Fellas,

Ever since I bought my 03 6.0L the tranny has shuddered when taking off. The engine must be warm (and therfore putting out close to full power), but the pedal doesn't have to be mashed. It just has to be a smart takeoff - not leisurely.

Anyway, it has been like that since I got it (used) with 18k on the clock so I assumed that it was normal cuz it only happened in first gear and this moter puts out GOBS of torque. I thought it was just slipping a bit to save the tranny. Well, my truck now has 41k on it and the shudder is now showing up in second and third gear too. Not nearly as bad but still there and still fairly obvious.

I had the tranny fliud replaced (they don't normally flush it do they?) by the Ford Stealer around about 30k but the problem hasn't shown up until the last 2-3000 miles.
Anyone have any ideas what might be the problem?
It wouldn't have to do with the limited slip rear end, would it? The LS is not limiting the slip. I have the crappy Pirelly Scorpion dry weather street tires on my truck (factory tires on a truck that came from Canadia) and the snow we have had here recently has revealed the junk that these tires are in the snow belt. That and they are reavealing that the LS is acting as an open dif now. I really have to work to get the truck to pitch sidways

What do you thinK?

Big

 

I'm not sure on the tranny issues, that doesen't sound good. As far as the pirelli tires, I had the same problem untill I aired them down to 40 psi. There still not the best but airing down sure helped. The ford limited slip doesen't seem to work like the older tru tracks did. I am having the same problem, I took my truck into the dealer last week and went for a ride with their differental guru. He said that ford wants you to preload the limited slip using brake pressure. Even with him driving the L/S only worked about half of the time. He said that the factory preload setting on these L/S is about 20 ft/lbs. not much when you consider that we are cranking out gobs of torque with these engines. Hope this helps

 

Seems to me that drive shaft alignment (or mis-alignment as the case may be) created the same shudder sensation you describe.

Try a 6.0 forum search as there was some discussion here a few months ago and I believe a Ford TSB was issued.

 

Now that you mention it, I do remember something about that. I will do a search and see if I can put some pertinent info here.

 

I had a F-550 that shook so hard on take off that the guages were out of focus. The TSB for the driveshaft shims helped some, but the vibration moved to 60-65 MPH and would not go away. It's not my truck, my company installed an aerial unit on it for someone and technically they bought the truck from Ford and I was just trying to make it right before we delivered the finished product, SOOO we sent it on to them and have not heard a word of complaint. It sounds like this COULD be your problem, I thought for sure it was trans slipping the first time I drove it, so give it a shot, just take the TSB with you when you find it. Good luck... Mat

 

I did a search on the TSBs here and other places on the web but couldn't get the info anywhere without a subscription. The truck is going in to the dealer today, plus I am too cheap to pony up for a subscription.

Just in case anyone here has one and wouldn't mind looking it up the Service Bulletin Number is 16915. The NHTSA Item # is 10002626. This is for a 2003 Ford F350 SD 6.0L Automatic 4X4. The TSB is (from memory) for: excessive shudder from a stop during normal to moderate acceleration.

I will let you all know what I find out.

Big

 

I have had this same problem too. What I noticed is that my rear tires were wearing too quickly as compared too the front. This might be the cause combimed with the limited slip (slips alot!). My right rear tire was worn more then my left. I lowered the rear tire pressure to 65 psi when not towing and changed my driving habits.
Ford should be using a Posi for these trucks. I hope this is the case, if not more insight would be appreciated, I now have 31K miles.

 

Well, it is still at the stealer right now. It doesn't look like they got it done today. I did, however, forget until late in the day that I wanted them to look at the LS diff. I told them to look at it and that is probably why it didn't get done today. Fortunately they gave me a loaner for free because they wasted two days last week for me. I will keep you posted on the tranny and the diff.

big

 

Been gone awhile so I thought I would give you an update.

Got the truck back and the service writer told me the shudder problem could be fixed by shimming the drive line. She quoted me $500 to do this including material and labor.(out of warranty) She said that would include as many as 3 sets of shims. I told her that I thought that sounded kinda high but to order the shims. After looking under the truck, I would think that installing those shims would be something that your average shadetree could do in an hour or two. I think I will pass on the $500 and do it myself - one set of shims at a time. Any thoughts as to weather I should do it myself or not? Any experience doing it yourself?

Now, on to the LS diff - well, what I thought was a LS diff. Mine is an open differental. Apparently not all 350s have the LS. I was sure I read somewhere that to be the case. Anyway, money being an object, I will have to pass on installing a Limited Slip at this point. That is not something I want to tackle myself. I read on another post about the different brands and some opinions on them. There is an Auburn Gear plant in the town where I work (ironically it is Auburn, IN) so I may stop by and see if I can get the bro deal on one there sometine. I remember reading that the Auburn uses conical clutches (I think?) instead of discs and therefore are not as durable but are easily rebuilt. I have a CC LB so maybe the longer wheelbase would help out a little with that durability. Maybe that has little or nothing to do with it?

Anyway, that is the update. I would appreciate any tips on doing the shims.

Cheers,

Big