Wheel hop

[dvdswan]

If you use 4x4 on dry pavement you get wheel hop in front. Shouldn't use on dry pavement, etc.
Dana 35 is an open differential, right? So why the wheel hop, it should just act like a regular open diff.

Front and rear driveshafts are turning identical, but, rear has LSD, it's not locked, and seems like the front/rear diff's should operate independently.

So what causes the wheel hop? It's like saying the fronts have a locked diff but they don't. I'm missing something.

If you're getting wheel hop going straight, then your diffs have different gear sets. Wheel hop is normal when turning. You won't get it on gravel, but you will hear the tires slipping if your windows are down.

 

[don4331]

If you're getting wheel hop going straight, then your diffs have different gear sets. Wheel hop is normal when turning. You won't get it on gravel, but you will hear the tires slipping if your windows are down.

The tandem would heat tires toasty warm in just couple miles if you left the IAD locked driving straight on pavement due to slippage caused by different tire size.* The differential ratios in both middle and rear axles are identical as were wheels.

*Tandem was near useless in soft dirt empty, so I tripped the IAD locker. Full, it was monster and didn't need help. I got some chewed out by dad for forgetting to release the locker.​

​

Not relevant to Rangers, but my brother's CJ has 4.09 in front and 4.10s in back (or 4.10s and 4.11s respectively). Close enough for loose material, but not happy on firm.

 

[dvdswan]

The tandem would heat tires toasty warm in just couple miles if you left the IAD locked driving straight on pavement due to slippage caused by different tire size.* The differential ratios in both middle and rear axles are identical as were wheels.

*Tandem was near useless in soft dirt empty, so I tripped the IAD locker. Full, it was monster and didn't need help. I got some chewed out by dad for forgetting to release the locker.​

​

Not relevant to Rangers, but my brother's CJ has 4.09 in front and 4.10s in back (or 4.10s and 4.11s respectively). Close enough for loose material, but not happy on firm.

I wasn't talking about driving like that. this would be under 5 mph. My mistake for not mentioning that. 4.10 front and 4.11 rear or similar were setup that way from manufacturers as an effort to outdo other manufacturers, for the fact that the front would pull. Not really a thing.

I was talking 3.73 and 4.10, different gear sets.

 

[James Morse]

Well, no, I don't get it going straight. That would be something entirely different. What you describe, on gravel, is exactly what I'm talking about.
I know it happens, and I understand the reasoning. What I have a hard time getting my head around is imagining the movement of the two diff's and if I had a scale model I could turn that would help a lot.
It seems like the situation is that if you force two side gears (f/r) to turn at the same rate (or not turn) then there is no combination of differential action that will accomodate different rotation velocities.
I don't even know if I'm saying that right; but I understand that the rear (w/ lsd) is trying to act like it's a locked differential, but only up to a point, after which the diff clutches will slip. In theory this moves more torque to the not-slipping wheel. I was told yes this works but if the truck is at a dead stop then, no, it doesn't - I'd like an explanation why that is so. ?

And the clutches are what wears out if you put different size tires (using small spare) on the back because it's forcing the clutches to slip/wear all the time so after awhile what you have is an open diff.
I would suppose that to have a fully locked rear diff in the new trucks they just tighten up the clutch so it can't slip at all.
Obviously the front with no lsd the side gears are always free vs in the back where they are restricted, to a point.
I guess what I'm saying is, as you say the front if operating independently (disconnect the rear) then you don't get binding because it has open diff. With 4x4 you get the binding (when turning). But the front is heavier, seems like more traction, so if something slips, you'd think it'd be the rear, not the front. See what I'm saying?
All that said, I want to be clear I'm not arguing about anything I'm just trying to fathom the why of it because it nags at me.

Interesting quote from shop manual - this is actually about hubs - "Unfortunately, many Ford customers do not know about differential motoring torque or how to deal with it.."
"Buzzing and ratcheting noises were a constant concern with the older 4x4 vehicles."
They are saying if an auto hub is ratcheting that's not the one that's bad, it's the other one that isn't disengaging and causing the good one to ratchet.
Kind of interesting to know even if it's off topic plus I'll likely replace my auto hubs. Were the oem Ford manual hubs any good? Probably I'll go Mile Marker.

You are saying I could make the truck to front wheel drive only by disconnecting the rear drive shaft. But it's not made as a native fwd so I wonder about that, plus it would probably drive the computer crazy. I wonder if running the chain drive all the time would be good - although motorcycles do it. It was just a thought experiment, but it makes me wonder, why didn't they just make a fwd Ranger? More expensive? Fwd is great for traction (I drove Saabs many years) but torque steering was always something they worked to overcome.

 

[Ranger850]

 

[00t444e]

And the clutches are what wears out if you put different size tires (using small spare) on the back because it's forcing the clutches to slip/wear all the time so after awhile what you have is an open diff.
I would suppose that to have a fully locked rear diff in the new trucks they just tighten up the clutch so it can't slip at all.

True locking differentials are all mechanical and have no clutch packs in them.

Interesting quote from shop manual - this is actually about hubs - "Unfortunately, many Ford customers do not know about differential motoring torque or how to deal with it.."
"Buzzing and ratcheting noises were a constant concern with the older 4x4 vehicles."
They are saying if an auto hub is ratcheting that's not the one that's bad, it's the other one that isn't disengaging and causing the good one to ratchet.
Kind of interesting to know even if it's off topic plus I'll likely replace my auto hubs. Were the oem Ford manual hubs any good? Probably I'll go Mile Marker.

Hubs shouldn't ratchet at all, the Ford and Mile Marker manual hubs are both good and work far better than the junk auto hubs.

You are saying I could make the truck to front wheel drive only by disconnecting the rear drive shaft. But it's not made as a native fwd so I wonder about that, plus it would probably drive the computer crazy. I wonder if running the chain drive all the time would be good - although motorcycles do it. It was just a thought experiment, but it makes me wonder, why didn't they just make a fwd Ranger? More expensive? Fwd is great for traction (I drove Saabs many years) but torque steering was always something they worked to overcome.

Yes you could pull the rear driveshaft and drive around in FWD without binding, but you shouldn't do it permanently because the front axle and u joints aren't made to pull the weight of the whole vehicle around all the time. The computer wouldn't know any difference it only controls the engine running and how the transmission shifts if it's an automatic. They don't make FWD pickups because the engine would have to be sideways, and FWD systems aren't that heavy duty so they would wear out quicker if you used your truck to tow and haul often.

 

[James Morse]

So the new trucks run either open or locked diff? No lsd then? If the thing itself locks mechanically there still has to be a button on the dash or something to turn it on/off so there has to be a servo or something. I'm talking about the new Rangers that have fully locking diff's. Or so I was told.

Yes you are right they should not ratchet (auto hubs) that's a sign the -other- side is failed. What they were saying is, if one ratchets, customers replace that one and it's the other one that's bad, because they don't understand differential motoring torque. As if we should just know that, it's common sense. And that they have to be broken in. As people here have said, you should use 4x4 at least every couple weeks. Disuse is bad.

The owner manual says explicitly you may hear "momentary clunk and ratcheting" when you go into 4x4 so they knew people would go, what is that awful noise and are saying it's ok.
I don't know if my 4x4 was ever even used. Just guessing.

With the manual hubs of course ratcheting is a non-issue, it can't happen. That would be one of, if not the, first upgrade for me. With manual trans you would have got manual hubs. I think it's likely you could have special ordered manual hubs on an auto trans.

That said, people here say the auto hubs aren't that horrible. But manual hubs are cheap, probably a pain to put in, but more reliable.
I suppose you could also put a manual xfr case (could have got that special order too I bet) but I think that's a less likely point of failure.

Yes good point the trans is upstream of the driveshafts I missed that.
Why do you say the engine "has to" be in sideways? Are you saying that way the transaxle is a lot simpler than the way it's done on the Ranger (which is not sideways)?
Certainly later model Saabs had the engine sideways, I never thought of that, being so used to it. I think the earlier Saabs using the Ford V4, the engine wasn't sideways though... can't remember.

Thanks.

 

[don4331]

Manual hubs can ratchet - when you turn the knob to engage the hub, it just increases pressure on a spring. Then when the parts line up, they slip into position. If grease in hub gets old/cold, the engagement might not happen and you get "ratchet" as the teeth pass by each other. They aren't a pain to put in if you plan for it - if you're in Sunday best and get stuck in axle deep mud, it can be a little messy.

My dad's truck had manual transmission with auto hubs until Ford replaced them with manual one following several warranty repairs.

Transmission doesn't have to be sideways - it just most FWD set ups have engine sideways. Oldsmobile Tornado set up would be example of north-south engine with FWD.

The issue with a truck - when loaded/towing, most of the weight is on the rear wheels, so they have better traction.

A FWD Ranger actually makes sense as very few were ever loaded to limit day in/day out. But the buying public doesn't want to be told what they want. And as they are voting with their money, Ford made what the buyers wanted. Dodge took things too far with Rampage, Subaru was just ahead of time with Baja.​

 

[pjtoledo]

 

[superj]

Honda ridgeline is not fwd? Or at least did not use to be fwd? It looks like they only come awd now

 

[sgtsandman]

Honda ridgeline is not fwd? Or at least did not use to be fwd? It looks like they only come awd now

It’s based on a FWD powertrain. Honda did that with the CR-V as well. They just took an Integra powertrain and modified it with a PTO for the rear wheels. I believe the Ridgeline powertrain is a modified Honda Odyssey one with a PTO as well. It’s also used in the Pilot. All the Ridgeline is, is a modified Pilot.

 

[sgtsandman]

Manual hubs can ratchet - when you turn the knob to engage the hub, it just increases pressure on a spring. Then when the parts line up, they slip into position. If grease in hub gets old/cold, the engagement might not happen and you get "ratchet" as the teeth pass by each other. They aren't a pain to put in if you plan for it - if you're in Sunday best and get stuck in axle deep mud, it can be a little messy.

My dad's truck had manual transmission with auto hubs until Ford replaced them with manual one following several warranty repairs.

Transmission doesn't have to be sideways - it just most FWD set ups have engine sideways. Oldsmobile Tornado set up would be example of north-south engine with FWD.

The issue with a truck - when loaded/towing, most of the weight is on the rear wheels, so they have better traction.

A FWD Ranger actually makes sense as very few were ever loaded to limit day in/day out. But the buying public doesn't want to be told what they want. And as they are voting with their money, Ford made what the buyers wanted. Dodge took things too far with Rampage, Subaru was just ahead of time with Baja.​

Dodge did that with the Intrepid. Longitudinal engine with a transverse transmission. It made working on it easier. Good thing since you’d be working on it a lot.

 

[James Morse]

An Olds dealer in my town had the Toronado. It was an oddball for its time, but front wheel drive is what I grew up with my dad had Saabs since mid 60's. No question they were awesome in snow. I remember my dad driving me to college after break going up Gorham Hill he passed a plow with chains, the guy looked down at us with his jaw dropped a foot.

I think the simplest engine was the 850cc 2-cycle they have a lot less parts. But I don't think the V4's (from Ford) were very complicated. I guess 2-cycle cars never were very popular though. I myself had a lot of Saabs, a couple were Aeros, they were nice, but got real complicated like everything else.

As to the hubs, thanks, I didn't realize manuals could ratchet too. You mention about the cold grease and at one point someone posted that they should be just oiled, or lightly greased, not packed with grease, or this happens. Interesting that a manual trans would come with auto hubs and the lousy performance of the autos. That would push me more towards swapping them for manuals.

In my shop manual are the instructions for auto or manual trans, auto or manual hubs, and electric or manual xfr case, so I suppose in all you have 8 possible combinations. I don't know how much you see auto trans with manual transfer case in Rangers, but old Broncos had it.

Old Saabs had free-wheeling too that was something else entirely. You had a little handle down by the floor you push in/out to use or not use. They also had a fabric screen like a window blind, on a chain that you could lower in front of the radiator so it would (eventually) warm up in the winter. Odd, but it worked.

Seems to me that sometimes getting the car started was the big problem. If it was -10F or colder outside and you didn't have an oil heater even if the thing would turn over it wouldn't start, and we'd take out the plugs and warm them in the oven then hurredly put them in before they were cold. It seems almost inconceivable today... doubt if anyone can relate to that.

About the differentials, is it true that there will always be one driven wheel even with open or limited slip differential? The differential doesn't stop things from turning, it just allows the opposite wheel to turn at a different rate.
So if you say, yes, there is always at least one driven wheel, that may go a ways towards me understanding the binding front/rear. Differential whether open or lsd doesn't stop power from getting to wheels, is what I'm getting at.

I still don't understand why the lsd doesn't work if you are at a standstill, I was told the wheel on ice will still spin, while if you are in motion, the non-spinning wheel will receive more torque. I don't get why that is.

 

[alwaysFlOoReD]

 

[Roert42]

The newer rangers that have locking diffs from the factory. They are electric, you press a button and it locks everything up. Also you have hydraulic or pneumatic versions that are aftermarket.


I've always found that FWD cars were pretty terrible in the snow. By virtue of the engine being on top of the drive wheels, you do have more traction from the get go. However, a RWD with added weight over the rear is 40x better. Once you loose traction in a FWD car, you loose all control and you're just along for the ride. Especially in an automatic where it's harder to get the trans in neutral to let them coast and regain traction. With a RWD car, even if you loose traction on your drive wheels, you can still control the direction you are going since it's harder to get the non driven wheels to slip. You let off the gas a bit or push in the clutch and the rear wheels will just fall back into line with the front and straighten you back up.