2 zones of vibration.

[RobR'35]

I've totally rebuild the complete drive line on my roadster. It has a vibration starts at 25 mph and is worse at 30 mph. as speed increases it diminishes until I get to 55 mph and at 60 it's worse and remains to 65 mph. Ive not driven it faster because the vibration is terrible. Tires balanced. Wheels checked (Kelsey hayes) with a dial indicator for out of round max was .068 on one the rest were in the .040 or less range and the faces were .048 at the worse.
Transmission, original to the car rebuilt using Macs book to exact specs. All new bearings. Wherever it needed parts and wherever I could aquire nos it got it.
Rear axle is a '46-'48 with the columbia. All new bearings,Timken, Bower or Ford script, ring and pinion nos. All spec's and pre loads checked and rechecked. All the mods to update the Columbia had been done to the axle before I bought it, I checked and spoke with a few Columbia guys. John Connelly being one.
Driveshaft hollow type, modified with 6 spine to mesh with the pinion. These things done by a reputable drive shaft shop and set straight and true. I had the torque tube checked for straight and to make sure the end that bolts to the axle center was 90° to axis. Nos bearing and race. Bearing area on the shaft wear area was only .0015 wore.
U joint was an old used Ford one. I checked it the best I could. Used a feeler guage between the trunion bearings and trunion pins. .002 max I could fit. Spline fit was great!
I do notice with all of the u joints I have and the one installed that they all wiggle laterally. Slide from trunion to trunion across from each other all 4 points by about 3/32". When all installed and coupled to tha trasmission it was packed and grease added after it was coupled. Corn head grease.
I've got about 600 miles only on it and don't know what to think.
U guys have any ideas, experiences to help me out?

[JSeery]

It would help to isolate the vibration, but easier said than done! Few questions:

1. Did you have the engine balanced when it was rebuilt?

2. Was the flywheel, pressure plate balanced?

3. Was the driveshaft balanced?

4. Have the tires been dynamically balanced?

It could be a lot of things, but I would start with the easier ones. Sounds like the driveshaft would be a good place to start. Tires would be another one, have them spun up on tire balancer.

[drolston]

If you push the clutch in at one of the bad vibration speeds, does the vibration stop or lessen noticeably? If it stays the same, it is likely a wheel/tire problem. If it diminishes when the driveline is not loaded I would look at U-Joints and drive shaft. That seems like a lot of lateral play in the U-Joints. Second suspect would be less than perfect alignment where the drive shaft was cut and welded for the spline change. And what is a hollow-type drive shaft? All of the drive shafts I have wrung off were solid steel shaft.

[oldford2]

Does the vibration continue when you depress the clutch and let the engine idle down?

[RobR'35]

I haven't touched the engine in respect to rebuilding.
I did match mark and checked the clutch and pressure plate visually when I rebuilt the transmission. All was in good condition and reinstalled. I didn't have them balanced.
When I bought the car I ran it a bunch. It never vibrated until right before I heard the sheared pin rub on the torque tube.
What caused me to go through the drive line was the spline coupler on the drive shaft to pinion had sheared the through pin. On inspection it wore both male and female splines way to far.
When I had the drive shaft work done the guy at the shop told me it ran true. It didn't have balance weights on when I took it to the shop and none were on when I picked it up from the shop. It made me wonder actually.
Tires I had balanced at a Pomps tire business locally.
I asked to go in the shop and watch. I was concerned of run out on one of the tires. Visually I didn't see anything over 1/16".

[RobR'35]

Sponsored Links (Register now to hide all advertisements)

It does continue to vibrate when the clutch it pressed. I tried pressing the clutch while vibrating on a load up a slight incline on a smooth road and on the return down hill.
It'll still vibrate at those speed ranges.

[RobR'35]

I've looked and never seen any specs. for the u joints.
Anyone know what the specs. should be?
Anyone else notice this lateral play in the u joints.
Out of the 3 use ones I have. All are very close to the same.

[JSeery]

Sounds like you are answering your own question! The driveshaft/ u-joints sounds like the most likely cause.

[Kurt in NJ]

Lateral play is normal--- the bearing centers the shaft

Perhaps remove the floor boards and drive and have someone feel the torque tube-- or if you can find a place with old style 2 post axle lift and run it on the lift

[RobR'35]

Thing is with all the care and time and money spent to make it right. I really don't know the true cause and a few specs for reasurrence.
I took it to a reputable drive shaft shop. I don't want to doubt their work without some kind of proof.
As to the u joint. It's the only thing not new put back in.

[RobR'35]

Old two post axle lift. I'm not aware of this.
Can u elaborate on this more please.

[drolston]

With the clutch pressed in there is no energy going through the u-joint and drive shaft to feed a noticeable vibration, unless the joints or shaft are so grossly out of balance or alignment that being turned by the continued motion of the car causes them to shake hard enough for you to feel.

Next clue would be frequency. Wheel RPM at 30 mph is about 360, or 6 revolutions per second. That is a pretty low frequency, like a rumble. Drive shaft speed will be about four times that, like 24 cycles per second; about half of a neon light hum. Which is it at 30 mph, rumble or hum?

Test suggestion. Jack the rear end and set it on stands. Chock both front wheels. Push, pull and try to jerk the wheels up, down, left, right. Any vertical, horizontal or axial play is a bad sign.

If that is all fine, start it, put it in high and slowly set the throttle to 30 mph. Whether or not the vibrations occurs, watch the wheels from the sides for any sign of out-of-round or shaking. Look at them from the rear for any sign of lateral wobble. If no tire wobble or shake, move on to the next test.

If there is little of the vibration experienced on the road, that leaves the u-joint a the one component whose ability to cause vibration if dependent on the energy it is transmitting; that is, the load it is driving. If that is the case, you should have noticed more vibration going uphill than downhill.

Last test: If you do not have a tachometer, note the pitch of the engine at 30 mph. Put the transmission in neutral and brake the rear wheels to a stop; run the engine up to about the same speed as 30 mph, approximately 1500 RPM. if you still have the vibration, you may have an engine balance problem, anywhere from the fan through the clutch pressure plate.

Good luck!

[JSeery]

On the driveshaft, have you talked to the folks that did the work? If it is a reliable shop they should be able to provide some input. A lift would remove the wheels as a source and tell you it is drivetrain.

[RobR'35]

I haven't spoken to the drive shaft shop yet.
Was hoping to eliminate things by suggestions on here first.
I did jack the rear tires off the ground with front wheels chalked. Securely set on heavy blocks.
I ran the car in high gear and unreal how the one wheel and tire was out. Looked out of round more than wobble.
I tested the speed ranges and the vibration was there in both places.
I exchanged a front wheel and tire and ran it again. Considerable difference (better) in both speed zones! Wobble and out of round considerably better as well.
Im unable to take it on the road and test it today because its raining. Im anxious to try it tho.
Interesting how it can act so differently under actually running it vs when I took dial indicator readings off the wheels.
Thanks everyone for ur ideas and suggestions.
I hope this will be the fix.

[Capt Kirk]

A wheel vibration will have a longer period than something spinning a lot faster such as a driveline. Harmonics will cause things to vibrate at certain speeds...lower or higher speeds may not vibrate. Having two zones of vibration is interesting to me and I can't wait to hear what you find.

[Kube]

In all of my years working with vehicle repair, nearly always, the vibration that sets up at the speeds you note is driveshaft related. 99.9% of that time, it's a bad u-joint or two. On occasion the drive shaft inclination is too severe.
With what you have described - check the shaft and joint very carefully.

[Lawrie]

One thing I did when the local driveshaft shop welded in a new spline was to check it in my lathe BEFORE fitting it back in the car!the shop told me it was spot on true,in the lathe it was..140 in runout., how I checked it was to hold it by the front part of the shaft with the u/joint spline and see what you have,once I did that and fixed the play in the front roller bearing it was good.
Lawrie
D me

[RobR'35]

So Lawrie, did u go about straighting the shaft your self or did u take it back to the shop?

[40 Deluxe]

If you can, try a different set of tires and wheels-all four. I have had tires that looked good, ran true, were balanced several times, and still had weird vibrations. I had checked and adjusted wheel bearings, checked steering linkage, adjusted steering gear, etc. Finally put new tires on. Problem solved!

[RobR'35]

40 Deluxe:
Tires would be the easier of the two to change and try.
I don't have a spare set of wheels unfortunately.

[Kurt in NJ]

When you had it up on stands take off the wheels, this will eliminate tires

[grumppyoldman]

While you have the rear end jacked up with the tires off, look at the brake drums inboard at the back plates to see if you have any run-out in the drums. I had a bent shaft on passenger side. Fixing that now, hope vibration goes away. Just a thought, maybe your drive shaft is bent also. Al

[Lawrie]

Rob,I straightened it my self, I set up a dial indicator on the other end of the shaft I used my welding torch to heat up a small hot spot ,on the low side , about 3/8 dia,and cooled it with the coolant from the lathe,
It was an easy job ,and it's been in the 33 now for 1000,s of klms and is as smooth as.
Another thing I found was the four fitted bolts that hold the u/jount ball onto the back of the tranny were loose in there bores,this allowed the u/j ball NOT to be concentric with the tranny output shaft I fixed that as well,
I,m away from home in the 33 at the moment but when home could shoot you some pics of that fix.
Lawrie

[RobR'35]

Thanks guys. When able I'm going to check each thing suggested.
Lawrie: When ur able I'd like to see those picks.

[1931 flamingo]

Part way thru this thread I thought tires also. FWIW
Paul in CT

[Clem Clement]

Sponsored Links (Register now to hide all advertisements)

Jack it up and run it without the wheels?

[Mart]

Anyone near you with a set of wheels and tyres that would be prepared to swap? (temporarily for the sake of testing).

Otherwise, you might try this:

If you can find a suitable piece of quiet, smooth road, and drive to a speed above the vibration zone, select neutral and turn the engine off. If you feel the vibes in the usual speed zones as before, you have ruled out the engine from fan to flywheel, including clutch and the input side of the transmission.

If you feel the vibes, (as mentioned above) you need to judge the frequency. Low frequency = wheels/tyres/drums/hubs/bent axle shaft. High frequency = drive shaft/ uj.

Sideways movement in the uj is perfectly normal. This is to compensate for any axial misalignment between the trans and the driveshaft/torque tube.

Mart.

[RobR'35]

When I rebuild the rear axle I put new races and nos wheel bearings in.
Is there a certain amount of play I can expect to see?Hub to bearing to axle housing stub where the race is pressed on.

[supereal]

You didn't mention the center bearing, unless I missed it. It is normally held in position by a rubber case and the grease fitting. If it comes loose, or for any other reason, it causes driveline vibration, particularly if the coupler alignment is off by a very small amount. At our shop, when weld a coupler to the driveshaft it is done in our long bed lathe, and first tack welded into position to prevent heat warpage as it is welded. Then it is checked with a dial gauge to be sure it is in line.

[cas3]

tubular drive shaft

[RobR'35]

Yes. It's the tube drive shaft.
I do need some insight on what kind of rear wheel bearing ply I can expect. Look at post 28 please.

[rich b]

Does the speed range of the vibrations change with rear axle in low vs high?

[RobR'35]

No. Same in Ford gears and in Columbia OD.

[RobR'35]

Today I jacked up the rear and ran it without the wheels/tires on. I didn't feel the vibration in the ranges I've mentioned before. It's looking like it's tires/wheels doesn't it........
I also used a dial indicator in the bottom of the drums and pushed up on the axle nut area to see what sort of play there was in the wheel bearing to hub to race on axle housing. All new bearings and races like I've mentioned in a past post. .008 - .009 play both sides.
What's the +/- range I should have?

[JSeery]

Originally Posted by RobR'35

I also used a dial indicator in the bottom of the drums and pushed up on the axle nut area to see what sort of play there was in the wheel bearing to hub to race on axle housing. All new bearings and races like I've mentioned in a past post. .008 - .009 play both sides.
What's the +/- range I should have?

I have no idea, but that seems like a lot.

[RobR'35]

I've looked through a mess of manuals and books.
I didn't see a spec. for this.
Anyone have any insight experience with this tolerance?
Wheel bearing to hub to axle housing stub where the race is spressed on.

[Mart]

You're measuring something that no-one else has measured. That's why there isn't a spec. it's also hard to envisage exactly what you are doing. The bearings are non adjustable. It is a broad faced roller bearing. It is what it is. The rear wheel bearings are not the cause of your vibration.

Mart.

[RobR'35]

I realize they are not the reason for vibration.
Just something in the process I figured would be good to know.
Ordered new tires last Fri.. should be in on Wed., Thur.
I'm curious what'll be the result.

[1931 flamingo]

Your post #34................................How tight are the axle nuts??
Paul in CT

[RobR'35]

220 ft. pounds. I laped the axle shafts to the hub's when I rebuilt the assembly this past winter.
7/8 ths contact.
Took it for a short spin then checked the torque again.
It did loosen a bit. Torqued it again. It's not moved since.

[Lawrie]

Rob, look at my post on this date 6-13-2014 at 04-27 PM, drive line vibration, it has all the fix and pics.
Lawrie

[RobR'35]

Thanks Lawrie.
I looked up past posts and it takes me back only to 2-22-16. Not sure if I'm missing something in looking back at past posts. Also only goes back 20 pages.....
New tires arrived today and I've an appointment to have them installed this Fri.
Looked up on Coker, they're recommendations for installation. I ended up ordering the Excelsior 6.00X16.Interesting stuff on links to u tube.
Lug centric vs hub centric, match mounting, road force balancing, massaging the bead, that's a complete new thing I've never heard of! both sides of wheel for weights.....lots of good info.
That Corky fella at Coker seems quite a character!

[rich b]

Lawrie's referenced thread

https://www.fordbarn.com/forum/showthread.php?t=141800

Guess this was the wrong thread, sorry.

[RobR'35]

How did u go about finding posts that far back rich b.?
And thank u.
Lawrie had mentioned an even earlier post. 6/13/14.
I believe it pertains to drive shaft straightening...

[RobR'35]

Was actually a post three days later....... in 2014

[rich b]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by RobR'35

How did u go about finding posts that far back rich b.?
And thank u.
Lawrie had mentioned an even earlier post. 6/13/14.
I believe it pertains to drive shaft straightening...

I had the same results as you did, searching for "post"; I then searched by threads he started; but looking back now, I see they are organized by the date of the last response. Not real useful by that criteria; search sometimes not very handy on here. Maybe easier if Lawrie could post a link to the thread.

You had said the vibration remained in the same speed ranges both in low and high rear axle; wouldn't that place it beyond the driveshaft since it's speed would have changed with the axle shift.

[JM 35 Sedan]

Rob, I found this old post on axle housing bearing race/stub diameter spec.

https://www.fordbarn.com/forum/showt...aring+diameter

[RobR'35]

Beyond meaning tires/wheels?
New tires to be installed tomorrow. We'll see what comes of it.

[RobR'35]

Thanks JM 35 Sedan.
Looks like that was the larger wheel bearing and hub.
Was that phased out to the smaller wheel bearing in '35?

[JM 35 Sedan]

Originally Posted by RobR'35

Thanks JM 35 Sedan.
Looks like that was the larger wheel bearing and hub.
Was that phased out to the smaller wheel bearing in '35?

The EFV-8C/A 1935-36 Ford Book states that the larger 3-3/16" OD (#B-1225-A) rear wheel bearing was initially carried over from '35 production, and then a new smaller 2-13/16" OD (#68-1225-A) rear wheel bearing began use early in '36 production, replacing the larger bearing.
The inner bearing journal on the axle housings remained the same at ~ 2.062" +/- 0.001" diameter.

[RobR'35]

Yesterday I took it for a cruise.
Long nice smooth straight stretches with some slight inclines and slight down hill.
Run it up to 70, press in the clutch shut it off, let out the clutch. Vibrates in the "zones".
Ford gears and in Columbia. Clutch presses in or not, up and down hill. Vibrates in the "zones".
New rubber tomorrow.
Going to have the wheels matched to the tire, lug centric,
wheel weights on both sides if needed, road forced balanced, I'm trying to cover all bases possible with the tires and wheels.
If that doesn't do it I'll tear into the drive shaft and axle assembly again.
I really appreciate all the help from u guys.

[FlatheadTed]

One thing I do when fitting the clam shell is check it for play and if so pack it with a thin Teflon shim ,any ware there and movement allows the end U joint to jump up and down ,Ted