98 Mark VIII Base Trans

bhans40

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I've read in more then one place when changing trans fluid do not flush the trans completely just drop the pan change the filter....I have about 35k on the fluid and am going to change out the fluid/filter....All this for this: Why not flush the torque converter too....Until one of you folks gives me an answer nothing gonna happen..... Bruce L. Hansen....Senior Citizen ( By the grace of God still alive)
 
This is almost like a religious thing.
Personally, I always do a full fluid exchange. Some call this a flush too, but I look at a flush as when they put cleaning chemicals in and flush them (mostly) back out. A true fluid exchange connects to the transmission cooler lines. The engine is started and the pump in the transmission pumps fluid into one side of a cylinder with a piston in the middle. As old fluid goes in one side, it forces new fluid out the other side and into the transmission. The procedure is stopped when new fluid starts coming back out. It's very important to use the correct fluid.

I think that a lot of people don't think to change the fluid till they start having problems. Often it is too late by then, but they blame the eventual failure on the fluid change anyway. Alternately, I think that going somewhere like Iffy Lube for this is just asking for trouble. Do it yourself, or find a good independent (non-chain) transmission shop to go to.
 
This is almost like a religious thing.
Personally, I always do a full fluid exchange. Some call this a flush too, but I look at a flush as when they put cleaning chemicals in and flush them (mostly) back out. A true fluid exchange connects to the transmission cooler lines. The engine is started and the pump in the transmission pumps fluid into one side of a cylinder with a piston in the middle. As old fluid goes in one side, it forces new fluid out the other side and into the transmission. The procedure is stopped when new fluid starts coming back out. It's very important to use the correct fluid.

I think that a lot of people don't think to change the fluid till they start having problems. Often it is too late by then, but they blame the eventual failure on the fluid change anyway. Alternately, I think that going somewhere like Iffy Lube for this is just asking for trouble. Do it yourself, or find a good independent (non-chain) transmission shop to go to.
 
Thank you for the quick response joegr.... I think I will do a complete flush including the torque converter.....And I'll use Amsoil Trans fluid 13 quarts....
 
drain and fill.
12-13 qts.
there should be a bolt in the torque converter.
remember the 96+ cars need the filter with the pickup tube.
 
drain and fill.
12-13 qts.
there should be a bolt in the torque converter.
remember the 96+ cars need the filter with the pickup tube.
Thank you too chris2523 for this response I'll remember about the pickup tube
 
I strongly recommend Motorcraft Mercon V only.

germansheperd while I can agree with you on your choice of trans fluid....I have always used Amsoil fluids in my Mark....After this trans was rebuilt it was serviced with Amsoil....Never looked back, never had a single issue....no drips,no leaks operates as advertised....Now I don't want to get into great big blow out about trans fluid.....good/bad/indifferent cause no matter what you say I'll continue to use it......Bruce L. Hansen....Senior Citizen....(Still alive by the grace of God)
 
Well, if you've been using that, continuing with it is understandable.
 
Well, if you've been using that, continuing with it is understandable.
Thanks joegr.....appreciate it.....My thoughts are if something works for you why change it no matter what others think.....
 
I'll be doing the same procedure on my 97 soon and I'm also a believer in Amsoil universal trans fluid. That fluid completely fixed a horrendous low RPM trans shudder in my 05 Honda Odyssey and did wonders for the same issue (not as bad) in an 10 Toyota Rav 4. Both vehicle previously had "recommended" factory fluids. I'm not knocking Motorcraft here at all since this Mark is my first ford product ever, I'v no experience with it. Other full synthetics may work as well as Amsoil, IDK. But from what I'v seen in those 2 vehicles, The stuff worked a miracle in the Honda big time.
 
Amsoil is good stuff no doubt and comes with a cost. Originally the Marks came with Mercon. Mercon V is substantially better than the original Mercon (stay away from Mercon LV for these cars it is different yet).
If you were to have driven my car when I got it at 31 or 33k vs now at 38k J-modded and a full Mercon V swap you would not believe it could be the same transmission. Its silky smooth like a Lincoln around town under light and medium throttle but put you foot in it and it will hammer you back in the seat with authority and bang each gear at 6800.
Do you need or is Amoil bad nope. Is it better than Mercon V for a 4R70W nope.
 
Amsoil is good stuff no doubt and comes with a cost. Originally the Marks came with Mercon. Mercon V is substantially better than the original Mercon (stay away from Mercon LV for these cars it is different yet).
If you were to have driven my car when I got it at 31 or 33k vs now at 38k J-modded and a full Mercon V swap you would not believe it could be the same transmission. Its silky smooth like a Lincoln around town under light and medium throttle but put you foot in it and it will hammer you back in the seat with authority and bang each gear at 6800.
Do you need or is Amoil bad nope. Is it better than Mercon V for a 4R70W nope.
germanshepard while I don't have a j mod I do have a shift kit and it operates similar to your's.....nice and smooth around town and on the road but when I get into it,it roars (doesn't shift at 6800 rpm) and will break the tires loose going into 2nd this with 136k on the odometer....thanks for your opinion....Bruce L. Hansen....Senior Citizen....(By the grace of God still alive)
 
Mercron V and Amzoil are both synthetic. Might even be possible that Amzoil makes Mercron V for Ford.

I agree that an "exchange" would be better than a "flush".

I've always done a drain and fill, (with filter), because I don't like taking a chance on disturbing any accumulated debris inside the trans.
 
Amsoil is good stuff no doubt and comes with a cost. Originally the Marks came with Mercon. Mercon V is substantially better than the original Mercon (stay away from Mercon LV for these cars it is different yet).
If you were to have driven my car when I got it at 31 or 33k vs now at 38k J-modded and a full Mercon V swap you would not believe it could be the same transmission. Its silky smooth like a Lincoln around town under light and medium throttle but put you foot in it and it will hammer you back in the seat with authority and bang each gear at 6800.
Do you need or is Amoil bad nope. Is it better than Mercon V for a 4R70W nope.
Hah I knew there was a difference the guy at autozone said it was the same as the V it seemed like he was just trying to push LV i told him I just wanted to grab a bottle of mercon V he literally told me that it will destroy my trans I laughed and walked over to advance
 
Thats what I figured when I can help it I only put what the manuals call for in the car because thats the way ford intended lol.
 
Yeah... I think the parts store guys need to take update classes on parts and fluids... just like the auto techs do for technological advancements... and it should be on the parts stores dime.
 
And there's a big difference between the "store brand" Wal-Mart Mercron V... and the name brand versions.

And any "universal" brand fluid is junk too.
 
I got a quart of carquest mercon V from advance and it did the trick for me since it was only about half a quart low
 
Don't make the mistake I did; took our '97 to a "we're good" tranny shop which only dropped the pan and then filled it with "Universal fluid", which was TOTALLY wrong!! Took it to another shop recommended by a Mark VIII owner and they did it right. Drained and flushed it all, converter, etc. Filled it with the correct Mercon fluid. The difference between the "wrong" and the "right" was noticable as soon as I drove it home. Smoother shifting, more positive engagement .. didn't "slide into gear" .... Lesson learned: DO IT RIGHT THE FIRST TIME!!! Shop says it's good for two years normal city driving before I should do it again. And the cost was reasonable. Don't take it to a dealer .. ever.
 
Don't make the mistake I did; took our '97 to a "we're good" tranny shop which only dropped the pan and then filled it with "Universal fluid", which was TOTALLY wrong!! Took it to another shop recommended by a Mark VIII owner and they did it right. Drained and flushed it all, converter, etc. Filled it with the correct Mercon fluid. The difference between the "wrong" and the "right" was noticable as soon as I drove it home. Smoother shifting, more positive engagement .. didn't "slide into gear" .... Lesson learned: DO IT RIGHT THE FIRST TIME!!! Shop says it's good for two years normal city driving before I should do it again. And the cost was reasonable. Don't take it to a dealer .. ever.
At the time when I completely drained the 23 year old Mercon with 31k miles and completely refilled with new Motorcraft Mercon V my results were exactly as you described.
 
I had a shudder in my transmission on my 95 Mark VIII. Usually between 2nd. & 3rd. gear. I completed a fluid and filter change last year, I used Royal Purple synthetic transmission fluid. Shudder is completely gone! Car runs like a scarred squirrel! I love these Mark VIII's!!
 
when you drain the torque converter, I believe the manual says to use a new bolt, correct? I haven't changed mine, but do have a tiny leak at the torque converter bolt. I always thought the previous owner had it changed and they reused the bolt. Sound right?
I recall reading a member on here that used a coat hanger inserted into the converter to help drain the oil faster, as it takes some time to drain otherwise.
 

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