Major vibration

[Bluewater Man]

Got a 1993 Bronco with 166000 miles. Trying to find out what is shaking my truck! First I replace the front end (just about everything), all new tires, rechecked the front. Still shaking even at 20 mph or so. The shaking stops when you back of the gas. Could it be in the rear end? u-joints and drive shaft look good. What next? Help an old guy out please.

Thanks in advance

Gene

 

[bluesman17]

Did a rim throw a balance weight off? what about the wheel bearings or driveshaft to the front end u joints?

 

[Bluewater Man]

Did a rim throw a balance weight off? what about the wheel bearings or driveshaft to the front end u joints?

22070[/snapback]

​

if the 4wd is not engaged would the front driveshaft/u joints matter? I am somewhat new to 4wd's.

Thanks in advance

 

[BLADE262US]

Mine was shaking pretty bad the other day and it ended up being the rear ujoint in the driveshaft was bad . /emoticons/[email protected] 2x" width="20" height="20" />

 

[Broncoholics]

I almost gaurantee its a rear u-joint on the driveline (axle end). This joint is the #1 caise to vibration like you explained. Pull off the rear driveline and check the two caps that attach to the yoke. These will be the ones that fail first due to over tightening the caps. They only need like 15-20# otherwise the added pressure one needle bearings will cause failure quicker. Also check the driveline slip yoke splines, you can have a shop rebuild it if need be. Take a good look at bushings, bearings and steering too.

 

[Busted89]

Got a 1993 Bronco with 166000 miles.  Trying to find out what is shaking my truck!  First I replace the front end (just about everything), all new tires, rechecked the front.  Still shaking even at 20 mph or so.  The shaking stops when you back of the gas.  Could it be in the rear end?  u-joints and drive shaft look good.  What next?  Help an old guy out please.
Thanks in advance

Gene

22066[/snapback]

​

I have a 89 that was shaking real bad after taking off from a stop and would quit if I let off the gas, turns out it was my AT transmission going bad. Now all I have is reverse no forward gears, I think my bands broke.

 

[Broncoholics]

If the trans is shaking, like at a stop light and you slightly let off the brake and allow the truck to move forward. This is a computer telling the torc converter to engage/disengage. If you pull off the wire connector to the treanny it might fix it. In your case it sounds too late.

 

[theHIGHLANDER]

I had a similar situation on a 91. Turned out to be the yoke in the rear axle (8.8 style). I gave it a new seal and tightened it up, problem solved. For some reason seams like this was a common problem when I fixed it, but that was 4 or so yrs agao.

 

[White90Bronco]

I have a 90 w/ automatic hubs and this happened to me. Turns out the hubs weren't fully disengaged so my dad got under it with a pry bar and took it out of 4WD. That might be it.

 

[Broncoholics]

Best bet is to start looking around and tighten stuff up

 

[jasonblock]

The EXACT same thing happens to me and it is driving me crazy! Look forward to someone who knows what this is.

 

[Seabronc]

Just a remote possibility, but have you changed a fly wheel or harmonic balancer lately? If you have the wrong one, it can cause a whole lot of shaking to go on. There are 50 oz. balance offsets and 28 oz. balance offset. Small blocks built prior to 82 require a 28 oz. balance offset, the later ones use a 50 oz. balance offset part. If you use the wrong part, either way, will cause a lot of engine vibration.

Just a thought 0

Good luck,

>-

 

[Bluewater Man]

Got a 1993 Bronco with 166000 miles.  Trying to find out what is shaking my truck!  First I replace the front end (just about everything), all new tires, rechecked the front.  Still shaking even at 20 mph or so.  The shaking stops when you back of the gas.  Could it be in the rear end?  u-joints and drive shaft look good.  What next?  Help an old guy out please.
Thanks in advance

Gene

22066[/snapback]

​

OK GANG!!! FOUND IT...

I feel a litle stupid now but here goes. The vibration was due to a bad pinion angle. I never thought to look at that because the truck had no lift kit. The problem was that somebody had changed, repaired or otherwise screwed with the leaf springs and did not replace the spacer/shims or whatever they are called. As a result the angle was all wrong, hence the vibration.

Went ahead and replaced the u-bolts and everything that came with the kit. Drives like a dream now!!!!!! Thanks for all of your help Guys!!!! Time to go fishing now.....

 

[Maddog]

Just got done fixing the same problem...Drive shaft.. It looked fine also until one day it got really bad and I pull over to find the U joint busted through the housing. Try taking the rear drive shaft out and running on 4 wheel high around 20 to 25 mph to see if it shakes. If the shaking stops then you know the deal.. GL

 

[murph]

My 91 does the same thing around 30 mph. Seems to be a common thing.

 

[c5bronc]

OK GANG!!! FOUND IT...
I feel a litle stupid now but here goes.  The vibration was due to a bad pinion angle.  I never thought to look at that because the truck had no lift kit.  The problem was that somebody had changed, repaired or otherwise screwed with the leaf springs and did not replace the spacer/shims or whatever they are called.  As a result the angle was all wrong, hence the vibration.

Went ahead and replaced the u-bolts and everything that came with the kit.  Drives like a dream now!!!!!!  Thanks for all of your help Guys!!!!  Time to go fishing now.....

22914[/snapback]

​

How did you find the right angle for the rearend.. Mine is doing the same thing after installing a lift..

 

[ocalabronco]

c5bronc, all broncos had angled shims underneath the leafsprings installed from the factory. those set the pinion angle for stock height. but lifting it, you changed that angle, possibly more than the truck likes.

BLuewater man, i noticed you are a fisherman (duh). where's your homeport? i'm a professional deckhand out of south florida/bahamas, wondering if i've run into you at one time or another

 

[danimal2]

[-o<

Got a 1993 Bronco with 166000 miles.  Trying to find out what is shaking my truck!  First I replace the front end (just about everything), all new tires, rechecked the front.  Still shaking even at 20 mph or so.  The shaking stops when you back of the gas.  Could it be in the rear end?  u-joints and drive shaft look good.  What next?  Help an old guy out please.
Thanks in advance

Gene

22066[/snapback]

​

i just got a 93 bronco and am haveing the same trouble. at about 20 on up theres quite a vibration. i took it to a mech. and he told me the rear driveshaft u joint. he wasnt wrong it was bad but it didnt stop the vibration when fixed. if you figure it out please let me know.

 

[Broncoholics]

uhhh... He did fix it and you probably have the same problem. Read posts above first. He probably used 6* shims by the sounds of it.