1993 transmission flush questions

[lurker]

I want to replace my old unknown transmission fluid type with synthetic fluid. I’m doing some searches and I wonder if someone can expand on these ideas?

https://forum.ih8mud.com/showthread.php?t=13777&highlight=transmission+flush

“make sure the tranny flush is a low pressure one using the vehicles own pump, not high pressure.”

How does this apply to my situation, the low pressure is a drain/refill...drain/refill...ect, right? I need to flush the entire old fluid out, which really I guess is a best case scenario of 80%, or so I’m told by the transmission flushers.

https://forum.ih8mud.com/showthread.php?t=13613&highlight=transmission+flush

“unfortunately the 343 only drain 4qt of its 12QT capacity (some say the actual capacity is more like 16qt) so it takes quite a few to get close to 100%, but the fluid exchanges don't get 100% either, not sure on the #'s for the 442 bus transmission but IIRC they are larger”

“I have been quoted around $85 for the swap procedure, and that includes up to 16 quarts of normal ATF, they said I could bring in Mobil 1 and they would refund me the approx $0.80/quart their stuff costs. If you did in fact get 16 quarts of Mobil 1, and them to do it for $90...sweet deal!

I get the impression here that the 442 takes up to 16qts of ATF, so my fork in the road question is with a flush is it 4 qts or 16qts, and to make things more confusing my service manual says 6.3 qts?

I’m sure it obvious what I’m trying to do, I’m just trying to figure out how much synthetic ATF fluid that I will need to deliver to the transmission flushers?

 

[erics_bruisers]

For my vehicles, I did the swap slowly, over time -- get a bucket with quart increments on it, drain your ATF pan, note the amount that came out, and re-fill with the adequate amount of syn. ATF --- do it every 1,000 miles -- till you forget to do it --

-- there are differing opinions on this, but this angle seems most conservative (least disruptive) --

eric

 

[MoJ]

Suggest Eric'c method. I've had a few friends flush a trans that was working fine only to have trouble afterwards.

 

[cary]

There are many who have found the trans flush procedure to be okay. I am still wary and will not use it. I would stick with the drain and refill procedure. Drain the pan (3-5 quarts), refill with fresh fluid (use the dipstick to check warm). Drive a few thousand miles. Do it again. Once you have done this 2-4 times, just do a drain and fill every 15,000 or 30,000 miles.

Cary

 

[lurker]

Thanks guys.

I think a side question was, if I was even going to do a full flush.

With your responses I think I'll just DIY with the drain and refill method. Better safe than sorry.

 

[RavenTai]

I agree with all the posts above,

Here is the method I came up with, right wrong or indifferent makes sense to me.

Bought 2 cases of a good quality dino ATF, used about 5qt's for the PS system flush. I have been dropping 4qt's every oil change this not only displaces the old fluid but each batch of new fluid picks up dirt and sludge as it is run some of witch gets removed at the next change, about 2 weeks ago I was almost through with the dino so I dropped the pan cleaned inside and outside of the pan the 4 magnets and the filter put it back together with the last of my cheap fluid as I did not want to test the new FIPG seal for leaks with pan full of expensive Syn.

The tranny and its fluid should now be about as clean as I can get it without rebuild. Next change I will start introducing in Mobil 1 atf. When I get about 70-80% syn I’ll move to 4qts ever 25k or so,

Next time I may try blowing out the cooler lines with compressed air to get a better exchange rate for each drain/refill, the lines and the 2 coolers look like they may trap a lot of fluid, to bad the LC does not have a Torque converter drain plug, will also jack the front of the cruiser, the angle of the pan keeps a lot of the nastiest fluid from draining

Found an interesting spread sheet that shows the % of new and old fluid after each drain/refill or the # of drain refills required to get a certain percentage of new fluid, you plug it the total capacity and amount drained it figures the rest, right click save target as:



http://members.aol.com/xzleezx2/Turbochem/Tranny4Bobistheoilguy.xls[/

 

[lurker]

Thanks for all of the responses, but to use the spreadsheet effectively is the total fill of the transmission 6.3 qts or closer to 16 qts?

I guess the cruve ball here is if torque converter is included in the 6.3 qts or not?

 

[RavenTai]

You have a ‘93 so I think you have the larger 442 bus transmission I have no idea on its total capacity or how much drains from the plug, torque converter is included in total capacity of the transmission but is not drained when pan is drained, torque converter holds the bulk of the "un-drainable” fluid

 

[Daskoff]

Dealer Flush

I've had the Toyo dealer do a "power" flush where they evacuate the transmission fluid via a machine and replenish with new fluid. They charged me about $130 for the whole thing. This included 11 -12 quarts of fuild (i think) and a couple of bottles of additives. I used to have a slight lag when starting from a stop and after the fluid change it's gone. So I'm pretty happy with the result.

Adrian

 

[Darwood]

Here is some more info an tranny flushing from a guy on the Tacoma boards... note his warning on the bottom. Take it for what it's worth but this guy is very retentive not unlike some on this board

http://www.gadgetonline.com/TransFlush.htm

 

[instigator]

ive done the gadget/amsoil way of flusing its works pretty good