Help w/ Bad vibration in 12 sec street car

[DUECE'SDAD]

I have the vibration demons from hell in the 57 chevy 2dr psot right now and cannot seem to track them down it has a 454 that was in my boat for 3 years and was perfectly fine with no vibration and it has a turbo 400 and a nine inch ford with 410 gears and 31 spline axles.... In the last 3 months i have changed
wheels
tires
harmonic balancer
flywheel
driveshaft
brake drums
torque convertor
wheel studs
lug nuts
transmission
third member
transmission mount
So here is the story, put car together year or so ago, very minor vibration from 2600 to 3400 rpm very minor i just avoided those rpms while cruising. . . it was so minor most couldnt feel it from the pass. seat. about 6 months ago it started getting worse little by little but quick. It got to where you couldnt make it all the way thru 3rd gear for the vibration. . . it just seemed like something was swinging in an oval instead of a circle, almost like harmonics.
So about 3 months ago i jacked it up pulled the wheels and drums from rear and ran thru gears still had minor vibration so i unhooked torque convter and about 90 % better so i bought another convertor . . . went and drove still there so talked to old timer that i trust and he reccommend not running solid trans mount since i am running solid motor mounts, so i buy rubber trans mount drive 5 miles toward home stop at gastation. . . get on it when leaving since only 5 miles left and vibration gets even worse, worse yet and notice oil all over windshield its dark
So when i got home the oil turns out to be trans fluid and the case is broke damn near in half at the bell housing. So i send the transmission out to get case changed and pull the engine out at same time and check some bearings all look great and oil pan is perfect. . . i added a fluidampner, new tci heavyduty flywheel both for a 454 ext. balance, i know thats right i built the motor and the vibration wasnt there for the first 3 years. I also added an electric fan, electric waterpump and electric fuel pump while waiting.
Put the new trans back in go on a light test drive and still there though not as badd as when the case was broke so its a little better. . . wait no its not. .
So i jacked up the rear and for grins left the brake drums on and put two lugs on each run it and it shakes like hell, pull the drums and not near as bad so i inspect the drums to realize one has a crack in the braking surface that is abou 4 inches long and the holes are lightly ovaled where the studs go thru.
And some one has drilled chevy pattern on these 9 inch axles so i think . . "might as well go back to the ford pattern and get new drums, eliminate any run out on the bolt pattern." So today i get new studs, drums and wheels to fit and mount my mickey thompsons b/c im gonna finnally make a pass out in front of the house. .. . Well it leaves hard as heck and WHAM... FREAKIN TRANS CASE BREAKS IN HALF AGAIN. . . .
What the Hell. . . So i just got in from pulling the transmission and looking everything over. I found some weird things out. All the ujoints which were new when first got going. . . . but now i think when i had another trans shop make another new one they reused the ends and joints . . . and it looks like they never even took them out while welding to the new shaft. . . Are now wallered out not like normal joints where you can rock them in a circle but where you can rock them the direction of the caps like if the caps are facing
(-------) then you can rock them back and forth and see space between the rubbers. Also i found that the bronze sleeve that the yoke slides onto in the transmission is wallered out some to where you can move it quite a bit. I asked the dude that swiched the case to put a new one and its obvious that he didnt. . . .
So now i think this might be my problem as with the combination of the bronze and the unjoint slack it rocks back and forth about a 1/4 to 3/8"
Or did all this just get wore out from the original vibration what ever it be ????????????????????????
I know for ceartian that my balancer and flywheel is right, I also no that the yoke is right in the turbo 400 and engaged the right amount.
Any buddy experience anything similar ?? ? ? or wanna donate to my parts chageing fund ????
HELP HELP HELP

[Squeezing Spectra]

Check your pinion angle and driveshaft lenght too much pinion angle will cause a vibration and cause u joint to wear bad, and to long of driveshaft can cause it to bottom out in transmission cause a vibration and break a tranny case just my 2 cents :D

[DUECE'SDAD]

Pinion angle is set at 4.5 degrees down and it has leaf springs with cal tracs. . . The trans yoke has 3/4 slip to the front when i slide it all the way to the front and then back into the pinion. But i have had two people on the rear bumper and jumped up and down and doesnt seem to bottom out. . . The drive shaft also used to be 1 inch shorter so the yoke was out further and it did it then also

[pro53]

I had a promblem like that in my 53 ford pro street pickup, some of it was fro the rear rims,We had a big block chevy and a turbo 400.Aftermarket built drive shaft, pinion angles set right.Never did get the vibe out.It was small but would piss you off.We had rubber mounts and put a torque chain on the front of the motor to limit the torque and hit a second gear chirp and cracked the bellhousing TH400.The reason the bellhousing keeps cracking is to much twist in the chassis.Are you running a cage?That stops alot of twist.Put a good ste of urathane mounts in the front.You will keep breaking bell housings if you dont.I think the brass sleeve in my th400 needs to be changed two.I tore the truck down for a second rebuild and did away with the th400 and running a TH350.Has a lower first gear.My bagged dually had the same promblem and it also had a Th400 and I also put a 1 piece drive shaft, and redid the 2 piece.I feel your pain and frustration.Do you have a slip yoke or a bolt in?
http://i69.photobucket.com/albums/i76/pro53/630200633449PM46901.jpg

[Robert1050]

I feel your pain, I had a 1970 El Camino with the same sort of vibration you describe & I finally tracked it down to the drive-shaft itself being out of balance. Sent it to a driveshaft shop, they spun it up, added solder to the side that was out & the vibration went away.

[Mr. Crusader 83]

Double check to make sure the driveshaft is not bottoming out. Also. I had a vibration in my truck at those rpm's. it was the drive shaft rubbing on the frame under exceleration. Also have it checked to make sure it is balanced and straight after they shortened it.

[Lightning]

Have you done anything to add strength to the frame? It sounds like you have a lot of power for that ride to have a stock frame with no reinforcement.

[BoatPI]

You do not say where you are located, but I use Driveline Specalties to balance, and work on ALL of my muscle cars and have never had a failure. they are in Garden Grove, CA. Might be a start. And not being a Chev expert, but is the 454 internally or externally balanced? Make sure the torque converter is corect for the specifc engine family.

[73kona455]

might check that the output shaft of the transission isnt bent

[SummitKarl]

You do not say where you are located, but I use Driveline Specalties to balance, and work on ALL of my muscle cars and have never had a failure. they are in Garden Grove, CA. Might be a start. And not being a Chev expert, but is the 454 internally or externally balanced? Make sure the torque converter is corect for the specifc engine family.
doh you beat me to it....I am betting thats the case being as it was in a boat and he changed ballancers....
BTW PI you going to bring out any cars for my LaPaz show this year

[DUECE'SDAD]

motor is external and i had the same flywheel/balancer as in the boat when first in the car only changed to see if any different, i really dont think its in the engine

[Oldsquirt]

Pinion angle is set at 4.5 degrees down and it has leaf springs with cal tracs. . .
At normal ride height, is the engine/trans centerline approximately parallel to the pinion centerline? In other words, if the pinion is down 4.5*, is the engine/trans also down approx 4.5*?

[DUECE'SDAD]

the overall pinion is 4.5 down but no the trans and output and the driveshaft are -5 and the rearend is .5 up
I have heard of people talking about the equal but opposite angles of trans output and pinion but dont understand it becuase it seems that 4.5 down is 4.5 down, and how would you acheve your number if you had opposite. . . . .
-5 at trans and +5 at rearend is 0 -2 at trans and +2 at rearend is 0

[Devilman]

I had a promblem like that in my 53 ford pro street pickup, some of it was fro the rear rims,We had a big block chevy and a turbo 400.Aftermarket built drive shaft, pinion angles set right.Never did get the vibe out.It was small but would piss you off.We had rubber mounts and put a torque chain on the front of the motor to limit the torque and hit a second gear chirp and cracked the bellhousing TH400.The reason the bellhousing keeps cracking is to much twist in the chassis.Are you running a cage?That stops alot of twist.Put a good ste of urathane mounts in the front.You will keep breaking bell housings if you dont.I think the brass sleeve in my th400 needs to be changed two.I tore the truck down for a second rebuild and did away with the th400 and running a TH350.Has a lower first gear.My bagged dually had the same promblem and it also had a Th400 and I also put a 1 piece drive shaft, and redid the 2 piece.I feel your pain and frustration.Do you have a slip yoke or a bolt in?
http://i69.photobucket.com/albums/i76/pro53/630200633449PM46901.jpg
That 53 Ford looks sweeeet. Sid does good work. LMAO :D

[Mandelon]

Perhaps if you played some of the Beach Boys Classic songs on the stereo, you could pick up some Good Vibrations... :)
Does it only vibrate under load or even when you get off the gas and decelerate through that rpm range?

[Lightning]

Perhaps if you played some of the Beach Boys Classic songs on the stereo, you could pick up some Good Vibrations... :)
Does it only vibrate under load or even when you get off the gas and decelerate through that rpm range?
All valid points....especially the first one. LMAO :D

[Oldsquirt]

the overall pinion is 4.5 down but no the trans and output and the driveshaft are -5 and the rearend is .5 up
I have heard of people talking about the equal but opposite angles of trans output and pinion but dont understand it becuase it seems that 4.5 down is 4.5 down, and how would you acheve your number if you had opposite. . . . .
-5 at trans and +5 at rearend is 0 -2 at trans and +2 at rearend is 0
This is what I'm trying to say. Engine/trans approximately parallel to pinion shaft, but with some offset. This has the front u-joint angling one direction while the rear angles the opposite. This is the correct way to set them up.
If the centerlines are such that both u-joints have to angle the same direction, you will have issues. Ignore the 3* part. It's the first pic I could find.
http://www.4x4wire.com/toyota/tech/driveline/04.gif

[ty34984]

http://www.4xshaft.com/index.html go to the tech info and read all about angles i learned on my jeep or you can call tom one of the best guys you will ever know when it comes to driveline. just my .02

[SummerBreeze]

I didn't see on your list .... Have you looked at the U-Joints?

[DUECE'SDAD]

Dropped the shaft off at Inland truck parts at lunch, guy just called and its ready had to retube. . . tube was majorly bent although you coulndt see impact . . . Maybe warped or the ends were welded on wrong ??? he didnt say but he did say that both ends were bad like they were spread out where the ujoints ride so that there was slop in the driveshaft .. .. I hope this will fix it !!!! But surely the old drive shaft wasnt as bad b/c the vibration was there before i had this one made . . . . And the ends were the ones off the first driveshaft so maybe the ends were the major part ???
Well im babbling now !!!! The guy says the shaft is PERFECT AND PERFECTLY BALANCED and he said he wanted to show me on the machine to prove it to me hwn i come to pick it up

[kcvega]

Check those angles as in the pic above!!! And Inland should do you a good job. I've had bad ones at some other places in town but you never know who's working where. My car has harmonics in about that same rpm range and I've found nothing wrong anywhere. But I did have case breakage problems due to those angles being wrong.

[Froggystyle]

Just got to this thread...
Good advice so far. The diagram posted about angles is the biggest thing. That is only if you have standard U-joints though...
My next suggestion would be to run a C/V U-joint in front. What you do is, run your pinion angle straight into the driveshaft with less than 1 degree offset at the carrier. The 1 degree allows the u-joints to spin a bit and keeps them from flat-spotting. At the transmission end, the CV joint will take up all of the angle difference. If you had six degrees total, you would run up to one at the carrier and the rest at the transmission. I have solved MANY driveshaft angle issues this way.
9 times out of 10 cyclic vibration is the driveshaft. Rarely, if ever is it the motor.

[MADDOG355]

First thing I would check it the Driveshaft. It could be bent cousing the viberation. You mentioned the U joints, were they hard to move in any direction? A frozen U joint will actually make the driveshaft flex at speed.
My next thing would be to make shure the motor, trans, and rear are strait inline (as in side to side) and make shure the rear is not moving foward under power.
I had a 80 Chevy pickup that had the same viberation and and also broke the trans housing turns out the frame was bent.

[SummitKarl]

9" ford rear end....I had this one before....check the pinion bolt it may be loose, the big bolt that holds the yoke on..DO NOT OVER TIGHTEN... 25 ft lbs max

[coolchange]

Sounds like you have it fixed. big power, heavy car that hooks up can twist the drive shaft and change the clocking of the u-joints to each other and wreck havoc on the flanges.

[DUECE'SDAD]

Check those angles as in the pic above!!!
You have told me this before, but i just now figured it out and i think this may be a problem.... in this pic you can see that the ujoints are angling the in the same line. . . My pinion is .5 up so basically perfectly parallel with the ground yet my transmission is pointing 5 degrees down so the ujoint will have a different angle and even accellorate/deccellorate at different rates than each other (taken from tom woods website mentioned above)
So like someone mentioned i need to raise my crosmember to get the transmission basically parallel with the ground. That may change to pinion able though if i lift the trans up it may make the driveshaft angle more ?????
http://www.4xshaft.com/images/2joint_angle.gif

[Oldsquirt]

Try adding shims at the trans mount to raise the rear of trans......Or get some tapered shims to bring the nose of the pinion up.....Or a combination of the two. If it solves the vibration problem do what is necessary to make the changes permanent.
Did you install the new driveshaft?

[DUECE'SDAD]

no i will be picking up the new driveshaft today but i still have to change transmission case !!!

[hazard]

It could be your motor mounts, trans mounts, leaf spring bushings, or body mounts. Try replacing all of these (especially the suspension components) with polyurethane mounts. That will help with any movement that may be causing vibration.
I have a large Jeep that I had similar problems with (I know its totally different, but all still the same parts!).
I also went and had the tires balanced and that made a huge difference.

[hazard]

You have told me this before, but i just now figured it out and i think this may be a problem.... in this pic you can see that the ujoints are angling the in the same line. . . My pinion is .5 up so basically perfectly parallel with the ground yet my transmission is pointing 5 degrees down so the ujoint will have a different angle and even accellorate/deccellorate at different rates than each other (taken from tom woods website mentioned above)
So like someone mentioned i need to raise my crosmember to get the transmission basically parallel with the ground. That may change to pinion able though if i lift the trans up it may make the driveshaft angle more ?????
http://www.4xshaft.com/images/2joint_angle.gif
Thats what the pinion on my Jeep looks like and I'm running approx 10" of lift. I set the rear pinion down about 4 degrees below the output shaft on the transfer case (or transmission). This is due to acceleration. You do not want the pinion to be at the same angle as the transmission output at rest. It should, however, be at the same angle when accelerating. They say that 4 to 5 degrees is the proper range to lower it.
I've yet to brake a u-joint with it at those proper angles and thats saying alot with the lift that I have!
How exactly is it vibrating? is the whole body shaking? Is it just and engine feeling, please expand. May help us diagnose it better.

[hazard]

Check your pinion angle and driveshaft lenght too much pinion angle will cause a vibration and cause u joint to wear bad, and to long of driveshaft can cause it to bottom out in transmission cause a vibration and break a tranny case just my 2 cents :D
Agreed. Sounds like the shaft may be a hair too long. Get a shorter long travel shaft. This will allow for more compression or extension if its really needed.
Also, I'm surprised that your joints didn't break first. Try swapping in some cheap u-joint till you get the problem solved. I say this because you want U-joints breaking, not major expensive components when problem solving!
Make sure that trans is anchored down nice and tight too. Use poly mounts!

[DUECE'SDAD]

driveshaft is right length

[DUECE'SDAD]

Well got the car back together last night, didnt have any trans fluid so didnt test it but i did spend alotta time looking over everything and taking many measurements, heres all the figures. . . remember cal trac reccommends -2 to -4 degrees of pinion angle so look this over and tell me what you think
harmonic balancer is neg 5 degrees
carb mounting plate is neg 4 degrees
trans crossmember is mounted at neg 5 degrees
drive shaft is neg 10 degrees front -9.5 rear
pinion is pos 4 degrees
and for hieghts
harmonic balancer bolt center 24.75
trans tailshaft center 19
pinion center 11.25
Looks to me like the pinion angle realitive to the driveshaft is -4.5 and realative to the crank centerline is -1 degree . . . Which do you think is more important to position it off of ??? And how do you find the working angles of the joints ??? And am i close on the working angles ???

[Sportin' Wood]

I just stumbled on this thread and thought driveline before reading the first post.
Big motor, big traction, bad angles= broke stuff.
The CV joint mentioned would be for a short drive line and extream angles, I would not go that route unless its a short shaft. I have blown CV into pieces with my Rock Buggy.
Leaf springs I assume traction bar as well?
The drive shaft could have been bent from the start as stated but wheel hop and axle torque could put a hurt on it.
Sounds like you are on the right track, I would check the yolk, No strike that I would replace the yolks on the axle and trans after the abuse it sounds like they have seen. Bad yolks will eat the Ujoints as well. Street cars don't see the movement my offroad stuff see's but having the angle correct before ordering a shaft is very important in our world does not sound like such a big problem in yours.
Post up what you find out please.
BTW if the angles are not the same you can get caster shims and change the angle at the leaf springs. Just make sure you keep an eye on them and try and find steel. The alum. shims don't last.

[DUECE'SDAD]

Well, i found some of the problem i think. . . drive shaft at 10 degrees seems too much for a hot rod and the 10 down on the shaft and 4 up on the pinion equals a 6 degree working angle on the ujoints, does that sound correct ??? That is too much on the chart that i have looked at. . .max rpm for that ujoint angle is about 2000rpm
Also a guy told me that the with the shaft angling that much there was more leverage to try and twist the driveshaft and he said that was why the driveshaft shop found so much wrong with the shaft
All the motor mounts were homemade and seems the engine/trans was mounted too high so i cut it all out last night and im starting over with it pushed all the way down in back in the frame

[bonesfab]

Just went through this on a customers car. the engine and trans were down 10 deg and the rear was up 5 deg. can you say major noise and vibration. went through and raised the trans 5 deg and low and behold it is quiet and smooth. The angles should be within .5deg of each other for optimal longevity and smoothness.

[DUECE'SDAD]

Looking like after all the crap that it may be the convertor. . . I bought it used with only a few passes, but they were nitrous passes and it may have ballooned ???? It shakes with no driveshaft running thru the gears and especially 3rd at 2300-2500 but doesnt shake with the convertor hooked up, any more ideas ?????

[thatguy]

You never said if you tried dropping it in nuetral during the vibration and doing a "coasting" test.
However, I went through this EXACT deal on a 71' Nova 10.90 car I built. Broken case every other weekend like clockwork. My tranny sponser made me bring the car in to look at. It was pinion angle.
Tranny was at like 3 deg. down / pinion was like 5 deg. down.
Did not really vibrate, but the broken cases ended as soon as pinion angle was fixed.
Be aware, as I am sure you know, this can cause damage all the way up to your crank thrust bearing. So don't be too quick to blame any damage as the cause, it is probably a result. That would include your converter.
Tommy

[thatguy]

Looking like after all the crap that it may be the convertor. . . I bought it used with only a few passes, but they were nitrous passes and it may have ballooned ???? It shakes with no driveshaft running thru the gears and especially 3rd at 2300-2500 but doesnt shake with the convertor hooked up, any more ideas ?????
I gotta think your mains and thrust are hammered. Converter can act lika a dampner with no load on it. If I am reading this right.

[BIGJOEDUCKSLAYER]

This may sound stupid but are both dowl pins in block and snug? I have seen missing dowl pins break cases. Where are you located?
BIG JOE (owns transmission shop)

[73kona455]

Looking like after all the crap that it may be the convertor. . . I bought it used with only a few passes, but they were nitrous passes and it may have ballooned ???? It shakes with no driveshaft running thru the gears and especially 3rd at 2300-2500 but doesnt shake with the convertor hooked up, any more ideas ?????
if the coverter is ballooned you need to pull the oil pan and check the thrust bearing on your crankshaft....:eek: