Pulsating transmission brake in 2nd gear

[Utah Driver]

My 16' has a pulsating transmission brake in second gear. When coming down a mountain from a ski resort in second gear the transmission brake comes on and off. Has anyone heard of this? Maybe a software update will fix? I have the 6sp transmission. I ended up smoking the brakes in 10 degree weather on Christmas because the transmission has no hold back in second gear. Otherwise great vehicle.

 

[Hamfisted]

Check the fluid level or when's the last time the fluid and filter was changed ?

 

[Utah Driver]

The transmission has never been serviced. I'm around 77,000 miles so well under the 150,000 mile change interval with no leaks. The transmission is a 6 sp and works great. Only the braking function doesn't hold well. There is no dip stick. I guess I'll have to order the service dip stick. I did find a TSB for the valve body. https://www.carcomplaints.com/Ford/Expedition/2016/tsbs/tsb-ssm-46451.shtml

 

[Utah Driver]

I got this trans dipstick confused with my Chrysler. It looks like the dip stick on the Ford is part of the fill plug. I'll check it and report back.

 

[Utah Driver]

Ok, first I found I have to remove the diaper. Had to put on ramps, remove bolts on one side of the diaper and let it hang down. Checked the dip stick on a hot transmission and the fluid is low. I found out you have to jiggle the dip stick to make sure it drops all the way in for an accurate reading. I have to get some ATF and report back to see if it fixes the problem.

https://www.f150ecoboost.net/attachments/transmission-level-check-2012-pdf.166643/

 

[Utah Driver]

Adding some trans fluid has been a royal pain. I tried a very long funnel. No way it will fit in there. Had to go to Lowes and get like 4ft of 1/2" tubing. Attached that to my funnel and added oil. The CAT melted my new tube after I added some oil. There is literally no room on this and checking the trans dip stick with the hot CAT right there sucks. I took the expedition on a test drive and the surging seems to be gone, but not a lot of hold back. I'll have to take it up in the mountains to be sure. It looks to me like the difference between cold and hot on the dip stick is very substantial.

 

[Utah Driver]

My surging came back again. Only when coming downhill in second gear. I got the transmission to 195 degrees and adjusted the transmission fluid level with the dip stick. After a quick check in the owners manual, it appears that they want you to use the tow/haul button for most effective engine braking. I still think this a software issue. Maybe they want the tow/haul button pushed and the cruise on. I dunno?