**ANOTHER UPDATE **My rims got "red fire" hot when I used 4 wheel drive?

[digmy76]

I recently replaced the front disk brakes (completely, rotor/hub assembly, all new bearings, calipers and pads). Then I found out that my booster was bad and replaced it. I then experienced the hot rims in 2wd. I adjusted the booster rod out a little and fixed that problem. Have been driving around in 2wd with no problems.
Today I used 4wd a little (about 5 min. worth for about 500 yds.) I noticed that my temp gage went up to 220 (it normally runs at about 180) then put it back in 2wd and drove 2 miles home. When I got in the garage I noticed that the rims were red hot.
I know I have the brakes adjusted correctly now since they were not getting hot when running around in 2wd. So, could it be something with the bearings or is it something else? I have no clue what else it could be, or what could cause the brakes to heat up again. ?:?

UPDATE - Please help! I tried to go off road and put it in 4wd and it was like I had my foot on the brake as hard as I could. I had to really get on the gas to get moving. If I went in reverse there was no resistance and it seemed fine. Also, after moving this way in 4wd for less than a minute my engine temp went from 180 to 210, in less than a minute!!! I definitely need help. I don't know if anybody at a shop here in Charlotte would know enough about the 4wd setup on my 76 to fix it. As a reminder I did totally replace the hub/rotor assembly (one piece) and all the brake components and bearings (inner and outer). As I mentioned before the "cups" that came with the bearings did not get used in the brake system, as they were not there when I removed the original setup?? Is this right for the one-piece hub/rotor setup? Anybody in the area willing to help out can plan on a case of beer or something!!


Eliminated the brakes from the equation. Now it is either the TC or the Hub/rotor assembly. See above for more updated info on 4wd problems.

 

[Jeepster]

Jack it up and spin the wheels......your looking for drag. there should be none.

 

[digmy76]

Could it be anything other than the brakes? Could using the 4wd have anything to do with the heated rims, (maybe the heat came from the hubs, not the brakes?)? Also, should using the 4wd cause the engine heat to increase so much? I have a new super duty 3 core radiator, and a rebuilt 302, with an aux tranny cooler in front of the radiator and have not had any recent heat issues with this setup)

 

[wildbill]

Only 2 things to do that 1st bad brakes hanging up the other is bad wheel bearings good luck.%) %) %) Bill 8) %)

 

[Jeepster]

........the other is bad wheel bearings......

or too tight wheel bearings

 

[72bronco]

Did you pack your wheel bearings with grease?

 

[digmy76]

Did you pack your wheel bearings with grease?

Yes! The new bearings were packed with new grease and the entire assembly was put back correctly. I took the rig for another ride in 2wd and the rims did not get hot. I then ran it in 4wd and the rims got hot again!!!?:? Am I the first and only person to have experienced this phenomenon? Please, any input or suggestions would be greatly appreciated. I have worked on this rig for almost a year and spent a lot of money on it, yet it seems that nothing gets foe (or done correctly)?. It is very discouraging:’(I am so depressed, the HEEPS are starting to look pretty good

 

[77sport]

i wonder if you have some binding in 4wd. Are you running on dirt or pavement, if you are on pavement that might be creating the problem. Is this a new problem , did you recently change something or was it always doing this. Are your tires all the same size? are they all inflated correctly? Do you have the same gear ratio front and rear?.Some of these might sound stupid but I have heard of stranger things. Might help to have more info on your rig.

 

[jpoore]

I went through the brake thing recently, so I feel you pain.

First off, does this occur when you drive around with hubs locked but front drive not engaged? How about with front drive engaged and the hubs unlocked?

Does it happen equally for each wheel?

How hot is the axle housing? I can't imagine differential problems heating the wheels before the whole front end goes aflame, but you never know.

Drive around and heat the wheels up some. Then jack up the front end and try to find the binding part(s). I'm guessing the hubs make no differance and you find the brakes are again the problem.

The brakes are the only system that is designed to take that amount of heat. Any bearing sourcing this should have seized, or at least given off some nasty grease smoke.

Good luck.

JP

 

[VBH289]

Perhaps when you put your hubs in it tightens everything up just enough to make the pads rub? Or maybe as said before, perhaps when the hubs are in, it binds up inside right around the back or the front bearing? Maybe it pushes against the hub nuts? Try taking the hub down to twhere you can see the nuts and see if you fried the grease, or keep going until you see stress marks or scuffing... My bronco went through the same thing after we did disc brakes and it was actually cured by repacking the hub and bearings... But now if my damn transfer case worked.... Good luck!

 

[bpatton74]

I might just be grasping at straws here but is it possible that the front and rear ring and pinion are different???:? This would probally cause some extra heat and strain on the engine and drivetrain... I know that some people that run in "mud bogs" do this, but I am not sure why.....

 

[digmy76]

(First off, does this occur when you drive around with hubs locked but front drive not engaged? How about with front drive engaged and the hubs unlocked?)

I have not tried this, but I will. Also, the gear ratios and ring and pinions are all stock. Everything about the setup on this vehicle is stock, except 31x10.50x15 tires. How would I know if I tightened the bearings down too much? I used a screwdriver in one of the slots to turn the retainer, so it wasn't possible to get it too tight because the screwdriver would slip when too much torque was applied. Also, The bearings came with these "rings", I think the Chilton's manual calls them "cups" that went around them, this is probably a stupid question, but, was I supposed to keep the one on for the rear bearing. On page 292 in the Chilton's manual the pic for the Dana 44-9f front axle (which was the closest match to my rig) shows a cup for both bearings, which when taking my original assembly apart, I found they were not part of the setup. However, none of the diagrams really matched how mine was setup, hub/rotor as a single unit, and no "cups". Sorry, that was kind of long, but maybe this info will trigger the solution.

 

[Rustytruck]

Are you sure you have a disc brake master cylinder and not one for drum brakes they are different. The load on the bearings are the same when in 2wd or 4wd so I doubt that is your problem. I would check the free spin first (in 2wd) if you cant spin the tire with 2 fingers you have a problem. Next is it the same on both sides if it is then I think you have a brake problem if it is only on one side Ill bet it is on the passengers side. If the bearings are set wrong this side will self tighten. Also to loosen up the brakes in a power booster you shorten the rod not lengthen it. Un bolt the master cylinder from the booster and pull it away a little and jack up the front end and see if the wheels turn more easily. I think your problem is still a too long connecting rod between the master cylinder to the booster or you have a drum brake master cylinder which has the residual pressure valves in the front brake side.

 

[jpoore]

On mine everything was O.K. cold- minimal rotating resistance. However there must have been enough contact to slowly heat the brakes so that eventually I needed full throttle to maintain highway speed. Needless to say my brakes were warm!;D Adjusting the booster pushrod in a couple of turns fixed it.

If, while the front end is jacked up and hot, the wheels are tight , crack the caliper bleader screw to relieve pressure on the front circuit and see what happens. If they free up, bingo brakes- MC or booster issues.

Sounds like you didn't set up your wheels bearing exactly right. The cups you refer to should have already been in the hub. They are pressed in and can be removed- probably should be replaced if you replace the wheel bearings.

You need the Dana axle nut tool (just a 1/2' drive socket with 4 tabs for the axle nuts). They are about $12 at Autozone/Napa/Kragen/etc.

Follow the Chilton directions for tightening the wheels bearings. Make sure you re-install the lock washer (the one with all the holes in it) and that it engages the pin on the inner axle nut.


JP

 

[jerry74explorer]

Ditto on setting the lock nuts correctly with the right amount of torque. If you follow the directions in your manual you will torque them then back them off a quarter turn before putting the lock ring and nut in. You should always change the bearing and the race at the same time (which it sounds like what you are calling cups) )

Also if you lock in the hubs and run around in 2x4 or if you put it in 4x4 but leave the hubs unlocked and you are still heating up you may want to make sure that you have enough gear oil in the diff. In 2x4 & hubs unlocked the ring/pinion would not move, but locked in or in 4x4 or both with little or no gear oil would certainly heat things up quick.

 

[digmy76]

UPDATE - Please help! I tried to go off road and put it in 4wd and it was like I had my foot on the brake as hard as I could. I had to really get on the gas to get moving. If I went in reverse there was no resistance and it seemed fine. Also, after moving this way in 4wd for less than a minute my engine temp went from 180 to 210, in less than a minute!!!?:? I definitely need help. I don't know if anybody at a shop here in Charlotte would know enough about the 4wd setup on my 76 to fix it. As a reminder I did totally replace the hub/rotor assembly (one piece) and all the brake components and bearings (inner and outer). As I mentioned before the "cups" that came with the bearings did not get used in the brake system, as they were not there when I removed the original setup?? Is this right for the one-piece hub/rotor setup? Anybody in the area willing to help out can plan on a case of beer or something!!;D

 

[JTCamp]

When you say "cups" do you mean the bearing races? If so you need races in the hubs for the bearings to ride on. I assume that you might not have noticed them in the hub if they didn't fall out(which they should not have). I don't know if new hub/rotor come with installed races, but I would think not. Just something to chew on. But improper bearing installs would create noise and heat all the time. Someone here will figure it out.

John

 

[72bronco]

Usually a new hub/rotor assembly will come with the races installed. But if you're not sure you should definitely take off the rotors and make sure they are in place. Also make sure your axle shaft is seated correctly and not giving you any resistance. Did you check your fluid level in the front diff? Since this is happening when you are in 4WD only I would think that your bearings and races are fine, otherwise they would heat up all the time. It sounds like there's some sort of resistance. Did you remove your carrier assembly? You might want to pull the cover off the front diff and see what's going on in there. Something seems out of alignment. Are there any unusual sounds when you are in 4WD? Do you have difficulty locking your hubs?

 

[Rustytruck]

If your hub and rotor came from someone other than Ford they probably came with the bearing cups installed. What I would do first before you get further into this thing is to pull the vacuum line off of the brake booster. Plug the vacuum line and drive the truck very carefully as you will now have only manual disc brakes. The brakes should be hard to push but the wheels should roll freely. if this frees up the wheels then the booster needs adjusting, or replacing or the check valve is bad.

If this test didnt show the problem then the next thing I would look at is the rod between the booster and master cylinder. If this rod is too long your brakes will be applied somewhat all the time. if this rod is too short then the brakes will apply a little late and just slam on. There is a delicate balence here to the tune of 1/8" turns on the adjustment rod.
As I said on an earlier post this can be tested some what by jacking up the front end and spinning the wheel if it is tight unbolt the mastercylinder from the booster and pull it back a 1/4" and spin the wheel if it turns free the rod is adjusted too long. Another test like this if the master cylinder is all bolted up and the wheel turns free while it is up on jack stands start the truck with the truck ideling in park or neutral try to spin the wheel if it is locked up you have a bad or mal adjusted booster.
If this doesnt point to anything now worry about the wheel bearings and possibly stuck caliper.
I would have started at the brakes hub and bearings first but since you replaced the booster I am sucspecting trouble there. They are not bolt on and go type things they need to be properly adjusted when installed.

Any good repair shop can deal with the hub, bearings, and brake system in a Bronco. It isn't rocket science. "Yea I know" the chain repair facilities (Sears , Midas, Pep boys cant do it but I did say Good repair shop) Go to Napa and ask one of the Guys there if they had to trust their truck to someone to fix it where they would send it you will probably get a good shop.
If i lived near you I would gladly take you up on your offer.

 

[jims66]

I went through the brake thing recently, so I feel you pain.

First off, does this occur when you drive around with hubs locked but front drive not engaged? How about with front drive engaged and the hubs unlocked?

Does it happen equally for each wheel?

How hot is the axle housing? I can't imagine differential problems heating the wheels before the whole front end goes aflame, but you never know.

Drive around and heat the wheels up some. Then jack up the front end and try to find the binding part(s). I'm guessing the hubs make no differance and you find the brakes are again the problem.

The brakes are the only system that is designed to take that amount of heat. Any bearing sourcing this should have seized, or at least given off some nasty grease smoke.

Good luck.

JP

This is some excellent troubleshooting advise, what was the result?