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I believe I am experiencing some torque converter shuddering between 3rd and 4th (od).I have read the cause of this is old transmission fluid. Fix obviously would be new fluid. I was wondering what peoples opinions are on getting the trans flushed vs just changing the fluid. The truck has 93,000 miles and I am uncertain if the fluid has ever been changed. Pretty sure it hasn't. The fluid is a tan color similar to used motor oil and doesn't smell burnt. Would it be safe to get the trans flushed or would that be risky with a 30 year old trans with an unknown service history?
Transmission "flush" is a scam that auto shops use to make more money. Pro mechanics will save the old fluid when they're repairing an old transmission and put it back in.
If it's tan than it isn't burnt and it's time for a change. But you may just want to top it off.
Well a heated flush is best, however if you do it yourself you can drain the pan and the torque converter and get 90% of it out. Just use Mercon V when you do the service. As for saving the used fluid above, I know of no shop that does that. It all goes in the waste oil bin.
If you will drain the pan and also the TC, you will get about 12 of the 14-15 qts. out of it. That is plenty good. Do that every 25K miles and that thing will last forever. Put a drain plug in your pan and you won't need to pull it next time.
I disagree about Mercon V, tho. Your truck does not need it and it costs quite a bit more. Just get the stuff at Walmart that is labeled "ATF". It is Mercon III compatible and that is what your truck takes.
I'm basing this on 1) your avatar pic and 2) the forum you are posting in. It would help if you put your truck in your sig so we know for sure what you are working on.
Transmission "flush" is a scam that auto shops use to make more money. Pro mechanics will save the old fluid when they're repairing an old transmission and put it back in.
If it's tan than it isn't burnt and it's time for a change. But you may just want to top it off.
A dealership where I worked had a flush machine. You connected to a cooler line and while the transmission pumped out the old fluid the machine pumped in new fluid to keep the trans full. That way it would completely flush the old fluid from the lines and cooler.
Originally Posted by ford390gashog
As for saving the used fluid above, I know of no shop that does that. It all goes in the waste oil bin.
Agree. I worked at a local service station, a Ford dealer and also a Chrysler/ Dodge / Jeep dealer. Not one of them reused old fluid.
Originally Posted by jas88
I disagree about Mercon V, tho. Your truck does not need it and it costs quite a bit more. Just get the stuff at Walmart that is labeled "ATF". It is Mercon III compatible and that is what your truck takes.
Ford published TSB many years ago stating that the replacement for Mercon is Mercon V.
[QUOTE=My4Fordtrucks;19548929]A dealership where I worked had a flush machine. You connected to a cooler line and while the transmission pumped out the old fluid the machine pumped in new fluid to keep the trans full. That way it would completely flush the old fluid from the lines and cooler.
Thanks for the info, did you have have any instances in your dealer ship where the flush machine caused damage to a transmission? The main thing I would be concerned about would be washing gunk out of the pan and into the main body of the transmission. I assume that would not be an issue though because you would pull the pan and change the filter first.
Any reason why you recommend not flushing? Too risky on an old transmission?
A flush where you disconnect one of the cooler lines and let the truck run and pump the old fluid out while someone is adding new fluid through the dipstick is OK to do, but don't do a machine flush, that often causes problems. Just a drain and refill with a filter change every 30-50K is all that is really needed.
A flush where you disconnect one of the cooler lines and let the truck run and pump the old fluid out while someone is adding new fluid through the dipstick is OK to do, but don't do a machine flush, that often causes problems. Just a drain and refill with a filter change every 30-50K is all that is really needed.
Exactly what I did on my 93 and have not had one issue with it doing it this way. Drive it every day and tow with it.
If you will drain the pan and also the TC, you will get about 12 of the 14-15 qts. out of it. That is plenty good. Do that every 25K miles and that thing will last forever. Put a drain plug in your pan and you won't need to pull it next time...
Agreed. You can spin your converter around to see if it has a drain plug.