Boppa's old yeller truck

[hgs_notes]

Originally Posted by Low Elco

Confabbed with my boss, who builds 2,000 hp 11.5 Outlaw cars ground up, and he says I'm on the plan. A big 4x4 guy at work says the same. Just ordered the shims, tech guy at the roundy-round place says I'm on the right track, oughta be a fun weekend! Gawd I hope this works.

Sooo, did it work?

[Low Elco]

I've been meaning to get off my butt and update, thanks HGS. Well, took Fri off last week to try to make progress. Found a trans shop full of hotrodders when we went to have the tailshaft bushing (only thing I could find appreciably loose) replaced. Much better, still didn't fix the problem. They said bring it in. Took the truck to them, we put it up on the rack, you can still feel it vibrate running free at 60. The only thing we could find using a snap-on amplified stethoscope was a slight throb at the front of the motor. We were there for an hour and a half, the pros could find nothing. We bought 'em lunch anyway. Stock Car/ Carl's racing products are about worthless, they've been promising my shims, no soap so far. Nice people, though. Took the front tires off LBT, still the same, that's three different sets now. I made my own shims, and shimmed up the trans/rear combo to approx. 2 deg from 5 to cure the straightline problem, smoother, but still there. I've been jumping shims around, some change, but still there. Note that the vibe is not a constant rotational, but more a cyclical. WUBWUBWUBwubwubwubwub WUBWUBWUBwubwubwub WUBWUBWUBwubwubwub, that kinda thing. Vibe is not tied to motor speed. We have a 3.73 rear on hand, need to paint it up. I was waiting to do the mild drop we have planned until after we sorted this out, but the Kid had some good logic-why get it fixed just to screw it up again? Screw it all up the way you want and go from there, maybe it'll fix itself in the process. I'm thinking about a new trans mount also, this one seems a bit soft, although I've had perfectly smooth cars with the transes falling out of them. Hell, I dunno, I've heard of a-arm bushings causing this type of thing, although all seems solid, and the steering wheel is smooth as can be.. Just seems like the truck is being grabbed at the seat base and shaken. Maybe this weekend we'll bust out the sawsall and have at it. Also tried to fix the stereo, 25 year master stereo guy said rectifier could be back feeding AC through the line. Auto electric guy disconnected alt, fired truck, buzz still there. He asked about tiny fuze in the motor harness on the driver's side, it was broken in 2. Don't know what it does. He gave me a new one, REALLY loud buzz now. God, I love being me. Truck has been sitting for a few days now, as I'm pissed off and have a really good cold, and pre thanksgiving bidness and a wife's birthday to attend to. Don't really know where to go from here. I'm gonna drop it (just a coil), and check out the front bushings, etc. while I'm there, then make up a set of blocks and drop the rear accordingly while swapping in the 3.73.`Throw everything at it, maybe it'll come out in the wash. Thanks for playin' along.

[Vic1947]

As you know, Chip, I've been fighting the same issue with mine and I hope to post some photos by this weekend along with latest results. Previously, I've replaced tires, balanced all four corners using latest Hunter GSP9700 Road Force system, replaced the rear trans bushing, shimmed the pinion angle to the recommended orientation, installed new u-joints, balanced driveshaft - all to no effect. With the rearend up a couple of inches on a floor jack and the speedo on 65, there is still a noticeable vibration.

So I removed the rear tires, ran all the lug nuts down on the brake drums and spun it up again, vibration was still there. Removed the driveshaft and used a high speed 1/2" electric drill to drive the pinion nut, still the same. Removed the brake drums entirely and turned it over again, vibration was still there. At this point, I had removed all external sources of vibration and the rear axle housing was still shaking, so I pulled the rearend out of the truck and went back thru it.

I've replaced the gov-bomb with a new Auburn posi, put in new axles, swapped out the 3.08 gear for a 3.40 and most importantly, I dusted off the line up bar I use for narrowing rearends to check the straightness of the axle tubes. Both sides were off-center slightly (about 1/8"). One side was off up and down, the other side was off front to back. I used heat to draw the tubes back into line, reassembled everything and put it back under the truck.

I've been working on revised shock mounts for a new set of QA1 shocks that will mount vertically instead of being laid back at the stock ~160 degrees. I wasn't able to find a kit for a moderately lowered leaf spring truck so I had to build my own. Lower mounts are done and my plan today is to identify the optimum upper mount point. If all goes as planned, I should have it all buttoned up by the weekend and out for a test drive. Of course, if it's fixed, I won't know exactly what did it, but I'll post pics anyway, either here or on your driveline angle help thread. If it doesn't fix it... I don't know what to try next. About the only thing left might be to put a four link under it. An awful lot of expense with no guarantee of success.

[Low Elco]

Originally Posted by Vic1947

As you know, Chip, I've been fighting the same issue with mine and I hope to post some photos by this weekend along with latest results. Previously, I've replaced tires, balanced all four corners using latest Hunter GSP9700 Road Force system, replaced the rear trans bushing, shimmed the pinion angle to the recommended orientation, installed new u-joints, balanced driveshaft - all to no effect. With the rearend up a couple of inches on a floor jack and the speedo on 65, there is still a noticeable vibration. We've done the same thing, with the same result. Should have done the brake drum thing, though. I may try that.

So I removed the rear tires, ran all the lug nuts down on the brake drums and spun it up again, vibration was still there. Removed the driveshaft and used a high speed 1/2" electric drill to drive the pinion nut, still the same. Removed the brake drums entirely and turned it over again, vibration was still there. At this point, I had removed all external sources of vibration and the rear axle housing was still shaking, so I pulled the rearend out of the truck and went back thru it. Sounds like a good plan. Wish I had your guts/skills. I can field strip it no prob, do the seals, but am afeard of setting them up. I get pattern/backlash, but the whole preload/crush sleeve bit escapes me, and I ain't got the kinda dough to just take a stab at it.

I've replaced the gov-bomb with a new Auburn posi, put in new axles, swapped out the 3.08 gear for a 3.40 and most importantly, I dusted off the line up bar I use for narrowing rearends to check the straightness of the axle tubes. Both sides were off-center slightly (about 1/8"). One side was off up and down, the other side was off front to back. I used heat to draw the tubes back into line, reassembled everything and put it back under the truck. Now, I think you may be on to something.

I've been working on revised shock mounts for a new set of QA1 shocks that will mount vertically instead of being laid back at the stock ~160 degrees. I wasn't able to find a kit for a moderately lowered leaf spring truck so I had to build my own. Lower mounts are done and my plan today is to identify the optimum upper mount point. If all goes as planned, I should have it all buttoned up by the weekend and out for a test drive. Of course, if it's fixed, I won't know exactly what did it, but I'll post pics anyway, either here or on your driveline angle help thread. If it doesn't fix it... I don't know what to try next. About the only thing left might be to put a four link under it. An awful lot of expense with no guarantee of success. I keep forgetting you're a leafer. If you look in the suspension thread, and under some of No Limit's threads, search shock mounts, you might find a design for uppers to get you close. Please let me know with pics how it comes out! Fingers crossed for you. Personally, I'm about one click short of a pound of c-4 and some det cord! I hope it works out well, and you're back to hi-ho silver this weekend!

Yee-haw!

[jlsanborn]

Hmmmmmm.......panhard rod bushings?? I know your friend is a "leafer" there Chip but maybe that could dampen your jiggles? Think the carrier is just unbalanced and it's transmitting?

[Low Elco]

Not a bad guess, but they're urethane, replaced in I think 08, and the rear is within 1/16 side/side, and passes the shake test with no slop as of last Fri. See, this is why I'm stumped. It's gonna be something waaaay outta left field.
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[jlsanborn]

Hmmmmmm..... So the "WUBWUBWUBwubwubwubwub WUBWUBWUBwubwubwub WUBWUBWUBwubwubwub" (glad that didn't come from the mobile device!) means harmonics / natural frequency stuff..... Some source of oscillation at a frequency and a spring (rubber, air bubble, flexing metal....) thats trying to hold it still but can't keep pace. Hmmmmmm..... I bet something is outta balance and it's shakin the $hit out of whatever is supposed to hold it still
What frequency did the fancy scope measure, or did it? What turns at that RPM??

[Low Elco]

Wasn't a fancy scope, just an amplified stethoscope. (doctor listener) Thanks for the technical end of the noise, I'm with you! Trouble is, what? That's why I'm kinda gonna replace a tranny mount that seems ok, if a tad soft. 'Cause that's exactly what it feels like, like a damper that can't keep up with the harmonics, and the wave has to whip it's way out, only to start again. I'd swap balancers, but it doesn't change with engine speed. The cyclical vibe is what led the street rod shop guy to suggest rear shocks. Maybe this weekend, me and Neighbor Jay will pull the driveshaft and go out to a lonely road we know and strap Yeller to Big Blue and see what happens with no drivetrain. I'm starting to think it may be like Vic's problem with the axle. I dunno, we'll see.

[Low Elco]

Also, a buddy at work has offered his GoPro to strap under there and try to catch it on video, although we didn't see shat with it on the lift. Bah, we'll see. Oh, no carrier, one piece shaft.

[jlsanborn]

Well even if the GoPro won't catch any jiggles it'd sure make a cool smoke-show video!

[Low Elco]

I'm thankful that I have a cool truck to gripe about, one waiting in the wings, a Dad, a Mom and two boys to do this with, a great wife, a nice house to do it in, and a good job to pay for it all! Lots of prople don't have that. And thanks to y'all on here too, for your patience, understanding and encouragement. Happy thanksgiving!

[Bomp]

I agree. The truck is cool! Inspires me to get workin' on mine.
Since its a one piece drive line is there any chance it (the drive line) got knocked out of balance? A buddy of mine years back pulled his drive line and lost a weight and didn't know it. He had a vibration that when he hit 45 it would pop the tail gate open. It wasn't a bad vibration but it just drove him totally NUTZOID. Being intune with your ride thing.
Just thought I'd ask.
Hope your Thanksgiving was a great one.

[jlsanborn]

Any high-speed, smoke show, tow-strap movies this weekend!?

[Low Elco]

Tow strap hopefully tomorrow. Tried to fix some electrical with so so results. Watching Secondhand Lions with the Kid.
Posted via Mobile Device

[Vic1947]

Originally Posted by Low Elco

Wasn't a fancy scope, just an amplified stethoscope. (doctor listener) Thanks for the technical end of the noise, I'm with you! Trouble is, what? That's why I'm kinda gonna replace a tranny mount that seems ok, if a tad soft. 'Cause that's exactly what it feels like, like a damper that can't keep up with the harmonics, and the wave has to whip it's way out, only to start again. I'd swap balancers, but it doesn't change with engine speed. The cyclical vibe is what led the street rod shop guy to suggest rear shocks. Maybe this weekend, me and Neighbor Jay will pull the driveshaft and go out to a lonely road we know and strap Yeller to Big Blue and see what happens with no drivetrain. I'm starting to think it may be like Vic's problem with the axle. I dunno, we'll see.

I also think the shocks may be a help, but not necessarily the complete answer. I finished rebuilding the rear axle and relocating the shocks on mine. I didn't want to clutter up your build thread with a page full of pics, so you can see what I did here. Results were just okay, got rid of maybe 80% of the vibration I had. My gut feeling is that repositioning the shocks vertically did the most, but swapping diffs and straightening the axles may have also contributed.

[Low Elco]

Well, it's been an interesting day. We towed it with no driveshaft and the motor off and it lit up vibrating at the same speed as before. Ergo, rearend. Et Voila! We just so happen to have a 71 3.73 on the trailer. So, a corporate decision has been reached. Time for the El Slamola! (Not a lot, just a little bit.) So, we're gonna gather the stuff for the drop this week.

Ok, here's how it currently looks.


Seems awfully high up, doesn't it?


Thaaat's ok, Daddy has the cure!


Here's our crusty new friend, I hope this works!


We're hoping to remove and repair our battered and sketchy control arms, as well. Stay tuned!

[Bomp]

Ahhh,,, Your working on a Chevy. The hammer isn't needed.

[Low Elco]

Ah, but I beg to differ, sir! That's a 12-pound sledge on a standard hammer handle. Pops ball joints right apart! One of me favorite tools!
Posted via Mobile Device

[hgs_notes]

Good luck with the swap and drop.

[Bomp]

How far ya takin' the yellow one down?
Its already one sweet ride. Dropping it in the weeds will put it over the top.
So how much is an airplane ticket to fly you out here to paint my '66?

[jlsanborn]

That's great news!!!! What's the timeline?

[jlsanborn]

Originally Posted by Low Elco

Ah, but I beg to differ, sir! That's a 12-pound sledge on a standard hammer handle. Pops ball joints right apart! One of me favorite tools!
Posted via Mobile Device

We call that a "meat stick" in the NW!

[Low Elco]

Originally Posted by Bomp

How far ya takin' the yellow one down?
Its already one sweet ride. Dropping it in the weeds will put it over the top.
So how much is an airplane ticket to fly you out here to paint my '66?

Thanks for the props! Probably gonna go a coil in front, and get some 1/2 alum. flat bar cut to size and u-bolts and drop to taste. If I wasn't so paranoid, I'd buy the 1.5" spacers that push the wheels out to the edge of the body in the rear to work with the rallys. We'll see how it goes. Really would like to re do the shock mounting. The 71 we had that these same springs were from sat a LOT lower. Just another weird quirk of this truck. You don't wanna fly me out there to paint the '66. I am nobody special. You can get the exact same results, especially if you're shooting a solid color. Go slow, shoot one piece/chunk at a time, it'll be great! Now, cut and buff, beer swilling and smartassery, THAT you wanna fly me in for!

[Low Elco]

Originally Posted by jlsanborn

We call that a "meat stick" in the NW!

John, John, John. Poor, Poor John. Have you learned nothing by now? You can't give me a softball over the plate like that! Meat Stick, indeed! Thanks for the Mon. chuckle!

[Xeen]

The best way to find out whats going on with the radio is to pull it out of the truck and bench test the entire system, head unit, amps, capacitor, everything, if it still buzzes when its out of the truck then its not an electrical issue its a hardware issue.
At that point you need to start breaking down the problem even further and start eliminating hardware untill you find the problem, start with nothing but a head unit and known good speakers if it buzzes then its the head unit, if it doesnt add amps untill you find out which component is the problem. Its likely that you have a bad head unit or amplifier, but it could also be something as simple as the signal cables between the head unit and the amps.