transmission flush

[87GrangWagoneer]

hi is it good to do a transmission flush on a 87 grand wagoneer with 149k miles?

[88GWSteve]

Explain "flush" Do you mean replacing all the ATF with new fluid? Flushing the system with lots of ATF? Or flushing the tranny with water?

[SBJeep]

I had my F-150's C-6 flushed by my mechanic as the fluid was browner than my engine oil. That seemed to bring that tranny back from the brink. If your's is nice and red and clean, I'd just do the normal fluid change and filter.

[87GrangWagoneer]

flush it with transmission oil. i didnt know you can do it with water??? i dont think i will. im just thinking off just draining and refill. also i was wondering how many quarts do it put in from just doing the draining?

[88GWSteve]

If I remember, i think its 6 qts to refill.

[85wagoneer]

I am doing mine this weekend and its 6 quarts

[hampton123]

ok it looks like my trans fluid has never been changed before. my brother (my personal mechanic...) said that it will probably make my trans slip more and be worse off if i change my fluid and filter and all that great stuff. he said it will do that because iaa the sludge and built up stuff is holding my trans together. do you think he knows what he is talking about?

[drlocke]

ok it looks like my trans fluid has never been changed before. my brother (my personal mechanic...) said that it will probably make my trans slip more and be worse off if i change my fluid and filter and all that great stuff. he said it will do that because iaa the sludge and built up stuff is holding my trans together. do you think he knows what he is talking about?

My take on this is if it aint broke don't fix it. But if it has started slipping, and fluid/filter change makes it even worse then the tranny was heading in that direction already, and needs more in-depth servicing.

[hampton123]

ok so your saying change the fluid and filter and see what happens?

[Jayrodoh]

Changing the fluid is good maintainence for a tranny, but it won't "fix" anything. If the tranny is in good working order but your fluid is dirty, go ahead and change or better yet exchange(flush) it. If the fluid smells burnt or you have tranny problems other than sluggish shifting, then changing it may make things worse.

[710 Burner]

Jay and Doc are correct. If its working and you want to keep it that way, do your maintenance. I flushed mine because it was in such bad shape. I hesitate to say how I did it, but suffice it to say that the fluid is all new.

[grand_wag_85]

Valdez-Redneck bucket/hose flush out?:D

My TJ was starting to act up before I changed out the ATF and it's doing ALOT better now than it ever has.

Yes the built up sludge coming loose may in theory cause a problem but that's where a fluid exchange or flush comes in handy as it cycles about 15-20 quarts thru the transmission taking any possibly loose debris with it.


On a side note, what about synthetic ATF? Will it hurt to put synthetic in if the trans has only known DYNO ATF? About 11K miles on the tranny, if that.

[Hankrod]

Changing the trans fluid will allways help the trans's future and it should be done at least every 30K - in a FSJ. If you do not know when it was last done, you should do it. Changeing the fluid in the pan only replaces about half of it. If it has a real problem, like needing high revs to get going or noise - it will not help. Alot of quick lube shops say 'flushing my make thinks worse' this is a directed disclaimer. Clean fluid will aid in cooler operation and correct clutch friction. Good luck, Hankrod

[Rogue]

with regular services the drop the pan method removes enough dirt that the total amount of fluid replaced is acceptable in long term reliability.

IF only the "flush" method is used where they disconnect the cooler lines and the filter is never serviced then it indeed could have a partially plugged filter and premature failure.

IF the "flush" knocked something loose, then you were already on borrowed time as they say, anyways.

IF the "flush" also included a harsh chemical that is not compatible with the trans fluid/clutch plate coefficient of friction fluid modifier properties and other fancy smancy word mumbo jumbo then the flush most indeed could "cause" problems but again you were probably already on borrowed time to begin with if the chemical tore up the clutch plates that badly.

[710 Burner]

That's funny, I'm the one from Oklahoma and I have never heard the term "Redneck bucket"....and we have lots of Yankees here. :cool:

[grand_wag_85]

That's funny, I'm the one from Oklahoma and I have never heard the term "Redneck bucket"....and we have lots of Yankees here. :cool:

HA! Trust me, I'm no yankee...I meant doing a flush w/o the $3K machine using a couple of buckets, some hoses on the cooler lines and u do the math...

[Merc69]

No one has mentioned adjusting the bands as per factory manual when changing the fluid. The one inside the transmission is the easy one to get at when the filter is dropped, the other is on the outside of the case and is tough without a body lift on the rig...but can be done.

Of course I am refering to the 727...I have no clue on the TH-400

[Careful34]

I was having hard shifting problems with my 727 and did the drop the pan, change the filter, adjust the bands (you'll need a very low range torque wrench for this. 15 in-lbs as I remember), and power flush, and I made a HUGE difference. Well worth it!

[ncchaos]

I have always flushed them.For the most part the "filter" is a glorified screen.If you got crap and it, ya most likely are on the way to having other problems anyway.

[710 Burner]

HA! Trust me, I'm no yankee...I meant doing a flush w/o the $3K machine using a couple of buckets, some hoses on the cooler lines and u do the math...
An 11qt oil pan works good. :D
Careful 34 I think you meant to say in-oz.

[letank]

I have always flushed them.For the most part the "filter" is a glorified screen.

be aware that some filters have a label requiring replacement every 12,000 miles.....

But as said... these filters look like improved scrubing sponges.

And yes, replacing only 3 to 4 quarts when dropping the pan on a total of 11 quarts would be the equivalent of changing your oil by only replacing your oil filter.....

I do the redneck stuff... dc the cooling line.... and drain at least 6 or 8 quarts by letting the engine idle... in neutral for the TH400 and in gear for the TF727. I have a 3 quart bucket.... so i can refill w 2 quarts when the bucket is getting full....