I was driving in the rain the other day and i went to take a turn quickly and my rear wheel (notice i said wheel singular, want posi) started to spin and the rear of the truck was bouncing around and making some clunking noise. I had to let off the throttle all the way before i could start moving again. Is this wheel hop? and is there anything i can do about it.

By the way i have a 2001 F-150 7700 4x4 5.4L regular cap long bed . When this happened i had no weight in the back.

 

Yep, It is caused by the rear springs winding up. It is not uncommon for trucks to do this due to the lack of weight in the rear.
Traction bars work, but their not real feasable ion a truck.
I guess my only suggestion before you get a posi, is to try not to spin the tires for now.
Jimmy

 

but i like spinning the tires

will a posi help the wheel hop??

 

lxman,

Can you expand your explaination?

I have a 4 X 4 with a 5 speed manual and LS. I have noticed that at a certain stop light, when I make a left hand turn with a fair amount of power the rear end hops around almost like it wants to come around and meet the front (no rain or moisture is involved here). I have to back all the way off the gas to get the truck under control. The road at that point has a lot of bumps and I guess the bumps get the process started.

Is LS the same as posi?

If so, the LS doesn't get the job done. I can't remember this issue (so far) in any other driving situation but I can reproduce it at any time at that intersection.

Comments?

Chip

 

Chip- You are sliding the rear. With a posi, its much easier to break loose both rear tires, and that is probably what you are doing. I definitely noticed this going from an open rear to a limited slip.

As for POSI or LIMITED SLIP, there are MANY MANY ways to indiated a non open rear.

Typically POSI is short for Positraction, the trade name for many GM limited slips. Such as Trac Lock is for Ford, and Trac Lok or Powr Lok is for other brands.

Generally though ,POSI is shortened for POSITIVE TRACTION DEVICE, or anything that is not an open rear and gives you POSITIVE traction, that is power does not go to the wheel with the least (or negative) traction, it goes to the wheel, or is split to at least one wheel with POSTIVE traction

UMD, a LS will not HELP with wheel hop, instead you will experience the above phenomenon, or slide both wheels. It makes it a little harder to spin a wheel, but easier to spin both. The wheel hop on a 7700 is because you are spinning them REALLY fast. I used to spin a tire all the time before my LS install, and NEVER had any wheel hop. But I wasn't TRYING to spin them fast. My old truck with softer springs suffered bad from wheel hop and spring wrap (the drivetrain wrapping up before moving forward).

Similar to traction bars, you could install a torque arm. This is a beam that goes from the pinion, or top of the differential case to the driveshaft output, either on the transmission, or a crossmemeber mounted at the transmisison. A trick to keep it from hindering suspesion movement is to put it on a shackle. It still keeps the pinion from rotating, but allows the rear to move along its normal arc.

Chris

 

ya
the wheel was spinning fast as i took a left hand turn in the rain.
i wasnt trying to spin them in that situation. I do commonly get a little chirp from the tires on dry pavement whether i am taking a turn or not.

So what you are saying is that i just have to be more carefull with the throttle to control the "Wheel Hop" and wheel spinning.

When i said posi i meant i want to get the <eaton posi> unit for my differential. or any other limited slip unit.

 

Yep, the 7700 has even tighter springs so there is no weight transfer to the rear to keep the tires from jumping off of the ground. My Traction-Loc will scoot the inside tire when accelerating around a corner ( kinda like a locked rear end) but I haven't experienced any wheel hop. But I have never tried to to a burnout in my 2001. 17" tires cost too much, besides, it is a 4x4 and if it did wheel hop, there is too much expensive stuff under there to replace ( transfer case, tranny, motor mounts, drive shafts, axles, etc).
Becides, I have a 5.0 Mustang that will jump all kinds of sideways if I punch it fron a 10mph roll!!! Even with 265/50R15's stuffed under the rear.
I got my truck for hauling loads and cars, I got my car for hauling A$$.
Jimmy

 

Spring wrap and wheel hop kinda go hand in hand. While the weight might not transfer to the rear as easily with the heavier springs, the springs also reduce the tendency for the axle/springs to wrap up. When the wheel hops, it bounces off the road. This allows the springs to unwind (not like a clock spring, they really don't 'wind up' that much). When the tire hits the ground again it winds the spring up again, and then the tire bounces off the ground etc etc.

 

Thanks for all of the good info...

I am now enlightened...

The bottom line is I need to be a bit lighter on the accelerator (go pedal).

Chip

 

As best as I understand it from wheeling old leaf spring jeeps is the following....

The following applies mostly to suspensions that have leaf packs installed on top of the axle, (most trucks) referred to as a "spring over" vs, leaf packs installed under the axle (stock CJ's) referred to as "spring under" . Wheel hop can happen on spring under suspensions, but most of the time it really shows it's ugly head on spring over suspensions.


The rear leaf packs actually bend into a "S" like shape if you look at them from the side during wheel hop.

It's because the rear axle itself is trying to rotate, and the twisting force of the axle against the leaf packs is what causes the leaf packs to do this, (Lift blocks between the axle and the leafpack actually provide more leverage for the axle to do this to the leaf packs).

As the tires brake loose , the axle then rotates back to it's normal position, this process occures occures many times back and forth as your accelerating and spinning the tires. The wheel hop is caused by this action.

Getting a limited slip installed will only aggrevate the situation if you have a heavy foot and a big V8. Because, you'll now have two tires getting traction which will put more pressure on the axle to rotate against the leaf packs.

Traction bars are available to reduce wheel hop and still provide articulation. SAM's offroad (search on Google for the web site) offers kits for CJ's and YJ's, and he can probably reccomend a setup for the truck.

I have 3.55's and a Track loc in the rear with a V6 and a 5 speed in my F150, I can break the tires at will, especially in the rain with an empty bed, it's best to avoid this, since when the wheel hop occures and the axle rotates it put's a lot of stress on the ujoints in the driveshafts and doesn't let the leaf packs live a long happy life.

 

Thraher
that is probably the best explination of wheel hop that i have heard.

i still am going to get a limited slip for my truck b/c i need it during the winters i spend in VT on a mountain.

I dont think that the heavy foot problem will ever be elimintated no matter what i drive. but i am trying to watch what i am doing with the accelorator more consously (sorry for spelling) especially during wet weather.

 

Glad it helped.

Have you decided on a limited slip yet? If a detroit tru-track is available for your particular axle, (you can check thier web site) it's a worthwhile consideration.

Unlike the factory supplied trac-loc limited slips for our Fords, there are no clutch plates to wear out or requirements to run limited slip additive to the gear fluid for the detroit tru-tracs because thier design is gear based. They enjoy a good repution and their performance will not deteriorate over time unlike the trac-loc's.

 

This is all very informational and all and i do understand the technicality of wheelhop. But i still wander why when lightin up my 2003 auto, 4.6, LS 3.55, at first the whole suspension loads when i barely spin, then when increasing the wheel speed (still in a brake torque) the mother will wheel hop, which i can understand.... but if i start to brake torque and I just bury the right foot, it will just sit and contently smoke the living demons out of the baloney skins, weither i move forward at any speed or sit and pile it up. So I wander if the whole basis of wheelhop starts at the tires?
If you overspeed the traction point of the tires it will happily spin wheelhop free, but if you drop down to the level of wheelhop, or the level commonly achieved when accelerating, the tires are on the brink on looseing traction. It's at that point when the suspension loads and overloads the tires.
When that suspension energy is released by spinning the tire, it builds back up again until the tire bacomes overloaded.
I don't know if any of that makes sense. Just a different spin on things. Either Way----Smoken"

 

Hmmn, after reading Smokem's post I gave a little more thought to when/where I have experieced wheel hop.

Making a left turn after stopped for a light going up an upgrade with undulations in the black top (dry pavement). I am accelerating but with maybe only 1/2 throttle at most, not trying to smoke tires or anything.

It seems that there is a sort of resonance that sets up and causes the wheel hop.

After backing completely off the go pedal, the wheel hop continues for a bit (maybe 2 seconds - which seems like forever) before things are under control.

Chip