So i have heard two conflicting stories about doing tranny flushes.

One buddy that graduated from wyotech recommends to do a flush saying it will be good for my transmission and it wont hurt anything.

My other buddy who has been working at a auto shop for quite some time now says that doing a tranny flush could screw it up because it releases alot of junk that is actually holding alot of seals together.

I have no leaks, tranny fluid level is perfect and it looks and smells good. No problems shifting. Only problem is my overdrive doesn't work. The light flashed for awhile and now it doesn't flash anymore but the overdrive still does nothing.

SO WHO IS RIGHT?? I want to hear what all of you guys think about this. I'm just past the 100k mark and not to sure what to do.

 

They both are right to some extent, and they both are wrong to some extent. Let me try to clear that up.

Your vehicle has over 100,000 miles on it. If you have been draining the tranny fluid and changing the filter regularly, then you shouldn't have any trouble with a tranny flush, which is what the Wyotech friend may be basing his opinion on.

Now, if this is the first time in 100,000 miles that the truck received ANY type of tranny fluid drain and replace, then the other guy is right, as there is quite a buildup of gunk that could break loose and clog transmission passages in the valve body and other areas, thereby making your transmission fail.

Now my opinion: If the transmission fluid has never been changed in the previous 100,000 miles, and the filter not removed, then I would be leary of doing the transmission flush. If the transmission fluid has been changed regularly, then I see no real problem in getting a tranny flush.

Personally, I have always used this system: http://tccoa.com/articles/tranny/flushing.html

 

I have no clue what the maintenance history of my truck is. I bought it 6 months ago with 106,000 miles on the clock and i have put about 4,000 miles on since then,

 

I agree with the above post and in your case, I think I would do the tranny service which is drop the pan, change the filter and put in the 5 or 6 qts needed. I doun't think I would do the flush. However, the flush at a dealer is not the same as most lube shops. They run a chemical through the trannsmission while hooked to a machine, which supposedly gets the gunk out. I had a service done at 30,000, a flush at 60,000 and now have 102,000. I plan on another flush at 120,000.

 

Well maybe ill do as you said and just drop the pan and change the filter and fluid. Get a good look at everything. I will have to do a bit of research to learn what to look for first.

 

The dealership part is right. They run some type of chemical that gets all that trash out of there. I had mine done about 4000 miles ago, at 111,000, and as far as I know my truck had never had a flush before. It's still running great and have not had any problems with it at all. Definitely take it to a dealer instead of some random tranny shop.

 

I just went to aamco to get my transmission flushed and filter changed. They called me after they dropped the pan to tell me there was an abundance of material in the pan and that my transmission was on its last leg.... GREAT

i bought the truck with 88,000 on the clock with no service records. I changed the engine oil, powersteering fluid, and flushed the transmission the first day. No tranny problems at all. Now I'm at 120,000 and this may be the first time the pan has been dropped for all I know. I told the guy to just change my filter and replace the fluid from the pan. From everything I read I didnt want to risk flushing this "abundance of material" through the transmission.

 

Fluid exchange = good
Flush = bad

The machines in use these days can do it either way. A fluid exchange uses the tranny pump to move the fluid, just like it does when you are driving it. A flush pumps solvent through the tranny using a pump in the machine, which I consider to be a no-no.

 

I followed the advice i read on these forums. I had em use the fluid exchange machine, and I told them no solvents, just exchange the fluid. Had it done today 60,000 miles. (fingers crossed!)

 

I recently bought my 97 f150 with 157000 iles on it. figured i would do a tranny flush at the local lube store. (they did it in a jiffy) at 181000 miles. Never had an issue with it. They flushed it and changed the fluid, with a multi vehicle tranny fluid by valvoline.

BIG MISTAKE:

After i went about 2000 miles the tranny with no indication just quit. no slippage, no noise, I was going about 35 mph, had a lil noise in the back, like something thrashing, slowed down to about 15 mph to go ver a speed hump, went to speed up and got nothing but the throttle. not 1st 2nd 3rd or OD, no 4wheel, nothing.

So my advice is that if you get a that is used and you do not know the service record on it, take it to a dealer, or tranny shop. Don't take it to The local quick lube. They are a bunch of kids and do not know anything about transmissions.