the issue of synchronizers too. Will a thinner oil have higher wear rate?

I can also try and follow a middle path route.
For example current gearbox oil is 75W90. I can probably try a 75W85 which is slightly thinner, but not in Power steering oil territory.

Engine and Gearbox experts, please help!

sgiitk · 21st April 2011, 15:29

@tsk1979; You can try a thinner oil, but make sure it is EP even if the current requirement is not. EP will cover a lot of sins, esp. shearing of the oil film.

AVR · 21st April 2011, 15:42

I was recommended to move to a thinner oil during the winters (like power steering TQ oil) and change back to regular for summers as I faced the same issue as you mention.

Didn't feel comfortable with the idea and then someone recommended a Gear additive that I can't recall right now but it worked awesome. This winter I could change gears quite comfortably thanks to that. Will check about the brand and let you know.

Cheers,
Adi

sgiitk · 21st April 2011, 15:55

One additive which a lot of people in the UK swear by is something containing Molybdenum (Liquid Moly or something). All sorts of miracles are claimed for it.

Deeps · 21st April 2011, 15:58

@TSK: I used to have the same problem with my indica Xeta. Gear shifts used to be hard during winter and 1st to 2nd and 3rd to 4th shifts offered a lot of resistance. I used to replace transmission fluid at 20K as recommended but the problem never went away during the 4 years I had it. So what i am saying is that it may just be a TATA trait. therefore, if you can then live with it rather than experimenting with the already fragile white elephant.

vikram_d · 21st April 2011, 16:09

Please rename the thread to "Lower Viscosity Oil in Gearbox: Pros & Cons". When I looked at it I thought you were talking about paint thinner. Call me crazy but that is how it looked to me and I found myself asking "what happened to Tanveer?"...lol..

tsk1979 · 21st April 2011, 16:11

thanks Vikram, I have made the change!

that said, I think I will experiment with a gearbox oil additive rather than looking for a lower viscosity oil.

Sutripta · 23rd April 2011, 19:38

Quote:

Originally Posted by sgiitk

@tsk1979; You can try a thinner oil, but make sure it is EP even if the current requirement is not. EP will cover a lot of sins, esp. shearing of the oil film.

Hi,
AFAIK, EP is specifically not recommended for gearboxes. Only for hypoids. At least that was the case till a few years back.

Maybe basic lube chemistry has changed recently.

Regards
Sutripta

Mpower · 23rd April 2011, 20:44

Tsk, another option you can try is synthetic gear oil.

BTW, the recommended oil for my manual transmission is ATF (auto trans fluid). I switched to synthetic ATF and it helped a little

Sutripta · 23rd April 2011, 20:54

Quote:

Originally Posted by Mpower

Tsk, another option you can try is synthetic gear oil.

BTW, the recommended oil for my manual transmission is ATF (auto trans fluid). I switched to synthetic ATF and it helped a little

Hi,
ATF used to come in different types (GM and Ford, and later on, even Chrysler's was also different) and absolutely not interchangeable. Has that changed now? And if it has not, which one is recommended for MTs?

Regards
Sutripta

BuRnT RuBbEr · 23rd April 2011, 21:00

Quote:

Originally Posted by sgiitk

One additive which a lot of people in the UK swear by is something containing Molybdenum (Liquid Moly or something). All sorts of miracles are claimed for it.

there seems to be some logic there. my car's manual has this entry in the "lubricants and greases for transmission" section:

molybednum disulphide,lithium-soap based grease, water-resistant N.L.G.I. consistency =2 : MRM 2 : CV joints.

Tutela MRM2

Molybdenum disulfide - Wikipedia, the free encyclopedia

SPIKE ARRESTOR · 23rd April 2011, 21:43

Quote:

Originally Posted by Sutripta

Hi,
AFAIK, EP is specifically not recommended for gearboxes. Only for hypoids. At least that was the case till a few years back.

Yes! EP- Extreme pressure is preferred for Hypoids due to the tremendous heat generated due to localized tooth pressures, is this applicable to GB also? How does this EP oil affect the Synchros then?

Quote:

Maybe basic lube chemistry has changed recently.

Dada, good one!

Spike

Sutripta · 23rd April 2011, 22:15

Quote:

Originally Posted by SPIKE ARRESTOR

Dada, good one!

Hi,
No, actually I don't know. Recently, esp. due to environmental reasons, lot of changes in fuels and lubes. Haven't kept abreast.

What do you think of Moly, (or colloidal graphite) added to lubes?

Regards
Sutripta

SPIKE ARRESTOR · 23rd April 2011, 22:31

Quote:

Originally Posted by Sutripta

What do you think of Moly, (or colloidal graphite) added to lubes?

Have heard of these (Moss) base being used in various applications, what constituents were leading to environmental pollution?

Spike

Sutripta · 23rd April 2011, 22:45

^^^
Hi,
Moly was w.r.t. effectiveness/ cost effectiveness, not environmental issues. I mean adding a (very costly) solid lubricant to a liquid.

Regards
Sutripta

21st April 2011, 15:01	#1
tsk1979 Team-BHP Support Join Date: Feb 2005 Location: San Jose, CA Posts: 23,717 Thanked: 22,825 Times View My Garage	Lower Viscosity Oil in Gearbox - Pros and cons? MY Safari has the problem of hard shifts when engine is cold. ITs more pronounced in winters, and this problem has been there forever. I was wondering whether shifting to a thinner oil, like Power steering oil will solve this problem. Moreover, I am worried about potential issues. For example, gearbox oil has 130 degrees boil resistance, definitely power steering oil may lose lubrication properties much early. Then there is the issue of synchronizers too. Will a thinner oil have higher wear rate? I can also try and follow a middle path route. For example current gearbox oil is 75W90. I can probably try a 75W85 which is slightly thinner, but not in Power steering oil territory. Engine and Gearbox experts, please help!
	() Thanks

21st April 2011, 15:29	#2
sgiitk BANNED Join Date: Dec 2007 Location: Gurugram Posts: 7,969 Thanked: 4,788 Times	re: Lower Viscosity Oil in Gearbox - Pros and cons? @tsk1979; You can try a thinner oil, but make sure it is EP even if the current requirement is not. EP will cover a lot of sins, esp. shearing of the oil film.
	(1) Thanks

21st April 2011, 15:42	#3
AVR BHPian Join Date: Apr 2008 Location: Ahmedabad Posts: 978 Thanked: 847 Times View My Garage	re: Lower Viscosity Oil in Gearbox - Pros and cons? I was recommended to move to a thinner oil during the winters (like power steering TQ oil) and change back to regular for summers as I faced the same issue as you mention. Didn't feel comfortable with the idea and then someone recommended a Gear additive that I can't recall right now but it worked awesome. This winter I could change gears quite comfortably thanks to that. Will check about the brand and let you know. Cheers, Adi
	() Thanks

21st April 2011, 15:55	#4
sgiitk BANNED Join Date: Dec 2007 Location: Gurugram Posts: 7,969 Thanked: 4,788 Times	re: Lower Viscosity Oil in Gearbox - Pros and cons? One additive which a lot of people in the UK swear by is something containing Molybdenum (Liquid Moly or something). All sorts of miracles are claimed for it.
	(1) Thanks

21st April 2011, 15:58	#5
Deeps Senior - BHPian Join Date: May 2004 Location: Delhi/Noida Posts: 1,116 Thanked: 170 Times	re: Lower Viscosity Oil in Gearbox - Pros and cons? @TSK: I used to have the same problem with my indica Xeta. Gear shifts used to be hard during winter and 1st to 2nd and 3rd to 4th shifts offered a lot of resistance. I used to replace transmission fluid at 20K as recommended but the problem never went away during the 4 years I had it. So what i am saying is that it may just be a TATA trait. therefore, if you can then live with it rather than experimenting with the already fragile white elephant.
	() Thanks

21st April 2011, 16:09	#6
vikram_d Senior - BHPian Join Date: Jul 2006 Location: Bangalore Posts: 2,427 Thanked: 1,185 Times	re: Lower Viscosity Oil in Gearbox - Pros and cons? Please rename the thread to "Lower Viscosity Oil in Gearbox: Pros & Cons". When I looked at it I thought you were talking about paint thinner. Call me crazy but that is how it looked to me and I found myself asking "what happened to Tanveer?"...lol..
	() Thanks

21st April 2011, 16:11	#7
tsk1979 Team-BHP Support Join Date: Feb 2005 Location: San Jose, CA Posts: 23,717 Thanked: 22,825 Times View My Garage	Re: Lower Viscosity Oil in Gearbox - Pros and cons? thanks Vikram, I have made the change! that said, I think I will experiment with a gearbox oil additive rather than looking for a lower viscosity oil.
	() Thanks

23rd April 2011, 20:44	#9
Mpower Senior - BHPian Join Date: Mar 2005 Location: Bangalore Posts: 10,409 Thanked: 1,730 Times View My Garage	Re: Lower Viscosity Oil in Gearbox - Pros and cons? Tsk, another option you can try is synthetic gear oil. BTW, the recommended oil for my manual transmission is ATF (auto trans fluid). I switched to synthetic ATF and it helped a little
	() Thanks

23rd April 2011, 22:45	#15
Sutripta Senior - BHPian Join Date: Jul 2009 Location: Calcutta Posts: 4,668 Thanked: 6,217 Times	Re: Lower Viscosity Oil in Gearbox - Pros and cons? ^^^ Hi, Moly was w.r.t. effectiveness/ cost effectiveness, not environmental issues. I mean adding a (very costly) solid lubricant to a liquid. Regards Sutripta
	() Thanks