View Full Version : weird noise or vibration

09-02-2016, 07:33 PM
As you know, I changed to a 9" rear end. Also, I was having problems with the rear half of the exhaust pipes rattling against the new rear housing and leaf spring hangers so had that replaced.
I have driven the car but up until Tuesday had not gotten above 45mph. Well Tuesday I drove the car to the golf course and got up towards 60-70. When at those speeds, I have a noise I will call it. I can also feel it in a vibration. Worries me.
I have the car up on jack stands right now trying to see if something is amiss. Any input? Checking the driveshaft for issues. Not sure what it is, but if I can't locate the issue, Roger would you be willing to go for a little ride and see what you think. I will keep it under 100. Unless someone wants to race. Larry

Bill Pierce
09-03-2016, 07:22 AM
Did you use the same Driveline? You were running a 8" before?

If the yoke is setting too deep in the transmission it may be transferring vibration.

09-03-2016, 08:02 AM
No... wait... that was my problem. Your car doesn't have one of those anymore.

09-03-2016, 11:09 AM
Bill, it is interesting that you mention the driveline. It was an 8" before and when I put the 9" in the car, the old driveshaft was too long. I was going to get it shortened. Took it in and they showed me it was totally worn out. So, made a new one, 4" diameter instead of 3" much beafier u-joints.
I gave them measurements, but it actually looks a little short. Maybe it isn't in the transmission far enough. Not sure, appreciate your help. Thanks Larry

09-05-2016, 01:38 PM
What did put in for a 3rd member ? Is your noise - vibration like a chatter ? What kind of oil are you running ?

09-06-2016, 11:16 AM

Of course I'd go for a ride. :3g:

You did a lot of swapping of bits in this car... so have you ever checked driveline angles? If you have a smartphone Tremec makes an app for this analysis. If not, Google this. If the angle of the engine and rear end are out of sync from each other, the u-joints in the driveline with not rotate as designed. Not so much a vibration as it is a resistance to movement causing a seeming imbalance. I have a similar issue on my Ranchero - also with all new rear end and driveline, and I think this is the next thing I'm going to be checking on it.

Here's a link to learn about this:


Instructions for use:


09-07-2016, 12:00 PM
Roger, this really makes sense that it is my issue. I didn't think the noise or vibration was coming from the rear end. It felt more like it was related to the driveshaft. That is why I thought maybe it was too short. Thanks and I will check it as soon as I figure how to get it raised up and level. Thanks Larry

09-07-2016, 12:34 PM
Of course you should check transmission tail-shaft/slip yoke engagement. You should have about 3/4"-1" visually exposed (see note below) - just enough to be able to push the driveline into the transmission a little further when removing the rear u-joint from the 3rd member.

Note: Some early extension housing tail-shaft seals were two depth seals. The end pressed into the transmission was like a regular seal, but it had a rubber dust shield as part of it to protect this otherwise exposed 3/4"-1" part of the slip yoke. This shield kept that part of the driveshaft from rusting, but still allowed you to push the slip yoke into the transmission. Lacking this dust shield you could basically ruin the seal when you pushed the slip yoke into the tail-shaft when removing the driveline; especially if the slip yoke had significant surface rust on it. Not all replacement seals look like this and you should clean any rust off the exposed area of the slip yoke when pulling the driveline.

Factory looking seal:

5852 5853

09-08-2016, 02:03 PM
Well, as usual Roger has given the advice that I believe is my problem. I went underneath and was going to check pinion angle, but didn't get that far. I found that the traction bars that we made were holding the rear end in a nose down position.
I took off the rubber bumpers at the front of the bars, and the pinion angle is better, (will have to measure) but now the traction bars are touching the fasteners that hold the leaf springs together. So, I will have to remove the bars, then check pinion angle.
But that creates another problem. The bars are welded to the leaf spring shock absorber plates where the u bolts attach the rear end to those plates.
Now, does anyone happen to have a spare set of those plates lying around you want to get rid of.
Don't know what years will work. I do know that I had to slot the holes just a little in my plates to get the u bolts installed because the diameter of the 9" housing was just a little bigger.
Thanks for all the help and I will keep you all informed on the progress. Larry

09-08-2016, 03:22 PM
Probably got some small ones for the 6 cyl but not for the V8 and certainly not the big tube 9" - if that's what you have.

You may just have to grind off the welds regardless, since these are not welded where you want them to be.

09-10-2016, 08:59 PM
More investigation shows that the traction bars were really torqueing the leaf springs and holding the rear end with the pinion facing down. Just the opposite of what it should be.
It will be very hard to cut the welds on the plates/traction bars, but that is where I guess I'll start.
More to come. Larry

09-18-2016, 05:31 PM
Not getting a lot done on this car. Headaches will not let me lie down under this thing.
The traction bars that I had installed were indeed preloading the leaf springs holding the rear end facing down 4-5 degrees. Just the opposite of what it is supposed to be.
I cut the traction bars off the leaf spring plates and installed the rear end again. Now the rear end is still pointing down just a little.
The way the leaf springs were preloaded has created a warp in the springs that is visibly causing the rear end to point down.
When I first started this car rebuild it was evident that the leaf springs were weak and thought about replacing them. But, decided to try the old ones.
Now that these are so weak and warped I am going to replace with new.
Here is my question. Since I plan on racing the car, and since I like the rear end up just a little bit, should I go with 5 leaf springs? I know the ride is supposed to be stiffer, but it can't be as bad as it was with the traction bars holding it stiff.
Thanks Larry

09-18-2016, 08:25 PM
Ordered leaf springs from McVeigh and the Cal Tracs for the car. Going with 4 leaf springs instead of 5.
Thought about making the cal tracs, doesn't look that hard, but so many problems with the homemade traction bars before, don't want more problems. Larry

Bill Pierce
09-18-2016, 08:37 PM
There is some information here http://www.hotrod.com/articles/91758/
This one is better http://www.hotrodhotline.com/content/drive-shaft-harmonics-drivelineuniversal-joint-cancellation-jim-clark-hot-rod-md#.V99iOyNlC2f

It may take some trial and error to sort out. There is a company in Spokane called watts wheel and driveline that I have used for years. They build custom driveline and even wheels for race cars. I think they have been around as long as I can remember. At least into the mid sixties.

There must be something similar on your side of the mountains, or give Watts wheel a call and see what they say.

09-19-2016, 12:09 AM
Thanks Bill. In changing over to this 9" rear end I have found some underlying issues that I am sure were there before the swap. No. 1 is the biggest culprit. My neighbor made some traction bars for me and they were beautiful. But, I just bolted them on never checked what they were doing to the pinion angle. Just never crossed my mind that they would change anything.
The rubber pads at the front of the traction bars were contacting the front of the leaf springs. They were hitting so hard, that they were bending the leaf springs and forcing the rear end so that the pinion was pointing down.
Here is another issue that I have found out now that I have those bars off. My car was sitting with the back of the car up a little more than the front, which I liked. But I thought the car was being held up at the back by my air shocks. Well, now that the bars are off, the rear of the car is quite a bit lower now.
Also now that the bars are off, there is a bend in the leaf springs that was caused by the warping affect of the bars. Also, there is zero curve to the leaf springs when on the ground. As a matter of fact there may be a little negative bend to them.
I tried putting some spacers between the axle housing and the leaf spring plates to make the pinion angle better, but all that happened is the leaf springs just bend. Just the weight of the rear end makes it tweak out of position.
Sooooo I ordered the new leaf springs. Then I will set the pinion angle, which really isn't that difficult to do. Did it before when I installed the new engine and the old rear end a few years ago. Got a lot of good info on that from Pat.
After I have the pinion angle set, then I will install the Cal Trac traction system that I just ordered. More to come I am sure. Larry

09-19-2016, 01:48 PM
Wow - what an ordeal! If they were original springs, it was probably due anyway. So it's probably good you're doing that.

Have heard good things about Cal-tracs, so will be interested in seeing pictures of these installed!

09-25-2016, 05:19 PM
Got the new leaf springs and the Caltrac system. The bars are a lot beefier than I expected. Very good quality, they are expensive but now am glad I didn't try making a set. Here is a picture. Will take more during installation and let you know how it goes, good or bad. Larry

09-25-2016, 09:48 PM
I have leaf spring envy ! I'm curious to see how the 4 leaf will change your ride height. I think it's going to be awesome !!!

09-25-2016, 10:37 PM
I will take some before and after shots of the ride height. Larry

09-26-2016, 07:02 AM
I will take some before and after shots of the ride height. Larry

Thank you sir, looking forward to that, and to your observations on the Cal-Tracs. I am considering the Cal-Tracs for my 64. I need something to stop the spring wrap-up, she bounces like crazy under hard acceleration.

Ken in SSF CA

09-26-2016, 11:06 AM
The pictures of the car now are with the old traction bars off. The car is a lot lower now than it was before I took those bars off. I will try to find side pictures of the car with the bars on, with the bars off like now, and then with the new springs and Caltrac bars on. Larry

09-27-2016, 04:21 PM
The new leaf springs are installed. The Cal Tracs are installed. The pinion is set 3 degrees up with the transmission 3 degrees down. Hope this works.
The car is sitting 2 inches higher with the new springs than it did with the old springs. It is still sitting lower than it was with the old traction bars holding it up.
I am attaching some photos. The first is the car sitting on old springs. The next is on new springs. There are a couple of picks of the cal tracs, the new driveshaft loop, the new exhaust from the mufflers aft, and the new 9" rear nodular rear end.

09-27-2016, 04:25 PM
The rest of the story. Pics that is.

09-27-2016, 05:08 PM
Very nice.

Is the ride any stiffer with the Cal-Tracs?
Do they control the wheel hop?

Thanks again. :BEER:

09-27-2016, 07:05 PM
Haven't had the chance to drive it today. I will tomorrow and am sure the ride will be better. There was zero movement in the rear with those traction bars holding it so tight.
As far as wheel hop, positive there won't be any, but I will definitely hit it hard tomorrow and let you know.

09-28-2016, 04:21 PM
Took the test drive today. Well, poop. The weird noise/vibration is still there. At about 70-80 MPH it has a definite vibration. I haven't changed the speedometer gear since changing to the 4-11 gears so estimate actual speed at 60-70.
The ride with the new leaf springs is excellent. I did not get on it real hard because I want to figure out this vibration/noise first.
My next task is to remove the rear u-joint and take it and the drive-shaft down and have them checked out. After that, I think the only culprit could be the rear end itself.
Poopers. Larry

09-28-2016, 05:44 PM
Well that's a bummer. I guess you'll have to give me that ride after all.

I have little doubt, based on what you said, these changes you just did were needed. Hopefully you don't feel as though they were unnecessary.

I'm pretty good at sleuthing these sorts of things out, so let's work out a time, soon, to do a test drive. I would have them check the driveline though. Leave the U-joint in when you do.

09-28-2016, 06:14 PM
For sure the changes had to happen. The springs were shot, the traction bars were causing all kinds of problems.
I was thinking about taking the driveshaft down to Drivelines NW where I got it and see if they could check the shaft for balance. Also, can they check the u-joints? Larry

09-28-2016, 07:03 PM
They absolutely can check u-joints. Probably the most qualified to do so.

Bill Pierce
09-29-2016, 10:09 AM

Did you measure how far the yoke is in the transmission? Wondering if it is only about 1" of free play outside as recommend?

Also, who set up the lash on your 3rd member? That could cause a problem as well.

09-29-2016, 06:28 PM
Bill that is an excellent question. The third member was made by Performance Products. I am assuming the lash is correct, but it may be an issue to look at after I get all these other questions answered.
Now, as far as the drive shaft. I took it into Drivelines NW today where they made it. Here is the issue. When I put the 9" rear end in the car, my existing driveshaft was too long. So I took it to them for shortening. They showed me that my driveshaft was worn completely out. I agreed. They made a new one, 4" instead of 3 1/2 diameter and were supposed to make it 1 inch shorter. Instead, they made it one inch too long. Took it back and they agreed they screwed up. So, they said they shortened it one inch.
Took it home and installed it. Now here is where the funny stuff begins. When I talked to them today, they thought, as you, that the yoke might not be going into the rear far enough, therefore creating a vibration.
So, took the yoke home, measured the distance from the centerline of the yoke u-joint to pinion yoke c/l and called them with that dimension. They said my driveshaft was 1" too short and could be causing the problem. Now, did they cut off 2" the 2nd time? No way to know.
Anyway, they are going to make a new one. I will let you know what happens and thanks a bunch for all the great input from you all. Together, we can conquer the world, by ourselves we just screw everything up. Maybe a little too philosophical on the conquer the world thing. :banana:Larry

09-30-2016, 02:09 PM
This started out as a weird noise. But now, this is really getting weird. When I installed the 9" rear end, my driveshaft was too long. So, took it to drivelines NW to get it shortened. But, as I mentioned before they said it was worn out. So, bought a new one, 4" diameter instead of 3 1/2". They were supposed to make it 1" shorter, but made it 1" longer instead. Got it home, wouldn't fit, the found out they screwed up, and they said okay, they would shorten it. Well they did.
I took it back to them yesterday to have them look at the balance and check out the u-joints. While there, I asked to check on the original paperwork to see the length because it was not inside the transmission far enough. The dimension they were supposed to make the driveshaft was 51 1/2. Guess what? It was 50 1/2. They admitted they cut off 3" making it 1" too short. They are making me another driveshaft today and will get it Monday. Sheesh, no wonder I am bald. Larry

09-30-2016, 06:53 PM
While there, I asked to check on the original paperwork to see the length because it was not inside the transmission far enough. The dimension they were supposed to make the driveshaft was 51 1/2. Guess what? It was 50 1/2. They admitted they cut off 3" making it 1" too short. They are making me another driveshaft today and will get it Monday. Sheesh, no wonder I am bald. Larry

Thanks goodness you had the documentation/paperwork to back up your claim. :doh:

Good luck and let's hope this exorcises the demons!


Ken in SSF CA

09-30-2016, 07:27 PM
I didn't mean it to sound like Drivelines NW has done anything purposely wrong. It was their paperwork. I knew they kept it on file because Alan at the desk showed it to me last time I was there. It had all the dimensions that were used. They have been very good and helpful, just made a couple of mistakes. Larry

10-01-2016, 10:34 AM
Glad you have been able to sort it out - but, what a pain to get there.

Fortunately, for me my vibration ended up being caused by the rear tire. New ones have fixed the problem.

10-03-2016, 06:05 PM
Well, continuing on in this debacle. Got the driveshaft back. Installed. Took it for a test drive. It's not as bad as it was. IT IS WORSE. They tell me they did a spin balance and it was great.
Vibration before would go away at about 60 if I let off the gas or gave it more gas. Now, all the time. Just more severe.
I am not sure which way to go now. I don't like this, not one little bit, if it keeps up, I might say s*^$. How's that Dr. Seuss?

Bill Pierce
10-03-2016, 07:04 PM
Time to find another drive line shop :doh:

10-04-2016, 09:48 AM
Larry - that is odd it is now worse. Seems to me that the driveline must be a contributor if changes to it make it worse or better. You are certain now, with it installed, you only have about 1" of exposed yoke at the rear of the transgression?

May seem a silly question, but when you got this transmission, did your motor need the 28 or 50 oz flywheel and harmonic balancer? If any of these are wrong for the setup of this hot motor you have, it would cause one heck of a issue. Ask me how I know...

Again, the offer is still open to have me sit in the car and feel it for you as well. I can sit in the front and back and try to sense if the vibration is fore or aft - something that is hard to do when you are driving.

10-04-2016, 10:34 AM
I checked the dimension of the yoke into the transmission and it is 1" after bolted to rear end. So, that isn't a problem.
As far as the 28 to 50 ounce balance, I never had problems with the 8" rear end and the tremec transmission, so not sure how that could be a problem now. Wouldn't that have shown up before? Especially since I had the car over 100mph then.
I am going to put the car up on jack stands and run the car up to about 60-70 and see if there are any obvious issues.
Then if I don't see something, Roger you are on for the ride.
More to come, I am sure.

10-04-2016, 08:05 PM
Major bummer Larry ! On the upside those leafs and Caltracs look killler . Did you have issues or a failure on your old 8" or did you just upgrade to the 9" for drag racing ? Did you buy a new 9" axel housing or have a used one narrowed ?

10-05-2016, 10:31 AM
Mike has a good point there about the rear-end. You had no apparent issues with the 8" so, although there were a lot of fixes needed to make angles correct (needed no matter what), if the issue only really started post-9" install, then there must be something going on there. Only oddity is that changing driveline altered it.

I am free this evening after work and for a bit on Friday morning after physical therapy (10am-ish). Willing, as usual, to come give it a look-see.

10-06-2016, 02:41 PM
Weird again. I put the car on jack stands. Ran the car up to 50-60 mph and the left rear tire looked out of round.
Took it to Les Schwab and they did a spin test.
They said it is definitely very out of round. Probably from molding process.
The weird thing is, when we were in Reno last year going from Carson City to Reno, I had it over 100 mph with zero vibration. But, that was the last time I drove it over 45 till just the other day going to play golf.
I am thinking it might have caused the tire to fail at the high speed? Doesn't matter I guess.
The tires are BFG radial TA's. Since Michelin bought them out, they haven't been making that tire. They will I guess, but for now they found someone with one.
I will let you know what happens after I get the new one. Larry

10-06-2016, 03:18 PM
Fingers crossed.

10-09-2016, 08:25 AM
Hope that takes care of it !

10-09-2016, 08:55 PM
Carol and I took the car out for a test run. No need to keep my fingers crossed any longer. This is definitely a problem in the rear end. We didn't even get to the freeway and the rear end started to howl.
Bad news. Don't know why. Guess I start tearing it apart to look for gremlins. More to come. :doh: Larry

10-10-2016, 10:47 AM
If you haven't already, double check tire roundness and balance before you dig too deep into rear-end. Coulda changed somehow (ply separation or sumpin')..

11-12-2016, 02:01 AM
If you have been following this post you know that it started with a noise or vibration. I fixed everything I could think of except the kitchen sink.
I fixed the pinion angle, replaced the leaf springs, installed new Cal-Trac traction bars, had a new driveshaft made, (3 times to get that correct), bought a new tire (thought it might be out of round), and other less obvious items.
After all that, I decided it had to be in the new rear end. It is all brand new, but it was all that was left. I bought it from Quick Performance which supplies a whole lot of car racers. I got a new 9" Ford Housing. New Nodular third member case, Nodular case, posi-trac and everything is made for higher horsepower since I am going to drag race the car.
After I pulled the third member, I could see that the wear on the ring and pinion gears was not good. Also could see some very small metal flakes.
Called QP and sent them pictures. Brydon from QP in Iowa sent fed ex the next day, picked it up, and they now have it checking it out.
Hopefully they let me know what was wrong with it. But I am very happy with their immediate response to help.
Really weird and hope a new setup fixes this. More to come. Hopefully all good news this time. Larry

11-12-2016, 10:16 AM
What a saga Larry ! Glad they are standing behind there products and taking care of it. Keep us posted

11-12-2016, 04:09 PM
Yea, what a saga Larry. Thanks for keeping us posted.