Shake, rattle and roll

[Madurski]

Hello,



New member here checking things out...



Since I haven't posted yet I'm not certain my sig will work so here is my vehicle info...



I have a 92 W250 4x4 Ext. Cab long bed w/ automatic as far as I know it is bone stock. I bought it with 190,000 miles on the odometer.



It has had a bit of a shake to it at highway speeds for awhile but lately it has really begun to shake badly around 45-50 mph. I haven't been able to isolate the problem yet. Here's what I have done/checked so far.



Front end



New bushings, bearings, and tie rods. Nothing is loose on the front end. I have tried adding a 1 and a 2 degree shim to adjust the caster but that did not help. Tires and wheels are in good condition and have been balanced.



I recently did a complete brake job on all 4 corners.



Checked the drive shaft and it is OK. I put in new u-joints within the last year and they are all still OK. I flipped the shaft 180 degrees and it still does the same thing. The rubber carrier is really worn out (I don't recall it being that bad when I replaced the u-joints, is it difficult to replace?.



One of the rear axles is just slightly bent. I took it to a machine shop and he indicated that it was right on the verge of being out of factory spec. He didn't think that it was causing my problem, I'm not so sure, but a new one was around $150 or so.



The truck just turned 245,000 miles.



Any suggestions?



Thanks,



Ron Madurski

 

[ERMiles]

Welcome "new member" - I don't have the answer but I have a similar problem. In fact, I was just logging on to post it when I saw your post. My shaking starts at 35-40 mph and again at 65-70. Does yours feel like it's coming from the rear? I've changed rims, tires, and shocks and re-balanced many times. Also had new rotors and calipers on front and freed a dragging brake in the rear. The ujoints and supports seem OK. One member mentioned a 1/2 inch spacer on the front driveshaft mount which can cause a misalignment - which I have. My garage mechanic says it feels liks a drive train problem 'cuz it happens only at specific speeds. So I'll be watching your replies. Good luck!

 

[Madurski]

It's really hard for me to pinpoint the source of the problem. Sometimes it feels like it is just the front of the truck and other times it feels like it may be the rear.



Does the 1/2" spacer cause the problem or is it supposed to fix a problem? I don't have one on my truck.



I'm pretty sure the problem is somewhere in the driveline as well, it's just a matter of trying to intelligently replace parts as needed. Not that I mind replacing parts, it just that the wife would rather not have to write the checks for them



I may take the driveshaft in and have its balance checked. I don't think it is very expensive.



Ron Madurski

 

[Lil' Dog]

Welcome aboard!!



Is the shake at a high frequency?? You know when a tire has a broken belt or such its low frequency thud thud. If its the seat of the pants buzz it is typically u-joints, which you already took care of, or drive shaft balance.



From drive shaft balance it could be masked as too much play in the slip yoke on the secondary shaft. If the yoke splines wear too much the shaft starts to whip at certain speeds due to the accelleration and decelleration of the u-joints.



Take a boo at the slip yoke and have the shaft balanced.



The Spacer is a TSB from Dodge. I also do not have it but don't exhibit any of the symptoms.



Good luck



J-eh

 

[RamAZ]

Shake Rattle and Roll

If it is not the u-joints then I would take a real good look at the tires.



I went thru the bouncing and vibrations for a good while and it was the tires. Belt had twisted or seperated and there was nothing I could due to to take the vibration away.



Changed tires to Michilen XPS rib and the problem was cured. They ride a little rough but worth the money



Good luck



Jim

 

[Madurski]

Originally posted by Lil' Dog

Welcome aboard!!



Is the shake at a high frequency??



Not really, it's more of a violent lurching and shaking, as speed increases the shake goes away but it still shimmies at around 70-75.



You know when a tire has a broken belt or such its low frequency thud thud.



The tires are all in good condition.



If its the seat of the pants buzz it is typically u-joints, which you already took care of, or drive shaft balance.



From drive shaft balance it could be masked as too much play in the slip yoke on the secondary shaft. If the yoke splines wear too much the shaft starts to whip at certain speeds due to the accelleration and decelleration of the u-joints.



I'm supposed to take it in tomorrow for balancing. The silp joint looked to be in good condition the other day when I flipped the shaft around.



Take a boo at the slip yoke and have the shaft balanced.



The Spacer is a TSB from Dodge. I also do not have it but don't exhibit any of the symptoms.



I'll check with the local Dodge dealer and see if there is any info on it.



Good luck



Thanks



Ron Madurski



J-eh

 

[Lil' Dog]

I hope it works out for ya. I am also sensitive to the vibrations as I like a smooth ride. We had quite a runaround at my work with an old Dodge van. . I bet I had the shaft balanced and straightened about 4 times before they got it right.



The shuddering might be that center bearing support with the rubber getting loose.



Again good luck and keep us posted. .



J-eh

 

[CToney]

Bad Vibes

Check out the u-joint yoke on the back of the transmission mine was wore out on the reg cab. The u joint would not fit tight. Also replaced the slip yoke at this time and the problem was solved. Check output bearing on the transmission.



Hope this helps CR Toney

 

[BushWakr - RIP]

I also have similar problems. I have a pronounced shake, hopping actually, going up through 60kph to 70kph. Above and below, no problem. It is most noticeable coming down throght that same range. The truck actually hops (feels like rear). My toolbox on the floor behind passenger seat hops up and down too. Stangest damn thing.

I've closely checked U-joints, steady bearing, tire balance, rims and all. I've even re-balanced tires to 120 MPH and rotated. No change!

If ANY of you guys figure this out please let me know, i'm at a loss right now.



Thanks



Bob

 

[Madurski]

Reinstalled the drive shaft with the new carrier bearing and it is better but it still shakes some. I am going to inspect the spring bushings this weekend sometime.



I know that one of my axles is just slightly bent. I may replace it, does anyone have a source for them other than the dealer?



Thanks,



Ron Madurski