First time poster here...I love this site !!!
I recently bought a 2002 F-350 Dually 7.3 Crew Cab Short Bed as a tow vehicle for a 5th wheel camper. The truck is in pretty good shape and runs great, and has 250,00 miles on it. My question is this. I took the truck to Aamco yesterday to have the transmission fluid and filter changed before my trip from North Carolina to Florida in a couple weeks. I really have no true maintenance records so I thought the safest thing to do was to service the transmission so I was not stuck in Georgia on the side of the road with 3 kids, wife and 2 dogs all mad at me. To my surprise, the manager at Aamco said he would not do an oil and filter change because of the miles that were on the vehicle. He said that transmission fluid has a high detergent quality and would loosen contaminants and create problems that do not exist. I called a friend back in Buffalo that has worked at another Aamco for well over 15 years a he told me he never heard of that and he would have power purged the oil and changed the filter for me without a problem. Anyone else heard of this? Who is right ?.
The Aamco here in Moorseville did do there $39.95 inspection and that was all. Would love some feedback and also...I could do the service myself, I thought because they have more experience they could inspect also.
Thanks so much....Bill

 

Pull the dipstick and inspect the fluid. If it's in relatively decent shape, change it. If it smells burnt or is really nasty, don't expect much more life out of the trans either way. DO NOT POWERFLUSH it. Use the engine to pump out the fluid through the cooler. Here is a write-up on how to do it. The only change is that you CAN use Mercon V now. Ford changed the specs on it so it's compatible with our 4R100s.

Changing ATF Fluid in a E4OD and 4R100 transmission .: Articles

 

I changed mine 3000 miles ago and no problems yet. Same thing, I did not know the history of the old fluid.

 

Welcome to FTE, i would change all of the fluids in the truck just to be safe.

 

Welcome to FTE and some great folks...I would go with what was said by these folks ^^^^....You will be fine.Then stay on top of the maintenance as the miles go by...Have a safe trip

 

I heard the stories that on badly contaminated fluid -the power flush pushed contamination into small passages and created a problem.
I think draining the pan and replacing the filter is always safe way to go. It will exchange only like 30-40% of fluid, but it will not disturb the transmission. Most of contaminants rest at the bottom of the pan anyway.

 

Would a person want to add any extra conditioners to the change?

 

Pull the pan & inspect a very thin layer of dirt looking material across the pan would indicate some clutch pack wear and that would be normal with that many miles. But if there is a lot of friction material in the pan clean pan refill new filter put a bottel of Lube Guard Red in and hope for the best & start saving money for a build!!! If the pan is clean and the ATF is in good shape ( still pink & no burnt smell) you should be good to go. I have been told by many buliders if you service it on a regular basis keep it up but if you dont it can & most likley will accelarate a failuer
The guy at AAmco is kinda correct ATF is very high in detergents & will clean like a solvent, Ever seen a tranny builder with dirty hands?
Hope it turns out well for you 250K is a bunch of miles for @ 4R100

 

Welcome to FTE Bill. Great first post, the achilles heel of our trucks! lol
Follow the link the link Izzy351 (Joe) posted, it is detailed instructions on how to
do the fluid change and it is relatively easy to do. Stick around we will save you alot
of money on repairs and teach you how to spend the saved money on mods!!

 

Utter BS. When they have real scientific proof behind it, I'll believe it. Obviously if you have 250K and not done any service, the trans is living on borrowed time. Flush it and it might break anyways and when it does, it is the fault of the flush. We had a Ford dealership that hung a "Not Working" sign on their dyno because a few kids had brought a POS car there, run it on the dyno at WOT and blame them for breaking the engine. I think that manager got bit a few times from people bringing in transmissions with poor service done on them. Had them flush it and when the trans broke, the flush is at fault and tried to squeeze money out of them for a rebuild.

Edit: Aamco transmissions. Well, they are a real good supplier of rebuilt anything. That is why I would use them if I were selling the truck.

 

Again, not a shard of science has proven that yet.

 

I'm not sure what type of machine Aamco uses to do transmission fluid flushes, but the one I used when I used to work at a Penske Auto center just tied into the cooler lines. You plumbed the machine inline with the cooler and started the car. The pump in the transmission pumped the old oil out and into a tank in the machine, and the machine pumped new oil in. I'd have to adjust the dials to keep the flow the same and keep some back pressure on the pump, but I'd run fresh oil through till it was nice and red. I'd put 20-30 quarts of oil through a normal transmission just to make sure I had all fresh stuff in it. I'd also go and shift it through the gears while it idled to clean out the valve body and pistons.

The pressure going back in was the same as what the transmission would of been pushing.

The issue with flushing a older transmission that hasn't been serviced may be more with the new oil holding pressure better and blowing out piston seals, but I'm just guessing.

If your truck made it 250k miles towing a 5th wheel and hasn't had the transmission fluid changed, or the transmission replaced, I'd be surprised.

I'd also check to see if you have a larger transmission cooler, or if there is a transmission gauge installed. Could mean that the previous owner cared for the transmission and might of kept up on the service.

 

OK.

Are you sure the oil holds pressure? I thought fluid is very hard to compress. I think the issue is if you crank up the pressure to way more than the trans was designed, like you are talking about in the first paragraph, you might blow a seal out.