Driveshaft balancing question

I replaced the carrier bearing and had a driveline shop replace a U joint and balance the driveshaft in hopes of fixing a 65+ mph vibration that I feel through the whole truck up to the steering wheel. It’s almost like hitting a long, bumpy rumble strip. (Rattle, smooth, rattle, smooth, constantly)

The driveline shop balanced and painted the whole shaft (which made it look great) and thus painted over my marks that would match the shaft up to the transfer case and rear diff flanges. They told me that it shouldn’t make a difference how it bolts to those flanges. They also said they knocked a large manufacturer-placed weight off because the shaft was “way off balance”.

Is it true that I shouldn’t be concerned about the flanges? It very clearly could bolt on 180 degrees opposite from its current position. Acceleration from a stop is smoother than it’s ever been, but that highway speed vibration is still there and actually seems to have gotten worse.

 

The drive shaft should be rotationally balanced independent of the xfer case and pinion. No worries there.

When's the last time you've done a rear brake job?

 

I’ve never replaced the brakes on this truck and I’ve had it for four years. So it’s definitely time and I have been planning on it. Would bad drums be a cause of this? Definitely more of a constant vibration in the steering wheel when applying the brakes at high speed.

 

There’s your sign… possibly the front brakes..check to see how hot the calipers are after a run down the road might have one freezing up or have a warped rotor

 

is this a manual transmission, R150F?

 

It is indeed

I will be sure to get on the brakes ASAP….
Truck just turned from a round town beater to a 400 mile/week daily driver

Thanks for the advice

 

I chased a vibration for a long time- changed out everything I could without avail. Finally replaced the rear brakes drums (I had the OEM ones turned, which was a mistake) and my vibration went away. There might be other reasons for your vibration, but the rear brake drums and shoes and a pretty cheap one to check off the list.

 

How old are your tires - any irregular wear?

You can inspect your drums and rotors pretty easily but my intuition would be tires at a specific speed, but you also said you noticed it get worse under braking.

If you can pull your wheels off and inspect your front rotors for uneven wear inside and out (try to find a good place to see behind the dust shields on the inside) and pull the drums to also look for uneven wear on the shoes and drums it may show signs of irregular wear.

I had a rock the size of a grain of rice dig into one of my rotors and it would make the vehicle pull to one side and shake when I hit the brakes and once I pulled the rotors it was obvious what caused the problem.

This video explains the Taco / 4runner brake drum system pretty well.

https://m.youtube.com/watch?v=IJkVEBYSecs

 

I’ve had pretty strong vibrations caused by both the rear drums and driveshaft (different trucks). Sounds like you’ve done your check on the driveshaft and should look elsewhere. I’d move to the rear drums.

 

I’m looking at RockAuto and see a Raybestos rear drum kit, 4wd for $102. I’ve considered doing the big brake upgrade but am thinking I’ll stay with 15 inch wheels. Any experience with Raybestos?

 

Just as another data point for rear drums, I put napa everything - drums, shoes, springs except for centric wheel cylinders. Everything fit up great. Did initial adjustment then another one 200ish miles later. Wasn’t too horrible price wise bought online 20% off delivered to store just in case I ran into any part problems.

 

That’s what I used. No complaints with fitment / parts. I adjusted e brake per FSM instructions in Timmy’s video and can defeat it pretty easily by pushing the vehicle or (occasionally) forgetting to take it off when driving, but I didn’t have a chance to test it prior due to a leaking axle seal which coated the brakes in oil.

 

Update:

Replaced shoes and drums with Raybestos parts and reused all spring hardware (brand new horseshoes and E clips).

Brake shudder is TERRIBLE now. No change in highway vibration it seems. Gonna throw old drums back on and see about getting new ones turned because olds are out of spec. Brake pedal is also mushy now, wheel cylinders bad? Picked up cheap replacements… Then start looking at fronts…

 

Original wheel bearings? Wheel bearings can go bad and not look noticable - is there a noticable difference before and right after you were working on the rear?

You could rule out rear brakes if you run it without the shoes and block off the hard lines, but where your wobble is at highway speeds it's obviously putting you and others in danger unless you have a farm and dirt roads.

Regarding the mushy pedal, I'd bleed the everloving heck out of your brakes - I noticed a lot of air got in mine when I had the cylinders disconnected after doing my wheel bearings / axle seals and I finally got it all out with them working as they should.

 

Haven’t touched wheel bearings, but yes VERY noticeably worse immediately after swapping drums and shoes, whole truck shakes like a jackhammer when coming to a stop. Never did disconnect the brake lines so I’m wondering if a cylinder got damaged somehow. Had a nice firm pedal before…

 

Hmmm if the brake lines were never disconnected it seems like it would be that the rear brakes are probably out of adjustment - did you take pictures and / or follow a video of how to set them up? Can you lock up the wheels with the ebrake?

What kind of wheels do you have - oem or aftermarket? If they’re aftermarket do they have the right kind of lug nuts (acorn / mag / etc.)?

 

E-brake was working fine although seems to have more “clicks” than before, I did follow Timmy’s video and got the shoes expanded to the point where the drum was making contact but still went on fairly easily, I then went and pulled the e-brake handle and released it many times but I was consistently getting about 20 “clicks” which seems high.

I have 15” oem 3rd gen 4Runner wheels with acorn style nuts torqued to 83 ft lbs

 

You mean mag style lug nuts?

 

You mean these wheels?



And those lug nuts you posted? They don't take those - they take oem lug nut style lug nuts like I posted, not a conical acorn lug nut.

Like these:

https://www.ebay.com/itm/383209094669?var=651742505686