tomasulo

Almost two months after clutch packs, it feels like shuddering has started again. Mostly after sitting for a while, I feel it. Almost feels like coming from front end, when wheels are turned just a little or all the way. The clutch pack job in rear end completely eliminated the shudder before. What could it be? Only happens after cold start and goes away after few minutes. If it's clutch pack again, I know my Ford tech said they are backed off quite a bit, that any further and I'll have no "Posi" in the rear end. It's more an annoying shudder/grinding feeling that goes away, but is there any damage happening? Why would it feel like it's coming from the front when I'm turning the steering wheel, even just a hair?

tomasulo

Anyone else run into the issue reoccurring?

tomasulo

Had truck back in after clutch pack was installed three months ago. Only variable shuddering came back just recently. My Dealer put in some Motorcraft Friction Modifier for free, to see if there's any change. They said they've done it to s few trucks and it's helped. Advisor told me that there's two spacers in the clutches that could be replaced, which may have a part in the shudder on takeoff (when turning) but to try this additive first. Will see how it goes. I know it's not hurting the truck, it's more the annoyance of the feeling.

mgarton

Update..

I haven't had the shudder return at all after a fluid change and adding friction modifier. That being said, I can feel the limited slip "slipping" sometimes when I'm taking off with wheels cocked all the way to one side. Feels like it grabs then releases every now and then. I don't know another way to describe it, but it doesn't bother me. Just thought I'd share that tidbit.

BrittainN

I have had a shudder since I bought my truck (2012 XLT 5.0). Today I finally got fed up with the shudder and decided to try some solutions I read online. First I placed a camera under my truck to see if the transmission was shaking. After it looked good I got under my truck and took the driveshaft of. I cleaned the yoke, filed off any knicks and applied some heavy duty high temperature grease (generously) to it. Once I put it all back together, I tried accelerating from a stop on a hill and BOOM! The truck drove like it was new. I don't know how often I'll have to grease the slip yoke, but it only took an hour and left me with my sanity of driving a smooth ride.

dhayes

[QUOTE=mgarton;4184520]SUCCESS!! No more shaking!

Here's how I figured it out...

I got some video from underneath and found no shaking at the transmission and no axle wrap. I then decided it had to be the differential. I took the cover off again and drained the fluid. It was kinda dark brown which was odd since I had just changed it, so I decided to put new fluid in. I used cheap stuff from the parts store last time, and figured maybe I should try the more expensive crap from the stealership.

I get to talking to the parts guy about my problem and he says he knows exactly what it is. He says you've gotta put friction modifier in it, but I told him I didn't think I have the limited slip diff. He takes my VIN and looks it up in the computer. Lo and behold, my truck came with an LSD. I've always seen LSDs with clutches or whatever in place of the spider gears, and apparently the clutches in the ford diff are NOT associated with the spider gears. My mistake!!

So I get the oil and modifier, put it in the diff, and it doesn't shake at all now! Moral of the story, know what equipment your truck has and use the right stuff!!

Thanks for all the replies and I hope this helps someone else

I thought you said you hade changed several diffs in the past how could you not tell the difference between an open diff and Limited slip it’s dramatically different….I’d try some additives or bad cv joint possible yolk issue