I've got a 1992 buick skylark with 110,000 miles on it, I plan on getting the tranny fluid flushed out and changed (along with the filter), I've heard both pros and cons about tranny flushes on older trannsmissions, the owner's manual dosen't call for the 1st fluid change until 100,000 miles under normal conditions, should I get it flushed and changed or just changed? Opinions? thanks.
tranny flush on high mileage car
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I forgot to mention that the tranny flush would also include dropping the pan and cleaning it and also changing the filter, it's not a quick lube but a local mechanic that I often go to. He told me that he hasn't had any complaints about tranny flushes on 100,000 mile transmissions.
My vote, drop the pan, replace the filter and refill. Don't take the risk of the flush if tranny is operating fine. As a last resort get the flush if not operating fine.
If you want to get "most" of the old fluid out with-out flushing (which I'm not a big fan of)is pull a tranny cooler line..run the tranny at idle in neutral...draing off about 3 quarts in a 4 quart pail..put back in 3 quarts of new fluid...put it thru the gears...park to drive etc..a few times(letting it run around 5-10 minutes)...shut off the vehicle..then do a filter change,adding the correct amount of new fluid with the filter change.Drive it for a couple of months to see if you are good to go..no fluid shock to the tranny...then do the cooler line thing again...safest method I allways use on older vehicles.
Originally posted by Greaser:
If you want to get "most" of the old fluid out with-out flushing (which I'm not a big fan of)is pull a tranny cooler line..run the tranny at idle in neutral...draing off about 3 quarts in a 4 quart pail..put back in 3 quarts of new fluid...put it thru the gears...park to drive etc..a few times(letting it run around 5-10 minutes)...shut off the vehicle..then do a filter change,adding the correct amount of new fluid with the filter change.Drive it for a couple of months to see if you are good to go..no fluid shock to the tranny...then do the cooler line thing again...safest method I allways use on older vehicles.
Greaser why do you do not like the flush method?I have a22 k Tundra I'd like to flush to synthetic.
Opions please!
RichR
If you want to get "most" of the old fluid out with-out flushing (which I'm not a big fan of)is pull a tranny cooler line..run the tranny at idle in neutral...draing off about 3 quarts in a 4 quart pail..put back in 3 quarts of new fluid...put it thru the gears...park to drive etc..a few times(letting it run around 5-10 minutes)...shut off the vehicle..then do a filter change,adding the correct amount of new fluid with the filter change.Drive it for a couple of months to see if you are good to go..no fluid shock to the tranny...then do the cooler line thing again...safest method I allways use on older vehicles.
Greaser why do you do not like the flush method?I have a22 k Tundra I'd like to flush to synthetic.
Opions please!
RichR
i was proven that flushes arent soo good. if u have a slight problem wiht the tranny and use a strong flush for it, then it can make the problem worse.
i like greasers idea of using the cooler line, im just ignorant that i might starve the tranny. =)
if u think about the transmission, its a almost closed system, not like the oil in the engine where dirt accumulates and stuff. since the tranny is a closed system then really there isnt alot of dirt in there. so basically a change in fluid and then filter will be great.
i like greasers idea of using the cooler line, im just ignorant that i might starve the tranny. =)
if u think about the transmission, its a almost closed system, not like the oil in the engine where dirt accumulates and stuff. since the tranny is a closed system then really there isnt alot of dirt in there. so basically a change in fluid and then filter will be great.
The old rule of thumb I've operated on was: if it still shifts decently then one might be best in leaving it alone as an untouched high-mileage transmission might not do well after fluid service.
I always took the chance with used cars new to me (no matter the mileage) and changed it out by disconnecting the lines and completely refilling trans. (Greasers method makes more sense with a questionable situation). I then pulled the pan to clean and replace filter, adjust bands (some trans types) and drain convertor (some trans types), refilled after idling in all gear postions and making numerous checks of fluid level in the following days (adding or removing fluid to exact factory-specified level under factory-specified conditions.) Usually changed all fluid again before year was out. Haven't lost a transmission this way, and usually got 150-175,000 out of a big or small-block trans before replacement was necessary.
Can't go wrong with annual changes and the addition of an external spin-on filter and supplementary trans cooler.
(There is another thread on this subject; and of fluid changes.)
[ April 15, 2003, 10:54 AM: Message edited by: TheTanSedan ]
I always took the chance with used cars new to me (no matter the mileage) and changed it out by disconnecting the lines and completely refilling trans. (Greasers method makes more sense with a questionable situation). I then pulled the pan to clean and replace filter, adjust bands (some trans types) and drain convertor (some trans types), refilled after idling in all gear postions and making numerous checks of fluid level in the following days (adding or removing fluid to exact factory-specified level under factory-specified conditions.) Usually changed all fluid again before year was out. Haven't lost a transmission this way, and usually got 150-175,000 out of a big or small-block trans before replacement was necessary.
Can't go wrong with annual changes and the addition of an external spin-on filter and supplementary trans cooler.
(There is another thread on this subject; and of fluid changes.)
[ April 15, 2003, 10:54 AM: Message edited by: TheTanSedan ]
A power flush (reverse flush) in an older tranny usually loosen deposits stuck in places where they were happy to be in,and get in places you won't be happy they are now..mainly the valve body.The convertor is the place where most of the stuff gets stuck to the sides ,due to the spinning of the convertor.Tranny fluid by itself is a cleaning agent.Introducing this new fluid in a forcefull manor(power flush) might get to deposits that ordinary drain and fills wouldn't bother.In a newer vehicle a power flush isn't necessary,even if you go from dino to syn.The typical tranny holds around 8-9 quarts of fluid in the system.If you take off the cooler line from the rad (usually the out going line is the first line in the front of the tranny going towards the rad)and pump out about 3 quarts into an empty winshield washer jug or the like,you won't harm the tranny.It isn't under load in neutral and if you get a bit of air in the system it will disissapate(fine bubbles) in a few minutes anyway.Now you re-attach the cooler line and add 3 quarts of new fluid.Run the vehicle in the garage for 5-10 minutes putting it thru the gears to get the valve body working.Now drop the pan,change the filter and add some more new fluid.You've changed about 6 quarts of fluid with new stuff.In about a month you can do the cooler line thing again and you are good to go.I've allways done this with various vehicles and nobody had any problems.Depending on your mileage/driving conditions you can do the tranny line cooler thing once a year and your tranny will live a long life.This procedure adds new fluid (not too much) refreshing the additive package in the rest of the fluid making tranny problems a thing of the past.A drain plug install in the tranny pan would get you away from the cooler line and is easier...but all in all this procedure works great and greatly reduces the chance of getting stuff out of places that don't want to be moved,and you don't want them to be moved.
No way i would flush..just remove the pan and change the filter,then refill...
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