Wandering the road, saga continues

[ElJefe]

Well kick me in the a$$... I had no idea. I've not done the bearings on mine... it had just had the front redone at 90K when I picked it up.

In that light I agree with the BS of the fishscale. I never thought I would complement Ford but to set the bearings on my 71 bronco... torque to ~50ft-lbs and then back it off 1/8 of a turn and lock it down. Takes 30 seconds...

Now that you mention it I am having flashbacks to helping my roomate rebuild the axle in his 60 years ago and the FSM saying to use a fish scale to set the front bearing preload. We thought it was hokey then because the scale reading was higher than spec without the nut on it. There was an older mech at the stealership here that also had a 60. My friend had bought the parts there and we went back to ask some ?'s, and he gave us a slightly modified procedure that he uses on his own 60. Basically what he told us to do was torque the inner nut to the lock nut spec to seat everything. Back it off and tighten it by hand to JUST contact the washer. Take a couple of readings and average them to give you a baseline 0 preload torque for the bearings/grease/seal. Now tighten the nut until you measure the total of the (specified preload torque + the average baseline torque just measured) then lock it down and verify.

We also made a torque wrench, rather than using a fishscale which is probably why I didn't recall using a scale to set wheel bearing preloads. We made the torque wrench out of a piece of 1/2" aluminum bar to fit a 1/2" drive socket and some 3/16" music wire to deflect under torque. Calibrated it using a precision load cell I had at work, but you could probably get a really good calibration with weights and careful measuring. We bent up a bracket that spanned 2 opposite studs right over the center of the hub and put a bolt through it to apply torque to spin the hub, and we were able to get VERY consistant readings. Used that to measure the baseline and preload. That truck now has 330k on it and going strong. He's now my roommate and probably still has the stuff we made to do this. If anyone is interested in pics of the torque wrench and bracket we made, I can dig the stuff up when I get home... probably a good idea anyway since it looks like I am going to need them sooner or later.

~Chris

 

[landtank]

Basically what he told us to do was torque the inner nut to the lock nut spec to seat everything. Back it off and tighten it by hand to JUST contact the washer. Take a couple of readings and average them to give you a baseline 0 preload torque for the bearings/grease/seal. Now tighten the nut until you measure the total of the (specified preload torque + the average baseline torque just measured) then lock it down and verify.

Chris

Now that's a proceedure I could get behind. At least your addressing most of the variables that affect the scale method. It actually makes some sense. But I'll stick with my 10 lbs as it's proven itself to me.

 

[semlin]

i agree. el jefe/chris, that is the best method I have heard for setting the preload. that's what i am doling next time.

also missing from this discussion is how notoriously unreliable fish scales are. ever weigh the same fish with two scales?

 

[ElJefe]

Maybe that's why every time I tell the story that fish gets bigger... It's the scale's fault!

 

[IdahoDoug]

Stress,

I'll ask this S-L-O-W-L-Y this time. OK, you know the shiny things that the tires wrap around? That's what I'm asking about. We call them thar things WHEELS here in Idaho. What WHEELS are you running.


DougM

 

[ElJefe]

One other thing that I haven't seen mentioned yet are the Track Bar bushings. This is the first place to look on lifted early bronco's with tracking issues... and since Toyota coppied a 30 year old Ford front end design it's worth checking. Have someone slowly turn the wheel back and forth about a quarter turn and look at the Track Bar bushings. If the bushings are worn you will see the bar moving relative to it's mount instead of/in addition to the wheels turning. This will cause all sorts of tracking issues on the road.

Good luck...

 

[jvoelcker]

Just going back to the preload issues, I think that one of things that people always forget is to ensure that the bearings are properly seated before checking the preload, if you don't do it properly the bearings will be too loose within a few miles.

I have always used the following technique which I think comes from the manual and seems to work well.

1. Torque the inner hub nut to 43lbs/ft.
2. Rotate the hub at least five times back and forth (more if cold) - Either use a screwdriver in the vanes of the vented disk to act as a handle for turning the hub or stick a wheel back on held on by a couple of nuts with the hub cap removed so you can access the hub nut.
3. Continually repeat the steps above until the nut doesn't move at all when torquing.
4. Just to double check, try spinning the hub ten or twenty times back and forth and check the torgue again.
5. Once happy, back the inner nut off until loose (avoid turning/moving the hub - if you do you will need to start again) and then re-torque at 3lbs/ft.
6. Check the preload by getting about 1m of string with a loop at each end and hook onto one of the wheel studs and then wrap it around them and then use a fishing scale threaded through the end loop to see what pull is required to rotate the hub, it should be between 6-12lbs.
7. Put on the nut locking tab and the outer nut and then torque the outer nut to 47lbs/ft and then use a screwdriver/drift to push over the locking tabs on the inner and outer nuts.

I agree that differences in the thickness of the grease and the ambient temperature will make a difference on the preload, but I have yet to see it go out of the 6-12lbs range.

If you are checking the preload, make sure that you have the brake caliper off and/or the pads out - I have seen people check the preload with these in and it can make a difference.

Also if checking the preload on the knuckle, do it when the wiper seals are off, this will also throw the readings off.

HTH

 

[StressPuppy]

Stress,

I'll ask this S-L-O-W-L-Y this time. OK, you know the shiny things that the tires wrap around? That's what I'm asking about. We call them thar things WHEELS here in Idaho. What WHEELS are you running.


DougM

:whoops:

Stock 16 inch alloys.

 

[StressPuppy]

Just going back to the preload issues, I think that one of things that people always forget is to ensure that the bearings are properly seated before checking the preload, if you don't do it properly the bearings will be too loose within a few miles.

I have always used the following technique which I think comes from the manual and seems to work well.

1. Torque the inner hub nut to 43lbs/ft.
2. Rotate the hub at least five times back and forth (more if cold) - Either use a screwdriver in the vanes of the vented disk to act as a handle for turning the hub or stick a wheel back on held on by a couple of nuts with the hub cap removed so you can access the hub nut.
3. Continually repeat the steps above until the nut doesn't move at all when torquing.
4. Just to double check, try spinning the hub ten or twenty times back and forth and check the torgue again.
5. Once happy, back the inner nut off until loose (avoid turning/moving the hub - if you do you will need to start again) and then re-torque at 3lbs/ft.
6. Check the preload by getting about 1m of string with a loop at each end and hook onto one of the wheel studs and then wrap it around them and then use a fishing scale threaded through the end loop to see what pull is required to rotate the hub, it should be between 6-12lbs.
7. Put on the nut locking tab and the outer nut and then torque the outer nut to 47lbs/ft and then use a screwdriver/drift to push over the locking tabs on the inner and outer nuts.

I agree that differences in the thickness of the grease and the ambient temperature will make a difference on the preload, but I have yet to see it go out of the 6-12lbs range.

If you are checking the preload, make sure that you have the brake caliper off and/or the pads out - I have seen people check the preload with these in and it can make a difference.

Also if checking the preload on the knuckle, do it when the wiper seals are off, this will also throw the readings off.

HTH

This is basically the process I followed. Caliper off, torqued nut, turned forward and backward, loosened, turned, torqued, turned, loosened, torqued to spec. All seemed well. With a fish scale, I was in the 6-12 lb range, about 8-10 actually. I feel that this is fine.

Good info though. Thanks!

 

[StressPuppy]

I think for now the remedy is a couple of minutes with a grinder.

Grinding what??? Not sure grinding suspension and steer parts is something I am comfortable with.

On yours, does it only contact the arms? Looks close to the diff. And is it in contact all the time? Or just bumps and such?

I've got a 1400 mile trip coming up at the end of the month, so at this point, I am probably at the best I can get it.


BTW - unless I am missing something, the FSM is not clear on how to adjust the steering play. I have seen some things mentioned here. Could someone give me a clear picture of what I need to do (without destroying the gearbox!!!)? Thanks.

 

[powderpig]

I know here in colorado, alot of the roads are grooved (worn). Just about any thing but stock non agressive tire will cause some wandering. So are your roads flat from side to side or grooved. How much steering play do you have (maybe need to adjust the steering box). Has this wandering showed up after the lift, or after the tires? The alingment numbers, as some one else pointed out do not add up (Some needed to stay the same).

Does this wandering stay the same if you rotate the tires or wander differently . Tire can be the biggest source of wandering and pulling. Maybe borrow a set(another type of tire) from a cruiser head and see if the wandering stayes the same or not. later robbie

 

[Steve C]

You didn't do anything to modify rear caster yet it changed? Come on, there is no way those numbers are accurate. I'd get it checked elsewhere to be sure.

I think (as an alignment guy in a previous career) that this is absolutely correct. These numbers are funky by quite a bit. Look at the change in rear camber and total toe. With a strait axle, these numbers should stay the same from alignment to alignment, assuming that there is not lots of play in the bearings.

 

[Heffenoche]

Does this wandering stay the same if you rotate the tires or wander differently . Tire can be the biggest source of wandering and pulling. Maybe borrow a set(another type of tire) from a cruiser head and see if the wandering stayes the same or not. later robbie

I'll second this one first hand. I had a set of tires I switch from my old 40 to my 60. It would pull moderately to the left even after the alignment. They guy at the alignment shop it may be the tires. Once I put new tires on the 60 it drove straight.

 

[IdahoDoug]

Aside from the strangeness with the alignment readings, the tires themselves are likely contributing greatly to the instability. Wider tires will themselves cause more wandering because of a wider tire's tendancy to constantly steer the truck around. It's called "tramlining" and is simply because a wider tire causes the contact patch to change from the stock ovalized in the direction of travel to an oval that's at 90 degrees to the direction of travel - a significantly destabilizing change and one that also reduces braking capability vs a stock contact patch shape and orientation.

In slow mo, when you then correct the truck to the left (let's say), the right half of the contact patch briefly receives more pressure and wants to steer the truck to the right. Then the weight shift diminishes and the truck's going left more than intended, requiring another correction. This minor shifting and resisting can often mean driving the vehicle is simply a constant chain of minor turns rather than tracking.

With a narrow or stock tire, the contact patch is inherently stable and will resist the tendancy to follow every little road irregularity (dips, cracks, humps, potholes, etc).

When I get on the Nitto website, I'd say the tread pattern is actually a reasonable one for tracking, vs the mud version which would be far worse for tracking. However, I see your wheel (factory 8") is the narrowest acceptable width for the wide tire you're running. This means the tire's contact patch is further impacted by having the beads jammed closer together than is ideal, which means - you guessed it - the tire is likely not as stable as the design could be.

I'm definitely NOT blaming all your issues on the tires, but if you have any minor alignment issues or bits of slack in the steering or suspension the tire choice you've made will exaggerate these. Toss in a lift for even more body roll/weight transfer during all those little 'mini turns' the truck's constantly doing and it's a recipe for wander.

Tire pressure will also affect things quite a bit. Just for grins, try running them up to the sidewall max pressure and seeing if suddenly the truck tracks straighter and the wandering diminishes. I'll guess it will, but do not recommend this other than testing. If so, you can chase all the other minor stuff down, but the biggest favorable change you could make would be narrower and more stable tires.

DougM

 

[powderpig]

What a vocabulary you have doug, It is amazing the stuff people on this board to offer. It is always fun reading your information. Yep tires can cause you problems, more than you know, or want to know. later robbie

 

[StressPuppy]

My wife is the one that originally said it was very bad. She drove it last night and said it is much better. So I must be looking for perfection, which doesn't exist!!!

I'm pretty sure the tires are part of the remaining problem. The other thing I think that is causing a little bit of an issue is excess play in the steering. I'll try to adjust that and see what happens. But I paid too much for the tires and lift to trade down now!!!!! Besides, my kids wouldn't have as much fun in the "truck"!!

Thanks to all for the input.

 

[IdahoDoug]

Robbie,

You're way too kind to say that, considering your b/g and all you provide this forum.

Stress,

Try the high pressure thing so you have a data point (much less wander points directly at the tires), but if you're going to keep things, consider having a bit of toe in dialed in. This is an old trick that will cause it to wander less, and the tires to wear *slightly* more (be sure to rotate more often). Check with the oldest guy in the oldest alignment shop in your town for suggestions on what amount this would be. I recall from some suspension development in a former life that a half degree or some fraction was enough to settle things down. The opposite (any toe out at all) will make things dramatically worse. I wrote this w/o looking at your current settings.

DougM