Help me diagnose vibration, after tranny mount swap

[euroZ06]

Hello,

So ill do a quick background and then onto the problem. Im 29yrs old, and dont know much about mopars, but have held a wrench before and im good following diy stuff. Did a lot of modding work on my newer cars. So with this being such an old car with so many specific tricks, i figured ill ask for some help. I found an older gentleman that is big into mopars, and he offered to help fixing the car up for me (for relatively small fees). Now, when i bought the car, it didnt really have any huge issues and was restored some years ago, however some of the items needed attention and some issues needed to be solved. Plus, recently i got orders to move to germany and i would really like to take the car with me, with that in mind i wanted to fix items that will fail german inspection as well as do some preventive maintanance so that the car wont break down on me in germany. So, me and this gentleman, over the course of last few months, have been doing some work. Not everything goes perfect, and sometimes we hit some snags (i guess i know where to point the finger, however i wont do that because i would probably make the same mistakes or even worse). One thing that kind of threw me off, is that when i asked him to adjust my carburater, he messed with it, but it didnt improve the starting issue i was having (car turns too long to start, need many tries). Also my battery was draining. He checked the charge on the alternator and said its not charging the battery (weird, cause after my batter dies and i drive for an hour the battery is charged a bit). So he said i should replace my alternator and the starter (just in case. Preventive). I said ok, he replaced it, charged me money, but after checking alternator again, it still wasnt charging. It eneded up being that shiny metal piece that is on the firewall ($30 part vs $220 that i spent on labor and new alternator and starter). I said ok, no biggie, maybe not a bad idea to replace those, so i dont have to mess with it in germany.

So fast forward to last project. My tranny mount was in bad shape, and needed to be replaced. I called summit and got the mount (polyurethane). When we got under the car and took out the old mount, we noticed that the holes on the new mount dont line up with the body. I wanna say its about an inch off. So, he decided to try and fiddle around and make it fit. After over two hours, with a lot of elbow power and crowbar he was able to jam it in there (i am not sure how it was possible). Now, right after i started the car i noticed that there was this noticible vibration (actually a better term would be harmonics). It almost felt like an engine mount was broken and engine was sitting straight on the body. So then i drove home and it was even worse. This sort of vibration/harmonics was shaking up the whole car, my side panels were just going crazy, all my mirrors went off the adjustment. This vibrations is worse at certain rpm and a bit better at other rpm. But the car is really undrivable like that. After getting home, i immediately called him and told him about the issue, however i immediately got a kickback saying its impossible for it to be the tranny mount. When installed it sat flush. This gentleman doesnt have much time on his hands, so getting together is difficult (mind u, i cant drive the car the way it is now, and normally i drive it every sunday... Thats y i bought it, i love driving it in sundsy, its my stress relief). Finally i was able to get him to agree to meet this sunday, but he keeps shutting down the idea that its the tranny mount thats causing that. Also, i should note, i usually give him my old parts, cause he sells them to recicling or something, so i gave him the old mount too. After I got home, i told him that because there is an issue, not to throw out the old one... Guess what, today he told me he threw it out. I also asked him to bring his grinder thingy, to make the wholes in the mount bigger, so that if we need to we can just fit it correctly. Again, he says its not the mount, and he wont bring the grinder thingy. I tried to explain to him that i think because the mount is soooo compressed now (because of showing it in there like that) all the engine harmonics are coming up. He says its impossible. Says i should change the body mounts, or maybe engine mount broke. Now my body mounts are bad, and i need them replaced, but this issue started immediately after we replaced the tranny mount, i had no vibrations prior.

Sorry for long post, im just trying to get another idea. Is he right? What could be causing this? Is it really impossible for the tranny mount to cause this? Wish i had the old mount, so i could put it back and see if this goes away, but now i cant.

I feel like this sunday he'll go under the car, wont find any issues and then tell me to change the body mounts. Ill change those and he'll say its something else etc... In the mean time the car is undrivable.

Like i said, the only thing we replaced was the tranny mount, issue started immediately on the start up, i could feel the harmonics as i reved the car after start up.

Help...

[xsr/tse]

what model and year mopar are you working on? with which trans?  Or did i miss that in your post?

[green69rt]

So many things going on here that you have to start somewhere.  Since the tranny mount was last and it was so hard to line up I would look there.  There are lots of close fitting pieces in these old cars.  If you have move the engine around a lot then maybe an exhaust pipe is against the frame or the drive shaft angel is wrong.  If the drive shaft alignment is wrong this can cause all sorts of problems.  Most will lead to drive shaft failure.  Think about that!!   You really need to take a long hard look at stuff.  Quit thinking about moving and concentrate on the car.  Does the vibration only hap[pen when the car is moving, good indication of drive shaft problems.

Do you have the old trans mount?  Put it back on.  See if the problems change.  Sorry to say, but it looks like this guy is an old shade tree mechanic that just fools around till things fit but doesn't really know how they work.

One thing you learn about these old cars, never, ever, ever throw anything away!!  Ever!!

Edit, just reread the post, so the old mount is gone.  Looks like you need to find another mount, makes me wonder if you got the wrong "new" mount.

[Charger-Bodie]

Never had any luck with poly transmission mounts. Everything above that Mitch has said is good advise.

[cdr]

ROFLMBO @ Mitch ,,,,,,,,  I have NEVER heard a statement SO true !!!!!!!!!!!!!!!!!!!!!!!  


One thing you learn about these old cars, never, ever, ever throw anything away!!  Ever!!



   EVER  

[RallyeMike]

It should not be off by an entire inch. I'd guess you have the wrong mount or something has been modified.  Try another mount -  you say you can handle a wrench so give it a shot. This is not a difficult job. BTW, the poly mounts are a lot harder than rubber and will not isolate the engine/trans vibration as much as rubber.

[myk]

Things either fit together and are correct or they don't.  I'd try another mount and go from there.  Who knows what sort of trouble "forcing" the new mount into place has caused...

[PlainfieldCharger]

Maybe the ujoint was going bad causing a small less noticeable vibaration and when you put the mount in you of pushed the u joint to a further postion causing more vibration... I like to compare the parts old to new before I attempt to install it.

[tan top]

ROFLMBO @ Mitch ,,,,,,,,  I have NEVER heard a statement SO true !!!!!!!!!!!!!!!!!!!!!!!  


One thing you learn about these old cars, never, ever, ever throw anything away!!  Ever!!



  EVER  

true that    



have you got a picture under the car  ! of the whole trans mount /gearbox etc  , fitted    

[Nacho-RT74]

we got a thread about that not too much ago...

latelly I have thinking about this:

https://www.youtube.com/watch?feature=player_embedded&v=gmV4qwLfOMY

[euroZ06]

Thanks for replies.

The mount sits flush. When we went to install it, it wasnt aligning with holes and was an inch off. The dude was determined to get it in there. So we used a jack to move transmission around(up and down) as well as a craw bar to try and get it together. First we got it a attached to tranny with two bolts, but didnt tighten them, so it was freely moving, then using using brute force we managed to get the mount attached to the body. Then we tightened the bolts to the tranny (they were intially angled). All this took us two hours and a lot of brute force. Right after i started the car, i felt the harmonics all throught the car, and even if i rev it just sitting there. Once i start to drive it gets worse.

We met this sunday so he can take another look at it, and to do an oil change in tranny (he thought maybe tranny was low on oil and that could have caused it). He went on the underside and didnt find anything, he said my body bushings are bad and my engine bushings could be bad, so all that is causing vibration. I know my body bushing are bad (one is torn to crap), but they have been like that for a year and i didnt have any of these resonances beofre we changed the mount. Currently i have no idea where to get a correct mount, i ordered this one from summit racing and ordered it over the phone (told them all the info about the car). The mount seems to be correct, except the wholes are an inch off. Im thinking its so hard pressed against one side of the mount that it doesnt allow for any play and is essentially acting like a metal mount. Ill go see him this week and see if he can get me another mount (he works in parts store).

All in all, he said he will not help me with the car anymore, because im nit picking. Wtf! I dont think this is nit picking. And on one side i also did want to part ways with him too, but now im not sure how ill get this car ready for germany im supposed to buy a different diff (i have 3.91 gears and need 3.23 for autobahn) and im not sure how to swap it. Ill be going from 741 case to 489 case...

[euroZ06]

Ok, i put in a cheap tranny mount (lines up correctly). I also replaced subframe bushings and crossmember bushings. There is still some strange harmonics coming into the cabin (less than before though).

[charger Downunder]

I would take out the tail shaft put in new uni joints and get it balanced. Most vibration come from the shaft. Do the work yourself and keep it away from that so called mechanic.

[PlainfieldCharger]

I would take out the tail shaft put in new uni joints and get it balanced. Most vibration come from the shaft. Do the work yourself and keep it away from that so called mechanic.

[JR]

He won't help you anymore, good. I was about to say stop throwing out your old parts and throw away that lousy "mechanic" instead.

Take a pic of the trans mount, post it here, and someone here can probably id the problem quickly.

[euroZ06]

Ok, minor update.

First, ill say that my mechanic dude does seem knowledgable, but he is an older dude and has a different approach to things than i do. He kind of writes everything off at first, and a lot of times goes by a slow and more carefull approach, especially on things that are not primary concerne to me.

Anyway, i bought a cheap mount, swapped it in (it fit just right), and for 80% my harmonics went away. But, they are still there... Around 2k rpm i have this resonance coming through the interior. It happens what the car is parked, but not as pronounced. Pressing the clutch in, doesnt change aything. So, from what i can tell i can eliminate driveshaft and flywheel.

Now, i went to a shop to get an estimate on my ball joint replacement ($450!!!! Plus parts), they told me that my oil pan is sitting on my steering rack. It wasnt before (was close, but never sat on it). So i wonder if that has anything to do with it and howmis it related to my initial tranny mount swap 

Are my engine mounts bad? Is there a way to adjust them?

im getting a bit demotivated by all of this, im trying to keep this thing on the road, and really want to take it to germany with me, so i can showcase american muscle car, but this is getting to be a lot of work. Just today i spent $250 on rear brake parts and lower ball joints... Need another $450 to swap them. Need another $100 to swap the brakes. Need another x amount to redo the spark plug wires and possibly engine mounts (i cant even put a price on that work).... Id try to do some of it myself, but i just dont know much about this, i only have a shitty car port, and im in the military school, so no time... I need to find motivation.

[euroZ06]

And to top it off, i got this whistling sound inside cabin when imstart the car, i press the clutch in and it goes away... Though, after i drive for a while it seems to go away, but not every time. So clutch bearing?? It started after i installed clutch/flywheel dust cover. I just replace the clutch 8 months ago

[303 Mopar]

Your trans mount may have adjusted the angle of the motor just enough to have it hit the steering, especially if it was already close.  To test your motor mounts, rev the engine with the brake on and have someone watch to see if the motor torques up on the drivers side too much. 

One way to determine if the vibration is the motor or trans and back is while driving press in the clutch (or slip into neutral) and disengage from the transmission.  If the vibration is still there it is the motor, if it goes away it is the transmission or driveshaft.