Hello, I have a 2002 F150 Fx4 4x4 with 105 000 kms. Recently, I have noticed a shudder when I'm turning from a complete stop. Also, when I'm in reverse going up my driveway. During regular and highway speeds, everything is running smoothly. I've checked the fluid level and it doesn't smell burnt. I've read other threads on what seems to be a common problem with every thread has a different solution, ( replace the fluid, check the universal joints, engine misfire, check the EGR, torque converter, Transmission range sensor, etc) Any guidance would be appreciated.

By the way, I have the 4R70w Tranny.

Thanks in advance.

 

This seems to be a common problem coming from the rearend. The clutches in the rearend probably need to be replaced.
Alan

 

Before you spend the money on the clutches, put a bottle of friction modifier from a dealership in the rear end. Do some figure eights in the truck and then see if it is better. Could save you some money!!

 

Thanks for the suggestions. I also thought this might be coming from the rear end. I will keep you posted with the outcome. The truck is getting checked tomorrow. I'm going to try a bottle of the friction reducer tonight.

Stabs

 

Don't spill it on yourself or you'll be sleeping on the couch (or in the doghouse). That could very well help, but I would service the unit so that it has new fluid in it.
Alan

 

I tried the friction modifer and the problem still exsists. I haven't taken the truck to the shop yet because the shudder doesn't happen all the time. A buddy of mine is a mechanic and told me there were no clutches in the rear end. Does that sound right? My knowledge of diffs is very limited. If anyone else has had the same problem or any suggestions, I would love to hear them before it goes to the driveline shop next week.

 

Is the transmission fluid full. Not all rearends have clutches in them you may have an open.
Alan

 

Yes, the transmission fluid is full.

 

How long has it been since the transmission fluid was changed? Ford recommends every 30,000 miles. My 2000 Lariat was getting the jitters occasionally. Had my tranny flushed and refilled. Took care of the problem.

Good luck in finding / correcting the problem.

Larry

 

I bought the truck used in Feb 2005. The problem didn't start till two months later. When I bought the truck, I took it in to get checked and the mechanic said fluid looked fine, good color and there wasn't a burnt smell. So, to answer your question when it was changed, I don't know. I'm going to get it flushed and filled today. The truck has 105 000 kms( 62000 miles?)

 

Mine also looked and smelled OK, so possibly the flushing cleaned out the filter or something, but there have been no problems since then. Instead of dropping the pan, they hooked some sort of gizmo in the tranmission cooler lines at the radiator, then started the engine. As the pump pushed the old fluid into one part of the thingy, new fluid was forced in from the top. They also added some sort of a modifier to make it compatible with the version of dexron fluid that our tranny are supposed to have. The service said it is the same process as used by the car dealers to change transmission fluid. I can believe that as I have also seen the same type machines in the service bays at my ford dealer.

Larry

 

I just had the transmission flushed and filled. Also, dropped the pan and replaced the filter and gasket.
I had some time to fiddle with the truck this afternoon and it almost seems that the front transfer case might be the problem. I think the viscous coupler, I think thats what it called, isn't disengaging completetly from 4 wheel or 2 wheel. I can almost feel some grinding. Like I said earlier, I'm only having the shudder problem when I'm at a complete stop and then accelerate to turn.

 

Didn't think of that. I can well believe the viscous coupler could be the problem as it serves as a clutch between the front and rear wheels so they don't fight each other when you turn. Sounds like you are going in the right direction.

Best of luck in getting the 'shudder' fixed.

Larry

 

I have an update to my previous problem. What I thought was a shudder was actually my limited slip chatter. As dirty dog had suggested earlier, the clutches in the rear end were shot. I tried all the suggestions, change the diff fluid, adding friction modifier, etc. Nothing seemed to work. Finally, I had the mechanic at Ford pull out the diff. We also found that both my rear seals were leaking and they soaked my emergency breaks. I also replaced my rear u joints.

Overall, these repairs fixed the chatter and the truck is good as knew. Although, it wasn't cheap.

I would like to say that this site was excellent. When I was trouble shooting with the mechanic, I mentioned to him many things that were suggested to me. It sounded like I knew what I was talking about.

Thanks

Stabs