Older car but low mileage. Change or not?
- Thread starter Martin10
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Old is relative! My old Jeep is 57 years old. What kind of vehicle and mileage?
If the fluid looks OK, I would leave it alone if the level is OK.
It is 17 years old but the fluid looks like new. I dont mean to be cheap but if its a waste of money I won't replace it. I dont know if GL5 gear oil degrades with time like motor oil does. The oil has always been changes along with the brake fluid and the coolant. The car is a Miata. Thanks.
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Fluid is inexpensive, change it.
Originally Posted By: Gebo
Originally Posted By: Mr Nice
Fluid is inexpensive, change it.
+1
+2.
Originally Posted By: Mr Nice
Fluid is inexpensive, change it.
+1
+2.
I would change it now, then u would probably not have to change it ever again
Here is my take on your 1999 Miata. At 15000 miles, it is good practice to change transmission and differential gear oil to remove most of the break-in wear particles. I would not worry about gear oil deteriorating as much as being contaminated by both internal wear debris and external water and dust through the shaft seals and breather. As mentioned above, if you change the fluids now, you should not have to change it ever again. You obviously value the car and its worth it to do preventive maintenance.
15,000 miles and 17 years is nothing for manual transmission and dif oils. There are trucks running older oils than that in daily regular intermittent service ...
Yeah, sure I change my tranny fluid at regular intervals - 50,000 miles regular. Time is pretty irrelevant to these oils as the system is mostly sealed. Yes, there is a small breather cap, but it's like a 1/4" hole. They do get warm, but not really hot, so thermal breakdown is very slow unless you like to hit 100 mph in Death Valley regularly at noon ...
Gear oils are very stable. Some cars and trucks will die with the original oil in teh transmission and differential. You are not hurting a thing by putting this off until it gets to say 25,000 miles
Yeah, sure I change my tranny fluid at regular intervals - 50,000 miles regular. Time is pretty irrelevant to these oils as the system is mostly sealed. Yes, there is a small breather cap, but it's like a 1/4" hole. They do get warm, but not really hot, so thermal breakdown is very slow unless you like to hit 100 mph in Death Valley regularly at noon ...
Gear oils are very stable. Some cars and trucks will die with the original oil in teh transmission and differential. You are not hurting a thing by putting this off until it gets to say 25,000 miles
Is GL5 the spec? IIRC there's an...um...school of thought that manual transmissions in general should have GL4.
Again, IIRC, usually someone will tell you to get Redline MTO stuff because its the mutts nuts.
Surprised it hasn't happened already.
Again, IIRC, usually someone will tell you to get Redline MTO stuff because its the mutts nuts.
Surprised it hasn't happened already.
Thanks for all the replies. I am going to change it for the reasons you guys listed. Ducked, the manual calls for GL5 in the transmission but I will use GL4. Guys on the Miata forums say the best transmission lube is Motorcraft Synthetic Manual Transmission Fluid. But that stuff is $25 quart. The car shifts fine with the factory fill so will just go with a synthetic GL4 and call it good.
Originally Posted By: BrocLuno
15,000 miles and 17 years is nothing for manual transmission and dif oils. There are trucks running older oils than that in daily regular intermittent service ...
Yeah, sure I change my tranny fluid at regular intervals - 50,000 miles regular. Time is pretty irrelevant to these oils as the system is mostly sealed. Yes, there is a small breather cap, but it's like a 1/4" hole. They do get warm, but not really hot, so thermal breakdown is very slow unless you like to hit 100 mph in Death Valley regularly at noon ...
Gear oils are very stable. Some cars and trucks will die with the original oil in teh transmission and differential. You are not hurting a thing by putting this off until it gets to say 25,000 miles
When I was a kid, a long time ago, I worked at a car dealership as their oil change guy. In those days no one ever requested manual transmission or differential fluid changes. Just didn't happen. I asked our best mechanic about it and he said there was no reason to do it. I realize now that was probably not good advice, but we opened up plenty of transmissions and diffs. for something broken. But you did not see many worn out gears even with high mileage and original fluid. Guess that early experience colored my thinking about it.
15,000 miles and 17 years is nothing for manual transmission and dif oils. There are trucks running older oils than that in daily regular intermittent service ...
Yeah, sure I change my tranny fluid at regular intervals - 50,000 miles regular. Time is pretty irrelevant to these oils as the system is mostly sealed. Yes, there is a small breather cap, but it's like a 1/4" hole. They do get warm, but not really hot, so thermal breakdown is very slow unless you like to hit 100 mph in Death Valley regularly at noon ...
Gear oils are very stable. Some cars and trucks will die with the original oil in teh transmission and differential. You are not hurting a thing by putting this off until it gets to say 25,000 miles
When I was a kid, a long time ago, I worked at a car dealership as their oil change guy. In those days no one ever requested manual transmission or differential fluid changes. Just didn't happen. I asked our best mechanic about it and he said there was no reason to do it. I realize now that was probably not good advice, but we opened up plenty of transmissions and diffs. for something broken. But you did not see many worn out gears even with high mileage and original fluid. Guess that early experience colored my thinking about it.
It's fine - save your money. 15k miles and kept in a garage? - jeez - it's not even broken in yet. No, gear oil doesn't go bad just sitting. You'll be spending money to fix something that's not broken - kneeling to the almighty god of routine maintenance. Watch TV and have a beer.
Also, being a Mazda guy, a lot of people recommend using a GL4 fluid in older transmissions such as Redline MT90. It seems to be better on yellow parts in the transmission such as the synchros.
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