BAD driveline vibration

butch27 · October 07, 2010, 07:42:29 PM

Finally got the "T" running.The whole driveline vibrates bad. The trans is 3 degrees down and the Banjo rear pinion is 3 degrees up--But with my short drive shaft ( about 9") the working angle is like 11 degrees. I've got about 20 miles on it and the whole driveline vibrates and gets a little worse when I throw it in neutral. Any Help? A whole lot of work. Oh A new torque converter also but it feels like it may also be the trouble.

kb426 · October 07, 2010, 10:00:10 PM

I think we need more info. Engine, trans, etc.

butch27 · October 07, 2010, 10:22:49 PM

Engine- 302" Ford-- Trans-c-4--- rear- 1947 Ford banjo converted to open drive with pro conversion kit. The car ran fine the first few miles that I drove it then I started to feel a vibration. It kept getting worse and today it feels like the whole car drive line is ready to blow. I took the trans cover off and drove with my foot on the bellhousing and could feel it but most of the shake was in the Ginnie shifter area. I jacked it up and ran it and everything goes fine. Although like I said the driveshaft angle freaks me out.

enjenjo · October 07, 2010, 10:43:39 PM

11 degrees sounds like about 4 to 5 degrees too much. Any way to raise the car a couple inches just to test it?

butch27 · October 07, 2010, 11:32:54 PM

The problem with the Banjo rear is that it makes the driveshaft run -uphill- from the trans when most cars the shaft runs downhill. It got worse as the miles increased ( if you can call all of about 20 miles increasing LOL).

chimp koose · October 08, 2010, 01:16:10 AM

Has the transmission mount possibly worked loose ,worsening the situation?I think the max. angle of the driveshaft to pinion should be 7 degrees.Are the driveshaft yokes out of phase? The greater the angle at rest the worse the vibration would be with an out of phase driveshaft.What angle is the driveshaft when you are sitting in the car ? If the suspension moves much when driver is seated it will change the angle more with a short driveshaft than with a long one. Could you weight the seat down to simulate drivers weight and then check driveshaft angle? A cure might be to raise the rear of the transmission.Raising the trans will require more height per degree change,than at the pinion end. you will then have to lower the pinion to match the angles. This should help to reduce the angle of the driveshaft. If you do this be sure to check that the driveshaft length is still correct, you may need to shorten the driveshaft more. Good luck and keep us informed please.

GPster · October 08, 2010, 07:56:36 AM

Quote from: "butch27"The problem with the Banjo rear is that it makes the driveshaft run -uphill- from the trans when most cars the shaft runs downhill. It got worse as the miles increased ( if you can call all of about 20 miles increasing LOL).

That means you need a "Quick Change". GPster

enjenjo · October 08, 2010, 11:01:35 AM

You couls use a 4x4 C4, it's 5 1/2" shorter, that would give you better U joint angles.

Jokester · October 08, 2010, 01:32:26 PM

QuoteFinally got the "T" running.

Has this been a long time project? Have the tires gotten square from sitting in one place for a long time?

Just a thought.

.bjb

butch27 · October 11, 2010, 11:06:24 PM

OH: So you know about my long time project huh? LOL
Frank: What year C-4 from a 4x4 ? I had one out of an old van BUT it did not have a way to hook up a regular U-Joint . Had some weird spline .

enjenjo · October 11, 2010, 11:25:38 PM

Quote from: "butch27"OH: So you know about my long time project huh? LOL
Frank: What year C-4 from a 4x4 ? I had one out of an old van BUT it did not have a way to hook up a regular U-Joint . Had some weird spline .

Early Bronco, pre 77. You can have that tailshaft installed in any C4

butch27 · October 12, 2010, 09:55:03 AM

Oh man : I gave one away 4 years ago.