I am somewhat surprised in that I could not find a write-up in the "stickies" describing the procedure of draining and changing the fluid in the automatic-overdrive transmission such as is in the wife's 1991.5 truck.


Believe it or not, I don't remember ever in my life changing fluid in any automatic; I have always owned and driven manuals.


Is the process so simple that no instruction is necessary ??


Thanks.

 

BK:

I have a friend who is the head mechanic at a local Goodyear place. He disconnected both my tranmission fluid lines where they enter the bottom of the radiator and connected them to a machine designed especially for the replacement of tranny fluid. This device puts new fluid in the system at the exact same rate the old fluid comes out.

I have seen instructions for replicating this process manually, but it involved some eyeballing and therefore guesswork. I changed my power steering fluid myself but for the automatic transmission I think it worth the expense to go to a shop that has one of these machines and pay to have the chore completed.

Jim

 

I agree the flush (actually "fluid exchange" is a better term) is an important procedure, but removing the pan to replace the filter, and checking or adjusting the bands is just as important. I always try to do both together when servicing an automatic.

I have used exchange machines, and also done manual exchanges by dropping the cooler return hose into a bucket then running the engine in neutral and letting it pump the fluid into the bucket while I pour a few extra quarts into the fill tube. It's simple, quick, and works very well.

 

I've done AT cars, and found it simple, messy and incomplete. They don't typically have drain plugs so you drop the pan and try to catch all the ATF flow. The sump screen is a bolt-in. The incomplete part is the fluid left in the "clutch", about 1/3 of the total. Evidently some have a drain plug but I've never seen one. James method of pumping via the rad hoses may address this. I believe that it's a job well worth doing given the cost and complexity of ATs, ..

 

I always say drop the pan and change the filter too, these "flushes" make it seem like it is getting all the old fuild out but it is not. It stays in the torque converter. and some in the pan. Drop the pan and change the filter every 30k

 

I always drop the pan and change the filter. And then rotate the torque converter around and look for a drain plug...sometimes it has one...sometimes not. If you do find a plug on the converter open and drain it as well. Otherwise your only really changing "most" of the fluid...not all.

What I like to do once the pan is off, and since Ma' Mopar doesn't seem to believe in drain plugs on tranny pans........I like to install one of these little B&M drains....



Handy little things and makes future changes that much easier. I usually install it in the front right hand corner...near the dipstick area.

 

A proper "flush" with a machine removes more of the old fluid then dropping the pan does.The flush machine is just a tank with bladder in it,fill it with new fluid,hook it tothe trans lines and as the vehicles transmission pumps the old fluid into the opposite side of the bladder tank, the resulting pressure pushes the new fluid in the other side of the trans resulting in very little, if any,cross contamination of the fluid


regardless,it`s necessary to drop the pan and change the filter

 

Exactly my thinking. I made the mistake of taking my chariot to a knuckleheaded Dodge dealer for the recommended "60,000 mile service." For the service, a dealer drops the pan and changes the filter but does not flush the tranny fluid.

My truck is old with relatively low mileage but my gut tells me deterioration of many automotive fluids is more time-based than mileage-based. So I feel the fluid flush is at least as important as cleaning the filter. And the bladder exchange machine is designed to get rid of almost all the old fluid, including that in the torque converter.

 

Thanks for all the good information thus far; I know a lot more already than I did yesterday.

There IS a drain-plug; it looks to be some brazed-in affair installed by the previous owner, who was a stickler for maintenance.


What fluid do I use and how much ??? ATF-+4 ??


How does one go about adjusting the bands ??




One thing I hear over and over at the shop is that those with several miles on their automatics lose REVERSE very soon after having those "flush" jobs done.

The local transmission guys recommend against it for that reason.

This is no hear-say, as I have heard about it from several who had it done and soon after did lose REVERSE.

Is this something one should consider with our type of automatic ??


Thanks and please keep the info coming.

 

I have seen these flush machines in action and all I can say is that I will never have one near my truck.
My experience with these machines is that they do work as advertised, however part of the flush procedure invariably loosens up some clutch material or metal fragment that finds it way into places it doesn't belong. Not long after using this machine at the dealership I worked, customers would be back after a month with a dead transmission. Might have been coincidence, but I saw more than 10 flushes and 10 dead transmissions in one summer.
I will stick to the old way of dropping the pan and changing the filter with a band adjustment.

 

BK, there is a sticky somewhere that explains how to take the line off the radiator, run the truck until the juice quits flowing and then drop the pan. This pumps most of the fluid out but still leaves the TC to drain. Also explains how to adjust the bands, super easy. I'll hunt it up.

BTW, I went for synthetic fluid from Amsoil (couldn't find anything else back then). Can't remember how many years ago (8?) but it still looks good and towing has been no problem.

 

Interesting, I can't find the thread here or on the other forums. I'll keep looking...

 

It is my understanding that this is mostly true when the trans has a lot of miles without ever being serviced.which makes sense because with proper service you shouldn't have an excessive amount of clutch material anywhere in the trans


I had a 96 powerjoke with the E4OD auto in it. I did the first flush around 65k miles and approx 3more times in the time I had it ,to the tune of 227,xxx miles on the truck with the original trans still knockin done the miles! That is the only E4OD I have heard of to this day with that many miles on it without a rebuild. Therefore I am a believer in flushing, however I think it needs to be done regularly.

IMHO, auto transmissions,next to differentials, are the most neglected part of the vehicles as far as maintenance goes.they're no different then an engine as far as maintenance goes,and that's why the manufacturer has a "suggested" maintence interval

Just my .02

 

thats my .02 cents worth....

 

I highly recommend getting the pan gasket and filter from your local Dodge dealer. Much better quality than any cork or rubber gasket from a parts store. It might be MLS or the like and is reuseable.

I'm old school and have no experience with a flush machine, I just drop the pan, change the filter, let it drain overnight and refill with fresh ATF.