another ? for the 06 F350

[K_Josh87]

Here goes another ? on this pig. I have a sweet obnoxious hippity hop out of the rear of the vehicle... crew cab long box.

I have replaced front and rear shocks last spring with Monroe Reflex shocks... Is it possible these are shot already? It has done this all summer... It runs okay down the road sometimes... and once it is settled in to its speed certain types of bumps get it going.

I have had all u joints and hanger bearing checked, checked out OK. Was told possible unbalanced drive shaft... but unlikely because no weights are missing.

Also have had it suggested it may be a shudder in the torque converter, It gets a hair better when brake is pressed and it winds up, but does not totaly disappear... and it has been doing this for several months, I would think this would have blown by now...

Could it possibly be a rear end issue?

Tires also have been checked and they claimed they where ok and balanced ok.

I just am stumped on this one, and it is pretty well a miserable pile to drive right now... and is really not doing anything else any favors by rattling around so much...

4wanderingeyes, If you have any ideas i'd appreciate it and could swing through H town and let you taker for a spin... Everyone I have talked to so far has been stumped..

Thanks!

[JOHNBIGDOG]

Is this a loud drone from the rear, with a vibration in your butt, or does it actually feel like the rear is hopping around.

Did anyone check to see if you have some frozen U joints. (I am just throwing this out there) there is a difference in a visual, versus take it out and flex the joints.

[K_Josh87]

there is a drone from somewhere yes.. and a helluva hop you feel in the seat... U joints where one of my first conclusions, we dropped the rear driveshaft and everything was great... we did not drop the one in front of the hanger bearing... I suppose it is possible this one is bad... I was under the truck when the tech dropped the rear shaft... maybe something to look deeper into... i bough the truck used, so it is possible the rears where replaced and that front is seizing now... I have done all of them on the front end... so very possible...

[Scott K]

Try adding a couple shims to the hanger bearing, to drop the drive shaft down more. Changing the drive line angle some. I am talking 1/4-3/8" maximum.

[K_Josh87]

like make up a 1/4ish plate and place in there or do they make shims for this?

[Scott K]

they do make shims, but all they are is 1x1" square 3/8" thick washers. I have used just plain round washers, and stacked them up. Make sure you dont over stack them, so the threads can still reach through the nut clip on the frame.

[JOHNBIGDOG]

I wounder if your drive shaft is out of ballance... It has a similar symptome as you are describing.

Try this, remove the rear drive shaft, put it in four wheel drive and test drive it. Be easy on it, the front drive shaft is not really intended to pull that big truck around. This takes the drive shaft out of the equasion.

[Lund4ver]

Do you know if the truck has a limited slip rear end? It could be the limited slip packs in the rear end that are binding up if it is happening when going around corners. Just a thought.

[K_Josh87]

Okay, so my game plan in tentativly this, once I get a chance to bring it in to the shop I am going to maybe give the shims a whirl, and also drop the lower nuts on the shocks and see how they feel. Even if they are new, they still could have been junk... or just need to go OEM...

It was suggested that maybe the shaft was out of balance, but there are no missing weights on it... so this doesn't seam real likely...

I do not think it is anything with the minimal slip, I have had that issue with half tons, and it is nothing like that... Not saying its not an issue with the rear end potentially, but its more so random at road speed down the road... and you can feel that it is still doing the hop when towing... but what is weird, is it'll be fine, and then just seem to go into its tantrum, then back out, then in, and out... and some particular roads are terrible compared to others...

[fishing tech]

Is this a vibration or an engine miss?

When it happens, is it speed related or rpm related?

Does it only happen in overdrive?

Is it consistant? You can duplicate it all the time or is it random?

If it is random I would think it is like an engine miss.

What is the speed of the shake/vibration/ miss? Real fast would be driveline or if its slower like tire speed?

[CAMAN]

Could there be any chance you bent the drive shaft ?

[Scott K]

Here is the tsb for the shims I was talking about. Usually it will shudder on straight heavy accell,

[K_Josh87]

thanks scott

[K_Josh87]

broke down and made an appt. at the dealership for next week... its getting more and more consistent, and I am thinking more drive train than suspension... I may just being a downer dave, but everyone who has rode in it thinks the tranny could be the culprit, or possibly the rear end somehow... so, we shall see what they come up with...

[K_Josh87]

Looks like fish tech might have nailed this one on the head, I wasn't thinking of the engine miss because when I had the miss before it was at an idle, and cleared out as the motor revved... But on the test drive today with the computer hooked up, cylinder three ran OK at an idle, and as soon as it was loaded up, or we leveled out on road speed it would cut out and miss...

So, looks like its the same ol problem I was having before, just actually time to do something about it... Just doing the one fore now, and hopefully that will get me through a bit, and if they start acting up again I think I will do the 7 at once...

Thanks guys!