I agree, a flushing or cleaning agent shouldn't be used, especially on a high mileage transmission. If the transmission is in good condition a fluid exchange with a machine won't cause any damage. If the transmission is weak or has been overheated to the point that the fluid is burnt, clutch and band material have probably been damaged. Extremely dark fluid without the burnt smell is the sign of a worn transmission. Transmission failure will happen with or without the fluid change. One thing you can't predict is when.

 

I know it sounds wierd but, I was told by a friend of mine who is a hell of a mechanic, to drop the pan change the filter and reuse the fluid. When you have high milage and dont know the history of the fluid or it has never been done.

 

Hi LITLEJIMMYNORTON and welcome to the forum

I personally don't agree with that but everyone is free to do what works best for them

 

Ramoone.....bring me a funnel and a torque wrench!


Seriously...I have had good results with dropping the pan, changing the filter, replacing the pan fluid and adding one can of K&W Trans-X to the fluid. It helps keep the seals conditioned and is not harsh enough to do any damage.

 

also in addition i added a drain plug you can get it at any local parts store
b&m #80250
that way you can change the fluid more often without changing the filter and gasket every time

 

Putting a plug in the pan so that you can do a few quick changes between complete fluid and filter changes is a GOOD idea.

The flushes that most every service advisor in the country is accomplishes four things: they put extra money in the pocket of the service advisor, they put a LITTLE BIT of extra money in the pocket of the techs, they put alot of extra money in the pockets of the BG people and they put a BUNCH of money in the pockets of the dealers. They do virtually NOTHING for your vehicle. If your vehicle was so neglected that the flushing does any good at all, then you should have been changing fluids on a proper schedule.

When the techs in the dealer open the can of solvent, there is a token inside the can. They collect the tokens and when the BG guy comes by, they get fifty cents for every token. Most techs are embarrassed to have any part in the racket, but they have little choice if they want to keep their jobs and the ten bucks or so a week that they get from the tokens gives them coffee money.

As far as I'm concerned BG is selling snake oil. This is the US of A and it is legal to make and sell whatever you want as long as it is not harmful to people. This is nothing but a legalized racket.

Have a great day,
Doc

 

I respectfully disagree.


Would you change half your engine oil? It seems more gooder to replace all 16 qts in my transmission than to drop the pan and only change about 1/4 of that.


I know that as a transmission ages, this can cause harm to the seals, but I still think it's better to change all the fluid in a system. I'm just sayin....

 

Maybe I need to be more clear. What I mean is doing a COMPLETE drain of transmission AND converter along with a fresh filter on the normal schedule, BUT IN ADDITION to that, do a few quick drain and fills BETWEEN the normal and complete service intervals. It is amazing how much this helps because you are making SURE that the used up ATF additives are always and constantly replenished.

So, I am not proposing this INSTEAD OF, I am proposing the quick drains IN ADDITION TO.

Also, putting a drain plug in the pan, makes it easier and more convenient even when you do complete drain, filter and fill service, because you can drain the pan before removing it.

Have a great day,
Doc

 

OK........ I am more confused then ever..... 2change or not 2change.... Well I as ignorant as it may sound, I am going with the old saying..."If it aint broke dont fix it"

 

You should be safe dropping the pan, replacing the filter, and adding the new fluid.

Good luck bro.

 

IMO it is more a question as to use and current condition. Daily driver vs hauler. If the fluid has miles on it and the fluid is dark, a flush should be done. If the fluid is a nice pinky red and the transmissin is in good condition draining the pan, and if there is a plug, the converter would suffice. Making a drain and fill part of a regular service, say every 30k miles, should be all you need to do. If you do heavy towing or hauling a flush every 30k miles is recommended. Even Ford says a drain and fill is an acceptable service procedure, even for a severe service schedule.

 

Not all the 4w70 trannys have a drain plug in the convertor. Mine is a Heritage and it did NOT. I dropped the pan and was surpised at how much crud was in the bottom of the pan and on the magnet at just ~15k. I tow a 4600 lb boat with my little 4.2L.

From here on in, the truck is going to get the pan dropped and cleaned, the filter changed every 15-30k. Since I can't drain my converter I'm still up in the air on how to change all the fluid. I need to review the tranny design so make sure operating the unit in park and having it pump the fluid out of the oil cooler line will not damage the pump or spin and seals when dry. I think you have to drop the pan to get all the junk out of the pan. I know I spent 20 minutes with a roll of paper towels and cleaner on the pan cleaning alone.

How fast does the tranny pump fluid out of the tranny? Would I be able to pump the fluid out and add new fluid at the same time, then stop adding fluid when the stuff being pumped out is clean and bright red?

 

Thanks to everyones input in here. Ramone and I changed my tranny fluid for the fist time in the trucks life w/180,000miles (no i am not the original owner i would never have let the tranny go this far with out a change). I added 4 quarts of tranny fluid and a bottle of Lucas as a preventative (Lucas products are the only ones I use in my vehichles when I use them). I have no problems since, neither did i have any before. The magnet in the pan looked like a big antisize covered doughnut all very fine metal dust particals no chunks so I guess thats a good thing. I figured it was the trannys first time because the plastic O-rig dart looking plug was in the pan thanks to this site I was able to figure out what the hell it was.I will keep the site updated hopefully I can prove the old theory wrong. That it is OK to change tranny fluid with over 100,000 miles and not blow the tranny in the next few thousand miles.