Front Brakes Sticking? Front wheels dragging?

For a few years now, I've had this issue with what feels like increased rolling resistance in the front end of my 2004 double cab 4X4. The problem seems intermittent. When I jack up the front end and give the wheels a spin, everything seems normal.

When it's bad, the rear wheels will break loose rather than propelling the truck forward under hard acceleration. I have new calipers on the front and neither of them are currently hanging up, although I've gone through several sets of front calipers on this truck. My tires are properly inflated, the front hub 4X4 actuators are working and are disengaged. The truck was frame-swapped by Toyota in 2016, and there has been a bit of a noise up front since the swap (highway noise). 350,000 kms on the clock, but running great otherwise!

Anyone have any idea what might cause this intermittent but significant increase in rolling resistance? Wheel bearings maybe? I would think wheel bearings would make a whole lot more noise if they were bad.

Thanks boys! Any thoughts or speculation could be helpful!

 

Have you ever jacked up the front end and been able to feel the resistance? You say you have gone through many calipers, have you ever replaced the rubber brake lines? They can have internal damage. Without more information from you it's hard to give you help.

 

This is an interesting one. Going to be pretty hard to find unless you can actually stop the truck while its happening and check things out.

First thing I would try to check is front brake temps when this is happening. If it is brake related and as bad as you sound, the front rotors will should get very hot very quickly.

But potentially, there are a lot of things thats in theory could bind up. Wheel bearings, CV axles, front diff...all are possible as well as brake problems. It could even be something else entirely is going on and it just feels like rolling resistance.

 

I’ve noticed this same phenomena on my truck as well. Usually, its felt when cold in the morning (summer and/or winter) and at a slow acceleration from stop.

Once the truck is warmed up and rolling for the day its never felt. Chaulk it up to old truck syndrome.

 

Thanks for this! No, I've never been able to feel the resistance while jacked up (one front wheel at a time, or both at once). I've actually replaced both front flex lines within the past 5 years. I know they can de-laminate internally and block the release flow of brake fluid. I actually purchased two new flex lines again, but haven't installed them yet due to my diagnostic uncertainty, mainly because I check frequently and never observe abnormal brake rotor heat build up, or a discrepancy between front and left wheel when I experience the drag at it's worst.

 

You're not wrong. I'm not sure if bad CV axles could manifest this much counter-force, but I do notice that the shifting smooths out and the sensation of the back wheels fighting the front wheels diminishes noticeably when I put it in 4WD.

It really seems like dragging brakes on the front, but I really cannot see how it could be brakes based on the service I have done and the observations I have made. Yes, I regularly check the rotor temperatures if I feel it dragging more severely. Everything seems normal.

Of course I was hoping for a silver bullet solution here, but I think I'm going to have to pull the front end apart and start inspecting/replacing bits.

Axles
Wheel Bearings
Front diff service (I think Toyota would have had to drain and refill the diff when they swapped the frame in 2016, but maybe somehow they didn't?)

Thanks very much for offering some advice. I'm still scratching my head here. When I come to a resolution, I will definitely post an update.

Cheers!
J

 

Could be old-truck syndrome as you say, haha! But it's horribly dissatisfying to drive the truck while it's doing this. Mine seems to get worse with heat sometimes. I'm beginning to wonder if my front diff is self-destructing. Wouldn't that be a treat! Have you serviced your front diff recently or at all?

 

I did a fluid change about a year and a half ago. No chunks or shavings. Oil was dirty, but was done 30k miles (imperial) prior. You should consider the 4.56 ratio upgrade on your gears if this is the case of your diff gone bad. You’d have to do the rear diff to match. Plenty of info and a few members here who have done this really like it.

You should take it to pro and have them look at it first for proper diagnosis. Might be something simple.

 

I've heard that first gen owners often upgrade the front diff, but I thought it was mostly because the stock diff gears are not as robust as you would like for off-roading. I don't do any serious off-roading. I use the 4WD in the winter, on the cottage roads in the summer, and at the boat launch to get the boat in and out, so I figured the diff upgrade wouldn't be worth while. You seem to be suggesting a gear ratio change in the diff. Is this taller than stock (revs lower) or shorter than stock (revs higher, more torque)? I really don't need shorter gears.

Yep, I might just take the truck in, but without some idea of what the problem is, I could waste more money and time on the diagnosis than it would cost to just swap some likely parts (axles and bearings). If it's the diff, I would probably try to find a good used one to swap in. I would probably have someone do that for me. If I had all the time in the world, I would take it off and rebuild it myself (maybe).

 

I actually checked the diff fluid in the summer. It was right up and clean as honey. I'm thinking I must have bad wheel bearings, although I would have thought that they would make more noise if they were failing.

 

This is certainly how I think. Although at this point I may take it to someone and just pay them for their time to diagnose it. I certainly have an old truck with a lot of miles 320k, and nothing like this so its not normal, something is borked.

I don't know anything about it, but just spitballing, I know our truck have an automatic front differential disconnect in front diff. The CVs turn at all times but the driveshaft doesn't, or isn't supposed to at least in 2wd. I wonder if maybe that fails sometimes and you are feeling extra drag from the front driveline turning without power.

 

Two ideas.

The pushrod between the brake pedal and master cylinder is adjusted too long, causing the master cylinder the not completely release the pressure. This WILL cause HOT brakes after any real distance, especially the front.

Your viscous fan clutch may be staying engaged when it shouldn’t. You should hear the fan roaring, along with the feeling of having an anchor tied to your a$$.

 

Yeah, I wondered about this, but I can hear them both engaging and disengaging. I don't think they can stay partially engaged. They really don't work like that.

 

Interesting ideas, but I haven't been able to identify actual brake dragging due to overheating rotors and such. The problem manifests as dragging specifically at the front wheels, so I don't see how the cooling fan clutch could cause this.

 

Thats interesting in itself. I can't hear my 4wd engaging or disengaging unless the engine is off and the windows are rolled down. Its very subtle. I could never tell it was happening while on the road if the light didn't come on.

But what I was getting at is that maybe your 4WD at the transfer case is working properly, but the automatic mechanical disconnect at the front diff is not.

In any case, look at it from a physics point of view. Drag means energy from your engine is not being transferred to the road. That energy has to go somewhere, that means SOMETHING is getting hot. Physics demands it.

 

You are absolutely correct! If something is dragging, it will manifest as heat. Every time I check the brakes or the hubs, everything seems normal though, not above what I perceive to be a normal operating temperature. Maybe the heat from the bearing is harder to detect if that is my issue.

I didn't do a great job of describing how the 4WD system was working. Mine is exactly as you describe, but if I happen to be turning slightly or accelerating a bit too much, or I hit the 4WD button when I'm stopped, it may make a slight engagement noise. I just tested it on my snow-covered street. No apparent issues.

 

Even if the axle disconnect isn't working it still won't create any extra drag like he's talking about. Different animal but most Jeeps from 96-on have no axle disconnect for 4wd just the transfer case. Having driven both there's no discernible between either one. *at least with a open front differential*

 

Are you sure you're not mistaking normal operation of a truck with overinflated tires on hard acceleration? Most trucks with an empty bed light load will break the tires loose on hard acceleration.

 

Good point. Mine would break loose on 90° turns accelerating from a stop during wet rainy roads. Even would chirp a little on dry roads. That changed after a

$419 Hellwig 7700 Rear Sway Bar

Hellwig 7700 rear sway bar was installed. She stays very planted now unless surface is slippery due to rare excessive loose gravel, wet leaves, ice, etc.

Edit: Truck has factory LSD.

 

Yeah, I brake my rear tires free easily too. But that doesn't seem to be his main complaint so I ignored it. Spinning rear tires on a truck in 2wd is normal. Even my four banger 93 toyota did it.

 

Presuming you have an open rear differential and are getting just one wheel spin, you may have a dragging rear brake. It can certainly feel like the front, because the truck will pitch forward a little. So, when you're checking heat, are you checking the rear wheels too?