Not so Good Vibrations

[whtbronco]

I found a thread where Hamfisted suggested part # 8L1Z-4612-A for a 2006. High probability that's correct, Mike always seems to be on point.

 

[whtbronco]

7L1Z-4B425-B is the bushing for the torque arm(8L1Z-4612-A). I'm not sure the bushing would fit the factory arm, but I am fairly confident the 8L1Z arm will fit the truck. So I've ordered the arm.

I also ordered a new Motorcraft fan clutch. Functionally it's working fine, but there's some play in it if I rock it and I have been wondering about it for quite some time. Sadly I just don't have time right now to swap to e-fan's

This might resolve some more of the vibration, how much we'll see.

I'll be getting a battery soon too.

 

[whtbronco]

To my surprise reinstalling my original transfer case with new bearings and seals did help to reduce vibration compared to the salvage yard transfer case that received the same treatment. Mine is in much better shape and felt smoother on the bench even. Maybe 40-50% less both under power and coast. Most notably when coasting from say 70mph it would start to vibrate some in the seat and floor, then if I hit the brakes to drop to 40mph for an exit ramp I could really feel it in the brake pedal. The brake pedal vibration is gone or mostly, it might just be in my head if it still exists. Once I get down to 35mph or less there's no wheel speed vibration.

Tasca has for the 2nd order in a row cancelled my order due to being out of stock, though they still show the part in stock, argh. This time for the rear diff torque arm, they show 26 in stock. My wife just went to local dealer and paid an extra $50, total $205 including the governor's share. They always charge MSRP or higher, but it'll be available tomorrow. I'll get that installed this weekend and see how much the new bushing holding the diff firmly helps.

Still have some engine speed vibration I'm tracking down. A new fan clutch has been installed, not sure that helped the engine speed vibration. It is certainly tighter. All I did was run it in the garage though.

Maybe someday I'll get all of the causes of the vibration figured out. I got most of this resolved a while back when I replaced the rear cv axles and hubs. Not all of it though and it clearly snowballed while it was being ignored until it just got to be too much for me tolerate any longer.

When I get done I'll compile a list of the things I replaced, adjusted etc...

 

[whtbronco]

The new water pump and fan clutch certainly made a noticeable difference in the engine vibration. There is still a bit more to track down, but I can only feel it when not moving. Below ~35mph this thing is really smooth going down the road now.

I got the rear diff torque arm/support bracket replaced today. Not sure that really needed to be done. The factory bushing is cut out on top and bottom to allow some movement, though it did only move up when shifted into Drive. I did not fire it up to test it. I can tell you one thing, the replacement was not painted, the factory one was. I cleaned the replacement and covered it in undercoating and then filled the front of it with RTV to help keep crap out of it, the factory had epoxy that closed the front.

Yes Ford and Tasca this does fit the 2004 Expedition, 8L1Z-4612-A. The only difference is that the replacement was not painted and had a solid bushing which I expect to hold it in place a little better.

 

[whtbronco]

I think I may have found the remaining engine vibration. There are some very intriguing clean'ish spots behind the harmonic damper. However, it looks like the rubber between the center section and pulley has moved. I was wondering if there might an issue with the damper, my other thoughts were the flex plate or torque converter. Of the 3 I sure hope it's damper. What do you think?

I know the front main seal is leaking, that'll get replaced soon maybe along with the damper. BTW, my son-in-law is 3D printing a seal installer for me. I did not want to pay $200+ for a front main seal installer.

The pics kinda suck, I'll try to get a better look and pic, it's hard to get in there right now

 

[whtbronco]

I went ahead and ordered a new OEM front main seal and damper.

Once again I am gonna be wishing I had e-fans since I have to remove the fan for the 3rd time this month.

 

[whtbronco]

Well the damper and seal arrived 5 days early somehow. So tomorrow I plan to take care of this. The seal installer my son-in-law 3D printed for me looks okay. I had expected it to be a bit wider, but I had no measurements. I just thought it would fit around the outer lip on the seal, but as you can see it will flatten the lip and push directly on it. Being a new seal it's quite pliable so I'm sure it'll be fine. Based on comparing the seal installer to the new damper it will fit perfectly over the crank shaft.

 

[whtbronco]

The front main seal and harmonic damper have been replaced. The seal appears to have resolved the oil leak. The damper didn't resolve the vibration, but it seems to have change the rpm ranges where it's vibrating in park/neutral. Of course it was inconsistent previously sometimes it just didn't seem to be there at all. I know when it did vibrate there was a spot a bit above idle and another just below 2000rpm. Now paying very close attention I noticed there is something tapping, like a light rod knock, at 1200-1300rpm now and then it vibrates from 1300-1400rpm and then calms down. I only listened from the drivers seat, maybe today I'll get under it and have someone hold it at 1200-1300rpm to try and isolate it.

The crankshaft bolt is too short to install the damper from start to finish. The seal installer worked fine though, I was able to tap the seal in with a hammer and then use the bolt for the last say 3/32" and it pulled it in.

A "you dummy moment":
I decided not to bother my wife to come start the engine while I kept an eye under the hood. Well that was a mistake. I had removed a trans line from the radiator so I could get the fan shroud out and I forgot to put it back in. Shot 1.5 quarts of ATF all over the place before I saw it and shut it off. My goodness what a dang mess. Took almost 2hrs to get it all cleaned up and re-filled.

 

[whtbronco]

Well this weekend it's time to get back under the truck, the vibration under power has increased a good bit again since the front main seal and damper were replaced. Sometimes it's worse than others and sometimes I can feel it in the brake pedal again. The inconsistency all the time is driving me nuts. I'm gonna pull the inspection plate on the trans and it sounds like there is some barely audible whining/humming in the rear at higher speeds. Could possibly just be tire noise, it's around 60-70mph.

The PCV grommet is leaking a bit, that'll get replaced tomorrow. Not a single store in town had one that would fit so I had the Ford dealer order a replacement, Only $9 anyway.

 

[whtbronco]

Well on the way home this evening the vibration felt more pronounced and I started thinking it was suspension. I took it up to 80mph twice and it definitely felt like suspension. Turns out the upper left rear ball joint bushing is loose. This makes sense as it was intermittent and varying in intensity. So now to get 4 new bushings(both uppers and both lowers), I wish I could just buy 4 new control arms as well from Ford.

PCV vacuum leak is fixed.

Just gotta keep nibbling away at this stuff.