GM 6T40 trans

[adsm08]

Does anyone know anything about these transmissions, or why they blow up?

If I understand it correctly this is GM's version of the joint project with Ford that turned into the 6F35, but I don't recall seeing the same types of failures in those transmissions. And I was the guy who pulled the transmissions out for our tranny specialist for about 4 years, so if a Ford trans had an endemic issue, I usually knew about it. I know we did a bunch of 6F30s, very early in their run, but I don't remember what for. I know a software update fixed most of them.

A friend of a friend has an 11 Malibu that just stopped going. I have not been allowed to examine the car personally, but she has it in her head that it needs a transmission, and that she wants to put her seriously limited funds into fixing this car. When I initially went searching for the list of symptoms she gave me I found page after page of reports of catastrophic failure between 50K and 100K miles with this transmission but nobody knew what actually broke, just that the dealership put a new trans in, usually under warranty. They were never told what failed.

I am trying to convince her to just buy a different car, rather than sink money into this one, when I can't find anyone who knows the cause of the low-mileage failures. In my mind it makes any OEM junk yard trans suspect, and any reman susceptible to the same failures.

I have figured the cost of replacing the trans, flushing the cooler, etc, between $3200 and $3500, if no programming is needed, and depending on where the reman trans comes from. Closes used unit to us with less than 100K is almost 100 miles away and still has about 90K on it.

I have found several Focuses, a few Hondas, and Prius in our area with mileage similar to her car, within a few years of the same age, between $2900 and $3500. I kind of feel that all of those are better options than sinking the same money into what will be, in my mind, a suspect repair at best.

 

[07nhbpsi]

Hell, just the fact that it’s a GM product is reason enough to dump that turd....

 

[rusty ol ranger]

I think its the non servicable nature of the tranny.

 

[adsm08]

I think its the non servicable nature of the tranny.

Lack of service probably is the root cause, but they can be flushed.

I am looking more for what part is breaking to cause loss of all forward gears, not root cause.

Is a gear set exploding? Is the mechatronic unit junk? I have done a bunch of 6F35 mechatronic units for a bad gasket. Those were easy, and if that is a common failure on these I might try that first.

 

[rusty ol ranger]

I have no idea.

The ol ladies escape has this trans. Its at 135k and still chuggin along. It seems kinda quirky (always has). It shifts weird, kinda rough to me, but im used to E4ODs/C6s. It also does weird shit like not upshift if you use the resume on the cruise.

Its always been this way and its had the software updates.

 

[adsm08]

I have no idea.

The ol ladies escape has this trans. Its at 135k and still chuggin along. It seems kinda quirky (always has). It shifts weird, kinda rough to me, but im used to E4ODs/C6s. It also does weird shit like not upshift if you use the resume on the cruise.

Its always been this way and its had the software updates.

Is it a 4-cyl? That 6F30 behind the 2.5 in the Escape was always screwy with the way it shifted.

 

[85_Ranger4x4]

My wife's '08 Edge has a GM/Ford conflagration trans.

Something died in it, possibly a sensor. It would barely move. We just about got out of her parents subdivision when it quit. Limped it back and I had to push it up the driveway while she drove. Her dad went and got his laptop from work (he is a Ford tech) and we took it for a drive, it didn't miss a beat. He got to poking around and found it is a semi-common problem, replaced whatever it was and it has been fine for two years since. Whatever it was was above the valvebody IIRC.

Thing has over 200k, sometimes it kind shifts hard into a gear (so many I can't keep them straight, I would call it fourth in my F-150) but otherwise it drives fine.

 

[rusty ol ranger]

Is it a 4-cyl? That 6F30 behind the 2.5 in the Escape was always screwy with the way it shifted.

Yeah its a 2.5.

Im not really impressed with the drivetrain in it at all. It gets good mileage, but its nutless, vibrates like a bitch with the AC on at a in-drive idle, shifts funky.

Come to think of it, im not really impressed with the whole vehicle.

 

[adsm08]

Yeah its a 2.5.

Im not really impressed with the drivetrain in it at all. It gets good mileage, but its nutless, vibrates like a bitch with the AC on at a in-drive idle, shifts funky.

Come to think of it, im not really impressed with the whole vehicle.

I was never impressed with the 2.5 Escapes either.

Our 2010 3.0 AWD only got like 2 or 3 MPG less than a 2.5, on average, didn't shift screwy, and still idles smooth at 130K.

Your vibration is probably the alternator. There was a TSB for the 20-12 Escapes with the 2.5L for a vibration in drive, with the AC on, from about idle to 1500 RPM. The fix was to replace the over-running clutch on the alternator pulley with a solid pulley.

 

[Craig0320]

Speaking of the alternator. My wife's 05 altima 2.5 belt was squealing and flopping really bad. Turns out the alternator clutch pulley locked up. It allows the pulley turn one way and not the other when functioning properly. WTF.

 

[adsm08]

My wife's '08 Edge has a GM/Ford conflagration trans.

Something died in it, possibly a sensor. It would barely move. We just about got out of her parents subdivision when it quit. Limped it back and I had to push it up the driveway while she drove. Her dad went and got his laptop from work (he is a Ford tech) and we took it for a drive, it didn't miss a beat. He got to poking around and found it is a semi-common problem, replaced whatever it was and it has been fine for two years since. Whatever it was was above the valvebody IIRC.

Thing has over 200k, sometimes it kind shifts hard into a gear (so many I can't keep them straight, I would call it fourth in my F-150) but otherwise it drives fine.

Output shaft speed sensor. It is one reason I am so proficient at the mechatronic removal on those transmissions. The valve body has to be removed to get the plug in and out.

This is another thing that I would think if it was a simple fix like that it would be plastered all over the internet.

 

[rusty ol ranger]

Can i just go to ford and get the alt pulley to swap? Or can i yank one off an older 2.5?

 

[adsm08]

Can i just go to ford and get the alt pulley to swap? Or can i yank one off an older 2.5?

There was a TSB about it, so you can probably go into Ford and just buy the pulley. They might have to order it in, but it should be at worst a next day item. This isn't the same 2.5L that was in the Rangers.

The screwiest part of doing it is that the bolt that holds it is a 17mm allen head. So what you do if you don't have a super rare 17mm allen socket is get a bolt with a 17mm head, and two nuts. Tighten the nuts together and use a regular socket on them. It works best with an impact wrench too.

 

[rusty ol ranger]

There was a TSB about it, so you can probably go into Ford and just buy the pulley. They might have to order it in, but it should be at worst a next day item. This isn't the same 2.5L that was in the Rangers.

The screwiest part of doing it is that the bolt that holds it is a 17mm allen head. So what you do if you don't have a super rare 17mm allen socket is get a bolt with a 17mm head, and two nuts. Tighten the nuts together and use a regular socket on them. It works best with an impact wrench too.

Im gonna look into that. It drives me nuts.