I guess you call it that. Have LSD on the F150. Replaced the rear fluid with 75W-90, what the manual says to use, M1 with friction modifier in it. I also went ahead and added the 4 ounce tube of Ford friction modifier also. When it's been parked for a while, as I take off, you can feel the rear end vibrate or kind of stutter. No noise, just that you can feel it. Been looking at Ford forums and there can be a lot of explanations anywhere from bad clutch packs, not enough friction modifier, u-joints, etc. etc. It also does it sometimes making a slow left or right hand turn. But it doesn't do it all the time, only when it's "cold" and has been sitting for a day or so. As much money as I've dumped into this truck, is this something I need to start digging into or just live with it. Going straight, no problems. I've pulled a boat behind it many times since I changed out the rear fluid and I've never had any problems.
F150 rear end stuttering
- Thread starter Schmoe
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I have the same issue. I forget which fluid I used, said it didn't need friction modifier, I added at least two bottles of the Amsoil friction modifier anyway. I still get the chatter when making turns. It is the nature of the beast on this truck? Including clutch packs that probably need to be replaced.
Disregard
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Sure you've got the right fluid in the rear end? Thought that generation of F150 used 75w140 from the factory in the rear, and 75w90 in the front differential. There should be a metal tag on the differential that states the correct fluid.
After that, even the fluids that say they don't need the additive added usually do to make things work right. If you haven't done it, add some.
If after that, it may be time to look at repairing the limited slip...
After that, even the fluids that say they don't need the additive added usually do to make things work right. If you haven't done it, add some.
If after that, it may be time to look at repairing the limited slip...
Correct
That stutter or vibration after being parked would only be a LSD/friction/fluid issue when turning sharp corners,
if the stutter or vibration is present in straight line driving it's another issue.
if the stutter or vibration is present in straight line driving it's another issue.
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Sometimes it does stutter when going straight after it's been sitting for a while. I just can't get my head wrapped around the fact that I need to add more friction modifier.....it was in the oil and I put the 4 ounces in it on top of that. What happens if you put too much modifier in it???
The more modifier you put in, the less effective the LSD becomes.
Since the condition is present while going straight, I doubt very much it's an LSD/fluid issue.
Perhaps a dry, rusty or damaged U-joint or driveshaft splines binding up when parked.
Since the condition is present while going straight, I doubt very much it's an LSD/fluid issue.
Perhaps a dry, rusty or damaged U-joint or driveshaft splines binding up when parked.
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MolaKule
Staff member
Originally Posted By: mlatour
The more modifier you put in, the less effective the LSD becomes.
Since the condition is present while going straight, I doubt very much it's an LSD/fluid issue.
Perhaps a dry, rusty or damaged U-joint or driveshaft splines binding up when parked.
The more modifier you put in, the less effective the LSD becomes.
Since the condition is present while going straight, I doubt very much it's an LSD/fluid issue.
Perhaps a dry, rusty or damaged U-joint or driveshaft splines binding up when parked.
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Mobil 1 75/90 solved the clutch chatter in my first BMW with LSD. It is the only synthetic oil I've ever used.
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