dhagen100

Approx. 9 months ago I had TSB 12-07-13 (lube drive shaft) and TSB 11-9-17(install new spacer on rear end/new U bolt and nuts) on my 2011 F150 screw with 6.5ft bed. I had these done due to a shudder on moderate acceleration and deceleration. After the TSB's the problem was gone, no shudder. 4 months ago I had a HBS 2'' leveling kit installed, never had a problem. Yesterday my shudder returned exactly the same symptoms as before. Have an appointment at the dealership next week. Anyone else out there had a similar issue? If so did you do anything else besides the TSB's listed above?

SkiSmuggs

Why not just install the RoadMaster Active Suspension and be done with it? Many here have done that and problem solved.

dhagen100

well the threads i read from 2011 some said it helped and some said it did nothing, have there been any issues with warranty coverage?

SkiSmuggs

I haven't followed the threads as I don't have the issue, but the original threads I saw were overwhelmingly positive about RAS fixing the problem if the problem was axle wrap. If I replace my current truck with a 6.5 bed for the HD Payload package, RAS will be one of my first mods among a Southern Speed (formerly SoCal) tune and an after market IC to replace that sorry IC they are using now.

zimmer0

iTrader: (1)

spring clamps placed on the leaf springs ~6" in front of the axle. Cheaper, same concept as RAS as far as axle wrap

dhagen100

well I don't believe it is axle wrap, since the TSB's done previous removed the problem completely, at least for a short time. I will definitely have to take that into account. Thanks for the info. I wonder if its possible the leveling kit has changed the angle enough that is now out of whack again, but why would it take so long to start shuttering again.

OddBall

It absolutely is axle wrap. I'm sure that some of the ancillary problems are related to the other TSB's but the ultimate cure is a helper spring added to the current leaf pack, clamped to the pack, or a set of ladder/traction bars.
The problem is you will lose some of that nicer ride when it's unloaded. Now, to be fair, the RAS does help quite a bit but it doesn't seem to cure all of the problems. I haven't decided yet whether to get the RAS setup or a set of helper springs.

See the image below so you understand it completely. I've dealt with this on other trucks and cars with live rear axles so it can be cured.

dhagen100

thanks for the picture, and I do understand what it is, but why would it not happen for 9 months after the TSB's were performed? With varying levels of throttle the whole time. Now it happens at soft acceleration/deceleration, it happens at harsh acc/dec. and it only started to show up again yesterday

dhagen100

i guess i could try this and see if it makes any difference...beats going to the dealership

OddBall

Thats a bit of a mystery to me as well. Perhaps lower temps, depending on where you are. Did anything change? Habits, driving style, temperatures, etc??

I get the shudder every single time I step on the gas, initially, then it disappears. I've noticed a slight shudder on deceleration too which would probably be axle wrap in reverse.