Mysterious front end rattling & vibration - baffles a dozen mechanics

Yes. A lanolin-based coating or Cosmoline, especially IN the frame would be a better bet in the rust belt. Really no matter what you choose rust prevention is an annual chore here

 

Yet another layer revealed. You are blowing my mind right now. I am going to get wheels balanced and a fresh alignment after my LCA replacement this week. I will definitely ask about this lug centric / hub centric situation. These wheels are from a 1st gen Tundra.

Here is an in-depth thread from 2010 on this topic. Quite interesting. A rabbit hole for sure. Once you enter there is no telling where or when you will come out.

 

Crazy stuff. Last year, I had the leaf springs replaced with these springs from General Spring. New bushings were included. My log says that it significantly reduced squeaks and squawks.

 

FWIW My 98 Tacoma had the shimmy shudder too and it went away with a Haweka balance. Now I have different wheels since then Alloy Enkei's and they don't seem to care how they are balanced which is a win IMO

 

Not to try and get too side tracked but do you have any frame coating recommendations? I pressure wash the bottom of my truck frequently so I want something that would hold up to that well. I also have surface rust so idk how that gets delt with when doing frame coatings.

 

i would spray something onto that existing coating to keep it 'soft' and not allow it to harden up

 

Surface rust on frame you want to scrape with wire brush, convert with phosphoric acid, then cover with POR-15. Easiest if the bed is off, but you can achieve decent coverage with bed on. Focus on the area behind wheel wells the most, in the unboxed section. I dropped my hitch and bumper to do the job right.

WoolWax or Fluid Film are your messy friends in the rust belt. Caveat: you shouldn’t power wash your underbody after these have been applied. Put on in fall, don’t wash your underbody all winter, then remove in the spring if you so desire. I just leave mine on all the time and refresh the application annually. It’s messy and collects grime but hey that’s better than rust I think (and saves me money during annual re-application, just a touch up instead of full job).

 

do not use POR-15
it will PEEL in sheets like latex
it is JUNK
just do NOT use it

 

Sorry to hear you had a bad experience. Personally it has worked great for me, going on five years since initial application.

I’m going to nerd out a bit about why I like it. It’s one of the few reactive, isocyanate containing coatings available for the DIY market. In my experience reactive urethane coatings typically achieve much better properties than rattle can coatings (usually marginally reactive alkyd-based). I’m actually amazed it’s sold direct to consumers given its health risks, isocyanates are quite toxic. The formula appears to be similar to Line-X, although Line-X is a more modern, derivative chemistry designed for very rapid cure.

That being said the reactivity makes it a “picky” coating so surface prep and cure conditions (temperature, humidity) will influence the final coating properties. IMO it is harder to apply correctly. It’s also not light-stable, so if you used it anywhere exposed to sun without a topcoat, it would explain the failures you saw.

 

i tested that on an old crusty wheelbarrow
also used the POR-15 cleaner degreaser AND the POR-15 Metal Prep etcher... spent some very good coin on all this
Topcoated it with barcelona red automotive paint to shield it from the UV...
thought everything was going swell until the springtime and the melt
an absolute waste of +100$

after all of that i found this geeker that does real-world testing and he appeared to have an ephiphany...

https://youtu.be/TABWPHutk-A?si=lYQRhnwXkAV-TE7e

 

Hmm, sounds like you did all the steps right. Only thing I can think of is that the rust may have laminated and you only got the top layer (oxidation continued inside) or if you didn’t rinse the acid off then it could have stopped the reaction (acids poison isocyanate crosslinking). Did it peel off with a layer of rust on the back? Sorry for all the questions, I love coatings and rust prevention/mitigation in general.

At work right now so I can’t watch your video, but I’m curious to learn more, definitely want to see what and how this person tested. Will watch tonight at home. Thanks for sharing!

 

Extremely well done test/video. I watched the whole thing. I suggest starting near the end at the 40:33 where he gives his summary. If you find that interesting back up to 17:00 for the corrosion testing portion.

 

Finally had some time to watch this. Interesting study and thanks for sharing. My perspective:

-He’s using methods that are similar to what we do in the coatings world, salt fog and south-facing UV are standard tests, as is gloss
-Adhesion test results are the most interesting to me. It’s interesting that POR-15 peels the way it does. His crosshatch method is essentially what we do. The biggest weakness in his study is that he has no method of evaluating applied or dried coating thickness. Adhesion is a function of drying/cure rate, applied thickness and % solids of coating. Without applying same thickness to each panel it’s sort of like comparing apples and oranges
-Bench vice bend test will fail any coating, a better method is to wrap around increasingly smaller diameter cylinder and note diameter where coating cracks

Formula comments: POR-15 uses aromatic isocyanate, which cures faster, is harder and more chemical resistant but sacrifices UV resistance. I can’t tell if there is a polymeric component or if it’s a pure moisture cure. If there’s no polymeric component it appears to be a cheap coating indeed
-Mastercoat and Raptor liner both use aliphatic isocyanate and appear to be 2K systems, which are more flexible, tough, and UV stable at the expense of cure time and cost. Raptor liner also appears to include a UV absorber - makes sense, the truck bed is always in the sun
-KBS appears to be a 1K moisture cure system using prepolymers and a more advanced chemistry than POR-15. Still aromatic, so same UV stability issues, also has some fatty acids I’m guessing as a surface wetting aid for adhesion

Based only on safety data sheet analysis and without any testing of my own Id probably conclude the 2K Mastercoat is the best product, assuming that you are patient and wait for full cure

In all cases the manufacturer’s instructions could be better regarding ideal cure conditions, emphasizing the importance of surface prep, re-coat time, and target applied coating thickness

In any case you’ve changed my mind and I’ll probably go MasterCoat the next time I refresh my frame. Thanks!

 

it is entirely possible that the Duplicolor red barcelona automotive paint used as topcoat on that wheelbarrow was in No Way UV resistant as it sat outside exposed the whole winter with snow and water in there

 

Did you ever get this ironed out? I did not read the whole thread, however I did pick up on the Monroe shocks bit. I installed the correct ones for my truck according to autozone, monroe website & tech service. Those puppies caused me nothing but trouble. There’s a bagillion page thread on here about it…. Hopefully you’re all set. If not & you want me to post the link, happy to. & I believe I summed it up in the final post. In other words, you wouldn’t have to read the novel….

 

I tried the Monroe junk from the AAP for a spell
The darn things made the lca bump stops keep smacking on the frame
Proven by the WoolWax grease transferred from the bumpstop to the frame section
Wasted some good coin on those thankfully I had a helper at the time to install assist and didn't have to pork out even more coin for a professional parts changer

 

I started this thread by asking for advice with 3 issues:

1. Rattle / clank sounds coming from front tire area (both sides)
2. Serious vibration over 60 mph
3. Play in the steering

The rattle-clank-sqawk sound was completely resolved upon replacing the LCA bushings. I ended up going with Import Direct bushings, for better or for worse.

Play in the steering was completely resolved by doing the five things listed below. Steps 1, 3, and 5 were accomplished at different times and each resulted in significant improvement. Steps 2 and 4 were preventative, but I include them for reference.

1. Put a piece of yogurt lid between the two halves of the "tilt ball". Very noticeable improvement.
2. Replaced the shaft dust seal (aka boot). Since this has no structure whatsoever, I assume this is mostly to protect the pivot gears from getting dirty.
3. Tightened the rag joint! It was just resting on the rack, held in place by gravity. The bolt was still there and keeping it from bouncing off entirely, but not from bouncing up and down 1/4 inch.
4. Regreased the tilt-ball and pivot joints and added anti-seize to the splines.
5. Added three drops of super glue into the telescoping shaft - the final critical maneuver that resolved all remaining play.

The vibration has been the most difficult problem to address. It is partially resolved.

It seems that the Milestar tires are to blame. I showed them to three different tire specialists who say that I screwed myself by buying Milestar tires to begin with, and one said that these showed clear signs of uneven wear, despite only having 15k miles and being rotated perfectly on schedule. A small miracle occurred - I ran over a nail with one of my back tires and it went completely flat while I was on the highway. I swapped it out with my spare, a dry-rotted Michelin all-terrain tire. I noticed immediate improvement. Around 50% of the vibration disappeared. I was able to find a used matching Milestar to replace the bad one with the nail. So far so good. There is still a small amount of vibration right at 65 mph, but I can live with this for a while. And I feel quite confident that getting a new set of decent quality tires will eliminate the remaining vibration.

Over all, the truck is much more pleasant to operate at this time.

All three issues did affect the front end, however, each issue had to be resolved independently of the others. The resolution of each single issue did not seem to have any affect on the other two.

Much thanks to all those who contributed to this thread!

 

I just had noticed you stated it (or some part of it) seemed to have started after you had the monroes installed. Glad you figured it out!

 

The three issues that I requested help with in my original post, caused me so much grief that I decided to get a different vehicle altogether. After several months of looking at available options, and with these 3 mechanical issues behind me, I now have a different perspective.

I like older vehicles like this '99 Tacoma because of their simplicity. But, it's nearly impossible to find any truck that old WITHOUT RUST here in the rust-belt. For me, that is the number one reason to keep this truck going.

And in my desperation I found this forum of Tacoma experts. So going forward with this vehicle I now have that support.

With Gratitude.