Teach Me: Ford 8F35 Transmission

So, my van (2020 Transit Connect) needs a transmission, or so the Ford Dealer says.  109k miles.  Googling symptoms seems to confirm this.

The amount they quoted me is... a lot.  $8200

Some follow up questions:

1)  Does anyone know what typically causes the failure on these?  Do they just wear out quickly?  They specify no fluid change interval, I could see that contributing.  But it doesn't seem like there is any hard item inside that just breaks.  As a result I'm having a hard time understanding if I fix it, is there any way to ensure the next one lasts?  Or more importantly, when they fix it, are they correcting some inherent design flaw?  They are used in a LOT of vehicles*, and there also seem to be a LOT of failures and I'm trying to understand why there isn't more information about it.

Brainstorming, I could see how maybe a cooler could help, 30k fluid changes, a remote filter?  

2)  I didn't get details over the phone, but I'll pick it up from the dealer tomorrow and ask:  Why is it that much, can you give me a breakdown?  But is this reasonable?  I figured its probably like $3k for a new unit then... 16 hours to install?  A $200 bill rate, thats still $2k short .  Anything else I should be asking?

3)  Is there any reason to go to the dealer over another shop (AAMCO or similar) if the other shops are offering a lower price and the same warranty?

 

I think I have accepted that I'm going to pay a good chunk for a transmission at this point, just would like to make this next one last.

*including heavier, more powerful stuff, with higher tow ratings.  Turbo Maverick for example.

Bump for the morning crowd, heading to the dealer shortly, any other advice?

Not sure what symptoms you're experiencing, but there are a couple of TSBs that might be helpful info to have:

https://static.nhtsa.gov/odi/tsbs/2022/MC-10226926-0001.pdf

https://static.nhtsa.gov/odi/tsbs/2021/MC-10203649-0001.pdf

From some brief looking around, it sounds like there may be an issue with the torque converter and/or lock up solenoid, but no one is really sure what is going on.

What does seem to be confirmed is that there is no actual fix in place at Ford, they are just putting in a replacement that has the same projected lifespan as the failed one.

There is an interesting section from one user about a larger cooler and a different fluid thermostat to allow a different flow pattern.

Below seems to cover most of what I saw.

https://www.reddit.com/r/FordTransitConnect/comments/1bccftp/ford_transit_connect_transmission_broken_at_80k/

I have it at another shop now for a second opinion and quote.

Ford said Parts are $5900.  Which seems like a lot for something they expect to fail in the same manner.  They couldn't tell me anything about the guts or give me any confidence that I wouldn't be back in 3 years for another one.

I picked AAMCO guy's brain and he said hes done maybe 3 8F35s in the past 5 years.  Which doesn't seem like a high failure rate, but obviously a single data point.  He also couldn't give me any confidence they've revised it or fixed the issue.

Dealer report says "CONDITION IS HAS FRICTION MATERIAL FROM INTERNAL CLUTCHES COMING APART RECCOMEND REPLACING UNIT" (exact transcription, not my typos).  I didn't get to speak with the tech who did the diagnosis, so I'm assuming that's just form a fluid sample or experience from doing these.

In reply to TravisTheHuman :

That kind of supports the guy in the reddit thread who was messing around with a larger cooler and different thermostat.

He put in a manual gauge and saw way above normal fluid temps with normal driving.

I don't really have anything constructive to add other than that this is your golden opportunity to do a manual swap on this glorious beast of an automobile.  Isn't there some shared DNA between the Transit connect and the Focus? In fact, it wouldn't surprise me at all if they made a manual version in Europe.  

Mr_Asa said:

In reply to TravisTheHuman :

That kind of supports the guy in the reddit thread who was messing around with a larger cooler and different thermostat.

He put in a manual gauge and saw way above normal fluid temps with normal driving.

I need to think about this some more.  I dont know what the thermostat is like and how easy it is to replace.  I dont have the facilities to work on cars at the moment so I'd need to be incredibly explicit with an ask like that for a shop.

rothwem said:

I don't really have anything constructive to add other than that this is your golden opportunity to do a manual swap on this glorious beast of an automobile.  Isn't there some shared DNA between the Transit connect and the Focus? In fact, it wouldn't surprise me at all if they made a manual version in Europe.  

As I mentioned above, I currently don't have any facilities to work on this.  Or a backup car.  If you know of a shop in NC that will swap it for me for a similar price, I'll happily pay for that instead.

This thing is used in so many vehicles there must a be a business opportunity here.  Maybe its a simple as a cooler/thermostat kit.
 

Damn man, I'm sorry to hear that.

To be completely honest, the transmission is why I got rid of my 2015 TC. The 6F35 isn't known to be very good. IIRC, it was also used in the Ford Fusion, which was either recalled or had a TSB because the axle shafts would wear the seals down due to a manufacturing defect. The 6F35 also didn't have an actual dipstick, so verifying fluid loss was difficult. No dipstick + leaking axle seals = unnoticed low fluid level = kaboom.

After finding that out and realizing the PO treated the van as disposable, I started monitoring the transmission fluid temperature. I had no record of the PO changing the transmission fluid. I was able to verify the fluid level; it was just a tiny bit low so I topped it off. The fluid temp would crest 250°F cruising on the highway. In stop and go traffic, it would reach nearly 260°F.

Fearful the 6F35 was a grenade with the pin pulled, I dumped it.

Also, the fluid cooler on the 6F35 also liked to plug up with clutch material and cook the transmission. I ordered a Ford replacement cooler but FedEx crushed it. The replacement didn't arrive until after I sold the van.

^All of that points to this potentially being fine if

A) fluid changes are done with some regularity (as opposed to never, as Ford recommends).

B) A thermostat bypass or cooler is used that results in lower trans temps

TravisTheHuman said:

^All of that points to this potentially being fine if

A) fluid changes are done with some regularity (as opposed to never, as Ford recommends).

B) A thermostat bypass or cooler is used that results in lower trans temps

The guy in the reddit thread mentioned he was working with Superior Performance for the thermostat and they may be developing a kit.

Mr_Asa said:

TravisTheHuman said:

^All of that points to this potentially being fine if

A) fluid changes are done with some regularity (as opposed to never, as Ford recommends).

B) A thermostat bypass or cooler is used that results in lower trans temps

The guy in the reddit thread mentioned he was working with Superior Performance for the thermostat and they may be developing a kit.

Been going down this rabbit hole for a bit.  Have I mentioned I hate reddit?  

Superior Performance doesn't list anything for the 8F35.  They do have 3 Kits for the 6F35, but understanding the difference is difficult.  Our Products | Superior Transmission Parts - The problem solvers of the transmission industry

The thermostat bypass kit seems to have a few options.  Based on the bypass design, I would be 0% surprised if the bypass was identical between the 6 and 8 speed.

Anyway, I found this lengthy thread which is about the 6F35, but mostly discusses the same issues.  Some people point out the overheating issue.  There are some useful diagrams in there.  Overall though, no real solution presented.  Lots of talk of coolers, which don't seem like they would hurt.  Some talk of adding an external filter, which could be a huge help, but I'm not seeing any success there.

Might be worth reaching out via phone?  Might not be something they have ready for mass production?

Good luck, man

In reply to stanger_mussle (Supported by GRM undergarments) :

that seems like a huge problem to me...all of the Chevy guys preach that if your 4L60e fluid temps get above 200F, you're cooking clutches. 260F is not bueno

Mr_Asa said:

Might be worth reaching out via phone?  Might not be something they have ready for mass production?

Good luck, man

I reached out to them, no they haven't made anything for it.

It does seem like the parts exist to use the cooler from an Escape, Maverick, or Bronco Sport with the tow package.

Makes me curious to know what the trans failure rate might be in those vehicles that are equipped with the tow package and it's associated cooler/hardware.