1959 Driveshaft

1959chevybr

1959chevybr

Well Known Member
I researched every page of every document until my eyes crossed.. Over all my car is higher than the specs in the AMA but still might be causing a problem. I cant find a measurement from top of rear to frame, that's where the money lies.. But I did find bumper to ground measurements..
Stock front bumper to ground,, 11.2 inches stock rear bumper to ground 11.7 inches
My car front to ground 13 inches my car rear to ground 17 inches
I challenge if I found the correct stock specs.. How can my car be higher? Just venting.. baffling.
I have 18 in wheels in back with lower profile tires.. 17 inch in front with lower profiles so that raises the car some. .
 
1959chevybr

1959chevybr

Well Known Member
oldskydog
I got the picture of the frame which alludes to the pinion and motor being offset from the frame in my manual but not the other pictures. Mine is a very poor reprint, bought it new but some pages are missing. I can read some of what you sent, some not but I got a program that might do it better on a different PC. I will be checking it out, but take a look at my next post.
 
1959chevybr

1959chevybr

Well Known Member
Today it got the angles I think the best I can get them even though not to the specs in the manual. From what I have found my vehicle height is higher than stock. But today I proved I got two problems. First I got the angles to the following specs (below) and though not what the chart says it is somewhat in line with other drive shaft specs, there is no getting to the GM example. Take a look, if you think the angles are junk say so. Once I got these angles set the car felt totally different while driving, the vibration was different. The drive shaft was for sure vibrating previously but these angles made it pretty calm. With the drive shaft vibration it was constant like a buzz, that was gone and now the vibration was cyclic which at first I just assumed was the shaft with different angles. I kept thinking this seems different. So we put the car back on the lift and I set it up for a 60MPH test. My friend cranked it up to 60 MPH and the drive shaft was almost totally smooth, the front unbalanced shaft had a VERY slight vibration but the left rear wheel was going crazy again. Shaking the whole lift, worse than ever. This is the wheel/tire area we had addressed before, replaced axle and bearing etc., after repair seemed ok. So when we got the angles better I was able to differentiate the issues. Don't know what is wrong with that area but something is wrong. Each vibration was masking the symptoms of the other. It is not masked now for sure. It does it with wheel off, brake drum on (not as bad as with wheel on) , makes a lot of noise also. I changed the axle and bearing before, sounds like same now. Tomorrow I hope to have 2 new drums and will see what it does with no drums. Tried all this before right after bearing change and all seemed ok, did not last long. tomorrow more investigation. I am sure there were two intertwined vibrations, one of them I am convinced is better the other maybe worse but something I can easily address once I find the cause. I took video of the noise but I would let me send from my cell to myself, says file too big. I am now thinking I can fix this thing.
 

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oldskydog

oldskydog

Well Known Member
Supporting Member 10
Has the axle tube been welded on? Had a bent tube in a 51 GMC with a 77 Blazer 12 bolt that had mounting pads welded on and it warped the tube on one side enough that it caused the bearing to wallow out….axle was not bent but tube sure was.
 
1959chevybr

1959chevybr

Well Known Member
It sure has been welded but it was by me. I added a second upper control arm and welded the bracket on the housing but with the differential offset you are mostly welding on the center housing and beginning of tube. I was very careful and air cooled as I went but things happen.. The first failure of whatever is wrong, happened before the addition.. We will know more tomorrow (I hope). I hope to look in there and see something wrong, I don't at this point much care what it is.
 
1959chevybr

1959chevybr

Well Known Member
After an evening of mulling over my results so far I think I got in my head how we got where I am. Originally we went thru the car with fine tooth comb looking for vibrations, we found the drive shaft vibration while driving on lift. Started working on that, on a subsequent test drive we found the wheel vibrating also, new axle and bearing and it was FIXED. After that we could never get the drive shaft to feel better or worse with any adjustment. So I feel the wheel had started vibrating again unknown to us and was masking the efforts on the drive shaft. We were probably making the drive shaft better or worse but could not really tell because of the secondary wheel vibration., no reason to suspect the wheel since it checked out fine after repair. I think we got the drive shaft good enough yesterday there were no longer combined vibrations, the feeling was totally new when we went for test drive. We knew we had changed something, liking the angle numbers we decided the drive shaft was actually better, lets go back to the beginning. I put car on lift and supported under the rear axle and we did 60mph. I got under car and the drive shaft was spinning very smoothly, the rear axle was bumping/vibrating and the left wheel was going nuts. Took wheels off down to brake drums and still had vibration/noise (not as bad but distinct). Being and old man I got doctors appointments this morning, maybe can do some checkout in the afternoon. I am still with vibration but maybe on a good path. As always thanks to all you guys and I is ok to call me DUMBA$$ !!!!
 
303Radar

303Radar

Well Known Member
Supporting Member 2
I would never call someone a dumbass who learns from what they're doing, it would be like the pot calling the kettle...
This is all a learning experience.
Now, going through a learning experience while being a jerk or otherwise know it all, that is dumbassery behavior. Being honest with a side of humble pie, asking questions, all quite the opposite.
 
T

turbo38s10

Member
just curious, shouldn't these angles be measure with the frame level? It just looks like it should be to me
otherwise the angles will be off by the angle of the frame. The manual pictures also look like the frame is level
although I don't think it says.
 
B

blkss64

Well Known Member
I have to ask. I think I read in an earlier post that you added the extra upper control arm on the left rear side of the differential. Did the vibration exist prior to this modification? Possibly could this be the source of some of the vibration? You can disconnect the upper link easily then retest. If it is pulling the left side forward , the frame bracket can be shimmed. If this has been looked at and posted...... sorry.
 
1959chevybr

1959chevybr

Well Known Member
Try to catch up some questions. It is not a posi.. The second (adjustable) banana was added from Global West to try to help the vibration. The 59 did not come with a cross member where the banana link connects (only later models have this cross brace), just a welded bracket on the side of the frame (very suspect). I fabricated a cross member somewhat like later (I think 61-64) factory cars had. It vibrated before and after doing these mods. The drive shaft angles are all relative, they "compare to each other so it is one subtracted or added to the other that makes the angle no matter how the car is sitting. The numbers would be different but the result the same (it is a little confusing). Today may be a progress day, still got to check a few things out and I will send another post, maybe some positive news.
 
1959chevybr

1959chevybr

Well Known Member
This has been going on intensely for almost 7 weeks. There are dozens of things we have done that I just never posted, just too much typing for me and too much reading for you so I just hit the high spots. A friend brought his 63 over one day and we examined his car, did some test drives and made some parts interchanges. ragtp66, dm62409, blkblk63ss, william malik and donssdd suggested taking different actions on the back brake drums so while we had my friends car we "traded" tires/wheels and brake drums ( at last minute decided against doing the axles). In our opinion this would prove a big hunk of parts good or bad. I still had the same vibration with the changes. This is a little hard to explain but here goes. Yesterday we got decent angles and went for a test drive, the vibration was different for the first time ( was still bad but different). I was convinced we had gotten most of the vibration out of the drive shaft and began to believed, now look elsewhere AGAIN. More on the lift test again and to make the story as short as possible, the back rear wheel vibrated bad again, after fixing with a new axle once. I am smiling, at least something is showing up. It vibrates with the wheels/tires off. More smiles. So we are now thinking we already switched the brake drums from another car so cant be them (of course we had switched back that day). But just to test we switched brake drums side to side, the vibration followed the drum. So why did it still vibrate when we put on my friends drums? In my opinion because the drive shaft was still vibrating. So now with better angles and the drive shaft not shaking and masking what we are doing with other parts of the car it is much easier to tell what is really happening. I am convinced the drive shaft vibration was tricking us when we did something "good" and the vibration in the brake drum was masking when we did something good to the drive shaft. Not sure I adequately described this, if not ask questions and I will explain farther if you are interested. How did I know
ragtp66, dm62409, blkblk63ss, william malik and donssdd has suggested brake drum? I made a spread sheet of all the things suggested and who made the suggestion, I am serious when I say I was at a point I desperately needed help and every word was appreciated. and still is. It is not fixed yet but maybe getting closer. My new brake drums come in tomorrow and we will see. ​
 
1959chevybr

1959chevybr

Well Known Member
We moved the drum from one side the the other and the problem moved with the drum. So I have to assume it is in the drum not the axle flange, We did not move the axle.
 
blkblk63ss

blkblk63ss

Well Seasoned Member
Supporting Member 5
Did you run on lift without drums? You might have to block opposite wheel one at a time.Since it changed sides (drum) maybe was balanced to axle more on one side than other
Who knows. I am thinking if axle has a twist in it.
 
1959chevybr

1959chevybr

Well Known Member
Not sure I explained very well, my brain is so scrambled I probably don't even understand the question, the situation is complicated to me and I am here on site.. I am running the car on the lift with no wheels or tires, just brake drums. We run it up to 60 mph and I get under the car and control which wheel is turning by pulling down on the E brake cable for that side, it will stop that drum from turning. The other wheel picks up full speed. I can switch from side to side easily by pulling the appropriate cable. So we move the suspected drum from side to side and alternate pulling the brake cables. The vibration definitely moves from side to side with the suspected drum. No I have not run with brake drums off yet because once the drums are off I can not control which wheel is turning with the E brake cables. AT 60 mph I am reluctant to jam something under the axle flange to stop that side from turning (call me chicken). I will definitely double check how well the drum/wheel fit together. None of my wheels are perfect true. Not bad enough to cause a problem but nothing to brag about. If I am missing a point or you have a better idea, shout it out. Lots of brain fade.
 
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