theduck21

Hey guys, finally got my 85 sr5 straight axle pickup on the road. Well today I took it into a little mud. When
I put it in 4wd (hubs locked) and let off the clutch I hear a grinding noise from the front passenger side. I bought my hubs used awhile back when I decided to convert from auto to manual hubs. With all 4 tires off the ground all 4 tires spin as they should. I seen on a seperate thread where a guy had this same problem but it had IFS. And everyone told him it was spindle bushings. Would it be the same for my straight axle? If so which part is the actual bushing? Thanks in advance!

wyoming9

iTrader: (1)

What are the bearings like in the front differential ??

Every thing else greased like it should be??

Wheel bearings I would think would always be noisy who knows.



It does this only with the transfercase in 4 hi/4Lo but not in 2wd with the hubs engaged

theduck21

Right onlt in 4wd. Seems to me if it was wheel bearings it would be noisy in 2wd too.

osv

so the grinding noise wasn't there with the auto hubs?

you are saying that you can't hear the noise in 4wd, with all four corners on jackstands or whatever? and the engine running, drivetrain engaged?

theduck21

The autos were bad when I got the truck. No grinding with tires off ground only when a load is applied

osv

maybe it's just a hunk of mud trapped behind the backing plate?

you could try switching the hubs to the opposite side, see if the noise stays on the same side, which would eliminate an individual hub as being an issue.

you could also try driving it in 4wd mode with the hubs unlocked, see if the noise is still there... because that makes the axle shafts turn inside the axle housing.

i'm not sure what a spindle bushing is, but on toyota solid front axles, there are bronze bushings that the drive axle shafts rotate inside of... the wheel itself rotates on bearings, mounted on a short stub axle.

whenever i jack up the front end of the truck, i always check for side-to-side play, by grabbing the top and bottom of the tire... there should be very little free play there, from the wheel bearing nut adjustment area... i had a wheel nut get a bit too loose once, and there was some grinding going on.

theduck21

Just drove it again and its only when I gas it. Rolling is fine but if I pop the gas it grinds

osv

how about with the hubs unlocked? because that loads up the drive axles... i can hear it working on my truck like that... not grinding, but making noise.

and most all of my front axle stuff has been replaced, including the bronze bushings and the axle housing itself.

test this stuff on dirt, not pavement.

theduck21

It only does it with the hubs locked. With all 4 tires off the ground the front passenger side wheel barely moves. Its between a grind and shearing kind of noise but only when I goose it.

osv

sounds like it's time to pull those hubs, look 'em over, maybe swap to the other side?

ultimately you should pull the axle shafts out and do a front end service on everything, so that you know what you got.

theduck21

Well I feel stupid. Turns out it was a broke motor mount allowing the motor to jump and causing the fan hit the shroud. Better than replacing hubs or a front end though!