Engin Vibration After Lift! Any Ideas?

[Tug-n-pull]

1071675

Here is the problem I have. Start up and feel a vibration I never had prior to the lift. It does it in nutral at idel! It is there at all RPM ranges. Faster and slower with the range changes. So I do not see it being a drive line or lift related deal. How ever it could be in the transfer case drop causeing a change in the alinement of everything. Motor mounts posibly in a bind? What do you think it may be? Greatful for any ideas. Tug

edited by: Tug-n-pull, Jun 16, 2003 - 07:08 PM[addsig]

 

[Green97TJ]

1071680

i wouldnt call this an "expert opinion" or anything, but im thinkin you might be right.... id check into the motor mounts and angles between engine/transmission/tcase

Nathan[addsig]

 

[joejeepny]

1071682

Did you drop you skid plate. You might be pulling or hitting something and its transfering the vibration of the engine to the body more than normal. Do you see the vibration at the engine with the hood open or do you feel it in the seat of your pants.[addsig]

 

[Snitty]

1071694

i spoke with you earlier on this.... and to this point, that is still the only thing i can think of... that is the only part of the pre-driveline system that was modified[addsig]

 

[Snitty]

1071696

or..... it could be.... are you afraid of heights?? fright tremors??[addsig]

 

[84_CJ7]

1071713

I had a similar problem recently with a motor I swapped out on my old Ford Pickup. Ended up being the passenger side exhaust pipe was barely touching the crossmember. Just enough to transfer any motor movement to the frame which vibrated the entire truck. Took a few attempts to find it but solved the problem. I would look very closely for anything that could transfer any motor vibrations, even the motor and transmission mounts. Probably something simple but can be aggrevating to find! Good luck!

Scott[addsig]

 

[Bounty__Hunter]

1071717

Check for a broken motor mount, or any part of the driveline touching the chassis. Check the transfer case at the back of the crossmember.[addsig]

 

[jterp]

1071722

Like someone already said, I would look to see if you can see the actual engine vibrate.. If it is just something you can feel in the seat of your pants, you probably have something that is a hair too close to something else. I had this happen in an old muscle car once-- swapped in a new transmission and had a terrible vibration that sounded like it was doing a lot of damage--- turned out the transmission was just a touch too close to the floor of the car, and the natural movement in the transmission would cause it to vibrate against the floor board. GOod luck. Let us know how it works out. [addsig]

 

[Tug-n-pull]

1071789

Thanks for all the advice. It is the motor mounts! The transfercase drop allowed the motor to angle up enough to let the motor toucj the metal part of the mounts in the front edge of the mounts. Rather than reduce the angle via shorting the drop kit I am going to cut of part of the motor mount front edge and add a rubber washer to the front of the mount bolt to give extra protection from it sliding back in the future. I just wish I had some urathane stock to cut them out of. Tug[addsig]

 

[Snitty]

1071809

way to go... didn't doubt that you could get it[addsig]

 

[Tug-n-pull]

1071820

One quick question prior to fixen this mess. When I trim my motor mount the transmission transfer case mounts will keep the motor from moveing to and fro or rather towards the rear of the jeep any further correct? If I understand this the motor mounts keeps the engin from twist and the transmission transfer keepit from to and fro. Does this make sence to you all or am I barking up the wrong tree here? tug[addsig]

 

[JE420EP]

1071821

If your motor jumps when you give it gas and you can hear or see it hit then you will know for sure. This motor mounts rip when thay get old. I am replacing mine in a week. Sometimes that extra angle will send it over the edge. If the exhaust pipe hits any where that will also make a vibration and a noise. I would not cut into the mount beacause there not made to be cut. That will weeking the mount and if it was to break o boy that could be bad. Hope you find it.[addsig]

 

[84_CJ7]

1071877

I agree, I wouldn't cut or alter the mounts. After all the work you have been through do yourself a favor and get some NEW mounts. You would hate for the old modified ones to become your weakest link!

Scott[addsig]

 

[joejeepny]

1071880

if you could afford the tailshaft conversion I would do it and put the skid plate back up where it was. That would be the proper fix.[addsig]

 

[Tug-n-pull]

1071881

The mounts are not in bad shape they just touch metal to metal on the front edge of the mount. And I wish I could afford the new Slip Yoak Elemantor and shaft, but I can not. Thanks for the feed back Tug[addsig]

 

[firemanharry]

1071885

Cut it as long as it won't affect the structural integrity of the mount. Always try the cheap fix first as long as it won't cost you more money if you're wrong. [addsig]

 

[jps4jeep]

1071900

Tug,
Before you start hacking at the transmission hump, what is inding you up is the most inner shifter boot.
I simple used a LFH (little f#$%in hammer) to roll the rear edge of the opening for the shifters and put a little splice in the most inner shifter boot and it shifted like a dream![addsig]

 

[Tug-n-pull]

1071980

Thanks again for all of your help and ideas that is what makes the jeepz board like a second home. I did replace the motor mounts today and adjusted the transmission mount forward to set the engin dead center of the new mounts. Oh yea Napa and Autozone are both about one half the dealers cost on these items. So now the vib is a piece of the past. Removed the drop Pitmanarm finaly and have that done. Retorqued the whole supension deal and now I am awaiting my new tires. Going for an alignment in the morning then put on the tires later same day, and then set back and wait for the trail week visitors to arrive. Well I guess I will have to go out and at least try out the new equipment a bit. I have not posted any pics due to it was not and is not done. Maybe tomorow it will be. At least the current mods anyway hehehehe tug[addsig]

 

[JE420EP]

1072021

Did the new mounts work? Did it stop the vibration. With the lift you have your drive line should not be a problem. It's when you have a 4+" in lift. You will feel the driveshaft in a slow take off.

edited by: JE420EP, Jun 18, 2003 - 09:46 PM[addsig]

 

[Tug-n-pull]

1072036

Yes it did the job. We loosened the transmission mount and slid it forward as far as it would slide. Now that took the pressure off the motor mounts. One was broken from the extra pressure of the new angle. Now with the new mounts it is setting ideal perfect center of the new mounts. Vibrations are all gone. Nothing cut nothing grinded. No drive line vibs and the line is not at a bad angle at all. You have to love this stuff! tug[addsig]