Shake at 35 mph

[Joopin]

As most of you know, there was a huge storm on the east coast. We got 20 inches here in Jersey! The night of the storm, I went out with the wrangler pulling people out of snowbanks and such. Ended the night by pulling some friends around the neighborhood in an inflatable zodiac boat... good times.

The next day was less stressful for the YJ, but I did go through some unplowed roads... the last one of course there was a pop right after changing from 2wd to 4H. I thought I blew a U-joint but seemed fine after looking under the jeep and everything was where it should be.

Long story short, going to work today... back roads were bad, but once I got on the main road, the traffic picked up. As soon as I hit 35-40 mph I felt a shaking... any faster than that I assumed I would drop a shaft.

I drove home at the end of the day and found that the rear shaft seems as solid as can be, no u-joint trouble that I can see without taking out the shaft.

The front shaft on the other hand seems to be loose in the slip yoke, so I assumed the vaccum was stuck in 4wd and making the front shaft turn. I jacked up the front end, turned the wheel... the other one didn't turn so the vaccum is fine.

So now I don't know where the death wobble is coming from... Any ideas? I would hate to drive it to work again tomorrow and have it fall apart!

thanks

 

[xt master]

I think there is a U joint in the axle.I may be wrong,but I think there is in the front Axle on the passenger side.

 

[Joopin]

I think there is a U joint in the axle.I may be wrong,but I think there is in the front Axle on the passenger side.

Yeah, but they should only turn while in 4WD too...

 

[Bounty__Hunter]

Loose splines on the front driveshaft will cause a vibration, and it will still turn a little in 2wd due to viscous drag of the fluid.

Watch both yokes of the transfer case to make sure they spin true, as well as the pinion yokes.

 

[Joopin]

Loose splines on the front driveshaft will cause a vibration, and it will still turn a little in 2wd due to viscous drag of the fluid.

Watch both yokes of the transfer case to make sure they spin true, as well as the pinion yokes.

Okay, I just had my wife watch the yokes and front driveshaft while I drove up and down the driveway slow enough for her to watch. The front shaft wasn't turning at all according to her... but like I said I was only going about 5 mph. I then put it in 4wd and she said the shaft was turning.

You think I should just take out the front shaft anyway?

 

[jps4jeep]

do you have snow paked in the wheels? had this happen, causes a mighty wobble. add in the 36" tires and it could be worse.

also, do you have a sye with a machined bearing or is a hack and tap style that still uses barrel bearings? if the latter, could be a bad bearing.

 

[Joopin]

No snow packed in the wheels, that's what I checked first... I wish that was it!
My SYE is not a hack and tap...

I drove it to work again today against better judgement, and it started shaking at 35 mph again. I was fine on the back roads, but once I got on a stretch of a main road I was the slowest guy out there.

A weird thing happened though, I noticed that the shaking went away when I was coasting (obviously) so I started holding in the clutch for a little longer. Then I noticed that after I pushed down and let up the clutch pedal the shaking would go away... I actually got close to 45 mph without shaking, but I didn't push it past that to test my theory. Maybe on the way home.

I'm going to pull my front DS out tonight just to see, it needs work anyway.

Any other thoughts? Thanks!

 

[54cj3b]

could be a number of things bad u joint , busted tooth on ring gear , bad wheel bearings , cv ujoints in front axle , stretched out chain in transfer case / busted tooth on gear , cracked yoke , busted motor or trans mount / transfercase mount , throw out bearing in clutch prob one of the above listed from what I read in your post good luck let us know if you find the culprit

 

[Joopin]

could be a number of things bad u joint , busted tooth on ring gear , bad wheel bearings , cv ujoints in front axle , stretched out chain in transfer case / busted tooth on gear , cracked yoke , busted motor or trans mount / transfercase mount , throw out bearing in clutch prob one of the above listed from what I read in your post good luck let us know if you find the culprit

Merry Christmas to me.
:x

 

[xt master]

I was going to suggested that may be you lost a wheel weight.Although if you say it does not do it with the clutch pushed in I would think some thing with the clutch is causing the problem.If you are at speed and push in the clutch the drive shaft and Axles are still going to be spinning.By any chance did you get stuck or when helping to pull some one out try going from first to reverse quickly to try and rock it out?Did that with the wife's car once messed the clutch up.Had to rebuild it.

 

[54cj3b]

Merry Christmas to me.
:x

dont feel bad your not alone motor in liberty craped out throwing a rod destroyed motor cost of new is $3500
and it went right after 50000 mile warranty went out

 

[Joopin]

I am in the process of looking for a Grand Cherokee Limited Daily Driver... this couldn't happen AFTER I bought one???!?!

Well, gonna drive it home now and see what she does.

 

[Joopin]

Well just got home, it's a mystery to me. I was hoping it was something as simple as a u joint but it may be something like the throw out bearing like 54cj mentioned.
How can I find out for sure? I do have 12 days off coming up starting thursday... but sounds like changing such a thing is over my head.

Looks like the down payment for the GC limited is going to be used to fix this situation.

 

[54cj3b]

symtems to look for if its a throw out bearing
clutch dont engage fully or spungie pedal
shifter chatters/major vibrations
pops out of gear after shifting or even while driving
bad squeeling coming from clutch
bad bucking feeling when driving
if I ever buy another jeep ILL never buy any newer than early 80s any newer there built like crap

 

[mud4feet]

..........it may be something like the throw out bearing like 54cj mentioned......... but sounds like changing such a thing is over my head........

I seriously doubt that, Joopin. If you're pullin' out shafts with no problem, the throw out bearing shouldn't be a problem to replace.

....if I ever buy another jeep ILL never buy any newer than early 80s any newer there built like crap.....

Well, I'll have to disagree with that. My '03 is still runnin' on the factory clutch - 147,000 miles (BIG knock on wood)!:lol:

 

[Joopin]

I seriously doubt that, Joopin. If you're pullin' out shafts with no problem, the throw out bearing shouldn't be a problem to replace.

Well thanks for the vote of confidence, I just never did anything like that... isn't the throw out bearing between the engine and trans?

 

[mud4feet]

... isn't the throw out bearing between the engine and trans?

Well, yes it is. Part of the "clutch assembly" which is between the engine and transmission. If you're problem is clutch related, you'll be learning soon. I thought perhaps you had done clutches before (vehicle type doesn't matter, they're all basically the same, although the hydraulics - master and slave cylinder throw a little monkey in the wrench), but I still have confidence that you could do it!!! Best of luck and keep us posted.

 

[Sine Deviance]

I have a question about this as it's looking like I am also going to need to replace my clutch/throwout bearing/clutch master and slave cylinders soon. When you go to replace it, is it an engine-out job or do you drop the trans/tcase? What is easier?

 

[54cj3b]

I jack jeep as high as I can get it put jack stands under it and remove fom underneath

 

[Weylyn]

trans and transfer case is the easiest. Move them back far enough to work. . Personally I don't think this is the problem. Vibration is under power. This I would remove engine as problem. Just for S and G, pull the front driveline, drive up to speed. If Vibration happens, put front back in and do the same with rear. Remove and then drive. What you are doing in this is isolating to trans and trasfer case. If it were a throw out bearing, you would get a metal whine. Do you have any slipping when you take off? Do you smell burnt asbestos? Where do you feel the vibration? In the steering, in your seat? Is it felt in the throttle.