4x4 hop
Champion
Joined: Nov 2005
Posts: 2,875
Likes: 1
From: North Eastern England
Something I never fully comprehended yet though. These trucks have an open front diff, Aka, Really only one of the front wheels is getting any actual power at any given time. In reality, Most our trucks our either 2wd or 2.5 wheel drive if you have the crappy LSD.
So My comprehension of why it is a problem to have the 4wd on in dry pavement is because the front wheel that is getting power is moving at different speed than the rear wheel that is getting power, causing binding in the driveline. As opposed the the idea that the issue is the 2 front wheels moving at different speeds.
Sorry if this doesn't make much sense, Im preparing for finals tommorrow and I may have had one to many swallows of the Jägermeister.
So My comprehension of why it is a problem to have the 4wd on in dry pavement is because the front wheel that is getting power is moving at different speed than the rear wheel that is getting power, causing binding in the driveline. As opposed the the idea that the issue is the 2 front wheels moving at different speeds.
Sorry if this doesn't make much sense, Im preparing for finals tommorrow and I may have had one to many swallows of the Jägermeister.
But, we don't have 2 or 2.5 wheel drive.....we have two or 3 wheel drive
Al.
Thread Starter
|
Registered User
Joined: Aug 2009
Posts: 16
Likes: 0
From: Vancouver BC
If the wheels hopping, you shouldn't be in 4x4. Your truck sounds like its a part time 4x4. Only for use on loose or slippery low traction surfaces. The hop is caused by the different wheels turning different speeds, which causes different speeds of rotation between front and rear differentials. This "hop" is the pressure trying release... if it can't hop to release something breaks to release the pressure. So please, be careful or you may damage something. On the other hand, your Rover was likely a full-time 4x4 system. This is similar to all-wheel drive in that there is a viscous coupling between the drive to front and rear differentials. This allows slippage so that wheel hop doesn't take place.
Hope that makes sense... this is my laymans understanding of it.
Hope that makes sense... this is my laymans understanding of it.
The Rover did have viscous coupling, and was fwd most of the time.
I was suprised the hop happened, there was a couple inches on the ground. I take it 4x4 is best in these trucks in only the most severe circumstances?
Also, If it's one front and 1.5 in the back with power, why does it say 4lock? What am I locking?
Last edited by bleepo; Dec 14, 2009 at 06:19 AM.
Captain
Joined: Jun 2009
Posts: 575
Likes: 0
I only count the LSD as being worth half a wheel because you can still get stuck with it and it only works if there is some traction on the other wheel. And if your peg leg, You only get power to one wheel anyways. That makes the rear 1 or 1.5 wheel drive
And the front is an open diff, really only one wheel is getting power at any given time making the front worth 1 wheel, making these trucks 2 or 2.5 wheel drive.
As far as 4lock, mine just says 4hi and 4lo, So I don't know why it would say 4lock. As far as what your locking, when you engage the 4wd, you are locking together the front diff to the rear diff via the transfer case.
Last edited by 05RamMan; Dec 14, 2009 at 11:46 AM.
3rd gen Ram, Newbies
Joined: May 2008
Posts: 3,815
Likes: 0
From: Chicago
this is going to get technically heavy
This is ONLY TRUE when you break traction. if both wheels are getting traction, both wheels are getting equal TORQUE. An open diff puts even torque on both wheels, wether they have traction or not. When the torque to one of those wheels overcomes the traction that wheel has, it breaks loose, this causes a loss in traction, which leads to less torque being able to be applied to the ground, so you don't move. if both wheels have traction, both wheels have torque, and therefore power.
Right! Drive through some clean snow while turning, you will see that the tracks your rear wheels leave are different than the fronts. The rear wheels turn a smaller circle than the fronts, therefore turn slower. The difference in speeds between the two front wheels doesn't matter because it is an open diff, so it can compensate.
But its not just the 'one wheel with power' that matters. The combined speed of the two front wheels and combined speed of the two rears is what is important with a transfer case.
definitely agree. try to avoid that, sooner or later something will give.
the rear two wheels aren't turning at equal rates. outer wheel turns faster. there is also a certain amount of 'scrub' that ALWAYS goes on with rear wheels while turning, but they also have to turn at different speeds to turn if you have any sort of traction at all. if they both turned at the same speed on dry pavement, you would also have hop, and all sorts of other bad stuff. that's why you don't drive with a locker on pavement, inside wheel needs to be slower.
So My comprehension of why it is a problem to have the 4wd on in dry pavement is because the front wheel that is getting power is moving at different speed than the rear wheel that is getting power, causing binding in the driveline. As opposed the the idea that the issue is the 2 front wheels moving at different speeds.
But its not just the 'one wheel with power' that matters. The combined speed of the two front wheels and combined speed of the two rears is what is important with a transfer case.
definitely agree. try to avoid that, sooner or later something will give.
the rear two wheels aren't turning at equal rates. outer wheel turns faster. there is also a certain amount of 'scrub' that ALWAYS goes on with rear wheels while turning, but they also have to turn at different speeds to turn if you have any sort of traction at all. if they both turned at the same speed on dry pavement, you would also have hop, and all sorts of other bad stuff. that's why you don't drive with a locker on pavement, inside wheel needs to be slower.
Record Breaker
Joined: Oct 2008
Posts: 1,394
Likes: 0
From: Bakersfied, CA
Bleepo... you have a megacab, so your chassis is what we like to call a "heavy half". Which pretty much means that you have a half ton truck on a 3/4 ton chassis. The 3/4 and one ton dodges have lockers in the fornt and rear diffs, and are on engaged when in "4LO".
With this said, you can probably make the connection. You dont have a regular 1/2 ton like myself. You have a 1/2 ton that picks on mine and take my lunch money. hahaha. So your switch says 4lock because it actaully does have a locker, and you have true "4 wheel drive".
With this said, you can probably make the connection. You dont have a regular 1/2 ton like myself. You have a 1/2 ton that picks on mine and take my lunch money. hahaha. So your switch says 4lock because it actaully does have a locker, and you have true "4 wheel drive".
