Should Manual Transmission Oil Be Changed?

[georgeb]

Why don't you pour a half-quart or so of NEW oil through the trans to get any remaining grit.

[JohnGunn]

I worked at a Ford transmission plant for 30 years. Every auto trans got a donut shaped ceramic magnet in the pan. The engineers said the fluid should last forever [no drain plug] but some will evaporate and will need to be replaced. The filter is oversized and will not encounter that much contamination. Trans fluid doesn't face products of combustion like motor oil does.

http://www.freerepublic.com/focus/f-chat/2713202/posts

Thanks for this very interesting information. Nothing better than firsthand information from someone who knows.

My quarrel is not with the way Ford dealt with the automatic transmission of these cars. At least they have a filter and, as you informed us, a ceramic magnet. With that it becomes a closed system that can be thought of as self sustaining. The same cannot be said of the manual version without a filter.

You could question whether the additive package in the original atomatic ATF fill will eventually weaken and fail altogether given enough time. But that is, in my eyes, a much lower order problem.

[nitrofarm]

I worked at a Ford transmission plant for 30 years. Every auto trans got a donut shaped ceramic magnet in the pan. The engineers said the fluid should last forever [no drain plug] but some will evaporate and will need to be replaced. The filter is oversized and will not encounter that much contamination. Trans fluid doesn't face products of combustion like motor oil does.

http://www.freerepublic.com/focus/f-chat/2713202/posts

Chewing gum last forever also. Bet ya they spit theirs out after the day was over though. :eeeeeek:

[Damkid]

I think I read about this somewhere. Is it also true of the Festiva/Aspire transmissions?

I am 95% sure the festiva/aspire manual tranny's have a magnet in them to catch the shavings

[nitrofarm]

Thanks for this comment, georgeb. I've decided to work at getting the transmission cleaned out by changing fluid about once a week and at that time pouring the removed oil back through the transmission several times, after, each time, running it over a strong magnet and decanting to leave any sediment in the drain pan.

I dont know if this will be our thread pitch.But you get the idea...

http://www.aptuned.com/BWAC-0227

[georgeb]

The reason there is no filter in a manual trans is because there is no pump. The teeth on the gears bring the oil to the top.

[Fordverde]

I remmeber that Porsche had oil pumps pour the oil on top of the gear on their racing cars from the 70s, 80s, mmmmm maybe if plug a nipple in the draining plug, conect a hose to a filter then pass it to a high volumen pump(maybe driven by a belt instead of the AC compresor) drill a hole on top of the box housing so the oil gets on the gears nice and clean.mmmmm
and maybe adding an oil cooler as well..... how much that will be????
I think the hardest thing will be the pump......

[JohnGunn]

Why don't you pour a half-quart or so of NEW oil through the trans to get any remaining grit.

I want to keep pouring fluid through the unit until it comes out grit free. I don't know how much fluid that might take and fear it could get to be pretty expensive if I were to limit myself to using only fresh ATF in the rinsing process.

I view this as an experiment which can be modified as the situation permits. Maybe it will only take a half-quart or less to come clean. In that case, using fresh fluid to rinse becomes more possible.

I plan to clean the drain pan before each use so that no new grit will be introduced during the process.

[blkfordsedan]

Even though the repair manuals all call for ATF, I'm 99% sure the original factory fill was actually gear oil. ATF does work, but does not really have the best characteristics to properly perform & provide the best gear protection. Do not use a GL-5 gear oil with extreme pressure additives. They are designed for rear differentials and the EP additives wil corrode the soft metal synchros. My suggestion would be to use a specific, high quality MTX lube like Synchromesh or Redline MTL.
Below is a link that has some good data.

http://www.redlineoil.com/content/files/tech/MTL%20and%20MT-90%20Tech%20Info.pdf

[Clay]

I found some possibly relevant threads.

http://www.fordfestiva.com/forums/showthread.php?t=25495&highlight=transmission+oil%2A

http://www.fordfestiva.com/forums/showthread.php?t=5&highlight=transmission+oil%2A

My Honda CR250R drit bike calls for 10-40 oil for the transmission. (2 stroke so no engine lube needed). It is a wet clutch so I usually just change the oil frequently, especially since I use cheep clutches and slip them a lot. I am not sure what percentage, but the newer four stroke motorcycles, both street and dirt use both 1 and 2 circuit systems depending on brand and or model.

[JohnGunn]

Even though the repair manuals all call for ATF, I'm 99% sure the original factory fill was actually gear oil. ATF does work, but does not really have the best characteristics to properly perform & provide the best gear protection. Do not use a GL-5 gear oil with extreme pressure additives. They are designed for rear differentials and the EP additives wil corrode the soft metal synchros. My suggestion would be to use a specific, high quality MTX lube like Synchromesh or Redline MTL.
Below is a link that has some good data.

http://www.redlineoil.com/content/fi...ech%20Info.pdf

WOW!!! Brian, I believe your post here to be one of the most important and helpful I have ever seen. For your revelation about the actual contents of the factory fill and your recommendations, but most of all for the link to the Red Line White Paper. I've only read it once, and some of it I don't understand because it refers to internal transmission components which I can not visualize, since I have never actually looked at a disassembled transmission. But I did understand enough to discover that there are smart, knowledgeable people who are just as concerned about the performance of my shifting as I am - not worried about CAFE standards or how much additional money they can make by an endless collection of cost-cutting compromises. Already, I've decided I want to do business with them.

I will surely read it several more times and probably have lots to say afterwards, but right now I've got to get on my bike and ride the 24 miles to Harbor Freight and back to get the magnets I plan on using in cleaning out my transmission. I'm prepared to allow that cleaning process to run its course, which may take weeks. And, when it's done, I'll have to give much thought to what I'll put into my freshly cleaned gear box. But, as I'm sure your can tell, this is important enough to me for me to spend whatever it takes to find the best, even if it comes to trying several expensive options before choosing the one I stick with.

From the Red Line White Paper:

In transmissions which recommend Dexron or Mercon fluids we recommend our D4 ATF which is very similar to the MTL, being a GL-4 Gear Oil also. The D4 ATF will provide better low-temperature shiftability, and the MTL would provide better wear protection for racing use.

This statement suggests I might have to add their D4 ATF to the list of fluids to consider. Maybe try them both before deciding which to live with.

There is important information in the Red Line Manual Trans Lube Product Data Sheet that should be useful to anyone making this decision.

Thanks again. Later.

[JohnGunn]

I found some possibly relevant threads.

http://www.fordfestiva.com/forums/showthread.php?t=25495&highlight=transmission+oil%2A

http://www.fordfestiva.com/forums/showthread.php?t=5&highlight=transmission+oil%2A

My Honda CR250R drit bike calls for 10-40 oil for the transmission. (2 stroke so no engine lube needed). It is a wet clutch so I usually just change the oil frequently, especially since I use cheep clutches and slip them a lot. I am not sure what percentage, but the newer four stroke motorcycles, both street and dirt use both 1 and 2 circuit systems depending on brand and or model.

Thanks, Clay. You're right, these are extremely helpful threads.

[blkfordsedan]

Personally, John, I would run the MTL fluid. My thought is that the original factory fluid was actually gear oil and not ATF. My Festy had ~30K miles when I bought it and I'm 99.9% sure the fluid had never been changed. When I changed it, it had a bluish-green tint and was definitely not ATF. I know it was definitely thicker than ATF as well, since I had alot more gear noise after I changed it to ATF. I also recall someone posting that the service manuals for the Mazda 121 call for gear oil. My theory is that since ATF will work and is readily available and inexpensive, it's easier & safer for the manufacturers to recommend ATF as a replacement fluid. Everyone knows what ATF is, but If they recommended a true gear lube, people would get confused or put in a GL-5 lube with EP additives by mistake. Plus, if you're in CA, low temp shifting should not be an issue and the MTL has the same low-temp properties as standard Mercon/DextronII. You may also consider Pennzoil "Synchromesh" fluid, which is available at any parts store or even WalMart.

[JohnGunn]

Personally, John, I would run the MTL fluid. My thought is that the original factory fluid was actually gear oil and not ATF. My Festy had ~30K miles when I bought it and I'm 99.9% sure the fluid had never been changed. When I changed it, it had a bluish-green tint and was definitely not ATF. I know it was definitely thicker than ATF as well, since I had alot more gear noise after I changed it to ATF. I also recall someone posting that the service manuals for the Mazda 121 call for gear oil. My theory is that since ATF will work and is readily available and inexpensive, it's easier & safer for the manufacturers to recommend ATF as a replacement fluid. Everyone knows what ATF is, but If they recommended a true gear lube, people would get confused or put in a GL-5 lube with EP additives by mistake. Plus, if you're in CA, low temp shifting should not be an issue and the MTL has the same low-temp properties as standard Mercon/DextronII. You may also consider Pennzoil "Synchromesh" fluid, which is available at any parts store or even WalMart.

Thanks for your recommendation, Brian. Though I won't make a decision until I have educated myself a little more, I find myself leaning toward MTL. Mostly because of the damage I feel I may have done in those 600 miles on fresh ATF. Before I stopped driving the car, I experienced a slight bucking rhythm which I had never felt before. I fear it was the result of lash from the extra wear the transmission experienced in those 600 miles.

My thought is the slightly thicker MTL would cushion that lash better and protect the gears from the effects of it.

Tonight I came across a magnetic drain plug that looks amazing. They're called Dimple Drain Plugs.

http://www.drainplugmagnets.com/magneticdrainplugshome.html

Would one of these be helpful in my transmission?

[blkfordsedan]

Certainly won't hurt. My dad used to use "cow magnets" and just push them up into to oil pan or trans case through the drain plug hole when he changed the oil/fluid. They are very strong with a large surface area and work incredibly well. You just push them in and forget about them.

http://www.magnetsource.com/Solutions_Pages/cowmags.html