Would someone please give it to me straight on whether a transmission flush is necessary or not. I have a 90 F-150 with the 5.8L and 172K on it.. Some people swear by having thier trucks flushed and yet others say it is a waste of money. WHICH IS IT?

 

not necessary.

drain pan, converter, replace filter and new fluid is all you need.

 

And that leaves how many quarts of old fluid still in the system?

 

maybe 2% or so in the cooler lines.

not feeling the love from you andy. ;-(

 

so how much fluid does the E40D actually take. I've been reading 16-20 quarts everywhere... how many 4L jugs do i need? 2 or 3?

 

Sorry.

I would flush it. Seems to me that there is more fluid than that left in the system, but I am not 100% sure. I think the E4OD takes 18 quarts total.

 

It depends on how long you want your transmission to last. Look in the service and owners manuals- they all recommend flushing the transmission at certain intervals [I don't know the specifics- I just do mine every 2 years].

The whole point of flushing the tranny is to give the internal parts a good cleaning. Just like your engine, regular cleaning can extend its life. So it's just up to you on how long you want the transmission to last. As for how much it extends service life, I don't know- it could be 200 miles or it could be 20,000- I'm sure there's been some research done at some point, and you can probably google it or something.

 

Depends if your tranny is acting up.
I know a few dealers (and I'm a little ashamed to say I do) who will have a cars tranny flushed and drop in some sort of transmission help additive if the transmission is on it's last legs. Often it makes a difference long enough to get some poor suckers money.

Other then that, I'm with post # 2 if the tranny is working fine, but, 91 above has a good point also.