new egine/trans now bad vibration!

BoostedSUV

BoostedSUV

Active member
Just put in a new engine and waller trans in my truck. I fired it up and went for ride the truck will shake my teeth out! Right off acceration you can feel it, then around 30-35 is rattles bad and then continues as a steady shake. I can throw it neutral at 60 and the motor idles and the shake and vibration continues. I put in new motor mounts and trans mounts so that's not the issue. is there anyway to put the driveshafts in wrong? I'm running a gilbert prop shaft and new universals in the rear drive shaft. Do the driveshafts need to be installed in any particular relation to each other or does that not make any difference? It never did this prior. Anu help would be great! Thanks! -Matt
 
Ty 1885

Ty 1885

New member
Re: new egine/trans now bad vibration!

Did you check to make sure its NOT ridding on sus stops?
 
Norm

Norm

Donating Member
Re: new egine/trans now bad vibration!

something is definaetly hitting something, check the support brace for the transfer case, it can maybe be upside down and it hitting the tranny tunnel.Look at all the places where it is a close fit, and see if there is any paint rubbed oof on the body/frame/engine/tranny areas. Also check to make sure the u-joints are seated into the yokes.
 
WyoSyclone

WyoSyclone

Active member
Re: new egine/trans now bad vibration!

Are you sure you got the rear universal centered within the yoke?
 
Don W.

Don W.

Stab it and steer it
Re: new egine/trans now bad vibration!

The drive-shaft alignment answer is yes. The yokes on the shaft portion HAVE to align with each other. Meaning that if the yoke on one end is vertical than the yoke on the other must be vertical. Can't happen on the rear, it's welded. Only happens on the front if the spline section was taken apart and reassembled wrong. The vibration will be high speed (higher than "tire" speed) and directly related to how fast you're going. Usually not as severe as you're describing though.

I'd look at tires. Maybe you threw a weight. New u-joints might be a clue. Remove both shafts and make sure all joints are free. The rear driveline (on my Sy anyway) uses pressed in u-joints. If yours weren't replaced correctly and are binding they could be part of the prob.

Are front and rear tires matched in diameter?

Does the truck "pull" one way or the other?

Put it up on jack stands and run it in gear and see if you can find it that way.

Just thinkin' out loud.
 
BoostedSUV

BoostedSUV

Active member
Re: new egine/trans now bad vibration!

I checked all the obvious. The shafts are seated properly in the yokes, the down pipe and transfer case braces are not touching the body or frame. The universals were replaced prior to doing the engine'trans and it did not vibrate before. Only thing I did was install the rebuilt engine and new trans. I've done the engine before but it was my first trans in this truck. I don't feel it in steering wheel at all. I can feel it the shifter and seats the worst. If I have my hand resting on the shifter I can feel vibrations.
 
Syclone#2960

Syclone#2960

What ever it takes!!
Re: new egine/trans now bad vibration!

What type of tranny mount did you use??? The Energy suspension tranny mount comes with a metal bracket. Do not use the bracket.
 
BoostedSUV

BoostedSUV

Active member
Re: new egine/trans now bad vibration!

Syclone#2960 said:
What type of tranny mount did you use??? The Energy suspension tranny mount comes with a metal bracket. Do not use the bracket.
Click to expand...
Yes, energy suspension trans and motor mounts with RPM frame pads.
 
Don W.

Don W.

Stab it and steer it
Re: new egine/trans now bad vibration!

Yes or no on the jack stand idea? You can watch everything. Pick your speeds, look underneath. Little spooky but what isn't spooky on these things. :lol:

Another question: Based on your original post the answer is no but I'm gonna ask anyway. Does the vibration change with power? In other words at a given road speed can you make it change by throttle setting?

Have you tried to determine if the vibration is "engine speed" "drive-line speed" or "wheel speed?"

Check the front of the motor for anything amis.

Is there any noise that accompanies the vibration?
 
BoostedSUV

BoostedSUV

Active member
Re: new egine/trans now bad vibration!

Its more in relation to driveline speed, not engin RPM. It will vibrate in neutral and rolling with engine at idle. I will try running it on stands and see if I see anything obvious. I had it up on my friends lift and didn't notice anything obviously wrong.
 
Syclone#2960

Syclone#2960

What ever it takes!!
Re: new egine/trans now bad vibration!

BoostedSUV said:
Yes, energy suspension trans and motor mounts with RPM frame pads.
Click to expand...

Did you install it with the x-tra metal plate? I'm running stock type motor mounts & Energy suspension tranny mount. Running all polly could be a little stiff. I hope you at least reused the heat shields on the motor mounts cause they are going to melt.

Read below:

http://www.syty.net/forums/showthread.php?t=12646&highlight=energy
 
BoostedSUV

BoostedSUV

Active member
Re: new egine/trans now bad vibration!

Syclone#2960 said:
Did you install it with the x-tra metal plate? I'm running stock type motor mounts & Energy suspension tranny mount. Running all polly could be a little stiff. I hope you at least reused the heat shields on the motor mounts cause they are going to melt.

Read below:

http://www.syty.net/forums/showthread.php?t=12646&highlight=energy
Click to expand...
I used the metal plate on the trans but not on the motor mounts. Mike from RPM told me not use them on the motor side. I didn't reuse the heat sheilds but I rapped them in header wrap wich should work fine. Time will tell about that.
 
BoostedSUV

BoostedSUV

Active member
Re: new egine/trans now bad vibration!

Syclone#2960 said:
Remove the plate from the tranny mount & your problem will be fixed.
Click to expand...
Really? Why's that? Energy suspension says it is required. Wouldn't hurt to try!
 
BoostedSUV

BoostedSUV

Active member
Re: new egine/trans now bad vibration!

I'm goimg to remove that plate as soon as I get home from work tomorrow. Hopefully my fix is as simple as that. Now if I can only get trans fluid to stop leaking out from in between the transfer case and trans!!!
 
Don W.

Don W.

Stab it and steer it
Re: new egine/trans now bad vibration!

BoostedSUV said:
Now if I can only get trans fluid to stop leaking out from in between the transfer case and trans!!!
Click to expand...

I wuz no help with the vibration maybe I can help here. If it's the case to adapter there IS a gasket that goes there. My NAPA didn't have it but the dealer did. HTH
 
BoostedSUV

BoostedSUV

Active member
Re: new egine/trans now bad vibration!

Don W. said:
I wuz no help with the vibration maybe I can help here. If it's the case to adapter there IS a gasket that goes there. My NAPA didn't have it but the dealer did. HTH
Click to expand...
it leaks right where the transfer case and the trans bolt together. I didn't notice a gasket there when I took the transfer case off the old trans? I also wasn't looking for one. Is there definitely supossed to be a gasket where they meet up? Thanks
 
Don W.

Don W.

Stab it and steer it
Re: new egine/trans now bad vibration!

BoostedSUV said:
it leaks right where the transfer case and the trans bolt together. I didn't notice a gasket there when I took the transfer case off the old trans? I also wasn't looking for one. Is there definitely supossed to be a gasket where they meet up? Thanks
Click to expand...

Yes, the GM# is 15642511

I've heard some use RTV. Gotta come apart either way to fix.
 
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