TSB 20-2277 2019-2020 Ranger - Shudder/Vibration When Accelerating From A Stop

[tmcolegr]

So, at one time I added shims under the carrier bearing bracket but took them out when I went to the dealer.
I put them back in today, 1/2” shims. My driveshaft is at 5 degrees now.

Works for me anyway but I’m just a grease monkey and not smart enough to be an engineer.
Thoughts are welcome.

Surely you realize by adding a shim under the carrier bearing you have now changed the working angles of the front section of the rear driveshaft which probably was within spec but now is not.

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[kieefer]

Surely you realize by adding a shim under the carrier bearing you have now changed the working angles of the front section of the rear driveshaft which probably was within spec but now is not.

Yes, so what is that spec tolerance??

 

[tmcolegr]

Yes, so what is that spec tolerance??

Ford does not publish that spec

 

[navsnipe]

Ford does not publish that spec

 

[P. A. Schilke]

Hi Folks,

As covered before, two piece drivelines are prone to start up shudder and field fix of shimming the center bearing are at best a guess. I have recommended this in the past understanding that it is not going to work in 100% of the cases. It is a field fix solution, not a systemic solution. So there is a shimming missmatch...So what if it fixes the concern as driveshaft U joints are normally operated at less than 4°, but more importantly is the difference between forward and rearward joint angle. There are some Rangers currently that seem to be problematic and shimming the center bearing, the rear axle pinion etc are not effective and usually, based on my experience, there is something else going on with the vehicle. Some vehicles seem more sensitive to this than others for some reason. We have put in place advanced diagnostic tools at the dealership to help with these vibratory issues, but the interpretation of results of evaluations remains problematic. So it is likely some fixes create a difference in working angles...if it fixes the concern...Great. The one degree referenced above is a guideline, not a "not to exceed". There are few hard and fast rules in the realm of NVH, of which I am a technical expert.... Ex is a has been, Spert is a drip under pressure.

There is mention of a double cardan U Joint. This is a very expensive but practical solution to high angle drive shaft concerns, on particularly short wheel based vehicles like the 1981 Bronco, for example...No way to get driveshaft angle under 3°.

Here is a pix of a double cardan joint...

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

 

[tmcolegr]

Thank you very much navsnipe !!

I overlooked that document

 

[rdgallo]

I never had the shudder that some have described here, see my other posts. Most of my issue was a vibration around 1500-2500rpm and TSB 2339 fixed that.
I did this for the heck of it, seems smoother at interstate speeds afterwards though but for whatever reason my truck will run great one day and be balky another when cold and it does great if I let it warm a few minutes.
I’m also running Exxon Reg fuel when it use to run like crap on Reg. Go figure.

My Lariat shudders almost all the time when accelerating from a stop. My truck also runs rough when cold....transmission/tc jerks like it doesn't know when to shift or how to shift smoothly. I had the dealer flash the software a few weeks ago. After that, the truck shifted a lot better, but is now back like it was before the flash. There are many things I like about this truck, but the herky jerky transmission and the shudder really irrtiate me. Mine feels like the engine misses/cuts out sometimes when cold. I have not been able to determine what that is all about. It is probably soomething new with the goofy transmission shifts. In general, it is not a good drive when cold. If I didn't have so much money in this one, I would be purchasing something else.

 

[jerardisflossin]

So 8 days and a 600 mile drive to NY after having the TSB done:

Large shudder is still gone but now I get vibes all over. Worse at 45mph. Also I am pretty sure the tech did the install incorrectly and put the shims backwards. I went and measured, I get 7 degrees pretty dang consistently. His notes mentioned it had 7 degrees to start and after adding a 2 degree shim it brought it down to 6 degrees. That math doesn't add up. Additionally, the fatter part of the shim is towards the rear which means it added pinion angle. So where did the 6 degree measurement come from? Not really sure what to do here as I have lost all trust in my dealer now.

 

[navsnipe]

So 8 days and a 600 mile drive to NY after having the TSB done:

Large shudder is still gone but now I get vibes all over. Worse at 45mph. Also I am pretty sure the tech did the install incorrectly and put the shims backwards. I went and measured, I get 7 degrees pretty dang consistently. His notes mentioned it had 7 degrees to start and after adding a 2 degree shim it brought it down to 6 degrees. That math doesn't add up. Additionally, the fatter part of the shim is towards the rear which means it added pinion angle. So where did the 6 degree measurement come from? Not really sure what to do here as I have lost all trust in my dealer now.

The first dealer that did my TSB did it wrong as well but rotated it to far down when all it should have been was maybe a degree up. It is getting done again at another dealer, hopefully it is done correctly.

 

[rdgallo]

When you say the dealer flashed it for you, was that a reset only or did they download the update the software as per the TSB?

I really don't know for sure what all he did. My truck is a 2020 and I thought the TSB was for earlier built trucks (2019's)

 

[navsnipe]

The first dealer that did my TSB did it wrong as well but rotated it to far down when all it should have been was maybe a degree up. It is getting done again at another dealer, hopefully it is done correctly.

I picked up my truck after having TSB 20-2277 redone. The shudder is not gone but is much more subtle. The service advisor told me due to the driveshaft design the shudder may not be able to be completely removed. The truck drives much smoother and, crawling underneath, I see the shims are installed correctly and my truck no longer sits higher on the right than left. Time will tell if this is good. I hope Ford figures out how to eliminate the shudder completely, this is too nice of a truck not to.

 

[rdgallo]

I picked up my truck after having TSB 20-2277 redone. The shudder is not gone but is much more subtle. The service advisor told me due to the driveshaft design the shudder may not be able to be completely removed. The truck drives much smoother and, crawling underneath, I see the shims are installed correctly and my truck no longer sits higher on the right than left. Time will tell if this is good. I hope Ford figures out how to eliminate the shudder completely, this is too nice of a truck not to.

I wonder why Ford didn't remedy this prior to the truck going into production? You know they had to have experienced it during testing and development.

 

[navsnipe]

I wonder why Ford didn't remedy this prior to the truck going into production? You know they had to have experienced it during testing and development.

Based on the votes on the poll not everyone has the shudder or notices it. I would guess the delay of production versus the severity of the issue played a part in this as well. I'm sure Phil S. can give some insight to this dilemma.

 

[navsnipe]

Its likely all Phil's fault.
The Ranger culture started waaaaay back then.
The good and the bad

Bad Phil. Bad.

He should have not retired, then our Rangers would have been Phil'd.

 

[Texasota]

I wonder why Ford didn't remedy this prior to the truck going into production? You know they had to have experienced it during testing and development.

The majority of Rangers don't do this. It must be some unfortunate combination of manufacturing tolerances that cause some to do it. I'm lucky that mine has zero shudder but I did test drive one that had a very noticeable shudder under moderate/hard acceleration.

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