I am starting a swap due to a premature failure of my original trans. Have around 72,000 miles but it was run on low ATF for about 30 seconds and destroyed one of the clutches.

I’m now having issues with my 3-4 shift.

I bought a used tranny as a replacement, it’s the whole unit with a 6 month warranty. Supposedly coming out of an identical truck with about the same mileage.

I’m questioning whether to proceed with this particular replacement trans and seeking advice from anyone that knows more than me.

My original trans has the code A4321
The replacement trans has code A4322
–> what do these codes represent and what is the difference? (Have searched for this and found no answer)

I was prepping stuff today for the actual swap and checked my replacement trans to see if it was drained. It wasn’t but the fluid is DARK. I attached a photo of the fluid. This is some of the darkest trans fluid I’ve ever seen and I’m concerned it’s indicative of potential problems I will run into after running this trans a while...maybe after the warranty expires.


Trans fluid in my donor trans. Very dark, no burnt smell but seemed darker than 70,000 miles of normal use to me.

My other concern was the dirt in the threads of the dipstick nut. When I was pulling the cap/nut off to check the dipstick, after I broke the torque and started to remove by hand, it seized up and I could feel the “gritty” feeling while unscrewing it. I ended up needing a wrench to remove all the way and there was dirt and grit in the threads. —> this makes me think there’s probably more of the same junk in the fluid and potentially throughout the trans.

I don’t mind doing the swap and am confident I can do it based on my mechanical aptitude but I do NOT want to put a bad trans in my truck only to have more problems later.

So question 1: based on the fluid, dirt on the threads (assume contamination) and different ID code- what would any local expert on the forum advise me to do? Proceed and hope a flush gets all the junk out anyway? I figure I can put it through it’s paces before my 6 month warranty runs out BUT my other question (2) is whether I should just rebuild the trans I have?

i have no idea how to rebuild a trans but know I can’t afford the $2700 my local tranny shop quoted for a rebuild so I would do it myself. I’m also confident with a good guide or manual I could do it, I know my issue is a bad clutch for the 3-4 shift and a rebuild kit has all the clutches. I have the factory ford service manual which has diagrams but I’m not sure it has a detailed rebuild procedure.

Should I try to rebuild my own or move forward and swap the one I already have or should I swap but get a different used tranny based on my concerns with my current donor trans?(I have a no questions asked warranty/return policy on the trans I already got, so I can return it for any reason. There’s just no way to really know if I’m going to get anything any better- FYI I am mostly just looking at used identical transmissions on eBay).

I know this is a long post but wanted to offer all the details in hopes of getting some help from you all.


(PS - I have a similar thread but it is specifically about programming requirements so wanted to keep these separate since they are separate issues and may help people in the future with either specific problem.)

Thanks in advance.

 

Fluid looks normal, mercon LV turns dark quickly. I suggest while the replacement transmission is out drain the torque converter and pan. Change the filter and refill while it's out. The 6r80 needs fluid changes every 30k due to metal contain sticking solenoids.

 

Thanks, that is a relief about the fluid color. I already have the new filter and pan gasket, had planned to do that (required for my warranty).

Is there any specific process to follow for draining the torque converter? Refilling will all be done by filling through the pan and letting it cycle through - is that right?

Does anyone have any idea what the two different codes mean? Also any input on the exhaust bolts on the cat converters? The official procedure calls for them to be removed, I think because they are just really in the way and pulling the trans out would be much harder with the exhaust in place...but if I don't have to fight those bolts I'd rather not...

 

For what it's worth: When buying used parts, get the VIN of the donor vehicle from the seller then Carfax it and see if their story adds up. This can tell you about the part as well as the seller.

 

For anyone that may see this, here's a quick update:

I pulled my original trans out of the truck. Wasn't that hard but took a long time due to some very grumpy bolts on the turbos/catalytic converters and drive shafts . Luckily I got everything off without anything breaking!

In preparing to do the swap of the whole transmission, I still felt uneasy about the donor trans I received. Closer inspection still made me think it wasn't as new or low mileage as advertised. The trans was advertised as out of a 2015 F150 with 68,000 miles. My truck is also a 2015 with 72,000 miles. I posted a photo already of the ATF which was VERY dark compared to my fluid that's still pretty deep red (even before running on low fluid and refilling). There was also a lot of dirt on and around the trans unit, even some in different ports and fittings on the trans/bell housing.

Ultimately this made me stop and think a bit more before installing. I would hate to do all the work and have a bad trans I am putting in - even if it does come with a warranty.

I decided to call Ford and was able to verify the serial number of the trans I should have received, based on the VIN of the donor vehicle. Unfortunately my suspicion was correct. The transmission I received is NOT from the donor vehicle as advertised.

I had a crazy day at work so will be contacting the seller tomorrow along with eBay/PayPal to see how I can resolve this. Under my warranty, I can return the trans with no questions asked but they will want me to pay freight shipping to do so which I absolutely will not do given that they intentionally did a bait and switch and shipped me a different trans than advertised.

I'm still wondering about how I can combine my current good parts (valve body) with a donor trans to avoid programming and just be done as soon as I put the last bolt in place.

Any suggestions would be appreciated. Even having my trans removed, a rebuild will cost me much more than a used unit but unless I can verify serial numbers before/after on the next one, I have no way of knowing the true history of any used trans. Appreciate any help anyone can provide. Will post another update once I have one.

 

It sounds like one of these "companies" that pulls them from a junkyard and posts them on the internet with plausible numbers attached. I'm interested to see how this goes.

I know cost is a primary factor here, but I submit that a few more weeks of fighting the issue this way will start to make the cost a bit more appealing.

 

^Not sure what you meant by this? That it's worth paying the extra money to not have this headache or it's still worth fighting this fight to save the money?

I'm calling the seller today and immediately going to follow up via email and contact eBay. I'm hoping to receive the proper trans by serial #. If they cannot guarantee that I expect a major discount on what I received and will run it through its paces while under warranty. I suspect what I received has much higher mileage than what I paid for. The mystery mileage is my biggest concern about the one I got.

 

Either the trans is for your engine and driveline combo or it's not. So not sure what the hold up is on the swap? Used transmissions are a gamble and why I don't install them on a four year old truck.

 

Understandable but I don’t have the luxury of buying a new trans. I can afford the time
to wait and sort this out though (although not ideal since now I’m without a truck).

The hold up is that I paid for a trans with 68k miles and got one that clearly has more usage. Not to mention it was clearly not well cared for before shipping (see attached photos).

I am not putting a trashed transmission in a nice truck when I paid for a better/newer/nicer transmission. In short- the hold up and issue is that the guy who sold me the trans sold me one thing and shipped me something else.

you are right that this trans will fit, but I don’t want to swap again in a few months because this one fails

 

That has been sitting out on the ground or it came from a truck that was abused, rolled or flooded. They could have at least pressure washed it. Send both transmissions as cores to a place like Suncoast and get a rebuilt one in exchange. I understand it's more, but it's better than all of the aggravation and frustration that you're dealing with now. Not to mention down time, shipping costs and the good chance that the one you have won't live long, requiring you to remove and replace again.

 

I don’t know anything about Suncoast. Are you saying i can turn both in for an even exchange for a rebuilt one from them? Are they overbuilt or just built back to spec?

I’m contemplating doing the rebuild myself- just getting the kit and replacing all the clutches if I can find a good write up I may go that route.

Open to any suggestions if someone can weigh in there.

 

When you buy a higher mileage used trans always consider them as cores. They should be priced accordingly, I know that for a under 20k mile 6r80 they average 1300.00 with the 75k and up units right around 750.00. The transmission you have doesn't appear out of the ordinary for that mileage. The fluid looks fine and it has some exterior dirt, I don't see the issue? I have to ask what you were expecting on a used higher mileage transmission? I always tell customers used parts are used and someone else already took all the new off of it. These transmissions do have issues after 60k without fluid replacement as you have found. If your end goal is to install a used unit you want the lowest mileage possible.

 

You wont trade both for a rebuilt one, you'll get core value. They build upgraded units that address weaknesses in the stock units.

 

Suncoast doesn't do rebuilds their focus is torque converters and parts. I believe this is way more than the OP wants to spend.

Probably so. Even a Jasper is going to be over $3k with a core.

 

I'm approaching 90K and the tranny has not been serviced. I'd like to have the pan dropped, filter replaced and refilled but everyone around here wants to do a flush only.