I always hear bad things about tranny flushes on vehicleS that have high miles and havenever been flushed. But it's just hear say and you don't have that many miles. I don't know if mine has ever been flushed but I did do a fluid and filter change a year ago. It had about 144k on it.
She's got a 155k now and still shifts out just fine. QUOTE]
ok so real deal... its not the mileage its the condition.. if u have 20000 miles on a trans and the fluid is all burnt up and the trans is effed.. then doing a tranny flush will only mkae it worse... if u have 199000 miles on a trans and the fluid is still clean and the trans is good... then a flush shouldnt hurt... but if u have dirty fluid and/or burt fluid or its not shifting rite.. chances are a flush will only make it worse.
was it an AT or MT?
if it was an MT and it was slipping then numb nuts had a bad clutch.
if it was an AT, then i'd just assume those beloved ford trannies are the culprit
with the manual it may be something other than a clutch, but if its not shifting rite its not the fluid.. because in a manual there is no trans "fluid" its gear oil and that doesnt really effect the way or how smoothe the shift is... u really dont do flushs in a manual trans.. well not in a mustang anyway!!! in a truck you should like if u get into a lot of mud or deep water...
I don't really remember. Either way he claimed it didn't act up until after the flush.
this may be true.. like i said before if his fluid was effed or his trans was going bad, then a flush simply made it worse.... and there really is no benefit of a "high performanc trans fluid" there is a reason the car was made with its own trans fluid inside... thats why there are engineers involved in creating these vehicles, they know what works best for them