Bonco II Won't drive strait in 4wd - lesson learned

[ab_slack]

I was just commenting in another topic that reminded me of an issue that confounded me for two winter driving seasons. While it seems obvious to me in hindsight I thought I would toss it out there for those with a Bronco II or Ranger that might experience the same since I haven't seen it mentioned before.

I had got an 89 BII used with about 115K miles. This one had auto locking hubs and a pushbutton selector. It needed some work such as brakes but no big deal. It also had one mystery problem. When in 4wd it would not drive straight. It would want to run in a slight turn to the right or to the left but not forward. Whenever I tried to correct to center, it would flip and want correct past dead forward and go the other direction.

I was using 4wd in snowy roads, like I had done many times in my 88 BII so I knew it should have been good.

Brought it back to the used car dealer twice. They claimed to find nothing and that it was fine the first time, and claimed to have fixed it second time after I explained better to them the problem. Their explanation as to what they fixed made no sense to me and I forget what the claim was. It didn't help.

So I took it to the Ford dealer and pay out of my pocket figuring the smarmy car dealer wasn't going to do anything serious anyway. Ford dealer said one of the locking hubs wasn't working properly. Okay and since auto locking hubs would be expensive I had manual hubs put on. In my opinion I preferred manual locking hubs anyway. That did not resolve the problem and even tho I could demonstrate the problem (there was snow on the ground to drive it in at the time), they couldn't identify any problem yet had no idea what it might be. To their credit the mechanics at the dealer didn't treat me like I was stupid.

Okay, so I decided, it was just snow, I could live with it. Also, now with manual locking hubs on it, I found that with hubs locked but still in 2wd that it tracked just fine. The problem only occurred when 4wd was engaged.

Some time later (still winter) I had to have some other service and had my local shop look into this problem. They declared it was the transfer case problem. They did some work (or claimed to), it made no difference.

So I just lived with it. I thought maybe someone had put a different ratio rear end so the front/rear was no longer matched.

I noticed eventually that if the snow was really bad and conditions were really poor I didn't experienced this stubbornness against going strait.

Eventually, it came time to replace the tires. The next snowfall after that, the problem was gone. The tracking was perfect.

I kick myself over that because I knew balanced tire set was important and one early suspicion was that one tire might be a different size so I checked that they were all the same size tire. What I failed to recognize was that not all the tires were the same brand and they were pretty well worn already when I got the vehicle.

So what was happening is that the net front and rear speeds didn't match when going strait and even though there was snow, there was still enough traction for the front to rear error to cause it to want to turn a little bit and fight going straight and created this situation where the roads could be bad enough to get into 4wd, but not so bad as to keep this tendency from showing.

 

[97RangerXLT]

Thanks for sharing this. Gotta love simple and somewhat cheap solutions.

Also flagging this for the Tech library

AJ

 

[ab_slack]

Thanks AJ

Title needs to be fished, should have been "straight" rather than "strait", one of a number words I know, but still end up writing the wrong one all the time.

 

[kunar]

When in doubt, I always run the (slightly) larger tire on the front. This keeps the front end pulling you, rather than the rear pushing.

Sent from my HTCEVOV4G now Free

 

[wildbill23c]

Haha, messed up tires, and even a Ford dealer didn't catch that. Running different size tires front/rear and side to side will cause all sorts of drivability issues for sure. Glad you figured it out, but at what cost?

 

[85_Ranger4x4]

Different brands can vary wildly in size even for the same nominal size.

 

[ab_slack]

Haha, messed up tires, and even a Ford dealer didn't catch that. Running different size tires front/rear and side to side will cause all sorts of drivability issues for sure. Glad you figured it out, but at what cost?

That was about 10 years ago. The new hubs and dealer labor was about $450 which is pretty darn pricey but I don't begrudge that one so much cause I may have made that change anyway. The transfer case service was on the order $700 if I recall correctly and in hindsight it wouldn't surprise me if that was a total rip-off with no work done.

More than the $$$ lost, it was two snow seasons I missed opportunity to really enjoy driving in the snow. Sure it got me around much better than I could have with my car at the time in these hills, but it certainly wasn't fun with the flakey steering. I always loved getting out in the snow with my BIIs.

 

[wildbill23c]

At least its fixed LOL. When I got my B2 the previous owner had mismatched tires on it that were trash to begin with. It got me around pretty well, but I never bothered trying the 4WD as I don't live where I really need it that often.

I can tell a huge difference in handling in 2WD just having a new set of tires on my B2. It makes a huge difference, it also helps that the tires I just had put on are also closer to the correct size, the old tires were a few sizes too big anyways.

 

[Chris_North]

That's interesting. At least no one that looked at it made anything worse and tried to make you pay for it...

My dad's '01 Explorer has electronic 4WD that engages when the speeds between the front and rear wheels are unequal by so much. It took him a while to figure out why it felt like the 4WD was engaging on a dry highway. Come to find out because he always bought tires used and in pairs one or two of the tires were worn and slightly smaller than the others and caused the perceived difference in speed. An an extra lockout switch for the transfer case motor fixed it.

 

[ab_slack]

My dad's '01 Explorer has electronic 4WD that engages when the speeds between the front and rear wheels are unequal by so much. It took him a while to figure out why it felt like the 4WD was engaging on a dry highway. Come to find out because he always bought tires used and in pairs one or two of the tires were worn and slightly smaller than the others and caused the perceived difference in speed. An an extra lockout switch for the transfer case motor fixed it.

Interesting I could see that happening. I have an 02 explorer so know the system.

I always have changed my tires as a set on any of the 4wd vehicles I have had. I was quite aware of how different sizes caused problems from the first time I had put a spare on my original BII which was smaller than the tires I was running at the time. This is why I kick myself cause I should have realized. I knew that different manufactures tires weren't necessarily well matched.

 

[wildbill23c]

When I first got my Bronco 2 last winter, all 4 tires were different styles and different tread patterns, gee wonder why it wanted to slide all over the place on ice LOL. Yeah, matching tires makes a huge difference, you wouldn't think it would but it certainly does.

Those 4WD problems in the explorers are those happening on the AWD models? I wouldn't think the 4WD would just randomly engage if it was a standard part time 4WD system like the rangers were. What exactly causes the 4WD/AWD to just decide to engage? Sensors?

 

[ab_slack]

Those 4WD problems in the explorers are those happening on the AWD models? I wouldn't think the 4WD would just randomly engage if it was a standard part time 4WD system like the rangers were. What exactly causes the 4WD/AWD to just decide to engage? Sensors?

In my 2002 it gives three options.

Auto
4x4
4x4 Low

You can't completely turn off the 4wd. It is intended, if you hit a slippery patch to automatically switch into 4wd. Serves similar function to a traction control system in cars where throttle is cut and/or brakes applied to a selected wheel to prevent slip. Rather than anything fancy, since 4WD available, it just flips into 4WD and is pretty effective.

I notice it mostly when starting to move when on a hill in wet weather when turning. I'll hear/feel a clunk and it will grab. I have sometimes felt a bit of a pull when it did this but unlike other traction control systems that did obnoxious things like cut throttle 90% on me when starting from stopped on a hill because of a little sand on the corner this does work.

Because it is based on wheel speed differential, the different wheel size as described above can false it into engaging.

It is not an all wheel drive system so when it does kick in, it does so only temporarily cause it has all the issues of a part time system in good traction conditions.

I think the old jeep wagoneers had a similar system going way back to the 70s.

The 4x4 selection locks it into 4WD.

 

[85_Ranger4x4]

I have heard some ubber expensive part that you can't even get likes to break in the AWD Explorer t-cases that makes them act like a regular t-case in 4wd too.

 

[ab_slack]

I have heard some ubber expensive part that you can't even get likes to break in the AWD Explorer t-cases that makes them act like a regular t-case in 4wd too.

I guess what you are referring to is something that allows AWD on dry pavement breaks and then has no front/rear diff function and thus chatters around turns and other reasons why not to use 4x4 on dry pavement?

I seem to recall seeing the Mercury equivalent in similar model year of my explorer with AWD . They definitely don't call this one AWD in mine. But that is over 10 years old and I guess newer explorers have AWD, I think I seen that.