|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
02-26-2019, 07:23 PM | #1 |
Senior Member
Join Date: Jan 2014
Location: egg harbor twp nj
Posts: 303
|
this does not make sense
I have a completely stock 1951 ford victoria with stock v8 with stick shift. I've had a slight noise and vibration from the drive train, so I jacked up both rear wheels to spin them and see if i could hear anything. Here's where it gets crazy, both wheels spin freely with no drag or noise but the drive shaft does not turn. it doesn't matter weather it's in gear or in neutral and yet if I put the wheels back on the ground the car drives normally with just this slight noise and vibration. I'm being told this is impossible but it's true.
|
02-26-2019, 07:26 PM | #2 |
Senior Member
Join Date: May 2010
Location: Oshkosh, Wi
Posts: 4,516
|
Re: this does not make sense
Yikes!
|
Sponsored Links (Register now to hide all advertisements) |
|
02-26-2019, 07:32 PM | #3 |
Senior Member
Join Date: Aug 2010
Location: Blenheim, New Zealand
Posts: 869
|
Re: this does not make sense
With both wheels off the ground you need to check that the wheel on the opposite side to the one you are turning by hand is chocked so that it will not turn. If there is any friction from the output of the transmission or the input of the differential this can make the opposite wheel rotate in the reverse direction to the wheel you are rotating by hand, if you follow my logic???
__________________
I need an 01A 1453 Brkt Spare wheel hold down for my sedan delivery - PLEASE HELP Gotta love my '42 Sedan Delivery's - Now that I own the only two in New Zealand https://www.fordbarn.com/forum/album.php?albumid=580 |
02-26-2019, 07:32 PM | #4 |
Senior Member
Join Date: Jan 2014
Location: egg harbor twp nj
Posts: 303
|
Re: this does not make sense
With my limited knowledge if you spin the rear wheels the driveshaft has to turn, if it's in gear you won't be able to turn the wheels because you would be trying to turn the engine, if its in neutral the wheels and driveshaft will turn together. Evidently right now in my case when the engine is running and the trans is in gear the driveshaft will put power to the wheels but with the car off the ground turning the wheels does not engage the driveshaft>
|
02-26-2019, 07:36 PM | #5 |
Senior Member
Join Date: Aug 2010
Location: Blenheim, New Zealand
Posts: 869
|
Re: this does not make sense
Re-read my reply above
__________________
I need an 01A 1453 Brkt Spare wheel hold down for my sedan delivery - PLEASE HELP Gotta love my '42 Sedan Delivery's - Now that I own the only two in New Zealand https://www.fordbarn.com/forum/album.php?albumid=580 |
02-26-2019, 07:46 PM | #6 |
Senior Member
Join Date: May 2010
Location: Reseda, Calif.
Posts: 2,188
|
Re: this does not make sense
Sponsored Links (Register now to hide all advertisements)
|
02-26-2019, 07:50 PM | #7 | |
Member Emeritus
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
|
Re: this does not make sense
Quote:
See if this helps any: https://www.bing.com/videos/search?q...7&&FORM=VDRVRV |
|
02-26-2019, 07:53 PM | #8 |
Senior Member
Join Date: Jan 2014
Location: egg harbor twp nj
Posts: 303
|
Re: this does not make sense
meric 42
just went out and chocked one rear wheel, when i spin just one wheel the driveshaft turns, when i was spinning both wheels together the drive shaft wasn't turning. |
02-26-2019, 07:55 PM | #9 |
Senior Member
Join Date: Feb 2013
Location: Eureka Calif.
Posts: 967
|
Re: this does not make sense
Raise only one of the wheels off the floor and try again.
|
02-26-2019, 07:59 PM | #10 |
Senior Member
Join Date: Jan 2014
Location: egg harbor twp nj
Posts: 303
|
Re: this does not make sense
thanks merc42 and JSeery- I just didn't understand the sequence and learn something new every day. Appreciate your knowledge and help. I assume I have no problem.
|
02-26-2019, 08:03 PM | #11 |
Member Emeritus
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
|
Re: this does not make sense
|
02-26-2019, 08:08 PM | #12 |
Senior Member
Join Date: Jan 2011
Location: sw minnesota
Posts: 4,543
|
Re: this does not make sense
except that he has a slight vibration. grab the u joints on the drive shaft and see that they are snug
|
02-27-2019, 11:51 AM | #13 |
Senior Member
Join Date: May 2010
Location: Yucaipa, CA
Posts: 1,091
|
Re: this does not make sense
1937 GM training film on spider gear operation. This is a good video explaining how spider gears work.
https://www.youtube.com/watch?v=yYAw79386WI |
02-27-2019, 12:13 PM | #14 |
Senior Member
Join Date: May 2010
Location: Napa,California
Posts: 6,007
|
Re: this does not make sense
The vibration could be worn U joints. What does the noise sound like? Have you checked the fluid in the transmission and rear end?
|
02-27-2019, 12:53 PM | #15 |
Senior Member
Join Date: Dec 2014
Location: Columbus, IN
Posts: 1,401
|
Re: this does not make sense
FF, awesome video, thanks for posting.
|
02-27-2019, 02:06 PM | #16 |
Senior Member
Join Date: Aug 2017
Location: ohio
Posts: 986
|
Re: this does not make sense
Vibration could also be drive shaft out of balance.
|
02-27-2019, 10:30 PM | #17 |
Senior Member
Join Date: May 2010
Location: Yucaipa, CA
Posts: 1,091
|
Re: this does not make sense
Bias ply tires with flatspots from sitting?
Spin the tires while watching them and make sure they are not starting to separate? Tire balance? You can try rotating the tires. U-joints, like everybody said? When you replace u-joints its a good practice to keep the front slip yoke, driveshaft and even the pinion yoke in their original positions Later year vehicles with two-piece driveshafts need to have their u-joints all lined up (in phase) Center support bearings on two-piece driveshafts. Bent driveshaft? Transmission tailshaft bushing alowing the driveshaft yoke to move excessively? Axle bearings pitted? Engine or trans mounts making metal to metal contact? It just takes one little spot to not be insulated by the rubber mounts See if the vibration is there while on the gas, coasting in gear, coasting in neutral? Do you feel the vibration in the seat of your pants or in the steering wheel? Do you feel the vibration parked, while revving the engine in neutral. Maybe something is out of balance like a clutch? At work we would put the vehicle up in the air on the hoist and have someone drive it at 50 mph. While you stand under there next to the whirling driveshaft, wearing a stethoscope and listening to the pinion bearings, axle bearings..... I've even stuck another mechanic in the trunk to listen and feel for a vibration and gone for a ride. We would also stick the vehicle on the smog machine's dyno so there was a load on the drivetrain to try and simulate a vibration. Last edited by Flathead Fever; 02-27-2019 at 10:40 PM. |
02-27-2019, 10:37 PM | #18 | |
Senior Member
Join Date: May 2010
Location: MN
Posts: 7,053
|
Re: this does not make sense
Quote:
Nice video. How does the differential not turn the driveshaft though? In conclusion. I guess if you only turn one wheel (or not lock one wheel) the spiders just turn in the differential . It's nice to get a straight forward explanation. Not a just because, that's how it is. Last edited by Tinker; 02-27-2019 at 11:04 PM. |
|
02-28-2019, 12:54 AM | #19 |
Senior Member
Join Date: Jul 2011
Location: SF Bay Area
Posts: 6,616
|
Re: this does not make sense
Tinker, The spinning wheel is directly geared to the spider, which is in turn geared 1/1 to the opposite wheel. The spider offers considerably less resistance to the turning, whereas the ring gear offers more resistance to turn the pinion/driveshaft, due to the gearing ratio. The result is the opposite wheel is turned reverse to the spinning wheel.
__________________
Alan |
02-28-2019, 10:47 AM | #20 |
Senior Member
Join Date: May 2010
Location: Reseda, Calif.
Posts: 2,188
|
Re: this does not make sense
Flathead Fever
At work we would put the vehicle up in the air on the hoist and have someone drive it at 50 mph. While you stand under there next to the whirling driveshaft, wearing a stethoscope and listening to the pinion bearings, axle bearings..... I've even stuck another mechanic in the trunk to listen and feel for a vibration and gone for a ride. We would also stick the vehicle on the smog machine's dyno so there was a load on the drivetrain to try and simulate a vibration. We did the same years ago. That is why i mentioned stopping one tire with a towel. Stop one and then do the other. We use to try to isolate axle bearings this way. Did it work? Usually. Some axle bearings were very loud. But some times not. |
Thread Tools | |
Display Modes | |
|
|
Sponsored Links (Register now to hide all advertisements) |
|