Guys, I recently starting having shudder when going from idle throttle on my 2005 supercrew 5.4 4x4 with 110k miles. Seem to be getting worse and very obvious when accelerating after taking a turn.

Any ideas on diagnosing are greatly appreciated.
Thanks.

 

New plugs & COPs. Clean MAF and Throttle Body. New fuel filter and FPDM.

 

It feels much more like a transmission/ rear end issue.

 

Limited slip clutch chatter. Change the diff lube and add Ford friction modifier.

 

X2
The dealer said they replaced my clutch packs because they were worn out, the shutter was really bad. I'm not sure if it's true or I was taken for a fluid change.

 

Yeah when you mention it happens after turning that tells me it has something to do with your limited slip. Maybe new clutch packs?

 

With 110k, I think a fluid change and modifier should take care of it. Service interval on Ford LS rears is 100k.

75W140 full synthetic and a bottle of modifier from FORD.

 

Same thing happened to me...change your diff fluids.

 

Ok. I changed the fluid with royal purple not too long ago...think I can just add friction modifier on top as long as it does not overflow?

 

You can always suck some fluid out to make room for it.

I don't know whether RP has modifier in it or not, but the only modifier that really works is the stuff from Ford, and in a 9.75 axle sometimes you need 2 bottles.

 

Thanks for the info, guys.

 

Interesting articles about the rear end shudder……Here's where I am at with mine:

2004 FX4 3V
65K miles
9.75 rear end
Original shocks
Stock parking brake removed

Mine has been shuddering off and on for about 15k. I just drive on average about 10 miles a day. The truck never gets used to haul much or tow aside from my buddy putting his 6500# boat in once a year. Lately it has been doing the shudder worse during around town driving, primarily during turning but I *think* I feel it sometimes just a bit during straight acceleration. It seems to do it for a day, and then be fine for several days. I had the rear end oil changed and my mechanic used Mag 1 75W140 synthetic oil and Lubeguard limited slip additive. While not Motorcraft, he advised they are both to Ford spec. I know the clutch pack replacement will be a grand, and frankly I am on the fence about having it done. I have read all the threads here on the topic and I am wondering how much harm it will do to leave it. The one thing I have NOT read is any proof that leaving it alone results in a differential failure. I also wonder if I should have the fluid rechanged to Motorcraft fluid first and see, or if I am wasting my money.

Now that this issue isn't a new one, I am wondering what you guys would do next if you were me. Thanks. It sounds like maybe the next thing to do is drain out enough oil to replace with a bottle of Motorcraft friction modifier and see what happens.

 

I would drain out enough oil to replace with a bottle of Motorcraft friction modifier and see what happens. Cheapest way to go. If it doesn't work ,then you know what you have to do, But give it sometime to work, not an overnight fix.