Hello F150online community,

This is my first post so please bear with me.


My '08 5.4L has always had a bit of a 2-3 flare. I would be behind someone at a light, light goes green, person in front accelerates and backs off causing me to let off. They accelerate and as I would begin throttling up, neutral, and after a second it would engage 2nd rather harshly almost a bang depending on how hard you were on the gas when it engaged. A couple weeks ago I was on my way to work in the morning and it happened with a loud bang and went free rev. Thought I totally blew my trans on the on ramp to the freeway. I then realized I have 1st and 2nd but in OD it would then act like it was going to go to 3 and just free rev until I slowed back down to about 25mph or so when 2nd would re-engage. With OD off, 1st and 2nd work fine and it does not try to shift into 3rd which unfortunately limits me to about 45mph. I read through all the forums I could find and pulled the pan. I found some shavings in the pan, nothing broken upon inspection(retaining rings are known to crack/break/shatter and get stuck in the valve body) and the valve body springs and channels all appeared clear and the check ***** all were same size and looked great(at least from someone who has never opened a trans). I didn't see any problems and the truck ran the exact same after putting the pan and fluid back in. I bought a service manual, rebuild kit, torque converter and assumed I was going to need a direct clutch so I waited to open it up before buying any extra hard parts. I watched every video I could find and read through every forum I could and pulled the trans. I went through each and every sub assembly meticulously and couldn't find any signs of excessive wear on any bearings, seals, machined surfaces, gear splines or anything. I have years working in machine shops working with mills and lathes and when I tell you everything looks good I almost can't believe how clean everything looks. And most importantly to my entire write up, nothing broken. All the clutch plates looked exactly like the new Raybestos I put in. All the oil channels were still apparent accept one side of the bottom clutch plate in the direct clutch cylinder. I replaced all the seals and I've used Assemblee Goo on all the bearings and seals per and lubed everything else with clean Mercon V trans fluid. Here is where I am now. I'm looking at everything, knowing I could put it all back in the box in an hour, however, I haven't been able to diagnose an actual problem. I don't want to waste my time putting it back together until I have an understanding of what happened. The truck has 230,000 miles and I rebuilt the entire timing system last year. Any help would be appreciated as I'm getting more and more stressed out. Thank you.

 

Jro - Hi and welcome. I moved your post to its own new thread because the thread you posted in seemed fairly inactive. (The OP has not added any new information.) I think you might get more helpful information this way.

You don't say anything about the transmission clutch bands, and my gut tells me they could be worn.

- Jack

 

Thanks Jack! The reverse band has some wear on the tips. The OD band is just a dark brown and the friction pad is thinner than the new one I have however no real signs of damage or failure. Really no different than what I noticed in most videos I've seen. I will say that the two contact points on the OD band for the case pin and the servo pin do look pretty banged up and clearly have been worn.

 

Is the overdrive servo snap ring broken?

https://www.f150online.com/forums/tr...roke-pics.html

 

No, I was hoping for something simple like that, a piece of the snap ring holding a valve open or closed but they're all intact. Correctly locked in place when I opened it up.

 

Well that is embarrassing. I have all the subassemblies in separate bins and didn't bother mating the intermediate stub shaft to the direct clutch drum until now. Clearly all the grooves are stripped from the drum so I have one on order. Thanks for the replies!

Direct Clutch Drum sans grooves for intermediate stub shaft.

 

I've done many embarrassing things in my life. It's one way to learn what not to do. Hope you get it working in short order.

- Jack

 

You were definitely on the right track - direct clutch!