Vibration in driveline

[BeBop138]

I looked at posts from Pete and JD and did get some ideas---I would like to run the car without the driveshaft---but will the T-5 spit out the tranny fluid even when the rear is jacked up? I could just bag the end and let er rip---let it puke and replace the fluid. I could put a yoke in but I think it would spit it out when the RPM`s get going. The vibration starts getting bad around 60 MPH----front end is aligned---driveshaft just been re-checked for balance---tires are balanced. Trying to use process of elmination---with the shaft out I could determine if the problem is coming from the engine---flywheel,pressure plate,tranny. The engine was balanced along with the fly and plate---but ya never know! If thats good maybe the pinion angle is off or the rear end and or housing is bad. I thought the pumpkin would just howl if it was bad not vibrate---with the welding on this over the years--such as relocating the perches and brackets for the sway bar-it may have tweeked it some-------any thoughts...................Thanks ...........Lee

[austinsailor]

if it were something in the engine it would be rpm dependent, not speed dependent. drive it in first at the same rpm as the vibration would be at 60. No vibration? Not the motor or tranny.

I would suspect an out of round tire or slightly bent wheel.

[55 Fargo]

if it were something in the engine it would be rpm dependent, not speed dependent. drive it in first at the same rpm as the vibration would be at 60. No vibration? Not the motor or tranny.

I would suspect an out of round tire or slightly bent wheel.

I 2nd this, check for bad tire, rim, etc...can bea real culprit and noticeable at the speed mentioned.

[BeBop138]

More testing today..........ran the car with the rear on jack stands---vibes at 60 and around 2000 RPM`s in 5th gear. At idle fourth and fifth made some grumblings---took the R`s up and it smoothed out till the higher RPM. Took the driveshaft out---very little vibration--shaft in and rear tires off, vibration is back:confused: Starting to think the pinion angle is wrong. When I converted this to the T-5 I made a cradle to hold the engine in place and welded it to the frame. Then put the adapter in place with the new rear motor mount, assuming the pinion angle would stay the same as nothing has moved---maybe I was wrong----anymore ideas......Thanks..........Lee

[Don Coatney]

I think I have posted these for you before. If not here they are again.

[BeBop138]

Thanks Don-----I just hate vibrations and so fun to find:mad:

[William Davey]

I had a dodge van baek in the "hippie era". The PO lowered the truck by having a spring shop "de-arch" the rear springs. Result was the pinion was always nose-up in relation to the trans. Symptoms were a vibration at 55-60 that was not engine speed dependent and shot rear U joints every 10,000 miles.

Mopar performance products makes wedges that slip between the springs and the axle mounting surface. The wedges used to be available in several different degrees of wedge. Only costs a few bucks, worth a try.

[BeBop138]

I had a dodge van baek in the "hippie era". The PO lowered the truck by having a spring shop "de-arch" the rear springs. Result was the pinion was always nose-up in relation to the trans. Symptoms were a vibration at 55-60 that was not engine speed dependent and shot rear U joints every 10,000 miles.

Mopar performance products makes wedges that slip between the springs and the axle mounting surface. The wedges used to be available in several different degrees of wedge. Only costs a few bucks, worth a try.

My next step is to re-check the angle and the wedges are already on hand. I have room to bring the rear motor mount up or down and the the wedges for the rear---maybe tommorow.........thanks

[BeBop138]

Been busy with yard work, work in general and life in general. I got my driveshaft back and it had 40K run out on it and they told me it was fixed.I got it in and the same problem----so today I went to a friend who builds race cars and is a super tranny rebuilder. He has all the dial indicaters and some very neat tools to check pinion angle and phasing of u-joints. It is one degree off on the pinion angle. Still has 10K run out and 12K run out after the shaft was turned 180. The biggie is it is 3 degrees out of phase. The quick check was done with a small torpedo level---we set it on the rear joint till level---then moved the level to the front joint and it was a full bubble off. Now these guys are supposed to be real good----I do wonder now. I will try to get my money back and go with the guy my buddy recomends---he builds shafts for race cars and uses much thicker tubing---he said they will be twice as heavy as the one I got----he said NO vibrations. So I ended up with three problems. The trick thing my friend used on the drive we took to check out the vibration was some kind of tool they used in Germany during WW2 to check vibrations in the engines so the props wouldn`t break. He put in on the gear shift and by the way this wire occillated you could tell if it was shaft or axels and tires---still confuses me:confused:---kind of a directional thing:confused: Well thats my story and I`am sticking to it........ I will let you know how it turns out............Lee

[BeBop138]

After a month or better we have the vibration issue solved. It was the driveshaft--I did have the other company build me a new one and the vibration is gone.Other things I did do before--rear end taken out and yoke replaced--axels were checked at this time--nice and straight.Also I installed some four degree shims. Went thru the exhaust--put in metal mesh flex pipes before the mufflers and new style all rubber hangers--all for any vibration harmonics. Installed all new body mounts--solved many small body ground outs that transfered vibrations back into the car. After each thing was done it was taken for a test drive---the noise level went down in the car the exhaust sounds much better and all these little things that were done improved the noise level quite a bit. But the major vibration was still there---I gave the other driveshaft company all I could do to solve the problem---in the end the new shaft fixed the problem. Ain`t vibration issues fun:rolleyes:.............thanks guys.........Lee