Slight Shudder During Deceleration

pa-powerstroke · Mar 29, 2013

So took my truck for about a 30 mile drive in the mountains today, lots of rough road and steep up/downhill. Didnt do anything crazy or hammer it much just an afternoon drive. Once I got back onto blacktop I realized that when Im slowing down, and I have to be on the brakes pretty hard, there is a shudder at almost exactly 20mph. The truck has a small jolt and the mph needle even has a jolt in it. Anyone tell me whats going on? I hope its not my tranny, Im about to be driving 1500 miles and I dont want something to give up in the middle. Any help?

Zmann · Mar 29, 2013

lifted non lifted

miles on the truck / trans service intervals
any other info ?

I think most tranny probs show up on acceleration (at least from My experience)

but the standing on the brakes thing might point to something

java · Mar 29, 2013

I'm having a similar issue.. I can't figure it out and it's driving me nuts!

pa-powerstroke · Mar 29, 2013

Stock height, I was looking into the issue some and could it possibly be a driveline problem? But it happened right at 20mph so thats why I was thinking it was a tranny issue downshifting or something.

pa-powerstroke · Mar 29, 2013

SCT w canned performanve tune, I honestly know when the tranny was serviced/flushed, i should probably have than done before I leave.

pa-powerstroke · Mar 30, 2013

Nothing?

ghostrider112 · Mar 30, 2013

Same problem here

pa-powerstroke · Mar 31, 2013

So i let my truck sit for a day while I went fishing, let her warm up this morning then went for a drive to get some tools. Once again I could replicate the same shudder when braking right at 20mph. The strange thing is that when I had it in tow/haul I couldn't get it do shudder like it had at any speed while braking. Shifting all the way through the gears seemed normal and no other issues. Except for slowing down in tow/haul the rpms seemed to drop below 1000 before grabbing the next gear, didnt shudder or anything and I honestly cant remember if this is normal but it didnt seem to be an issue.

Probably have my tranny flushed by the Ford house sometime this week, have no idea when it was done last. Also havent tried driving with any other tunes loaded, guna change out my bad ICP sensor then take it for a ride later tonight.

pa-powerstroke · Mar 31, 2013

Update: So I finished up the ICP sensor and pigtail and she runs nice and smooth again. But I also took the truck for a drive after loading the stock tune instead of any of my canned stuff and I couldn't get it to shudder like it was. Im honestly stumped on this...