Axle Wrap with OME Dakar Leafs

Hey there,
I have been searching TW for an answer but cant seem to find one. I have the EL095R Dakar leaf packs on my Tacoma but continue to have the feeling of axle wrap. From what I understand, I should not have any movement with the better leafs.

I have checked the ubolts and they are all torqued to 90 ft lbs. I have lubed the u-joints, but not the slip shaft. I need to check the u-joints to see if they have any play.

I am sure the driveshaft angles are off as I am getting the typical vibrations at takeoff, but no other vibrations at any speeds. Sometimes when coasting(no acceleration/braking) and I start to accelerate, there is a slight 'thump' feeling as if I am slipping a clutch before it engages. Possibly the driveshaft settling in the carrier bearing? The carrier bearing has about 1/2" of play, but this seems normal from what I am reading.

Next steps were to replace the carrier bearing and do a transmission flush/refill if nothing else works.

Any of you had this problem or have any suggestions? Thanks!

 

Had the same thing a few years ago with stock springs. Grease the splines on your driveshaft before throwing parts at it. You don't have to disassemble the whole driveshaft as just unbolting the carrier bearing and pushing the boot back will give you enough slack to get most of the splines. There isn't a grease fitting, so just smear some on by hand, bolt the carrier bearing back up, and then zip tie the end of the boot that your loosened. The same grease you use on everything else will work fine.

See below thread for the gist of what I'm talking about. I later added a grease fitting, but not in the same place as shown there.

https://www.tacomaworld.com/threads/greasing-slip-joint-boot.357521/

edit:
I added a fitting like this: https://www.tacomaworld.com/threads/2nd-gen-tacoma-slip-yoke-grease-fitting.263428/

 

3 degree STEEL shims between the leaf pack and axle mount.

 

Thanks. That was one of my possible next steps too.

My concern is that I am having the axle wrap feeling with the dakars, too.

 

Is this for the axle wrap or just the take-off shudder?

 

you wont ever get rid of axlewrap with leaf springs. Stiffer leaf springs like the Dakars will make axle wrap less but it will still always be there with leafs unless you get a traction bar setup in conjunction with it.

First things first, you need to measure U joint working angles at ride height and go from there. FYI with my OME EL095R pack i ended up with a 2* shim with the fat end FORWARD, to point the pinion down so that when during acceleration the working angle of the u joint due to axle wrap is closer to ideal, still have take off vibes but they are minimal now.

 

Sounds like greasing the splines and adding the shims will take care of it. I will try them out within the next couple of weeks and see how it goes. Thanks!

 

Helps both by putting the angle closer to factory specs.It was a must for my truck.

 

Never seen shims installed with the fat end forward.

 

It all depends on what works best. FYI factory toyota leafs had 0 2 or 3 degree setups for a TSB that pointed the pinion down so that upon acceleration when the axle wrapped up, the u joint angle was a few deg less.

 

The O.P is running Dakar's though.

 

Correct, and so am I... EL095R medium packs. I have the ford ranger CB with the driveshaft located about 1/2in lower than stock centerline (just as a stock CB + OME CB drop) and have found that the best of all worlds occurred with the 2deg shim fat end forward to make driveline angles under acceleration better.

You would be AMAZINGLY SURPRISED at HOW MUCH the rear axle moves up and down under deceleration and accel.

 

Did you measure your drivetrain angles before adding 2 degree shims?

I just installed a set of hd Dakars and was sold a set of 3* shims. Installed them (skinny side forward) and it pointed my pinion up to 7+ degrees. No good. I’ve removed the shims and remeasured. I’m 3.4 degrees up on pinion and my Tc is 2.2 degrees down. Will be milling my 3* shims tomorrow down to 1.35 degrees. Install fatty side forward. Hope to equal but opposite my tc and pinion angles. My two shafts are almost equal by spacing down the cb with fender washers. Need to eliminate my 3-10mph vibes.

 

I did, and i tried no shims, 2* down and 2* up, .... pointing it 2* down worked the best.

FYI, you want to go equal and opposite angles at either the first (tcase) and second (center) u joint, or 2nd and 3rd (pinion), not 1st and 3rd as those joints are not phased properly. My tcase joint is around 1* and center and rear joint are close but opposing angles, pinion slightly higher of an angle so under acceleration during wrap they are pretty close.

 

@nd4spdbh

Check out post#128 on link below.

https://www.tacomaworld.com/threads/just-fixed-driveline-vibration-for-free.153050/page-7

 

Option 1 will not work. 1st and 3rd joints can not cancel each other out as they are 90* rotationally out of phase.

Only proper options when it comes to rotational phasing are 1st and 2nd joints equal and opposing and 3rd at close to 0, or 2nd and 3rd joints equal and opposing and 1st at close to 0.... and really, the only proper option is to have 2nd and 3rd joints equal and opposing as the rear suspension cycles both joints will increase and decrease angle by essentially the same amount keeping cancellation proper and 1st joint will remain at a static angle because trans/tcase and CB are hard mounted to the frame.

If you did angle cancellation at 1st and 2nd joints it would only be good for static ride height, as soon as suspension moves up or down (due to bumps or load in the bed) then you would change both pinion and center joint working angles creating a cluster fuck of nothing canceling out.

There is a reason why toyota's driveline vibration TSB for the later model 2nd gens did 2 key points to driveline angles. 1. New trans/tcase mount which LOWERED the assembly by ~ 3/8ths of an inch which reduced the 1st u joint working angle down closer to .5-1*. Second was depending on measured driveline angles of the rear (3rd) u joint you got a new leaf pack with a degree shim that pointed the pinion DOWN so that upon acceleration 2nd and 3rd u joints were more closely matched in angle to cancel each other out.


The mostly IDEAL solution is a setup similar to the 1st gen tacoma. 2 piece driveshaft, 1st u joint close to 0deg, at the center you have a double cardan joint which cancels working angles out within itself, then a rear pinion joint slightly pointed down so that it becomes close to zero under hard acceleration.

Unfortunately there is NO perfect way to go about it with leaf springs as there is so much movement of the rear pinion up and down due to axle wrap regardless of leaf springs.

 

So your setup is 2* shims (fat side forward) to point pinion down.

1” spacer lower on the cb.

Can you share you three working angle measurements?

 

CB is probably around 1/2in lower than stock, hard to get an accurate measurement as im using a ford ranger CB.

If i get a chance tonight while im under the truck doing some other stuff ill take some measurements of working angles.

That stated, i still have some vibes around the 15mph mark, but they are subtle enough to make me not care, and at cruising speeds there are zero vibes.

 

Reinstalled my stock leafs and shocks last night to measure stock angles. Test drive with NO VIBRATIONS.
TC- 2.3* down
1st shaft 7.9* down
2nd shaft 5.7* down
Pinion 5.2* up

Drove over to my buddies house who has a 2015 4wd Tacoma sport. Bone stock.
Measured his driveline angles. Almost the same. He says he has not vibes.
TC- 2.5* down
1st shaft 8.0* down
2nd shaft 5.5* down
Pinion 5* up

Drove over to my parents house and measured their 2007 4wd Tacoma bone stock. Again another Tacoma with no vibes.
TC- 2.9* down
1st shaft 8.0* down
2nd shaft 5.5* down
Pinion 5* up

All three trucks with stock rear suspension. All measurements with a Johnson level magnetic digital angle locator. Took measurements off the flat part of the Tc output shaft, flat part of the pinion output shaft.

 

I'm about to install my Dakars in a few weeks, I'll measure my angles and post up too