Brake stutter when coming to complete stop

[Truck2019]

Hi,

That pretty much takes shift quality out of the equation. Wonder if there is some sort of driveline shutter occurring? Is your truck a 4x4? Is it a Supercab or a Super Crew? The Super Crew is a two piece rear driveshaft, and these are prone to shutter at the center bearing. U joints have acceptable performance limit of about 4° so in long wheelbases, a two piece drive shaft is used. There is also a critical speed and long shafts reach critical speed at much lower driveshaft speeds. Critical speed is where the driveshaft starts to become like a jump rope. You can increase critical speed by use of lightweight materials like composites or aluminum for example, but usually the design will dictate a two piece rear driveshaft.

There are some cases where you can shim the center bearing and minimize shutter, but this is trial an error and I do not recommend doing such.

Short answer is you may have to live with the shutter as it is symptomatic of the two piece design.

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

It's a Lariat Super Crew 4x4 with the FX4 package. While I'd prefer it didn't do this, I'm not going to be upset about it or change my view on the truck. I just wanted to make sure it wasn't evidence of a larger problem brewing. If it turns out to be something else, I have the 3 year warranty so time will tell. For now, I'll just accept it as is unless someone else confirms it to be something else or notes an easy quick fix.

Reading this on an F150 forum and it sounds exactly like what you are saying....

https://www.f150forum.com/f2/clunk-drive-shaft-129690/index2/


Thanks!

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[doug910]

Hi,

That pretty much takes shift quality out of the equation. Wonder if there is some sort of driveline shutter occurring? Is your truck a 4x4? Is it a Supercab or a Super Crew? The Super Crew is a two piece rear driveshaft, and these are prone to shutter at the center bearing. U joints have acceptable performance limit of about 4° so in long wheelbases, a two piece drive shaft is used. There is also a critical speed and long shafts reach critical speed at much lower driveshaft speeds. Critical speed is where the driveshaft starts to become like a jump rope. You can increase critical speed by use of lightweight materials like composites or aluminum for example, but usually the design will dictate a two piece rear driveshaft.

There are some cases where you can shim the center bearing and minimize shutter, but this is trial an error and I do not recommend doing such.

Short answer is you may have to live with the shutter as it is symptomatic of the two piece design.

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

Phil, why would the cab configuration change the driveshaft? Only one frame is used for either configuration so wouldn't the driveshaft stay the same length?

 

[P. A. Schilke]

Phil, why would the cab configuration change the driveshaft? Only one frame is used for either configuration so wouldn't the driveshaft stay the same length?

Hi Doug,

It probably does not make any difference to cab configuration except for the likelihood that the floorpan on the Supercab will respond differently to vibratory inputs and I have no experience with the Supercab as I wanted a Supercrew. Not familiar with the driveline releases for the various configurations on Ranger, but I think you are right that the driveline is likely the same for both cabs...I just do not know how this program evolved and have never crawled under a Supercab to look. Will be interesting if this shudder is more noticeable in a Supercrew vs a Supercab. Driveline shudder seems to be bubbling up on this forum and we should be able to amass more data. If it becomes severe, I would hope there would be some driveline development at Ford for problem resolution. One approach is to change the rubber isolator around the center bearing making it harder or softer for example or changing driveline angle via shimming the center bearing. Doubt this will pose a serious enough problem for a TSB, but who knows...Wish I had direct contacts inside Ford, but alas, all my friends have finally retired as well...

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

 

[HighFivenWhiteGuy]

I am having the same issue, there is a definite "clunk" when I come to a complete stop. I thought it might be something loose that was moving when the ranger stopped moving and the front suspension decompressed and the truck rocked back. I had this issue looked at during my recent service and was told that it was normal for the Ranger to do that.

Phil, thank you very much for your responses. Reading the information you provided has made me feel much better about the situation, amazing how much having a better understanding of how the Ranger works can alleviate worries. If anything changes I will report it here to add to the data set.

 

[Truck2019]

I am having the same issue, there is a definite "clunk" when I come to a complete stop. I thought it might be something loose that was moving when the ranger stopped moving and the front suspension decompressed and the truck rocked back. I had this issue looked at during my recent service and was told that it was normal for the Ranger to do that.

Phil, thank you very much for your responses. Reading the information you provided has made me feel much better about the situation, amazing how much having a better understanding of how the Ranger works can alleviate worries. If anything changes I will report it here to add to the data set.

When all else fails pull out the ole “it’s normal for x vehicle to do that” but can’t explain why. Definitely appreciate Phil’s insights as it gives us an idea of where to source the issue.

 

[akarisilver]

Im glad someone started this thread because I noticed the same thing.
It resembles like the park break engaging when coming to a complete stop. At first, I thought it was the auto start/stop kicking in, but noticed the engine was still running after the "clunk".

I still have some miles to go before my first service so hopefully someone will get an answer.

Crew cab 4x2.

 

[LJ12727]

I have the same issue with my Lariat 4x4 supercab. I think it may be two different things. The clunk just before stopping or just as you move forward does feel like it may be the downshift or upshift but could be from the rear.. The stuttering before stopping feels more like the torque converter not releasing soon enough, so the engine chugs at those low rpms. It feels almost like anti-lock chatter but lower frequency. You feel it in the brake pedal and steering wheel. As soon as the engine drops below about 1100rpm the stutter goes away and the idle is very smooth.

 

[Truck2019]

I have the same issue with my Lariat 4x4 supercab. I think it may be two different things. The clunk just before stopping or just as you move forward does feel like it may be the downshift or upshift but could be from the rear.. The stuttering before stopping feels more like the torque converter not releasing soon enough, so the engine chugs at those low rpms. It feels almost like anti-lock chatter but lower frequency. You feel it in the brake pedal and steering wheel. As soon as the engine drops below about 1100rpm the stutter goes away and the idle is very smooth.

For me it has nothing to do with shifting as I can see the gears shift to first before bringing it to a full stop and before and clunk. Ditto when letting off the brake to start going, if it clunks then, it’s still in 1st.

I had the truck loaded up last weekend with a few hundred pounds in the bed and it seemed like the clunk was more noticeable, more pronounced, but it may have been a fluke. I haven’t had my first service yet so I haven’t talked to the dealer about it.

It seems like the drive shaft is the first thing to check out. I’ve seen several F150 videos where they pull it apart at the rear and there is no grease to be found. They load it up with grease and the clunk is gone for a good 10k-15k miles.

Curious to hear what people find out

 

[ch47dmechanic]

My current Ranger has this and two of my previous F-150s did too. On the F-150's, it had to do with the drive shaft splines sticking and not sliding efficiently due to the factory not using enough grease when assembling them together. The resolution was to remove the driveshaft and regrease the splines. Solved the problem both times and I'm sure it will with my current Ranger as well but I'm waiting until the first service to just have the dealer take care of it.

 

[P. A. Schilke]

My current Ranger has this and two of my previous F-150s did too. On the F-150's, it had to do with the drive shaft splines sticking and not sliding efficiently due to the factory not using enough grease when assembling them together. The resolution was to remove the driveshaft and regrease the splines. Solved the problem both times and I'm sure it will with my current Ranger as well but I'm waiting until the first service to just have the dealer take care of it.

Hi Jason

The driveshafts come into the plant ready to assemble from the supplier, which could be Ford or an outside company like Dana etc. The Assembly plant just puts it together...does not lube anything...should be pre lubes and good to go, but apparently not in all cases as you experienced.

There is another aspect of two piece drivelines and that is the correct phasing of the two shafts. It may be accomplished by having a blocked spline on the forward shaft to prevent misassembly, but may also just be the responsible operator on the line to ensure correct phasing. If out of phase, it causes a continuous vibration felt in the vehicle at all speeds. Do not see reports of this condition, but something to be aware of. I have no idea on the 5G Ranger how this is done...

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

 

[ch47dmechanic]

Hi Jason

The driveshafts come into the plant ready to assemble from the supplier, which could be Ford or an outside company like Dana etc. The Assembly plant just puts it together...does not lube anything...should be pre lubes and good to go, but apparently not in all cases as you experienced.

There is another aspect of two piece drivelines and that is the correct phasing of the two shafts. It may be accomplished by having a blocked spline on the forward shaft to prevent misassembly, but may also just be the responsible operator on the line to ensure correct phasing. If out of phase, it causes a continuous vibration felt in the vehicle at all speeds. Do not see reports of this condition, but something to be aware of. I have no idea on the 5G Ranger how this is done...

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

I definitely don’t have issues with vibration so it must just be the parts manufacturer not supplying enough lubrication to allow the shaft to slide enough.

 

[t4thfavor]

Great, now I gotta pull my shaft out and lube it... Figures...

 

[P. A. Schilke]

Great, now I gotta pull my shaft out and lube it... Figures...

Hi Chance,

Maybe have the dealer do it? if you do pull the rear shaft and lube the splines and it makes the shudder go away, will be an interesting data point.

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

 

[t4thfavor]

I'd never pay someone to do that. I might let them do it for free though (Warranty work).

I'll see what they say when/if my rear axle ever comes in.

 

[lpgonzales]

I am also interested in what anybody finds out. I also have the exact same issue. I have a 4x4 Lariat Crew Cab but I do not have the FX4 package. I have experimented with the problem and found that if I come to a stop with pretty aggressive braking it doesn't seem to happen. If I very, very slow roll to a stop it doesn't happen. But any other kind of stop and it happens almost 100 percent of the time. I can also feel it occasionally right when I take my foot off the brake to pull out from a stop, but this happens much less consistently. It does not seem to happen when braking in reverse but I need to pay more attention to that. I have had the truck a little over two weeks and I noticed it immediately. I have not taken it back in for service because I wanted to be able to explain what is happening. It almost feels like something is loose in the braking system. Either that or a transmission gear shift thing. As a passenger, if you pay attention, you can feel it as well.

I just wanted to post a follow-up to my original post on this subject. I have done a lot more testing to try to isolate the problem. Like others, I have found that the clunk is not related to shifting gears because I too have put it in manual, kept it in first gear and still usually get a clunk just as I come to complete stop. The stutter that many have mentioned is different than the clunk. I have had the stutter, but not all the time and I have not been able to nail down when it happens. The clunk happens almost every single time. However, I also have shifted the truck to neutral from normal speed and come to a complete stop and there is absolutely no clunk or stutter ever, none at all. So it definitely is not brake or suspension related in my view. Both the clunk and clutter have to be transmission/drive train related. Also, when I have shifted into neutral to come to a complete stop and then shift back into drive I usually get a hard shift into gear. Much harder than the normal shift from park to drive or reverse to drive. Sometimes, it is almost like a double shift...a soft one followed by a hard shift and I think I have felt a clunk in that process a time or two, but not sure. At times, the transmission seems confused or just jerky.

Another thing I will note is that most of the posts on this thread seem to be Rangers with an FX4 package. While I do not have the FX4 package, I do have the electronic locking rear differential that is part of the FX4 package. I wonder if that says something?

I still have not taken it in for service...I just don't want to hear "that is normal" because it is not. I need hard enough evidence that what is happening is not normal so they will take a hard look and figure this thing out because it is annoying.

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