I've got a '99 F150,automatic trans, a shudder that only happens while accelerating after a stop with the wheel turned.
The shudder seems to be getting worse. It only happens if I'm turning after a stop, and then only under 10 mph. It's hard to tell if the shudder is from the front end, engine, transmission.
I still have a warranty ot it,does this happen in alot of other f-150's.
Thank's

 

I think I found my problem (LS Unit), I did a search and found the thread below, if it is the LS unit and I put friction modifier in the transmission how will that help, and how long will the car be tied at ford.I just had it in there for 2 week's with a oil leak on my heads.Also even though it is under warranty how much will it be.
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You did not mention if you had a limited slip rear axle. If you do, (which it sounds like you do) the LS unit could be worn out. More than likely, the plates are worn and they chatter against each other. You could try replacing fluid and the friction modifier additive for the LS. It would only be a temporary fix. I would suggest just rebuilding the LS or replacing it with a stronger unit like an Eaton. That should take care of your problem.

 

The LS clutches are the most likely culprit and the simplest place to start.

If you're concerned about Ford holding onto your truck too long, you can add the friction modifier yourself. Ford P/N C8AZ-19B956-A It is reccomended to add 4oz, which is 8 tbsp.... That's 8 tablespoons for those of you that don't cook

 

How hard is it for me to do the job myself,I mean brakes,plug's,oil changes etc is as far as I go.If I put in this friction modifer guys are talking about adding, would it be the right way to go.Or will I have problems later on down the road.I did plan to keep this truck since I just sent them the last coupon in my payment book.
Thanks

 

If you're concerned, just take it to the dealer. It's fairly common for the clutch packs to wear and need to be replaced by 80,000 miles anyway. Maybe yours are worn.

 

AjRagno,
Thanks for the help on answering all my posts on my shudder problem.I am going to drop it off monday and hope for the best.Thanks again.

 

WOW HAMMER DO NOT put friction modifer in your transmission it is for the rear end not you tranny. In saying that the shudder does sound as though it is the LS clutch pack sticking. I had the same problem after changing my Differential fluid With a Sta-Lube synthetic gear oil and my truck started getting that exact same problem after only about 35 miles so I Changed the fluid to Redline and the problem went away. So here is a warning to anyone wanting to try the STA-LUBE brand of synthetic Gear oil STAY AWAY from it it is worthless in my opinion.

Richard D.

While your here check out my gallery:
https://www.f150online.com/galleries....cfm?gnum=2479

 

Sorry,I meant the rear end.It sound's like everyone is in agreement that it is the LS clutch.So far when I have asked a question on this site you guys hit it right on the head,abs light on,oil leak in heads, (both)shudder at 66mph. .
thank's again.[IMG]
PS: IF you are wondering why I have two names it is because when I first signed up with hammer I changed to DSL and forgot my e-mail address and I couldn't get the same one back or something like that,it don't matter it is the same person.Me

 

It was the LS plates,I forgot to thank all you guy's.

 

So did you add the friction modifier or change the LS plates? If you changed the plates, how much did they charge?

 

My 1997 with 79000 miles has been doing this for a year. I replaced the diff. with new oil & friction modifier but there has been no change.

I'm curious as to know how big of a job is it to do this changing of the LS Clutch Plates, and what would I be charged to have this done?

Thanks

 

I am curious about how difficult the job is as well. My 2000 with 103K has started doing this. Does this job entail any specialty tools, or calibration equipment???

If it is something that is not a DIY repair, then is a reputable garage, other than a dealer capable??? Or is it something that should go to the dealer???

From experience what is the cost???

 

I have an 03 EB Expedition with 4 wheel IS. I have about 11K on it. I bought it in May 2003. I started having this exact problem about 2-3K ago.

I think my differentials are different than the previous models.?

I have been meaning to take it to the dealer. But I was also hoping it would go away. I notice it does not do it after a long trip or when I've driven it long enough for the driveline to get hot.

I notice it more on left turns from a stop than right.

But now I know what to tell the dealership when I take it in.

LS Clutch Pack is sticking, eh?

Anyone think it could be something else? Any other newer models have this problem?

Thanks!

 

White03EB

Mine began with left hand turns, and now does it in turns in both directions. Let me know what the dealer charged for the repair. My guess is it will be expensive. That is why I was asking if it required any special equipment or calibration. If not it is possible it would be cheaper at a different service facility.

 

I am under warranty so I dont think it will cost me a dime. Other than the pain of dropping it off, getting a free loaner, then having to pick it up. Only 2 miles from work and home.

Still a pain.

I will post what they find.