4l60e leaking rear seal and harmonic vibration

I think I may have vibration or harmonic issue in my driveshaft for my new LS1 E34 Swap . My new rear seal is leaking now. Not sure if they are related, but I suspect so. I have not determined what rpm or speed take place at. It start at a high speed, but now I think it is at lower speeds too. I am not sure yet though. I will have to do more investigation, but does anyone have any experience with something like this?

Thanks in advance for any info or ideas

Any seal that starts leaking right after changing it should be suspect of being nicked on installation. Is the differential pinion shaft parallel to a degree down from parallel from the trans output shaft?

grab the driveshaft yoke and see how much side to side play it has... if the bushing in the tailshaft goes bad or the yoke gets worn down too far it will cause a vibration and probably a leak, too..

Kenny_McCormic wrote: Any seal that starts leaking right after changing it should be suspect of being nicked on installation. Is the differential pinion shaft parallel to a degree down from parallel from the trans output shaft?

It's a two piece shaft, so the relationship between the trans output and pinion are not set in that relationship. But it looks like that matters.

novaderrik wrote: grab the driveshaft yoke and see how much side to side play it has... if the bushing in the tailshaft goes bad or the yoke gets worn down too far it will cause a vibration and probably a leak, too..

I did, and can make the yoke move. One thing though, I found my trans breather tube had come loose and was hanging down to the ground. Would the in ability for the trans to breath force fluid past the seal?

vazbmw wrote:

novaderrik wrote: grab the driveshaft yoke and see how much side to side play it has... if the bushing in the tailshaft goes bad or the yoke gets worn down too far it will cause a vibration and probably a leak, too..

I did, and can make the yoke move. One thing though, I found my trans breather tube had come loose and was hanging down to the ground. Would the in ability for the trans to breath force fluid past the seal?

Absolutely. It would push fluid out the first time it heated up, then slowly suck air back in when it was shut down and cooled, and that cycle would repeat forever.

Edit: This is assuming the trans breather system was blocked somehow, if your trans breather tube was just hanging down and the hole was open, that would just mean you might get dirt in your trans and fluid could splash out.

Thanks. Sorry for the dumb questions. I have not been a autotrans guy.

If the trans is overfilled a tad, would fluid seep out while the car was just sitting?

Mild overfilling shouldn't cause any seepage, severe overfilling can cause seepage from things that are more splash guards than seals (like the shifter boot/shift lever shaft) or can push fluid up the breather tube - if installed, or into the outside world if it's missing or uses a check-valve cap instead.

Ok. Thanks

I may gotten to the vibration. My output flange were a few degrees out of parallel with the diff flange. I shimmed up the trans and now within 1 degree of output flange. Thank you folks.