Alright guys I drove the truck Wednesday and Thursday, and my Dad drove it Friday. Again, I had a shop balance the rear part of the driveshaft. They took off the balancing ring, and most of old weights on it. They put on a new ring and welded on some more weights in different spots. It doesn't look like the nicest job, but not really sure if it could look much better. Its hard to explain without pics, I will try to get some tomorrow of before and after balancing the driveshaft and the angle that it is at currently. So after balancing it, the vibration is a lot better, but I would say that its still not quite right, and my Dad agrees. There is definitely still a vibration, I'd say its about what it was before we did all the work, maybe a little worse. I know it wasn't right before. There is also a grinding noise when coming to a stop, like under 5mph. Its hard to tell exactly where its coming from, but it is easily heard and you can feel it in the floor boards. It definitely sounds like it could be coming from the driveshaft, but also could be coming from up front. This grinding noise was also present before everything was done, so nothing has changed it. Definitely going to get some pictures and maybe a video of the noises tomorrow. Also going to try and pinpoint the noises more.



I get what you're saying. I believe my blocks are ok, but I still think that more than likely, the carrier bearing still needs to be shimmed. I think I'll also try to see if I can tell if there is any shims in the carrier bearing now, tomorrow.



When I had the driveshaft balanced, we just took them the rear part of the driveshaft. They did put some weights toward the top part of the shaft near the carrier bearing. I'll get pictures to show exactly what they did.



Thanks for the video Tom! That really cleared everything up. I get what you guys are saying now. I'll see if this could be a possibility as well, I doubt, but you never know.


Thanks again for all the help guys!

 

I tried the rear shaft first but it was the front shaft that was out of balance

 

Tom, this was my first impression when I started reading the thread, but had to read it through to see if you guys would get to the subject. I see that you have. Out of phase shafts can really cause problems, including ruining those new parts that were just installed. "GREAT FORUM!"

 

Hey guys going to bump this back up. Sorry for not getting back to you guys, I just got caught up in school and work, and didn't have time.


So to summarize, the really bad shake/vibration that I originally started this thread about is gone, or at least better. This occurred after doing all of the work that I listed in my first post, and was fixed after we had the rear part of the two piece driveshaft balanced. The new very bad vibration was gone, and the slight vibration that I had before all the work was still there.


So I have been driving the truck since my last post. And fast forward a few months and I still have a few issues that have progressively been getting worse. Its a set of grinding/rotating noises along with a slight vibration/shake. I had a slight vibration/shake that was most noticeable at around 50 or 55mph, but could almost be felt all the time. This could be caused by the tires though.


Now there is a few different noises that I could hear. There was a grinding/rotating noise that could pretty much be heard at all times, but was worst at around 25-30mph. This sounded kind of like vroom, vroom, vroom, is about the best way I can describe it. Like something which was rotating, was "grinding" I guess. This grinding could be easily felt in the floor boards through your feet, but was more obviously felt and heard in the passenger seat. Again it could pretty much be heard all the time.


Now there is also another grinding noise, which is separate from the last noise. This is only apparent between 10-15mph, anything below or above this and its gone, or at least its at a point that you can't hear or feel it. This is worse, sounds different and is much louder than the first grinding/rotating noise that I mentioned. You can hear and feel it, it sounds pretty bad, and is pretty loud. Definitely sounds like something metallic is rotating and grinding.


Now I asked my Uncle, and they are pretty sure that the driveshaft was not installed out of phase, as they already checked for that originally. I am going to ask again tomorrow to be sure.


I had been suspecting a bad wheel bearing, and we were finally able to confirm that at least one was bad, so we decided to replace both. This was just done last week. I just got to drive it today as I was out of town for a hunting trip. Now, after the new wheel bearing's the first grinding/rotating noise I mentioned seems to be gone/fixed, but the bad grinding noise that happens at 10-15 is still there.


The tires that I have on there, are very bald and unevenly worn so those aren't helping anything. I should have new tires on it sometime next week so we'll see what happens. I can't believe that those would change the grinding noise, as that definitely sounds metallic, but who knows. We did put the tires/wheels from my Uncles Excursion on my truck to see what that changed, before we did the wheel bearings. They were stock sized 265's, and I have 285's, so they are a little smaller. They helped a little, but pretty much every noise was still there, not as bad, less noticeable, but still there. Which makes sense with smaller tires right? Less strain on everything? The grinding noise at 10-15mph was harder to replicate, but was still there.


Before we did the wheel bearings, we also locked the hubs and put the truck in four wheel drive with no change.


Today we tried to mess with how many shims were in the carrier bearing in the driveshaft, as that was the only thing left that we could think of that would cause the grinding noise. The new blocks are flat 4" and there is a 1" add-a-leaf in the rear, for a total of about 3" of lift over a stock F250. The old block setup was a set of stacked blocks with the stock F250 block, which is flat, and an aftermarket tapered 2" block. This setup measured pretty much the same as the new block, other than the one block is tapered. Again the stock F250 block that I have is FLAT. So I think my new flat blocks are okay. According to PMF's website, which is where I bought the blocks and carrier bearing shims from, they say that a general rule of thumb is for every 1" of rear lift the carrier bearing should be shimmed 1/4" of course there's a few variables in that. So with 3" of lift that would be three 1/4" shims. There was an original shim in there, which was there before we changed anything and before I even owned the truck. That shim measures at 1 1/4" (and looks to be homemade), which is too much according to PMF. Today we added two 1/4" shims to the existing shim for a total of 1 3/4" and then took out the big shim and put in three of the PMF shims for a total of 3/4". None of those combinations took away the grinding noise or really changed anything for that matter, I didn't take it on a very long test drive. Currently it is sitting with three of the PMF shims in for a total of 3/4" of shim on the carrier bearing, which is where I think it should be. Where do you guys think it should be? How much shim should be in there for the amount of lift that I have? How should the driveshaft look, when its properly inline? I've got a few pictures that I'm going to post up. Not sure how helpful they will really be, as it might be hard to tell the driveline angle. I am going to try to call PMF at some point to see what they think.


New wheel bearings, locked hubs with no change, can't believe that tires would cause this noise, new u-joints in rear part of driveshaft and had that part balanced, new calipers, rotors and pads, brand new rear end and a various amount of different shims on the carrier bearing, and the grinding noise is still there. The truck made this noise before the new brakes and new rear end as well. Really kind of stumped. Is there anything else that is rotating that could cause this noise? Something we might be missing?


Sorry for the long post, lots of info to get to you guys. I might start a new thread just for grinding noise, but figured I'd post here first to see what you guys thought and to ask about the carrier bearing shim. Pictures will be in next post. I've also got a video that shows all of these noises pretty well. I'm going to try to get it up sometime tomorrow for you guys to hear. Again the only noise that still occurs is the grinding noise at 10-15mph. Also might try to get another video of just the current grinding noise. Thanks again guys!

 

Pictures! Sorry some of these aren't the best, but are all that I've got since we messed with the carrier bearing today.


Driveshaft before it got balanced.



New rear end.



Before it got balanced.



After it was balanced. Looks kinda sloppy, but might not be a better way to do it.












Old shim






Carrier bearing









PMF 1/4" shim



Old 1 1/4" shim.






Today after messing with the shims on the carrier bearing. This is with three of the PMF 1/4" shims equaling 3/4" of shims.





















Hope this helps you guys visualize some things. Let me know what you think! Again hopefully I'll have that video up tomorrow.

 

May have already been addressed, but have you checked the carrier bearing?

 

how does a hose clamp balance a drive shaft.....are we talking to install it with the screw part of the hose clamp in line with the space of something?

 

With the hose clamp, it's either:

-you notice that a weight has fallen off, and are replacing it [by putting the screw part where the missing weight was]

-straightup trial and error, trying out where to put the hose clamp and what angle to rotate it

 

That carrier bearing rubber bushing looks pretty nasty.
Have you replaced the carrier bearing and the u-joints in the front shaft?

 

I have no idea about the grinding but I will tell you this, a multi piece driveshaft must be balanced as an assembly, if you balance the shafts separately it will not come out in balance when assembled. Your drive shaft shop should have informed you of this.

 

Yes carrier bearing has been checked. Seems to be good, and feels solid, with little to no movement. Doesn't look very pretty to me though.



I would have to agree, I think it could be replaced. But my Uncle and our mechanic who help me work on the truck and supposedly know more than I do.... keep saying that its fine and are not worried about it. Not too sure about that, but I guess it could be worse. I like to think that I can trust their opinion since they do a lot of work on the truck but, that seems to be in question lately. I trust my Uncle more than our mechanic though. I really wish that I was able to do more of my own work on the truck, but I just never end up having the time.


And no the carrier bearing has not been replaced. The front driveshaft has not been touched at all, no u-joints and have not had it balanced.



I would have guessed the same thing, but my Uncle and our mechanic, did not say anything, nor did our drive shaft shop. I did not directly take it to the shop, my Uncle did, so I don't know exactly what was said. However, one of my coworkers told me that he has not heard good things about the shop that balanced it, the decision was not up to me though. Sounds like to me that I should be questioning the reliability of the shop that balanced the drive shaft. It definitely helped after they balanced it but, might not have fixed everything. And the work that they did to it, looks pretty sloppy and almost unprofessional to me. Looks like they just took off some old weights and threw some new ones on there and quickly welded it. Of course I'm no professional, so there might not be a better way to do it, idk. Also to me it makes sense that with a two-piece drive shaft both pieces should be balanced together. If this is the case, they should have known this right?


I think I'm going to start a separate thread on the grinding noise, but there is a few things that I would still like some input on.


Do you guys think the flat blocks are ok? I think they are good because the stock blocks are flat, and from what I have read that is what a CC SB should have.


What do you guys think about the balance job on the rear part of the driveshaft, from the pictures shown? And do you guys think that the front part of the driveshaft should be balanced as well?


How much shim should be on the carrier bearing for the 3 inches of lift that I have in the rear? It was about an 1 1/4" before and is now at 3/4", went with that according to what PMF says on their website. Also do you guys think that the carrier bearing should be replaced? And how should the angle on the driveshaft look? I'm sure its hard to tell in the pictures but how does the angle currently look?


I still want to call PMF on all this, but have not had time yet. Thanks for all the input. I don't really want to put too much time and money into it because I'm pretty sure that I've decided on going with a 1 piece driveshaft in the summer, once I redo the lift. I was going to wait, but that's what I really want and, I think it'll work better for, I'm tired of dealing with the two piece haha. I'm not 100% decided on it yet, but more than likely that's what I'll end up with. But I also don't want to mess up my new rear end if that driveshaft is that out of alignment. Is it possible to mess up the rear end if the driveshaft is out of alignment?


A pic of where the driveshaft meets the transfer case. Not sure if this is the double cardan joint that was talked about earlier.






Another shot of the driveshaft.



And here is a link to the video I talked about. You can hear all the noises I mentioned. Grinding noise at 10-15 mph is still present.

 

Sounds a lot like a bad wheel bearing or severely worn tires to me. You mentioned you replaced two wheel bearings (assuming fronts), but did you check the rears? A quick way to test them is swerve left and right (parking lot works great) and if the noise changes, suspect a bad wheel bearing.

Years ago, I had an Explorer that had the exact same noise at lower speeds and vibration at higher speeds. I was fairly certain the noise was from bad wheel bearings but after replacing them, the noise was still there. I put off getting new tires because I needed to replace the ball joints and get an alignment. After getting into an accident in my DD, I had to fix up the Explorer to make it road worthy. New ball joints, alignment, and new tires and noise disappeared.

You mentioned you drove around on your uncle's tires before the wheel bearing replacement and some of the noise went away or lessened. Ask your uncle to borrow his tires again since you've replaced wheel bearings and see if there is any changes in noise and vibration. Severely worn tires can sound like a bad wheel bearing and definitely throw off the balance and cause a vibration.

 

None of the u-joints are double. All single. What would work great is if one of them was absolutely straight, so as to have no effect, and the other two had the same angle. The straight one needs to be NOT the one in the middle. Here is why:

You can also see that they are close enough to in phase. Think about this. since the front shaft has to be in phase, and the 2nd shaft has to be in phase, and they have to be 90 degrees different from each other because they are joined in the middle by a single joint. then the assembly itself is out of phase AS BADLY as POSSIBLE. It can get no worse. That is normal for a 2 piece shaft with 3 u joints. You can see how how a double cardan universal joint starts looking really smart.

Since you don't have that, you need to get the angles the same on one shaft, and the other shaft needs to be straight. It follows from that the rear axle and the transfer case should be pointed along parallel lines just like they are with a one-piece driveshaft. It should be pretty obvious that the front one has to be the straight one. If the back one was straight, you'd need to shim the carrier down a foot.

If you have a double u-joint in the middle, then none of this is a problem.

 

P.S. driveshaft angles aren't related to the grinding I don't think.

 

Yup definitely a combo of bad wheel bearings and terribly worn tires. Yes front wheel bearings were just replaced. Rear wheel bearings were done last September when I did all new brakes. (Calipers, rotors, and pads)


And yup, had the same experience as you. Got new tires two Friday's ago, and sure enough it took away that grinding. Not sure how that works, but I guess maybe one of my old tires must have been that badly worn or out of balance. I was kind of hoping/expecting that, since like you said I was pretty sure when I drove on my Uncles tires it seemed to take away the noise. I think sometimes I still might be able to hear something at lower speeds, its hard to tell. Maybe I'm just being paranoid haha. I took it for an alignment and also like you I need new ball joints. So maybe after the alignment and new ball joints it'll get even better.



Yeah I didn't think any of them were double, but wasn't for sure. Thanks for clearing that up. That all makes pretty good sense. That is how I though the driveshaft should be, but again was not sure. With the front part of the shaft straight/at the same angle and parallel to the rear axle. That looks right, and makes sense that then it would be the same as a one piece driveshaft, just with a second straight piece at the transfer case. I'll be sure to try to get it like this, I think its close, but could probably be better.



I would have to agree. As I said, new tires and that noise went away!


Currently I still have a vibration between 50-60 mph. It is not that bad, but you can still feel it. Its more prominent around 55. You can feel it in the seats, and you can hear it. Its like a rotating noise or a grinding noise, sounds more like it is coming from the rear of the truck. Its subtle, but you can hear and feel it.


Also in this same range of 50-60 I can hear a whining noise. Not sure how else to describe it. Its almost like a whistle, but its not turbo whistle, and its not intake whine either. And I can only hear it at those speeds. It starts at 50 and slowly gets louder until it peaks around 60, that's where it the worst. It is definitely coming from the rear of the truck and is pretty easily heard. Right at 60, and at a certain throttle position. It is also present in overdrive and with overdrive off. If I let off or throttle it up just a little bit it goes away. It really is only at a certain throttle position. I've tried it at slower speeds but about the same RPM's and can't get it to make the noise.


One more thing, which I have not yet pinpointed if there's any specific times when it does it, is that if I let off and then tap the throttle, sometimes I will get a clunking noise or like something binds up for a second and makes a metal on metal noise. Seems to do it more around 30-40. I'll have to try and see exactly when I can replicate it.


So I'm guessing that all this might have something to do with the driveshaft still not quite being right. Whether it be the carrier bearing not being shimmed properly, or maybe the carrier bearing itself is bad, or the front part of the driveshaft needs to be balanced or needs a new u-joint. Would any of this cause the things that I listed above? Any idea on where the carrier bearing shim should be. Currently it has 3/4" of shim. Before that it had 1 1/4" shim and the two driveshaft pieces just about looked to be inline, at the same angle. So I definitely don't need more shim on the carrier bearing, if anything maybe less.


Also like I said, I got new tires, so I took it for an alignment and turns out I need new ball joints. They also found that the water pump is leaking so I need a new one, so I am not currently driving the truck until that is fixed. Not sure if the ball joints and alignment would help anything that I'm experiencing, but who knows...