Driveline Vibrations.
Thread Starter
|
Tuned
Joined: Sep 2003
Posts: 348
Likes: 2
From: Northern Michigan
Driveline Vibrations.
Truck is a 2WD, 79 F-250, 351M, 4 speed manual, Dana 60 differential stock as near as I can tell. I've got driveline vibes that are strongest @ 50 mph. I've replaced all three U-joints and the carrier bearing feels like new. If I have the rear shaft out and run it up to 50mph there are no vibes.
Any guesses?!
Any guesses?!
Posting Guru
Joined: Jul 2001
Posts: 1,613
Likes: 2
From: Gainesville, FL
Palm,
I've got a dumb question.
How do you get up to 50mph when the drive shaft is out?
Can you describe the vibe more clearly?
Does the vibe cycle? Is the frequency high or low?
Does it shake the steering wheel at all?
Does the vibe come and go?
Does the shifter move around when you go over a speed bump or curb?
Have you worked on the rear end at all? Is it a differential, limited slip, or posi?
Does the brake pedal pulse at all during use?
Have you replaced the axle bearings recently?
The generic question, "Why is my truck shaking?" Could be caused by about a dozen different things.
Throw me a bone over here!
KingFisher
I've got a dumb question.
How do you get up to 50mph when the drive shaft is out?
Can you describe the vibe more clearly?
Does the vibe cycle? Is the frequency high or low?
Does it shake the steering wheel at all?
Does the vibe come and go?
Does the shifter move around when you go over a speed bump or curb?
Have you worked on the rear end at all? Is it a differential, limited slip, or posi?
Does the brake pedal pulse at all during use?
Have you replaced the axle bearings recently?
The generic question, "Why is my truck shaking?" Could be caused by about a dozen different things.
Throw me a bone over here!
KingFisher
Thread Starter
|
Tuned
Joined: Sep 2003
Posts: 348
Likes: 2
From: Northern Michigan
Answers to dfisher1's questions:
I ran the speedo up to 50 mph with only the front driveshaft connected. (front shaft spinning and the diff disconnected)
The vibe is steady and @ a frequency about equal to the revs of the driveshaft. (~ 4 times per wheel revolution)
No shakes @ the steering wheel.
Vibe is always there with 50mph being the peak. Vibe is not related to engine rpm.
Shifter doesn't move around and motor mounts are solid.
I haven't worked on the rear end at all other than to check lube level which is good.
No pulse @ the brakes and upon inspection are almost new.
Other observations: Yokes @ the trans and diff are tight although there is some side to side play at the trans output. I haven't checked drive shaft angles but assume they are good considering this is a STOCK truck.
I ran the speedo up to 50 mph with only the front driveshaft connected. (front shaft spinning and the diff disconnected)
The vibe is steady and @ a frequency about equal to the revs of the driveshaft. (~ 4 times per wheel revolution)
No shakes @ the steering wheel.
Vibe is always there with 50mph being the peak. Vibe is not related to engine rpm.
Shifter doesn't move around and motor mounts are solid.
I haven't worked on the rear end at all other than to check lube level which is good.
No pulse @ the brakes and upon inspection are almost new.
Other observations: Yokes @ the trans and diff are tight although there is some side to side play at the trans output. I haven't checked drive shaft angles but assume they are good considering this is a STOCK truck.
Logistics Pro
Joined: Jan 2001
Posts: 3,740
Likes: 37
From: Central NYS
Originally Posted by palmrose2
The vibe is steady and @ a frequency about equal to the revs of the driveshaft. (~ 4 times per wheel revolution).
Is the pinion nut really tight?
Senior User
Joined: Jun 2004
Posts: 125
Likes: 0
From: Tavistock, Ontario
Just a thought but you could check for excessive play in your slip yoke. I heard of a trick to temporarily balance a driveshaft never tried it though but it cant hurt. put a hose clamp around the shaft just tight enough so it will stay where you put it but loose enough to turn easily by hand. Then run the truck up to speed and the clamp will balance itself. then all you do is tighten the clamp so it dosent under hard acceleration. If it works then you know its the balance and you didn't remove the shaft for nothing. if it doesn't you only lose about five minutes.
Postmaster
Joined: Dec 2002
Posts: 3,959
Likes: 9
From: USA
Trending Topics
Logistics Pro
Joined: Aug 2003
Posts: 4,701
Likes: 6
Hey, I have a vibe question. Mine comes and goes at steady speed. It starts, gets a little worse, gets a little better, goes away, and then starts over. I figure it is a harmonic vibration between the tires, but what do you guys think?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Senior User
Joined: Jun 2004
Posts: 125
Likes: 0
From: Tavistock, Ontario
Originally Posted by teds74ford
Hey, I have a vibe question. Mine comes and goes at steady speed. It starts, gets a little worse, gets a little better, goes away, and then starts over. I figure it is a harmonic vibration between the tires, but what do you guys think?
Freshman User
Joined: Apr 2004
Posts: 37
Likes: 0
Have you guys checked your driveshafts to see if the weights are still on them? If you shortened your drive shaft then it needs to be balanced. I found a shop that made a rear drive shaft for my truck that has no weights. The shop put it on the balancer when welding it, doing this there is no chance of throwing weights. Just an idea if you did throw a weight and need a drive shaft.