2009 F150 5.4 with 6R80. Codes P0741 and P0735. Looking to fix myself.

I've done a lot of reading already and it seems narrowed down to the pump inlet seal, lead frame, or possibly and least likely the valve body. I have read the TSB's. I also have read conflicting reports on what lead frame I may or may not be able to use.

Does anyone know a proper part number for the lead frame I could use here? I have read I can use any of the ones floating around on ebay and I've also read that 09-10/11 have units that are different from 12+. I just can't verify what's correct. Appreciate the help!

 

You may want to double check that - pretty sure the lead frame problems occurred starting in 2011 when they mounted computer module externally ( unlike the 2010 and earlier models that had the control unit mounted inside transmission).

 

There is actually a TSB about this issue and based on the codes you have you probably don't need a molded lead frame, which in your case would include the TCM, making it different from the newer 6R80 transmissions and more similar to how ZF designed the 6HP family of transmissions to begin with.

The pump inlet seals are known to crack and the good news is these seals are cheap and it's obvious when they've failed so looking at it you'll know right away if the seal is your problem or if you have larger, more expensive issues to deal with. If you find a cracked seal I would just install the seal and replace the fluid and filter while your there. If your worried about potential leaks in the future I would also install a new pan gasket and a new bulkhead connector.

The lead frame in your transmission cannot be replaced separately from the valve body in most cases simply because they are programed to the flow characteristics of the valve body they are sold with and are not sold separately, the good news is this probably isn't your issue. It is possible to read out all of the programmed data in your TCM before removing it and program it into a new TCM after replacing just the TCM assembly itself but I'm not currently able to find a listing for a TCM that is sold separately from the valve body and one sold with the valve body is $1,229.03 plus a $275 core.

Personally I would just pull your valve body out and check the pump seal.

AL3Z-7F401-A Pump Seal
6L2Z-7G276-AA Bulkhead Connector
9L3Z-7A100-C Transmission Control Assembly

 

Extremely helpful information here, thank you very much. The ~$1200 was exactly what I was trying to avoid. With you confirming I can't replace the lead frame by itself your approach at taking it apart and checking the pump seal seems the most prudent. I really appreciate the quick and very helpful response!

 

yes that was good info. Keep us posted if it was the seal that ended up blowing out. I’m curious because I have the same transmission as you and good to be on top of this if it becomes an issue down the road. Did you only get codes and truck shifted fine or did transmission act up with those codes you posted? Hope you get it resolved 👍🏻

 

The transmission acted up a couple of times a long time apart. Twice I got the wrench on the dash and the shifting acted odd and power was low, but I was able to limp it home both times. The third time the wrench came on I also got a check engine light which gave the codes. I just today started digging into the transmission and this is what I found:





I'll start putting it back together tomorrow but I have high hopes this was the problem. I'll follow up once I get it back down the road.

 

yup - looks like you found it - also I found this pic of that TSB he mentioned earlier in post . Chime in how u make out - good luck

 

All is well! Everything went back together without much of an issue. I did have to use some assembly lube on two tubes coming out of the top of the lead frame to get that to go back in but that was the only real point worth mentioning. I used the lube on the thermal bypass too to hold it in place which it did perfectly. I really let the transmission drain through this process and took my time (48 hours in total) so I used 10 quarts to get to the fill line while running in park. I would recommend putting in 4.5 quarts, turn the truck on for a few seconds to let the pump pick up that fluid, turn it off and fill the pan again. This will save time while doing the final fill with the truck on as you're working against that cat heat up time.

Check engine codes are gone and the truck is driving perfectly. Issues appear completely resolved.

 

Glad this fixed it - Also good point to remember when refilling trans to limit exposure to hot exhaust 👍🏻👍🏻