1936 chevy low cab build 1.5T

[CORPO]

Got a little truck time in... Feeling under the weather but I wanted to work on the wobble issue

Replaced the tie rods"".
Sleeved the tie Rod with a piece of 1.25" diameter tube
Set the to in to 3/16"
Adjusted the axle from 4 degrees to 6

Took it up the street and back still has the wobble...

It's just strange cause it was fine... Until that first wobble at 60 mph... Now it's not fine even at low speeds

Next on the list steering box

 

[Old Iron]

Change the tires

 

[DJ3100]

Don't you love it when you fix stuff and it gets worse?

You might try 1/8" toe out, since the toe in might have made it worse.

 

[earthman]

Tread seperated at 60.

 

[DozerII]

That sucks, makes me a little worried about my first test drive next summer some time

 

[kenny c]

E-man is probably on to some thing. sounds like a tire issue. How old are the tires? You may have already posted this but is there any play in the king pins?

 

[DJ3100]

I think Corpo's Dad mounted the new tires in August. Of course, a new tire can separate occasionally. Did they get balanced?

 

[CORPO]

Tires are new... King pins are new... Tie rods are also new now...

What I can't wrap my head around was never had one shake until the big shake ... And I probably had 30 min-1hour on it doing laps in the neighborhood probably up to 40 mph....

Now I'm getting them low speed 15-20 mph... Everything still seems nice and tight... But I have always had a little play in the box.... I'm going to look there next... Maybe after the big shake... It loosened it up more???

Kinda at a loss... As I said before my king pins are new but I did them myself and maybe it's not right... ? I may look at the shims but that will require pulling everything apart... But that still wouldn't explain it being fine and then not fine ...

But to answer your question... No the tires have not been balanced yet... Not sure where I'm going to take them... I think I will have to go to a truck place with them...

I really just want to go for a nice cruise ...

 

[DJ3100]

You changed two things on the last fix. The toe and the angle (king pin inclination angle?). I would start with toe because it's easiest. Put it at 1/8" out and drive.

I seem to remember reading that straight axles like 7 degrees of king pin inclination (can't find anything to verify that now, though). 6 degrees should Ok, but if the toe change doesn't improve anything put the angle back to 4.

At this point if should be back to the 60 mph wobble. If not, it is probably a tire/wheel issue.

I seriously doubt you put the king pins together with enough slop to cause the issue. I also doubt the wheel bearings could have been left loose enough to cause the issue. You replaced the rod ends.

That leaves the steering box, tires and wheels. I would think you'd have seen if there is a major wheel wobble, but if not, jack it up and spin them, maybe use an indicator. I would suspect the wheels might be out of balance.

I guess one other possibility could be the whole axle moving independently from the frame. I forgot what you used as a lateral locating device.

 

[CORPO]

I have a pan hard bar... both front and rear

The toe in setting is approx the same setting I had before, although it might be somewhat different ... During my research for wobble I was reading about setting the toe.

I read you should never set it using a tread or the outside of the tire but rather by spinning the tire and creating a line on it. Last time I used the outside of the tire.. this time I did the line technique...

One other thought I had this morning... I know that the bias ply tires can develop flat spots when sitting. I had been pretty good about putting the truck back up on jack stands every time I put it away, but I didn't the last time (3 weeks ago) how quickly will the develop a flat spot?

 

[CORPO]

Change the tires

Unfortunately I only have one set that will fit on the front...

Tread seperated at 60.

I hope not.. I assume u would be able to visually see that on the tire..?

That sucks, makes me a little worried about my first test drive next summer some time

no worries.. my first few drives were fine..! it wasn't till I started to push it (above 50 mph) that I developed the problem that now wont go away...

I will get the problem sorted.. just frustrated..

thanks everyone

 

[DJ3100]

I have had a tire separate internally, you couldn't see it. But it didn't cause the death wobble, it was an extreme vibration on one side. I think you would feel the difference.

I don't think a flat spot would develop that quickly.

 

[CORPO]

Thanks DJ appreciate the input.

I had yet another thought.. maybe the death wobble damaged/blew out one of my shocks..

Thats the problem with this.. so many places to look..

 

[smallfoot]

I don't see it suggested here, but I found a wobble in mine by jacking the front end off the ground and spinning the wheels/tires. Lots of things can be seen just doing that. I had new tires. I had balanced tires. I also had a bent rim.... It was apparent just spinning the wheels in a manner where you could see how well they rolled thru their entire circumference. Although mine didn't get to the death wobble intensity, it would get a pretty good shake that stayed there between 45-55. I know I had new stuff every where...king pins, tie rods and joints and like new steering box and I went through all the things you went through so far before changing wheels.

 

[CORPO]

Well if it is the rims I'm pretty screwed... But that would be confusing since it did run fine before... At least at speeds below 60

 

[CORPO]

Well I adjusted the steering box a bit... Should there be absolutely no movement in the pitman arm? I still have a bit of play, but I need to drop the box to get to the other adjuster... Is there any how toos out there for adjusting the lash in the box?

Changed my toe back to where I had it it seems excessively toed in but it's hard to measure as there isn't a good spot to measure the back of the tires , when you attempt to run the tape across just run into pulleys or suspension components...

I also added a dampner, you can definitely feel the added resistance... My steering was very light, maybe too light... I do think I need to look at adding shims to my kingpins but I'm going to hold off on that till winter time...

I have gotten bad about taking photos... But this clamp I made turned out really good, I made a hinge by slicing a bushing... You can kinda see that here


The dampner I bought had a threaded end which didn't make any since to me because you need it to pivot... So I drilled out the threads and sleeved it with a stainless bushing that is slightly longer so that you can tighten it down without locking up the movement

I need to fix the rubber, it slid on me


Here's the overall... Not ideal but ok


Took her out for a run... Seems better... Every little bump in The road was putting me on edge, but all went off without incident... Had it up to probably 55mph.. I did mess with the air a bit trying different pressures, she seems to like less pressure in the front around 30 psi seems to ride best..

Making progress on the issues... Still need to figure out why my alternator is getting hot... And seal my gas tank... Unfortunately the show I was planing on debuting her at is next weekend... That's not going to happen...

Another little thing I did was add helper springs to correct the door handle droop... I had ordered some from a restoration place... Yeah... Those didn't fit??? Modified them and changed how they mount and now I think it's even better than how they were intended to be used...


Thanks guys

 

[DJ3100]

To measure the toe I use a couple pieces of 6" angle about 2' long pushed up against the outside of the tires. Two tape measures make it easy to get a good measurement.

The dampener looks good. Given all that you've done, you must have eliminated the death wobble?

 

[CORPO]

Seems like it... But I need to put more miles on it... I also want to mess with the pressure in the front tires a bit..

I had read somewhere about not using the outside of the tires as they don't always buldge the same... But I think I'll give ur technique a shot

One other random thought... Has anyone ever added some sort of stuffing to the headers to quiet them up? Obviously I don't want to overly restrict the flow... I already have baffles in them but when I stomp on it ... I think the whole world might hear

 

[DJ3100]

On the F2stang I made over 30 different baffles and bought a couple. I bought a decibel meter and tested them all. The baffles changed the frequency but not the pressure - sound level.

The net result was that I bought fiberglass muffler packing from a motorcycle shop and essentially made glass packs based on photos I got of Harley mufflers. It went from 110+ db to 80 db. Weird thing was that it got more driveable - the torque moved to a lower RPM range.

If you're concerned about the tire bulge not being equal you can use spacers to locate on the wheel.

 

[willyD]

What kind of baffles do you have? My baffles are perferated tubes with two disks on them. The center of the tube is open all the way. Basically like a glass pack setup. I wrapped the tube between the disks with coarse steel wool. They sound good and definitely not too loud. The way mine are amed, it ends up being louder in the cab than outside.