Is your 4406 loud?

[Trolling]

Hi guys!

So I completed the 4406 swap this past Saturday and everything went smoothly. Test drove her around the block and did a couple of quick burnouts (that alone made the swap worth the while ) and so far everything feels fine and the drive feels lighter and more solid.

Today, I was able to take her up to highway speeds (i never go beyond 75mph for obvious legal reasons) and one thing i noticed is that when I go above 60 mph i hear what seems to be a loud roar. It closely sounds like an amplified road noise, sort of what a tire hum sounds like on concrete pavement. I really cant tell if I do have a vibration of some kind but I can best describe it as a very very minor vibration.

By the way, I'm comparing the noise level of the 4406 to the old AWD case I had which didn't really make any noise at all.

I also checked all the clearances (body, exhaust, fuel tank, cross members, etc.) and they are all pretty much rub free. I did replace the transmission mount with a new one during the swap.

Some details of what i have:

Tires: Stock Size Michelin Ltx M/S
Tcase Fluid Used: Castrol Mercon V
Diff Gears: Stock 3.73's
Used a Conversion U joint by PDQ bought from autozone and has a grease nipple (aka greasable u-joint)


Thoughts?
Suggestions?
Could It be a driveshaft out of balance? If so, How do I check it?

Appreciate all your help!
-Carl

 

[IZwack]

Well there you go, you did a burnout - you've "gone done" broke the thing

 

[Trolling]

Ha!
The poor 4406 can't handle a quick (less than 3 seconds ) tire scuffing?
Rechecked all the bolts again after dinner and they are all nice and tight.

 

[Trolling]

bump!

I'll remove the front driveshaft and see how it will affect things on my drive to school tomorrow.

By the way, I stopped by a driveshaft shop in long beach and they wanted $150 (and even more if it needs more work) to balance one driveshaft. just ONE Does it really cost that much?

 

[IZwack]

definitely not - retubing and balancing usually costs that much. $150 just for balancing is waaay too much.

 

[Trolling]

Drove around up to 70 mph and the vibrations and noise are gone. The front driveshaft was making all the fuss.

found a shop nearby (well, nearby my place..) that still has their feet on the ground. $45+ tax for balancing & new joints.

Will post future progress and road test after balancing.

 

[IZwack]

Yeah that $45 sounds much better.

 

[storlied]

Well there you go, you did a burnout - you've "gone done" broke the thing

Lmao.. that gave me a good laugh.

 

[Trolling]

update:

Installed and tested the now "balanced" driveshaft with new u-joints and the vibrations are still there. and in my opinion, more pronounced.

I called up the guy (driveline services~whittier) who balanced it out for me and he said to pass by so he can suspend the truck and check what's causing the vibrations.

any thoughts as to why this thing keeps buzzing?

 

[Trolling]

9-11-10 update:

The guy that balanced the driveshaft was nice enough to give some time to take a look at the whole driveline. Had the truck on jack-stands, shifted the 4406 to 4Whigh and put it in drive.

There is a definite vibration coming from the front differential radiating out towards the driver side wheel (front driver side). when I give it some gas you can really hear the thing grumble and feel it shake/vibrate.

Conditions and Observations:

Raising the vehicle:
The front suspension was at full droop since the jackstands were placed on the front crossmember and the rears was placed under the axle.

Driving Observations:

with front driveshaft on:
vibrations and loud "road noise" sound coming from the front driveline when driven above 50mph. No noticeable noise or vibration under 45mph.

without front driveshaft:
no noticeable vibrations or noise exhibited up to 75mph. no observations for speeds above 75mph since I haven't driven the truck beyond that after the conversion.

Symptom Details:
- rumble like sound
- rumble can be felt by placing hand under front differential.
- you can hear the noise when you place your ear right next to the front drivers side wheel.


Any thoughts?

 

[CDW6212R]

That test with it suspended likely isn't telling you much. I think both CV axles will make some noise or vibrate with them so far from normal ride height. The noise and vibration you are hunting is probably about the same as those CV axle joints when they are near full bump or jounce.

I wonder if the front driveshaft angle is part of the problem. That relationship of the frame/suspension/driveshaft does not change much at all no matter what the truck is doing. Maybe one or both of the u-joint angles(pinion angle) is off and causing the noise.

 

[Trolling]

i was thinking that there will be some acceptable play any if not all driveline components but when i heard and felt the vibrations/shuddering from the front components, i said to myself that it cant be right. the symptoms are too prominent to be considered within acceptable tolerances.

i'll post a few pics of the angles of the driveshaft.

brb

 

[CDW6212R]

I'd do that and look at the driveshaft itself, the joints/type. Ford made them like what you have for the early 2nd gens. They went to the CV joint I think to reduce the chances of vibrations, they are smoother in operation.

I hope you figure that out, I think it's typical of these TC swaps. I have a front driveshaft for mine made from my stock one and a double cardon shaft. Keep digging, it helps us all.

 

[backfrmcolorado]

have you looked at you wheel bearings by chance... just a thought.

 

[Trolling]

pics are up.

btw, any spatter you see are old ones. right now i have zero leaking seals.

here's what the front driveshaft looked like before the ujoint conversion/balancing/painting:

 

[Trolling]

have you looked at you wheel bearings by chance... just a thought.

not yet. it was a pain in the butt to check with the AWD so i haven't bothered myself to do so.

I'll try and check it tonight.

 

[CDW6212R]

I do still wonder if the u-joint angles may be a vibration problem. I'm not an expert, far from it, but I think basically the two driving shafts should be close to being inline. I know there needs to be some angle of all u-joints, you never want the driveshaft inline with a pinion shaft. Our front pinion angle is very close to being inline to the driveshaft.

I wonder if pivoting the front differential down would improve that angle. I've thought of that before, almost every time I see the clearance at the exhaust there. I'd love to have more space for a 3" cat pipe there.

 

[Trolling]

Haven't had the time to check the front wheel bearings but i did manage to shoot a quick low quality vid of the front differential front flange.

is it supposed to have that much play? and if you turn the volume up, is that sound normal?

the vid:

 

[boominXplorer]

The driveshaft flanges need to be within 5* on single u-joint setups. Yours are off by about 20* You need a double cardon end with 2 joints at the transfer case.

 

[Trolling]

did you use a double cardan joint on your 4406 conversion?

So if a double cardan front DS is the solution, what would be the best route to take?

1. convert my current driveshaft to a double cardan
2. buy a front driveshaft that already has a double cardan joint

what would be more cost effective? 1 or 2?

>>>>

oh, and how did you come up with the angle difference between the tcase and front diff flanges? care to share so I can check them myself?