kiotie

I have a 2010 F-150 Super Crew with 6.5 foot bed with 41,000 miles. A couple months back I had a hard bump when I would accelerate from a stop or from slow moving. It would also happen when I had to brake fast at low speeds. I looked through the forum back then and found some issues that people where having and told my dealer about them. First they did an update and a flash which did nothing. Then they lubricated the slip yoke and the bump was gone. The bump is coming back now, so I took it in and they said that it is caused by my "altered suspension" (2.5 in level kit in front and 2.5 in block in rear) They say that it threw my pinion angle off and it needs to be shimmed into place. This is not covered under my warranty of course. And they wont lubricate the slip yoke again. Has anyone had this issue on their truck?? I'm not sure what to do next. I don't think I really trust my dealer to get the right diagnosis. Any help would be greatly appreciated.

dootech

if you've already done some research you've probably read some of my posts, if not lookup my recent posts as i did a write up on the slip yoke lube job.

i have the same set-up you do (2.5" level, 3" rear block and 6.5' bed) and i haven't had any issues since i lubed it.

i strongly recommend you don't let them talk you into re-shimming the rear end.

your dealer is full of s***. how can the pinion angle change? the pinion angle in relation to the ring gear is set up inside the rear end, as is the shim needed to get the correct mesh. all you have done is slightly alter the angle that the [B]U-JOINTS[B] operate with.

kiotie

Thanks for the help, I read the article. I'll probably give it a try.I didn't spend this much on a truck just to have ford tell me they wont fix what needs to be fixed. I have already been through one lemon with them. If that is a know issue then ford should be willing to fix it when I have a 100,000 mile warranty.

BLACKOUT FX4

Weird thing is, My old 2010 had adjustable coil overs and 2" rear blocks installed the day after I bought it and always had the bump on take off issue, I just thought it was normal.. Well, I traded it on for a 2011 FX4 and didn't do modding to the suspension for the first 3 months and 8,000 miles.. Wouldn't you know, I have my 2" level and 2" block installed last week and immediately the bump appeared.. So, It definitely has something to do with lifting the truck but I don't know exactly what??

93Cobra#2771

iTrader: (2)

Pinion angle.

kiotie

ANybody else have any ideas how to get this fixed for good. I don't trust my Ford dealer to mess around with the angle of anything on my truck.

moule1991

Pinion angle is not internal. Rather external and in relation to the driveline. Your lift most definitely changed it. Made it more severe. However my stock truck did this as well and lubed the slip yoke and all is good. Lube again yourself and problem should be solved.

ns_redneck

i have this problem too. mine is all stock. they lubed the splines and it went away for a bit. but odley enouph mine seems to almost go away with realy cold tempatures. and gets worse the warmer it is.

moule1991

Didn't we clear this pinion angle bit before? You did absolutely change the pinion angle when lifting or lowering. It has nothing to do with the internal gear lash of the ring gear!! It would be the angle the pinion is in relationship to level which is also changing the plane the ujoints operate in. this can cause a binding or shudder on take off or acceleration.

However I have the same set up and have found that my truck required the slip yoke lubed every 20k miles and then it goes away again. The bump that is. And it's like day and night after lubed. It's only a 10 min fix under the truck. Just make sure you keep the splines in the same alignment or you'll get ujoint wear issues.