94 gcl vibration

[mtman]

hi,my 94 laredo with 4.0 -auto-awd--has a vibration while running between 1500 and 2000 rpms-any higher or lower and it runs pretty smooth--dont think its drivetrain related because it seems to be only during these rpm ranges--it idles a little rough also--thought it may be the motor mounts but when i rev it manually while looking under the hood everything seems normal--any thoughts would be appreciated--thanks

 

[daily_destroyer]

You could have lost a weight on a wheel highly doubtful but who knows, what about a transmission mount or a bushing

 

[Jester32]

Sounds like it could be a miss. If you load it in gear does it get worse? Don't load it to long as a ton of heat is made in the trans if you do

 

[mtman]

Sounds like it could be a miss. If you load it in gear does it get worse? Don't load it to long as a ton of heat is made in the trans if you do

yes upon acceleration is when i feel it-but if i'm running above 50 and have the engine downshift-going uphill for example --and the rpms are above 2000 the ride is normal--thanks

 

[Jester32]

Ok if it's only while driving. Could be a u joint starting to go or a pinion angle issue. Usually they are most pronounced at accel. From a stop.

 

[mtman]

Ok if it's only while driving. Could be a u joint starting to go or a pinion angle issue. Usually they are most pronounced at accel. From a stop.

sounds more like what is happening--whats the easiest way to check the u-joints-jeep is totally stock--thanks

 

[Jester32]

First block the wheels then in neutral check for play. If there's no play. Remove the driveshaft bolts and carefully remove driveshaft. Move the u joints to check for rough spot or seized needles. Any of which will cause vibration. Especially seized or rough spot.

 

[mtman]

First block the wheels then in neutral check for play. If there's no play. Remove the driveshaft bolts and carefully remove driveshaft. Move the u joints to check for rough spot or seized needles. Any of which will cause vibration. Especially seized or rough spot.

thanks-- will take a look as soon as i shovel the driveway -16" overnite in no.jersey--will let you know what i find-- thanks again

 

[Jester32]

Alright sounds good. I can't wait for snow. I'm in Canada and its still above zero. Getting frustrating haha.

 

[mtman]

thanks-- will take a look as soon as i shovel the driveway -16" overnite in no.jersey--will let you know what i find-- thanks again

ok while looking at the front driveshaft i saw one of the mounting bolts for the the trans bracket not tight and barely into the nut on top of the trans mount-will tighten it up (i hope ) as soon as i get the right size wrench for it --looks like its metric--sure hope this does it --also do you know where to get the grommet for the transfer case shifter --the linkage is off right now --and thanks for your help

 

[Jester32]

The grommet I believe is serviced with the cable I was just logged on Chrysler and couldn't find it seperate. Is it damaged?

 

[mtman]

The grommet I believe is serviced with the cable I was just logged on Chrysler and couldn't find it seperate. Is it damaged?

there is no cable --there is a pin that goes thru the grommet that connects both levers together

 

[mtman]

there is no cable --there is a pin that goes thru the grommet that connects both levers together

i don't think its damaged as much as worn out --if i put the pin thru the grommet it can pop right out with out any force --maybe there should be a clip on the backside--thanks

 

[mtman]

finally was able to get under the jeep to check the u-joints-everything seems pretty tight--no play that i can find--the transmission bolt is frozen in position so i dont think that would be the cause of this new problem--jester had mentioned a miss and now when i rev the engine in park i notice the vibration occurs just like when i am driving right between 1500 and 2000 rpms--if it is engine related what should i look for--i really appreciate all the help i am getting

 

[Jester32]

Basically check cap and rotor. Wires and plugs. You can pull plugs and read them. While your at it if they haven't been replaced in awhile you might as well change them. Any moisture or corrosion under the cap. And on the cap contacts are possible causes. Lots to check. Hard to diag over messaging.

 

[mtman]

Basically check cap and rotor. Wires and plugs. You can pull plugs and read them. While your at it if they haven't been replaced in awhile you might as well change them. Any moisture or corrosion under the cap. And on the cap contacts are possible causes. Lots to check. Hard to diag over messaging.

thanks i will go over it tomorrow --since i am thinking it could be engine related i'll see what i can find--first time really crawling around under this jeep-had it for about 6 months-surprised how good it looks down below(knock on wood) thanks for the quick reply--would like to take care of as much as i can on my own

 

[mtman]

Update on my situation--last weekend changed cap-plugs-wires and rotor--plugs looked pretty well worn as well as the cap and rotor--vibration still there--finally took a THOROUGH look at my motor mounts and found the drivers side busted--this weekend I changed both sides and while there is still some vibration not nearly as bad as before--thanks to this site and its posters I tackled my biggest repair ever with the least amount of worry--thanks again to all