In about the past moth Ive notice a wierd drivabity issue but dont know where to look. In first gear from a stop feels like rear wheels slip than grab almost like a miss from a cop would give you or a better idea is acceralting from a stop and running over those painted strips when there wet wheels slip then grab. I think I ve ruled out tran since Ford totally rebuilt it 2yrs ago than a 1yr later they also replaced torque convertor so fluid has been changed recently Im sure of. Ive dont have a cop problem cause Ive had 4 of those go I know that feeling without getting a check engine light. recently within 2 months replaced DFPE sensor and also cleaned intake, EGR, vaccuum tested all hoses so Ive think Ive ruled out engine relative issue and truck is always servired at dealership for free ( love the extened warranty) There are 3 places I thought to look when I put on my 285/70/17 BFGs on in Feb I dissconnectted battery computer reset itself alls ok.... Notice when drive my scanner autoXRAY5000 shows computer states vehicle speed is 3 miles slower then od reads (still trying to find a place to correct that). so maybe its telling the tran the wrong info? shift point cluth inguagement Also Ive never changed front diff, transverse case or rear end fliud (I know shoot me but Ive tried to go to store but didnt have the right stuff so just never got around to it) but Ive only have truck maybe 40000miles around 3yrs maybe . They check it at Ford right. Ive been to those 30min places and they also pulled plug on rear diff on my ranger and checked level and also color smell etc so I think Ford would do the same. So im not sure where to look only in first gear from a stop with lite to moderate throttle goes away with anymore then that. any ideas would be great Thanks its 99 Eb 4x4 AWD with LLS

 

from what your describing sounds like tranny problems. that is where i would check first. take it to a tranny shop and have them diagnose it. the places around here will diagnose it for free. if you take it to them. you might try that

 

If it hasn't been done before, try replacing the rear differential fluid and be sure to add the friction modifier.

 

just put royal purple rear end fluid in it and forget it. drain the old stuff and dn't worry about putting friction modifier in it as it's so good it doens't need it.

 

I'm starting to wonder if you're on Royal Purple's payroll!

 

Holiday wants you to put royal purple in everything, even a t-case, regardless of what Ford's factory specs say you have to do.