Vibration Fix
06-30-2015, 09:03 AM
#62
I played around with my truck last night with the drive line angles. Right now the carrier is shimmed down .400 and these are my angles. TC down 4 deg, jack shaft down 1 deg, drive shaft down 5 deg, pinion up 2.5 deg. It's better but there is still some vibration. The weird thing is my truck seems to change. It will be better for awhile, and then one day it will vibrate non stop on a return trip to home.
03-03-2020, 06:05 PM
#63
Sorry to revive this old thread. I have a 2015 f150 157" RWD. Since it is RWD, it has no transfer case and thus the first drive shaft from the transmission (I am assuming this is what you guys are referring to as the "Jackshaft") is longer than that of a 4x4. I had no block at first. I then installed an OEM Raptor block that is tapered (I don't know the angle) 2-3/4" to 2-5/8" ( to correct angle between differential and driveshaft... on a 1-piece raptor that is!). I started to get a little shudder on takeoff from a complete stop, but I figured that has more to do with axle wrap from having the taller block. I did install a 5/8" carrier bearing drop spacer, and that didn't do anything for the takeoff shudder.
I then went to a 4" tapered block from Maxtrac (I believe they said it was tapered 4deg, but I am not sure). and started to notice a slight driveline vibration. I removed the carrier bearing spacer and the vibration seems to have gotten worse (but I honestly not that sure ow much the difference is, if any). The vibration seems to be more noticeable when accelerating, but I can still feel light vibration while at cruising speeds (55-75mph). When in stop/go traffic (like at a traffic light), I sometimes get some lurching forward as I try to accelerate from a stop. It has actually scared me a couple of times. I sometimes get a harder shift than normal (all my 6r80s with 2-pice shafts have had a hard shift here and there, but these have been stronger since the 4" block and no carrier spacer). Seems like it might be binding at the u-joints from the extreme angles especially from low speeds or a stop. It didn't do this before I removed the bearing spacer.
Now I am trying to educate myself on all this so that I can start to adjust my angles. I understand how to measure the angles and I have the tools for it. I cannot, however, access the document in the links above from Spicer/Dana. It seems you guys got alot of info from it and I cannot find anything online other than some videos on how to measure. I understand I need to get my working angle between my transmission and jackshaft no more than 1.5deg, and the angle of my jackshaft and differential need to match in parallel, and the working angles between my carrier bearing joint and 2nd driveshaft and my 2nd driveshaft and differential need to be no more than 3deg and vary no more than 1deg from each other.
I am worried as to how to achieve this. With the tapered block, the working angle between the diff and 2nd shaft is not that much, and the working angle between the 2nd shaft and the jackshaft at the carrier is pretty steep due to the 4" drop. So I need to start shimming the carrier (I will use thinner gauge material, like washers for experimenting .. then will machine or fabricate a solid spacer at the necessary height when finished) to reduce that angle, but by doing that I will also be making the angle between the 2nd shaft and my differential closer to 0deg. I am thinking I am going to have to go to flat blocks instead of tapered, or use shims in the reverse direction on the blocks to get them closer to flat to make the shimming on the carrier bearing more effective. To me it seems like having a flat block in the rear makes the working angle greater between the diff and 2nd driveshaft, meaning that you could shim the carrier bearing more before you get to a 1 or 0 deg working angle at the diff.
I noticed. @winchested had the setup closest to mine. Did you use tapered blocks as well? The angle between your transfer case and jackshaft was 2.5deg. That is ore than the 1-1.5deg that is supposed to be allowed. Any issues with that? I am hoping I will have less than that, as my jackshaft is longer with not having the transfer case, so shimming the carrier bearing should change the angle less than that of a 4x4 due to the longer shaft.
@joedotmac do you have a link to that Spicer document? Any input on my situation.
At some point I might switch to the 2wd 6.2L transmission mount. This should hopefully improve the stiffness similar to you 4x4 guys using the Raptor transmission mount. But that can be a last resort. My truck had no vibrations at stock and only takeoff shudder with the Raptor blocks. So I am pretty sure this all has to do with the 4" rear blocks throwing the angles out of phase.
I will be measuring my angles tonight and will try and post a sketch of my findings asap. Thanks all!
I then went to a 4" tapered block from Maxtrac (I believe they said it was tapered 4deg, but I am not sure). and started to notice a slight driveline vibration. I removed the carrier bearing spacer and the vibration seems to have gotten worse (but I honestly not that sure ow much the difference is, if any). The vibration seems to be more noticeable when accelerating, but I can still feel light vibration while at cruising speeds (55-75mph). When in stop/go traffic (like at a traffic light), I sometimes get some lurching forward as I try to accelerate from a stop. It has actually scared me a couple of times. I sometimes get a harder shift than normal (all my 6r80s with 2-pice shafts have had a hard shift here and there, but these have been stronger since the 4" block and no carrier spacer). Seems like it might be binding at the u-joints from the extreme angles especially from low speeds or a stop. It didn't do this before I removed the bearing spacer.
Now I am trying to educate myself on all this so that I can start to adjust my angles. I understand how to measure the angles and I have the tools for it. I cannot, however, access the document in the links above from Spicer/Dana. It seems you guys got alot of info from it and I cannot find anything online other than some videos on how to measure. I understand I need to get my working angle between my transmission and jackshaft no more than 1.5deg, and the angle of my jackshaft and differential need to match in parallel, and the working angles between my carrier bearing joint and 2nd driveshaft and my 2nd driveshaft and differential need to be no more than 3deg and vary no more than 1deg from each other.
I am worried as to how to achieve this. With the tapered block, the working angle between the diff and 2nd shaft is not that much, and the working angle between the 2nd shaft and the jackshaft at the carrier is pretty steep due to the 4" drop. So I need to start shimming the carrier (I will use thinner gauge material, like washers for experimenting .. then will machine or fabricate a solid spacer at the necessary height when finished) to reduce that angle, but by doing that I will also be making the angle between the 2nd shaft and my differential closer to 0deg. I am thinking I am going to have to go to flat blocks instead of tapered, or use shims in the reverse direction on the blocks to get them closer to flat to make the shimming on the carrier bearing more effective. To me it seems like having a flat block in the rear makes the working angle greater between the diff and 2nd driveshaft, meaning that you could shim the carrier bearing more before you get to a 1 or 0 deg working angle at the diff.
I noticed. @winchested had the setup closest to mine. Did you use tapered blocks as well? The angle between your transfer case and jackshaft was 2.5deg. That is ore than the 1-1.5deg that is supposed to be allowed. Any issues with that? I am hoping I will have less than that, as my jackshaft is longer with not having the transfer case, so shimming the carrier bearing should change the angle less than that of a 4x4 due to the longer shaft.
@joedotmac do you have a link to that Spicer document? Any input on my situation.
At some point I might switch to the 2wd 6.2L transmission mount. This should hopefully improve the stiffness similar to you 4x4 guys using the Raptor transmission mount. But that can be a last resort. My truck had no vibrations at stock and only takeoff shudder with the Raptor blocks. So I am pretty sure this all has to do with the 4" rear blocks throwing the angles out of phase.
I will be measuring my angles tonight and will try and post a sketch of my findings asap. Thanks all!
Last edited by ARuezga; 03-03-2020 at 06:10 PM.
The following users liked this post:
joedotmac (03-03-2020)
03-03-2020, 09:15 PM
#64
Dana / Spicer Driveline Installation Guide
The rules posted above are paramount in getting the configuration right. At least 1 but no more than 3 degrees at any u-joint operating angle. Optimally you'd like to have all operating u-joint angles within 1 degree of each other. At my last measurement there was a maximum of .5 degrees difference on any u-joint operating angle.
I was able to take the u-joint operating angle at the rear differential from 4.5 to 3.0 degrees from loosing the leaf spring u-bolts jacking up the pinon side of the rear differential housing and re-tightening the u-bolts. I bought two different degree shims, didn't end up using any of the in the end.
Best of luck.
The rules posted above are paramount in getting the configuration right. At least 1 but no more than 3 degrees at any u-joint operating angle. Optimally you'd like to have all operating u-joint angles within 1 degree of each other. At my last measurement there was a maximum of .5 degrees difference on any u-joint operating angle.
I was able to take the u-joint operating angle at the rear differential from 4.5 to 3.0 degrees from loosing the leaf spring u-bolts jacking up the pinon side of the rear differential housing and re-tightening the u-bolts. I bought two different degree shims, didn't end up using any of the in the end.
Best of luck.
03-03-2020, 10:31 PM
#65
Dana / Spicer Driveline Installation Guide
The rules posted above are paramount in getting the configuration right. At least 1 but no more than 3 degrees at any u-joint operating angle. Optimally you'd like to have all operating u-joint angles within 1 degree of each other. At my last measurement there was a maximum of .5 degrees difference on any u-joint operating angle.
I was able to take the u-joint operating angle at the rear differential from 4.5 to 3.0 degrees from loosing the leaf spring u-bolts jacking up the pinon side of the rear differential housing and re-tightening the u-bolts. I bought two different degree shims, didn't end up using any of the in the end.
Best of luck.
The rules posted above are paramount in getting the configuration right. At least 1 but no more than 3 degrees at any u-joint operating angle. Optimally you'd like to have all operating u-joint angles within 1 degree of each other. At my last measurement there was a maximum of .5 degrees difference on any u-joint operating angle.
I was able to take the u-joint operating angle at the rear differential from 4.5 to 3.0 degrees from loosing the leaf spring u-bolts jacking up the pinon side of the rear differential housing and re-tightening the u-bolts. I bought two different degree shims, didn't end up using any of the in the end.
Best of luck.
03-04-2020, 05:00 PM
#66
It appears you have the calculations correct.
Working angles front 2°, carrier 6° and differential 6°.
I'm not certain there's enough range left in shimming the carrier bearing down to offset what the 4" block has introduced as there's only 1 degree you can take out from front down to 1° as per the minimum angle specification.
Optimally you'd need to drop the tail shaft of the transmission down and lower the carrier bearing. I'd be guessing 1/4" at the transmission, and maybe 1/4" to 3/8" at carrier. You could also offset the the need of lowering the tail shaft of the transmission by moving to a slightly smaller rear block. I haven't look around the transmission mount to see about what the possibilities are to lower it.
Working angles front 2°, carrier 6° and differential 6°.
I'm not certain there's enough range left in shimming the carrier bearing down to offset what the 4" block has introduced as there's only 1 degree you can take out from front down to 1° as per the minimum angle specification.
Optimally you'd need to drop the tail shaft of the transmission down and lower the carrier bearing. I'd be guessing 1/4" at the transmission, and maybe 1/4" to 3/8" at carrier. You could also offset the the need of lowering the tail shaft of the transmission by moving to a slightly smaller rear block. I haven't look around the transmission mount to see about what the possibilities are to lower it.
03-10-2020, 03:00 AM
#67
It appears you have the calculations correct.
Working angles front 2°, carrier 6° and differential 6°.
I'm not certain there's enough range left in shimming the carrier bearing down to offset what the 4" block has introduced as there's only 1 degree you can take out from front down to 1° as per the minimum angle specification.
Optimally you'd need to drop the tail shaft of the transmission down and lower the carrier bearing. I'd be guessing 1/4" at the transmission, and maybe 1/4" to 3/8" at carrier. You could also offset the the need of lowering the tail shaft of the transmission by moving to a slightly smaller rear block. I haven't look around the transmission mount to see about what the possibilities are to lower it.
Working angles front 2°, carrier 6° and differential 6°.
I'm not certain there's enough range left in shimming the carrier bearing down to offset what the 4" block has introduced as there's only 1 degree you can take out from front down to 1° as per the minimum angle specification.
Optimally you'd need to drop the tail shaft of the transmission down and lower the carrier bearing. I'd be guessing 1/4" at the transmission, and maybe 1/4" to 3/8" at carrier. You could also offset the the need of lowering the tail shaft of the transmission by moving to a slightly smaller rear block. I haven't look around the transmission mount to see about what the possibilities are to lower it.
I went ahead and decided to jist shim the carrier bearing. I found that if I dropped the first shaft by 3.5 degrees by shimming the carrier about 3.18" I would get my first shaft parallel with my pinion, my working angles would be about 1deg at the 1st/second shaft and at second shaft, pinion, and my working angle at the transmission would be about 1.5.
I forgot to take a measurement of how far back the carrier was from the u joint before I modeled, so my shimming was a bit off as I estimated it was 3" away based on a picture. It is actually about 5" away. Forgive the bad notes. These were done quickly and without intention to publish here. Note, all my angles are down about 1deg because I actually lifted my truck's front end about an inch last week. I also messed around with my rear axle and blocks (separate alignment issue) which could have moved the pinion angle. And I used an actual digital inclinometer I bought at Harbor Freight. I didn't trust my cell phone as it gave me a ton of varying answers since no surface of my phone is square or flat.
Top left are my angles with the 3.18" shimming. I thought this was pretty good. But I drove it and still some noticeable vibration. Axle wrap was much less.
So I came back and tried to match my first shaft angle a little closer to my diff. I shimmed 2.85" and got them lined up pretty well. At least within 0.2deg, as my diff reading was slightly different this time around. Angles at bottom right of picture.
Notice in both cases, I dropped the first shaft so much I went past the 0deg working angle at the transmission and back into having some working angle. My only concern now is not having enough working angle at the transmission with that 0.5deg.
I drove it and it seems like most of the vibration I am now feeling is in my steering wheel. I still feel some on my seat, but very little. I am running LT tires, and bilstein shocks front and rear, with the front being set to the 1" level setting. So this is likely where some if not all of the vibration is coming from.
I also know that one of my tires in the front is a little out of round. I found this out after road force balancing. It still passed, but was told it is slightly out of round. I don't know how much or if any of that is translating to vibration.
I don't know if it is the placebo affect but it seems to be much better, but it has been so long since I first noticed the vibrations that I can't remember what it feels like not to have them, so it is hard to gauge If I have eliminated them.
Any thoughts on the angles?
