tranny maintenance

[landyacht318]

Sorry to post a question that is not directly related to a Dodge. But the knowledge pool on this forum seems to be the best to tap and it very well could help someone else.

My unmechanically inclined friend some how managed to successfully replace the leaky radiator in his 108 k mile 2.4l toyota tacoma automatic.

I came over at the end and noticed that his tranny fluid was dark brown but smelled only slightly burnt. It hadn't been replaced for 65k miles.

I informed him of this very undesirable situation ( in my opinion)and how only a flush could fully replace all the old fluid, and the problems some people have when doing a flush with a real dirty tranny like his obviously was.

As toyotas come with a drain plug and have a fine metal mesh filter screen I recommended he just pull the plug and replace the amount that drained about 4 times or so a week apart.


The second time he did this he stripped the drain plug.
So I came over and dropped the pan and re tapped it for a 7/16 coarse thread from the stock 3/8 or it's metric equivalent.

Now there was only a very little amount of gray sludge on the bottom of the pan, and the magnets were not overly inundated and I think we caught the problem before it did major damage.

So the pan has been drained 3 times now. Dropping the pan and replacing the filter required approx 3 1/3 quarts of new fluid. Just draining it requires replacing about 2.5 quarts of dextron 3.

BTW, I highly recommend the filter/gasket kits sold at Autozone as all the pan bolts can be held in place by the rubber gasket, also keeping the gasket in place. The pressed paper type from Fram:mad: caused an improper seal as only the 4 corners hold the bolts and gasket in place.

So three times we've changed the tranny Fluid. The first time it looked closer to used motor oil than tranny fluid. The subsequent two replacements revealed the fluid to have been only slightly cleaner. After 3 times it is still very dark red, almost brown. The car was driven between 5 and 300 miles between pan or drain plug drops.

I'm telling him he should pull the drain plug every weekend and replace the 2.5 quarts untill the fluid looks to be a nice clean pink.
My stubborn friend does not want to do this as he is afraid to strip the pan drain plug again. He says it drives exactly the same(no shifting problems) as before and sees no benefit to having pristine tranny fluid versus possible stripping the pan bolt again by doing something unneccessary ( his opinion)

I don't know the full fluid capacity of his taco, but I'm looking to show him others' opinions on this matter.


I tell him as dextron 3 is only 3.50 a quart it's cheap insurance. Just dont overtighten the plug bolt again.

What do you all think?

[DANVAN]

I agree with u.

[moe7404]

moe in wichita ks
i see nothing wrong with changing the fluid a lot. i am going to recomend something that some may not like. put 2 qts of rear end grease in. i have done this to a number trans. however some trans may not like it

[alloro]

put 2 qts of rear end grease in.

1. Are you insane?
2. Do you realize he's talking about an automatic, not a manual tranny?

[alloro]

So the pan has been drained 3 times now. Dropping the pan and replacing the filter required approx 3 1/3 quarts of new fluid. Just draining it requires replacing about 2.5 quarts of dextron 3.


The reason the fluid isn't cleaning up is because of the fluid that stays in the torque convert. At every drain you're only removing about 1/2 of the fluid. There's about 3 qts in the pan and about 3 qts in the TC. So after the first drain and fill you have 50% old and 50% new fluid. Second d&f you have 75% new and 25% old. Third d&f 87.5% new and 12.5% old. That old fluid is what's causing the discoloration that you're seeing.

The only way to remove all of the old fluid (without disassembling the tranny) is to do a fluid flush. However, I think at this point enough of the old fluid has been removed to have dodged a bullet. At most, you might want to do one more d&f, but you will be taking out more new than old fluid at this point.

As far as the drain plug issue goes, even if he had to buy a whole new pan, I can promise you it's a lot cheaper than a tranny rebuild job.

[leeann]

I agree with you, too.

Change the fluid again. And again.

[B-300]

You might be able to drain more fluid out of the valve body and torque converter if the pan is removed again and the valve body (bolts) lossened overnight... with luck it will siphon the coverter. Also make sure the correct fluid.

[moe7404]

moe in wichita ks
to: alloro NO iam not insane! 75 wieght gear grease is about the same thinkness as 50 wieght motor oil. are you trying say that my 40 some years of being around cars is no good? incase you dont know it, and it looks like you dont, this is an OLD drag racers trick, to get a automatic to last longer. i have done this to about 4 trans over servel decades, with no trouble. i would not say to do somthing if i didnt know it worked. now if you dont want to learn things from old moe, ill just leave and not come back. your loss not mine.

[B-300]

This might be helpful.
www.dodgetalk.com/forums/showthread.php?t=119796

[landyacht318]

I know the new fluid is just getting diluted with whatever is remaining in the torque converter, causing the new fluid to be dark reddish brown.

Since the new fluid has the fresh detergents in it do you think the new fluid is also washing the varnish off the internals causing additional darkening?

Isn't this a factor in the problems some have with just doing a flush. The fresh detergents in the new fluid loosen so much old crap and it blocks the filter. Then not dropping the pan and replacing the filter causes the post flush tranny breakdown.

I know this thread is about a toyota, but I certainly would not put anything but atf +3 with lubegard or ATF+4 in my Mopar. Unless it was already on it's last legs. Did you ever see how thick Lucas tranny stop slip is? It looks way way thicker than 95w 140 gear oil. Some swear by that stuff.

Thanks for the replies, I'll force my friend to read them this weekend.

[B-300]

The idea as you state is to remove the old fluid, change the filter and adjust the bands.
For your freinds Toy they may want to follow the flush method and then drop the pan and clean the filter and adjust any bands (It may not have any like the later dodge 45rfe transmission).