Slipping tranny

[6speedsd]

Ok so I've had this truck for all of 3 weeks. Seems like its going to fall apart on me. I test drove the piss out of this thing before I bought it and found nothing at all wrong with it other than a clogged oil cooler. I got them down on the price because of it, knowing I could replace that myself, which I did this past weekend. One week into ownership start having stiction in an injector. Changed the oil when I put on a new cooler and it solved that problem. Oil that came out was as black as tar, even though they told me they just changed all fluids before they listed it. Anyways, on to this week. 2 days ago tranny starts to slip on 3rd and 4th shift. Not much, but it's a slip period. 3rd is every now and then, but 4th is almost every time. I got on it the other day and 4th slipped so hard that when it grabbed it almost broke the tires loose. Hasn't done it that bad since. It didn't slip the day I test drove it. Makes you wonder what they pour in with fluids to cover up stuff like that. Just doesn't seem to be a coincidence that it starts within 500 miles of me driving it off the lot. Now how the previous owner managed to do whatever damage he did to make 3 and 4 slip is beyond me. I would figure OD would go before those 2 did.

Anyways, is it common for a 3-4 slip to happen? Please tell me there could be something less expensive than a new trans that could be wrong! My wife will string me up if I have to drop more cash on this thing before I ever make my first payment! I know nothing about these autos. This is my 4th Powerstroke but my first one with auto. Any ideas?

 

[6speedsd]

Also, truck hasn't thrown the first code other than a cylinder 3 cont.

 

[willholl79]

What kind of miles are on the truck? I am assuming it's and 05 based on your sig. The
5r110 is one of the best autos offered in a 3/4 or 1 ton truck. The sad part is there is no way to know how the previous owner used the truck.

Usually in a truck with a 6.0, the trans. is the least of your worries, lol.

 

[brian89]

Torque converter? Drain trans oil and see if it smells burnt or if its completely black, if you want drop the pan and look at the magnet and see what it looks like, if you have a trans temp gauge drive it hard and see what the temp is, if it gets hot while in 3rd and 4th it could be bad clutches

 

[6speedsd]

About 118,000 miles on it. Fluid doesn't smell burnt at all. Still red in color. Don't have a temp gauge other than the stock one in the cluster. It always reads normal, but who knows how accurate it really is. My X3 shows where it can monitor trans temp, but it doesn't register anything. Guessing I need a sensor or something.

 

[6speedsd]

As I said I don't know much about these autos, but to me mine seems to run through the gears kinda quick. As in its usually shifted into 4th before I get to 35 mph. That seems a bit fast to me but it could be normal as far as I know. I can take off sort of hard, not like to the floor but faster than just a slow start and it'll do that. It'll be in 4th before I hit 40 mph. Is that normal?

 

[Mark Kovalsky]

Torque converter?

Torque converter? Really? How is that involved with the 3-4 shift? How can it make the trans slip on the 3-4 shift? Help me understand this.

The 3-4 shift is a synchronous shift. That means the intermediate clutch has to release as the direct clutch applies. The two clutches have to finish what they are doing within 0.030 seconds or there are problems. If the intermediate releases before the direct has applied you get an engine flare, or slip. This is what your trans is doing.

The first step in troubleshooting is checking for codes. A cheap scan tool WILL NOT read Ford transmission codes. They will tell you there are no codes.

The next step is to fix any problems, but if there are none, try disconnecting the batteries. This will clear the adaptive memory and let the trans controller relearn the transmission's characteristics. Once in a while the adaptive software can learn itself into a hole that it can't find it's way out of. This can create a slip on the 3-4 shift.

I'm surprised you (the OP) thought that OD would fail first. Why is that?

 

[6speedsd]

Codes were checked with my X3. Not a dedicated scan tool I know. Batteries were just disconnected a week ago when I replaced my oil cooler, and it was slipping prior to that.

My theory about OD.... I would think OD would be the weaker of the gears in an auto trans. Towing or a hot tune installed and someone flogging on the truck to me seems like a recipe to burn up OD, at least before 3rd or 4th. As I've said I'm no trans guru, and my theories may make no sense at all. I know it takes a lot to get mine to downshift out of OD, even with a loaded trailer behind it.

 

[Mark Kovalsky]

Interesting theory, but I'm not buying it. I don't know why OD would be weaker than the other gears.

 

[6speedsd]

Look I never said I was right, nor am I here trying to make you believe what I'm saying to be true. I just want to know what's going on with my trans, and how I can fix it. Simple as that. There are plenty of people here with far more knowledge of these trucks than I have. That's why I am here asking questions. To try and learn more about something I don't know a lot about.

Your sig says you are a former master trans engineer. Ok, what does it sound like to you and what can I do to fix it?

 

[bluedge8]

Mark is THE man when it comes to these transmissions, he is a great asset to any forum he is on.

 

[6speedsd]

Never questioned that.

I just want to know what's going on with my trans so I can fix it.

 

[bluedge8]

Never questioned that.

I just want to know what's going on with my trans so I can fix it.

I figured, and I understand you wanting to get your truck running right. It is amazing that we have access to such talent as Mark, in just about every post he has posted here I learn something new. Hopefully you get your trans worked out.

 

[Mark Kovalsky]

Ok, what does it sound like to you and what can I do to fix it?

I would start by reading this post that you must have missed:

The 3-4 shift is a synchronous shift. That means the intermediate clutch has to release as the direct clutch applies. The two clutches have to finish what they are doing within 0.030 seconds or there are problems. If the intermediate releases before the direct has applied you get an engine flare, or slip. This is what your trans is doing.

The first step in troubleshooting is checking for codes. A cheap scan tool WILL NOT read Ford transmission codes. They will tell you there are no codes.

The next step is to fix any problems, but if there are none, try disconnecting the batteries. This will clear the adaptive memory and let the trans controller relearn the transmission's characteristics. Once in a while the adaptive software can learn itself into a hole that it can't find it's way out of. This can create a slip on the 3-4 shift.

 

[6speedsd]

What actually causes that to happen in the first place? Poor maintenance? Over heating? Just trying to get a better understanding of it.

I thought about doing a fluid/filter change, but that may not help anything. Dealer said they changed all fluids as I said earlier, but I'm not so sure I believe them.

 

[Mark Kovalsky]

I think what causes it is some of the transmissions are outside the tolerance that we saw in development. We tried to cover every eventuality, but after building millions of transmissions something is bound to happen that we never saw when developing these.

 

[6speedsd]

That's understandable.

So say it shows no codes, and disconnecting batteries doesn't help. Is there anything else that can be done to fix or help the issue, short of a rebuild? Would bumping up line pressure with a tune help, or just make it slip harder? I assume with it slipping I'll eventually burn up the clutches.

 

[Mark Kovalsky]

It could be a bad solenoid, too, or a damaged direct clutch.

 

[6speedsd]

I wondered about a solenoid. I assumed there would be one for the 3 and 4 shift. Are the solenoids internal? Or are they on the outside?

 

[60powerplant]

I would try put a gogo direct clutch solenoid in. You just got to drop the pan and there right there. I don't know to much about this but in all our mustang Trans we run John deere hy gaurd fluid and it's like night and day it helps with slipping and the value body shifts way better and it take heat a lot better. I hav a 05 6.0 and it has a good shift with normal driving but half throttle pulls it slip in to gear. So this week I'm going to try the hy gaurd fliud. I mean we run it in our 1200 hp turbo mustang! I don't know maybe someone can give there in put about maybe try this.