Hello everyone, I recently replaced the ring & pinion on my truck and have experienced a high speed rumble since. The other day I got under the truck to check things and found the tailshaft to be a little bit sloppy.

Searching back through previous posts I found one concerning a TSB that replaces the tailshaft and replaces the 4 1/2" driveshaft w/ a 5" driveshaft.

My question is has anyone replaced the tailshaft alone with good results? Should I bite the bullet and replace the works or can I get by with just a new tailshaft and my factory 4 1/2" aluminum driveshaft. I want to get the Microtuner and eliminate the speed limiter but no sense in that if my drivetrain rumbles at just 80 MPH.

Thanks in advance.

 

I think you'd need to replace both the extension housing and the driveshaft to make this work.

https://www.f150online.com/forums/sh...threadid=93877

 

I have had my tailshaft replaced once, and I can see under it right now that I will need to get it done again soon. I have not heard of the driveshaft thing, but I am going to look into it now.

-Abrams

 

We see a lot of high mileage 97up trucks that are like that. If you replace the extension housing (comes with new tailshaft bushing installed), it will take care of that rumble from the work out bushing. The yoke on the driveshaft is usually fine.

 

Thanks for the replies guys.

AbramsM1, why do you believe it's time to replace it again soon? How long did the first replacement last you ?

Jefflaws, I could understand the bushing getting worn on high mileage trucks but I'm sporting 23,000 miles on the odometer, most of which are under really conservative driving conditions. I guess it was never intended to turn that fast?

As it stands now I spoke with a trans rebuilder that believes he can get the bushing itself without the entire assembly so I'm waiting to see if he comes through with that along with the seal and tailshat assembly gasket. If so, I'll take it from there and see if the rumble stops. If the rumble is still there afterwards I'll be replacing more stuff.

Thanks again to all for your input.

 

HI!... My dealer replaced my 4R70-W tailstock after it split opened and was leaking tranny fluid all the time. The cracked tailstock was caused by worn out slip yoke bushing. The wore out bushing destroyed my slip yoke. Took about a 1/8 inch chunk out of it about 1 inch wide. As usual the dealer was an idiot!!!!! They said that my tailstock cracked because I have aftermarket S/S braided lines on my tranny. MORONS! After threatening to sue the dealer the factory REP agreed to fix it under warrenty. Where do they find these guys? YA the mechanic installed a brand new tailstock and the dummy went and installed the worn out slip yoke back into it!!!!!! I got two weeks out of the tranny and it puked!!!!!!! I then filed a report with the dealer and FORDS. After that I will never let another dealer touch my truck again. That's when I had a professional build my race/duty tranny. When he tore down my tranny the slip yoke bushing was 90% gone and the whole tranny was completely filly with bronze particles. That's the 4th time a factory tech has screwed up my truck. Never again.

 

Hiya Neal I remember when you were going through all that cr@p w/ the dealer and reread that thread when I did a search on the bushing.

Besides getting your race duty trans put in did you also get the 5" aluminum driveshaft? I'm asking because I know you also have gears and probably spin your driveshaft to higher RPMs than were intended from factory. Do you still get the rumble at higher speeds or when you make a 1/4 mile blast?

Thanks in advance.

 

LE PEW,

I believe I need to to it again because I can see a little bit of oil leaking from the tailshaft (happened last time right before the seal popped out with the little bushing). Also, I can hear a rattle and a slight trembling inside the truck in 4th gear. That happened last time as well. Now, I believe it is my fault since the 4.56 gears spin the driveshaft faster than before. I estimate the fix has lasted 10000 miles.

On a side note, do you guys think the New tailshaft assembly from ford will solve the problem? Last time I found one used at a tranny shop and simple had a new bushing and seal pressed in.

-Abrams

 

LE PEW,

I have read you posting before about driveshaft vibration in your post (800 miles on 430 gears) but I never made a connection to my noise. This really sounds like what is happening to me. I have to also thank AjRagno for his link and for another one I found at that site that took me to Joe Lynch's article on his Cobra vibration. This makes perfect sense now. It also explains why no one can find a problem with my gears.
I now have a project for when the weather gets a little better. I was considering getting rid of the 430 rear because this is making me nuts. Maybe now I can cure it and keep it.

Thanks, keep us posted on how it goes for you and I will do the same.
BTW, if you didn't read the article here is the article then do so now. It is very informative and will probably save us some money.

 

HI!... LE PEW : No I am still using the stock 3-3.5 inch steel driveshaft, but have installed heavy duty SPICER "U" joints in it. This SPRING I plan on getting a custom chrome mole 3" driveshaft built for my truck. Half the weight of the steel and 3 times as strong. I'm going to be running slicks this year at the track so I want to make sure I don't spit out a driveshaft. As for the aluminum driveshafts, I will NEVER use one. They are bulky and weaker than the steel ones in my opinion.

 

Man, I can't wait to find out if this is what is wrong with my rear. It is going to be just above freezing tomorrow so I am going to try indexing. I'll let you know if it works.

 

I had a high speed rumble and it made my rear bushing come out of the tail shaft on my previous 01 Screw. Took the truck to the dealer and all they wanted to do was replace the tail shaft housing. I gave them the copy of the tsb and made them go the whole distance. The dealer story is another long horrible story. This did not fix my problem at all. In fact, I spun out the bushing another time as well only three weeks after the supposed fix. After continued arguing with that dealer I took it to another who had no problems in finding out the new drive shaft was so out of balance that that was the entire problem. Didn't have the problem after that.
This is a little off topic but a good dealer goes a long way. Once you find one keep going back.

 

Can a shaft get out of balance over time.
My truck is 3 1/2 years old and I never felt anything like this.
Maybe the problem was there all the time but I just didn't noticed it.

 

F150Europe, I guess it's possible that you never noticed it. I never drove fast enough to come near the speed limiter before I did the ring & pinion but I did flirt with 90 MPH once or twice and never heard any vibration. Now that I have a higher ratio things are spinning a lot faster for the same speed and the vibration only happens around 80MPH and I'm also hitting the speed limiter at the same time so I know for a fact that the driveshaft never revolved that quickly with the stock configuration. Also, part of the original TSB was to reflash the computer to lower the speed limiter thereby reducing top speed/driveshaft speed.

WLF, good link to the vibration diagnosis article. I had read it already and did the indexing on the driveshaft and the rumble remained the same regardless of any position I moved the shaft in relation to the companion flange. I'm going to try the hose clamp method and see if that helps any. I'm willing to try whatever it takes to exorsise these drivetrain demons.

I think it's funny that Neal has a steel driveshaft and does'nt have this problem. I'd bet the farm that he drives at high speeds and higher RPMs more often than any of us! It may just be the driveshaft wobbling around too?

Ecm747x, thanks for sharing your experience. It just goes to show that you really cant rule anything out of the equation when trying to find the cause of a problem. Did the other dealer replace the driveshaft with another one or rebalance the one that was aleady in the truck? Also, did you start out with an aluminum one and switch to steel or vice versa?

Thanx alot folks, keep 'em coming.

 

Well, I finally found the culprit!

My baby is smooth as glass all the way up to 85 MPH!!

I took advantage of this heatwave to do some work on the truck and finally got my drivetrain's high speed rumble straightened out!

It turned out to be that the driveshaft is out of balance! I did my own version of the field balance <makes the sign of the cross> using a 4 1/2" hoseclamp. It only took one clamp on the front of the driveshaft to smooth things out! And this is still with the sloppy tailshaft bushing! I still cant believe it and I already drove it at top speed for a few miles bouncing off the speed limiter trying to induce the noise.

It seems that the quality of the driveshaft balancing done at the factory leaves a lot to be desired. It's only sufficient to about 3,000 RPMs in my case. Oh man oh man, such great results from such a simple procedure. The interior of the cab is quieter at all speeds now. I think that replacing my tailshaft bushing along with rebalancing the driveshaft for higher RPMs will put this rumble out my misery.

I think it's finally time for that Microtuner now!

Thanks for all the help fellas!! I'm going for a ride!!!