Wanted to share this in a separate post from my build thread.
I recently removed by 2" OME lift 10MM spacers up front and exchanged it for the 3.5" Dobinson's Long Travel springs and MRA shocks with a DC front shaft. This netted a lift difference of 2-3/16 front and 2-1/2" rear of additional lift height over the OMEs. I also have the 4" Delta Arms installed.
I had a grumble on decel only. It may have actually there at all times, but I did not notice it. So, I added a front DC shaft.
The front DS was very UNHAPPY now! It grumbled like an old fart who just had is recliner taken away from him at the old folks home. I was measuring between 2.9° and 3° of angle from the DS to the face of the U-joint. After reaching out to the Mud brain-trust, I made a decision to play with this a bit - for may own edification and to share with all ya all.
I loved the soft sprung nature of the Dobi's vs the OMEs and wanted to retain that so ordered a set of 3" flexi springs. I also orderd some Delta 3L arms to play with.
Ride with the 3" springs are much the same but not quite as floaty being a bit more stable especially around corners. I attribute this to the rather significant difference in lift height - Wait - What??? While advertised as a difference of a mere 1/2" between these spring sets, on my rig I found that there was actually a difference of an additional height of 1-3/16" front and 1-1/8" in the rear of lift from the 3" springs to the 3.5" springs. I have a spreadsheet below with all the recorded measurements.
I was hoping that adding the 3L arms alone would cure the issue. The thought was between rotating the axle and increasing the distance from the rear flange to the front pinon flange would decrease the angles. It did but I was still at 1.4°, the front DS was still not happy, better, but not acceptable.
Finally, I pulled the front DC shaft and re-installed the factory shaft. DS angles angles improved to 0.7° and the grumbling ceased. I attributed this to the increased distance between the two u-joints which decreased the angles between the flanges and the DS.
So, while that has "cured" the unappy front DS (I also added adjustible upper control arms in the rear) I now have some complaints under hard acceleration, especially on left turns. I added more grease to the knuckles hoping that was it as it really sounds like the noise is from the passenger front. Perhaps sitting parked for 4 years created an issue? I need to put her up on jack stands and see if I get any play on the wheel bearings. Rebuilt the knuckles about 45,000 miles ago - may just rebuild the fronts again anyway.
Any thoughts on the noise? I have less than 40 miles on the 3 1/2" lift, I don't think that would be enough to bugger up the front pinon.
I recently removed by 2" OME lift 10MM spacers up front and exchanged it for the 3.5" Dobinson's Long Travel springs and MRA shocks with a DC front shaft. This netted a lift difference of 2-3/16 front and 2-1/2" rear of additional lift height over the OMEs. I also have the 4" Delta Arms installed.
I had a grumble on decel only. It may have actually there at all times, but I did not notice it. So, I added a front DC shaft.
The front DS was very UNHAPPY now! It grumbled like an old fart who just had is recliner taken away from him at the old folks home. I was measuring between 2.9° and 3° of angle from the DS to the face of the U-joint. After reaching out to the Mud brain-trust, I made a decision to play with this a bit - for may own edification and to share with all ya all.
I loved the soft sprung nature of the Dobi's vs the OMEs and wanted to retain that so ordered a set of 3" flexi springs. I also orderd some Delta 3L arms to play with.
Ride with the 3" springs are much the same but not quite as floaty being a bit more stable especially around corners. I attribute this to the rather significant difference in lift height - Wait - What??? While advertised as a difference of a mere 1/2" between these spring sets, on my rig I found that there was actually a difference of an additional height of 1-3/16" front and 1-1/8" in the rear of lift from the 3" springs to the 3.5" springs. I have a spreadsheet below with all the recorded measurements.
I was hoping that adding the 3L arms alone would cure the issue. The thought was between rotating the axle and increasing the distance from the rear flange to the front pinon flange would decrease the angles. It did but I was still at 1.4°, the front DS was still not happy, better, but not acceptable.
Finally, I pulled the front DC shaft and re-installed the factory shaft. DS angles angles improved to 0.7° and the grumbling ceased. I attributed this to the increased distance between the two u-joints which decreased the angles between the flanges and the DS.
| Lift | Front Panhard | Rear Panhard | Fender | Drive Shaft/U-joint Angles | Dobinsons Springs | Notes | ||||||||||||||||
| Bottom | Top | Difference | Bottom | Top | Difference | PF | PR | DF | DR | Front | Rear | Front | Rear | |||||||||
| OME 2" | 21.5" | 22" | Included front 10MM Spacer - No noise, DSs were happy. | |||||||||||||||||||
| 3-1/2" Long Travel | 16-7/8" | 21-1/2" | 4-5/8" | 17-7/8" | 23-5/16" | 5-7/16" | 23-11/16 | 24-1/8" | 23-5/8" | 24-3/8" | Stock Shaft, 4" Delta Arms - Stock DS grumbling under deceleration. | |||||||||||
| 3-1/2" Long Travel | 16-7/8" | 21-1/2" | 4-5/8" | 17-7/8" | 23-5/16" | 5-7/16" | 23-11/16 | 24-1/8" | 23-5/8" | 24-3/8" | 2.9° | 8.8° | C97-144VT | C97-145VT | 4" Delta Arms, Front DC Shaft - Grumble louder and continuous | |||||||
| 3-1/2" Long Travel | 16-7/8" | 21-3/8" | 4-1/2" | NA | NA | NA | NA | NA | NA | NA | 1.4° | 8.9° | C97-144VT | C97-145VT | 3L Delta Arms, Front DC Shaft - Grumble still there, slightly less pronounced. | |||||||
| 3" Flexi | 17-3/16 | 20-1/8" | 3-15/16" | 18" | 22-5/8" | 4-5/8" | 22-1/2" | 23-1/2" | 22-1/2" | 0.13 | 1.35° | .02° | C59-612V | C59-613V | 3L Delta Arms, Front DC Shaft. Added Adj upper arms - DS still not happy | |||||||
| 3" Flexi | 17-3/16 | 20-1/8" | 3-15/16" | 18" | 22-5/8" | 4-5/8" | 22-1/2" | 23-1/2" | 22-1/2" | 0.13 | .07° | .02° | C59-612V | C59-613V | 3L Delta Arms, Factory DS. Added Adj upper arms - Grumble gone! |
So, while that has "cured" the unappy front DS (I also added adjustible upper control arms in the rear) I now have some complaints under hard acceleration, especially on left turns. I added more grease to the knuckles hoping that was it as it really sounds like the noise is from the passenger front. Perhaps sitting parked for 4 years created an issue? I need to put her up on jack stands and see if I get any play on the wheel bearings. Rebuilt the knuckles about 45,000 miles ago - may just rebuild the fronts again anyway.
Any thoughts on the noise? I have less than 40 miles on the 3 1/2" lift, I don't think that would be enough to bugger up the front pinon.
