help me diagnose some grinding.... (1 Viewer)

[stumpy]

heyo-

so after doing my disc brake swap, i noticed some grinding. kinda expecting that ('90 4 runner calipers on '82 mini knuckles), i went to work with an angle grinder and shortened the fins on the brake calipers. thought the problem would end.

it hasnt. so i got some 1/4" spacers and slapped them on expecting the grinding would disappear. it hasnt. took the spacers off again and the sound hasnt changed.

i only hear it, and feel it, when i am coming to a stop, say 8 mph and less. it sounds like a wheel rubbing on a caliper, there is definately a metallic grinding tone to it. i am certain it is on the front axle, but not sure if it is left or right or both wheels. the 'grinding' happens only when i am going <8mph, and does not correlate with brake usage. after taking off the wheel spacers, it does not change... the noise goes away as i accelerate above 10 mph.

i thought maybe it was a warped rotor, but i dont feel a pulsing in the brake pedal, and it makes the noise regardless of brake usage. could it be a warped rotor anyway?

birfields? i couldnt get either end clip (the one just behind the hub) onto my birfs when i did the swap. i am told they arent necessary, but that could be misinformation....

TIA




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[andrewfarmer]

The clips do matter.
Jack it up and do some testing, wheel on/off etc.

Silly question (and I've seen this!) - you havnt put the pads in backwards?

Does it only happen when brakes are being used, or will it happen coasting to a stop?

 

[bandy rooster]

what would it mean if the brakes were applied when he was coasting to a stop? sticking pistons??

 

[stumpy]

the grinding happens during a coasting stop, braking stop, and very slow acceleration, all less than 8 mph. checked the pads, they are in right! flipping the pads would be something i would do though... hahah!

did some more 'diagnosis,' both on a lift with the wheels running, and off the lift idling around the neighborhood. my girlfriend walked beside the truck as i idled it along and concluded the noise was coming from all four wheels. so we swapped places and i agreed. so, i started messing with the e-brake and upon doing so found that pitch, tone, and occurrance changed. so, i am thinking the springs arent releasing, or the pads are toast for some reason.

havent yet gone under the truck with that in mind, but am planning to do so later today. any suggestions on drum removal or anything else? havent found a good tech link for the e-brake...

thanks for the reply, i am hoping to have this grinding gone before moab on friday!


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[Trollhole]

well if it's comming from the e-brake then it could be many things. I've seen bolts come loost and flop around inside of the drum making that noise. To take the drum off.
Drain T/C
Take 4 bolts off driveshaft. Transfercase side only.
Compress yoke on DS and ds will come off drum. Be ready for some oil to come out.
Unstake nut
Use 24mm? socket and remove nut.
Drum will slide off now.

Take pics and post them up if you still cannot figure it out.

 

[bandy rooster]

its a 27 mm ... or 1 1/8 is what i used to get the nut off

 

[stumpy]

solved!

got the grinding diagosed/solved. turns out it was coming from my e-brake drum. apparently when i adjusted the shoes, they tipped back into the drum, wouldnt release, and started grinding away.

the reason they did this was because the knucklehead (unfortunately not me) who put the thing back together when i had the drum brake output shaft put in the split case didnt put ANY hardware on the shoes! thats right, no retainer clips, no return spring, no cotter pins in the actuating mechanism... what a jackass... not sure which one of the grease monkeys it was, but i gots me a good idea...

i must have a different stake nut than yous guys, i had to fiddle with a 1 1/4 socket to get the nut off. that wasnt even the correct size. i think a 1 3/8 or so would have fit better. and wow was it a bitch to get the drum off. with the shoes tipped against the drum and not releasing, i didnt think i could get a pry bar long enough! came off with some persistant hammering and prying without too much of a hitch.

thanks for the input, all help is always appreciated!


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