Rear end troubles??..truck wont move forward easily..

[diesel4me]

More problems!..new year,same junks!.

Went to plow my driveway today,with my 82 K2500--first it took a half hour of jumping it with booster batteries and finally using ether to get it to fire up ,the 6.2 has been balky lately..that was the least of its problems though..

First,a little history..since I had this truck the past 5 years,it sits and rots more than anything,its used to plow mostly,and do the dump runs a few times monthly,about 3 miles away...

Many times when I went to use the truck,when I put it in drive and try going forward,it felt like one rear wheel was locked,it wouldn't move until I gave it some throttle,then I'd hear a "bang" ,like something stuck broke free,and it would drive normally after that..once I had the rear brake shoes hang up and had to pull the drum off,but all I found in there was a lot of brake dust,no busted parts,etc..(the rear brakes dont work right because the master cylinder leaks the fluid out of the rear chamber,and also both wheel cylinders leak a bit..so I left the chamber empty,seeing it'll just leak out onto the ground!)..YES,I know the brake system is long overdue for an overhaul,but up unyil today I never had any trouble driving it after that initial "bang" noise..so I assumed it was just the brakes hanging up..

What it did today was weird..in 4wd when I tried going forward,the right rear wheel wouldn't turn until I gassed it some,then the truck slid suideways on the icy snow when that wheel would not turn,the other rear wheel spinning madly..but backing it up it seemed OK..

I jack up the right rear with my floor jack,hoping that would force it to turn,but no dice--it will turn in reverse OK,but in drive it refused too,and the drivers side wheel pulled the truck forward and off the jack (evidently I have a posi??)..I jacked up BOTH wheels ,and in drive the right rear wheel turned backwards and the drivers side went forward..

I'm hoping when I yank the right rear drum off tomorrow I'll find it was just the brake shoes hung up,or a spring,etc fell off and jammed up the works..but its weird it plowed fine a bit more than a week ago after the usual "binding" and "bang" noise..I'm praying it doesn't have a "gov-bomb" that went off..thats all I'd need,this was the second storm I had to plow with a garden tractor,and I have a 220' driveway 30 feet wide,to say I'm sore would be an understatement--and I really miss that warm CAB when we had a -2 wind chill all day--took me 4 hours doing it with the tractor,lucky it was fluffy dry snow and only 6" deep..we have another Nor'easter coming friday too..

 

[edreid]

i cant offer any solutions but i have a 14bff and after doing the rear shoes and drums i am having a similar problem brakes roll just fine backwards but it barely moves forward. i have found nothing as far as info so at least here is a free bump and maybe someone else can offer some better insight.

 

[chriswalker(lordcag)]

probably wheel bearings you should pull a hub

 

[diesel4me]

Truck went to the dump again ,NO unusual noises or wheel "locking" symtoms at all this trip,so I dont see how it could be wheel bearings--they are lubed by the diff fluid and I did check it,its full,not the best looking 90W I've seen,but at least its not empty!..
..I suspect it has some internal issues with a posi perhaps,I have not ever had the diff cover off,so I have no idea what it has in there--for all I know it could be a gov-loc "lincoln-locked" and welded into a big ball of snot!...when the winter is over I'll pull the cover off and see whats in there,and change the gear oil,and pray nothing is torn up in there..I also have to buy new u-bolts and a leaf spring "plate" the u-bolts go through,one of them completely rotted away between the u-bolts,another joyous repair and expense I cant afford to do on top of everything else....

 

[diesel4me]

EdReid,maybe you got the shoes mixed up??..there is a long one and a shorter one,(primary and secondary shoe)..if I remember right the shorter one goes towrds the front of the truck..could be a wheel cylinder sticking perhaps,the truck might have less braking power in reverse than forward..I whacked my shoes inwards with a block of wood and mine were not seized,but I'm wondering if that is why it didn't show ant symptoms last time I drove it too?...

 

[Fordum]

First thing you need to understand, is that the brakes on these trucks are "self actuating".
That means that unlike the brakes on real old cars, which use the pressure from the master cylinder only to stop the vehicle, these use the rotational force of the drum to help stop the truck.

When you look at the brake shoe system with the drum off, you will notice that the whole assembly can rock from side to side on the keepers.
When the truck is rolling forward, and you apply the brakes, the pistons push the shoes out until they contact the drum.

As the shoes begin to drag on the drum, the assembly shifts with the rotation causing the shoes to bind more.

Your problem sounds like you have two related problems.
First, a stuck piston, or something is holding the leading shoe against the drum. When you start forward, the brake assembly shifts and binds locking the wheel.

When you go backwards, the shift releases the bind, and since the back shoe is not being held against the drum, it does not bind in reverse.

The other related problem is the "bang" you are hearing sometimes.
I will bet, if you think back when it happened, you see it is related to the weather.
If you drive through some water or melted snow, with the shoe close to the drum, it soaks up some water.
Then, the next time you try to drive, if it is below freezing, the shoe has frozen to the drum.
The bang you hear is it breaking free.

I once had all four shoes freeze on my old Jeep here in Fl.
We had a big cold front blow through. Bad rain.
I came in from hunting to the camp driving through lots of deep puddles.
The next day, it dawned 18 degrees.
The Jeep would not drive off. I put it in 4lo, and heard 4 loud bangs as the brakes broke loose.
Then had to drive into the ditch when the ice on the shoes would not let it stop the next time I tried.

Actually, I think I wrote that partially wrong. I have the leading shoe and the back shoe reversed.
J.

 

[kamm]

I agree with fordum. Sounds like a brake problem. Fix the system. Wheel cylinders, master and all. That probably will fix your problem. Bad wheel bearings tend to hum when driving and would be more persistant than what your describing. Good luck to ya and let us know what you find.