Speedo- fluctuation
Thread Starter
|
Elder User
Joined: Oct 2006
Posts: 843
Likes: 1
From: Redmond, WA
Speedo- fluctuation
I've recently noticed my speedometer fluctuates and wiggles during deceleration/coast between 75 to 60mph. This wiggling speedo- also coincides with a faint vibration/grinding felt in the driveline.
-Driveshaft is freshly balanced.
-Brand new U-joints
-Pinion/transfer case angles are within 0.25 of a degree.
-Rear-end freshly rebuilt. Backlash is at 0.011"
I've noticed this effect is getting more obvious over time. I checked my transfer case for the speedo cable to no avail. I am guessing my speedometer is run through the E4OD somehow.
Any help would be appreciated. I've been trying to nail down this vibration for some time now.
Hopefully someone can chime in with some prior experience....
Many thanks,
Mike
-Driveshaft is freshly balanced.
-Brand new U-joints
-Pinion/transfer case angles are within 0.25 of a degree.
-Rear-end freshly rebuilt. Backlash is at 0.011"
I've noticed this effect is getting more obvious over time. I checked my transfer case for the speedo cable to no avail. I am guessing my speedometer is run through the E4OD somehow.
Any help would be appreciated. I've been trying to nail down this vibration for some time now.
Hopefully someone can chime in with some prior experience....
Many thanks,
Mike
Posting Guru
Joined: Nov 2005
Posts: 2,442
Likes: 1
From: La Grande, OR
if this is for your '94, your speedometer is electronic, and is sent through the sensor on the top of the 8.8. There is no cable, just the sensor and the computer.
As for the vibration, is it always there? Or does it start at a certain speed, and then go away if you keep accelerating? Check your tire balance weights.
As for the vibration, is it always there? Or does it start at a certain speed, and then go away if you keep accelerating? Check your tire balance weights.
Fleet Owner
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Originally Posted by Mr. M
I've noticed this effect is getting more obvious over time. I checked my transfer case for the speedo cable to no avail. I am guessing my speedometer is run through the E4OD somehow.
Post Fiend
Joined: Nov 2001
Posts: 14,947
Likes: 6
From: Topsfield, MA
Did you check the spec of the runout on the carrier or ring gear?
Should be max of .003 on the carrier and .004 on the ring gear.
Was the carrier bearing preload set correctly?
If you didn't have any driveline issues I'd suspect the speedometer system itself, either the PSOM, the sensor, or the wiring...but with what you've described I'm suspect of internal axle problems.
May want to pop out the speed sensor and check to see if any metal filings are on it.
Only one time have I seen that sensor malfunction, guy came into work with one that was simply busted and falling apart...no idea how that happened.
Should be max of .003 on the carrier and .004 on the ring gear.
Was the carrier bearing preload set correctly?
If you didn't have any driveline issues I'd suspect the speedometer system itself, either the PSOM, the sensor, or the wiring...but with what you've described I'm suspect of internal axle problems.
May want to pop out the speed sensor and check to see if any metal filings are on it.
Only one time have I seen that sensor malfunction, guy came into work with one that was simply busted and falling apart...no idea how that happened.
Thread Starter
|
Elder User
Joined: Oct 2006
Posts: 843
Likes: 1
From: Redmond, WA
Originally Posted by MustangGT221
Did you check the spec of the runout on the carrier or ring gear?
Should be max of .003 on the carrier and .004 on the ring gear.
Was the carrier bearing preload set correctly?
Should be max of .003 on the carrier and .004 on the ring gear.
Was the carrier bearing preload set correctly?
Originally Posted by MustangGT221
If you didn't have any driveline issues I'd suspect the speedometer system itself, either the PSOM, the sensor, or the wiring...but with what you've described I'm suspect of internal axle problems.
May want to pop out the speed sensor and check to see if any metal filings are on it.
Only one time have I seen that sensor malfunction, guy came into work with one that was simply busted and falling apart...no idea how that happened.
May want to pop out the speed sensor and check to see if any metal filings are on it.
Only one time have I seen that sensor malfunction, guy came into work with one that was simply busted and falling apart...no idea how that happened.
Thanks for your help!
Thread Starter
|
Elder User
Joined: Oct 2006
Posts: 843
Likes: 1
From: Redmond, WA
Originally Posted by nighthawk285
As for the vibration, is it always there? .
Originally Posted by nighthawk285
Or does it start at a certain speed, and then go away if you keep accelerating? .
Hotshot
Joined: Sep 2001
Posts: 11,958
Likes: 228
My truck does this as well, but its just while driving. Decellerating doesn't matter. At least I'm pretty sure it doesn't. I has done so for the last 5 years. I replaced the VSS I think is what it is called sensor on top of the rear axle. It seemed to be better and then its back to the same old stuff. That could have just been my imagination that it was better. I have noticed that my sensor gets small metal peices on it after a while. Also so does my differential fill plug. It has a little magnet in the end of it. I think it is excessive though. Is this normal for this to happen every few months when I remove the sensor and the plug and clean them both off?
Trending Topics
Posting Guru
Joined: Nov 2005
Posts: 2,442
Likes: 1
From: La Grande, OR
when they pulled your carrier (im guessing they did), did they check to make sure that the axle splines were straight and not twisted? was there any metal filings in the oil?
I still say check your tire weights.......do a careful look over on the inside and outside of the wheels and make sure they're still attached, not many tires can be mounted and then are already balanced, so they should have some weight there.......I say this because mine did the same thing, vibrated at 55-60, then would go away, though I don't remember if it did the decelerating vibration too, found out I was missing the weights on both back tires...just food for thought.
as for texasguy, if you think the filing amount is excessive, pull the cover off the back and check everything...you'll see the wear marks if something is wearing excessively, so it shouldnt be too hard to find....
I still say check your tire weights.......do a careful look over on the inside and outside of the wheels and make sure they're still attached, not many tires can be mounted and then are already balanced, so they should have some weight there.......I say this because mine did the same thing, vibrated at 55-60, then would go away, though I don't remember if it did the decelerating vibration too, found out I was missing the weights on both back tires...just food for thought.
as for texasguy, if you think the filing amount is excessive, pull the cover off the back and check everything...you'll see the wear marks if something is wearing excessively, so it shouldnt be too hard to find....
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Post Fiend
Joined: Nov 2001
Posts: 14,947
Likes: 6
From: Topsfield, MA
Originally Posted by Mr. M
If there are metal filings on the sensor...is that indicative of axle problems? or just a puked sensor? Any way to diagnose this explicitly (without pulling the axles...)?
If there are metal filings there, it could be there from the last setup and not cleaned from when it was rebuilt....I wouldn't worry I'd just clean it and pop it back in to see if it helps.
Follow the wiring as far as you can from that sensor upwards and see if you see any corrosion or bad wiring.
It just sounds odd to me that you have these symptoms, it's either a coincidence that the speedo/axle issues are happening together or something in the drivetrain is throwing off the speedo at the same time.
Thread Starter
|
Elder User
Joined: Oct 2006
Posts: 843
Likes: 1
From: Redmond, WA
Originally Posted by MustangGT221
If there are metal filings there, it could be there from the last setup and not cleaned from when it was rebuilt....I wouldn't worry I'd just clean it and pop it back in to see if it helps.
Follow the wiring as far as you can from that sensor upwards and see if you see any corrosion or bad wiring.
It just sounds odd to me that you have these symptoms, it's either a coincidence that the speedo/axle issues are happening together or something in the drivetrain is throwing off the speedo at the same time.
Follow the wiring as far as you can from that sensor upwards and see if you see any corrosion or bad wiring.
It just sounds odd to me that you have these symptoms, it's either a coincidence that the speedo/axle issues are happening together or something in the drivetrain is throwing off the speedo at the same time.
Thanks for the previous help!
Mike
Posting Guru
Joined: Feb 2002
Posts: 1,712
Likes: 1
From: Atlanta, Georgia, USA
Mine does exactly the same thing. I've always written it off as an inherent issue with electronic speedometers. I did calibrate it scientifically and even though the needle has a slight bounce it doesn't affect odometer accuracy whatsoever. The wobble seems to be on a frequency independent of the vehicle speed, leading me to believe that whatever is causing is electical by nature.
Thread
Thread Starter
Forum
Replies
Last Post
rbrungard2012
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
23
Dec 16, 2013 07:00 PM
rbrungard2012
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
3
Dec 6, 2013 12:30 PM
Swoop03
1987 - 1996 F150 & Larger F-Series Trucks
2
Oct 28, 2013 07:05 PM
