Grinding/Whining sound and a Clunk i need HELP

[LiftedBronco93]

sorry if there is already posts about this but I've done a little research and haven't found what the problem could be...

First off, I have a 1993 bronco AUTO, 351 windsor bored 30 over, it has a 9 inch suspension lift, ford 9 inch rear axle with 4.56 gears and locked with a spool, and a dana 44 front axle that is gutted at the moment so no 4x4...I had 36 inch super swampers on it but needed money so i sold those and only could come up on some 33's so thats whats on it now...

i never noticed the noise when i had swampers on it but now driving down the road this thing screams, it has a real loud whining/ grinding noise while accelerating, it starts at about 1.5 to 2k rpm's, when i am all the way on the gas or mostly on it it whines LOUD and when i let off a little but still slightly on the gas the grinding noise starts, if i let off completely no there is no noise at all...

the other problem is a CLUNK noise it doesn't do it to often only a few times since i had this rig but usually when I'm slowing down and it shifts back into a lower gear...

PLEASE I NEED HELP ASAP, i need to get this thing fixed as it is my daily driver and I'm starting a new job next week, and as of right not its up for sale for $3300 obo so it'd help to sell it if i got these problems fixed other then that it runs and drives like a champ, couldn't go wrong with a FORD

THANKS FOR YOUR TIME AND HELP

[Saltlife]

The grinding whining noise could be bearings somewhere. Check your brakes too.

[LiftedBronco93]

thanks, yeah brakes are fine, i found this video on youtube and its a similiar noise but mine is more obnoxious, and the guy said it was a tranny bearing

http://www.youtube.com/watch?v=Qli4uQJJjrk

[JMBronco]

sounds to me like pinion bearings, jus went through this on my 94.

[LiftedBronco93]

Where are the pinion bearings located??? and how hard is that to fix??? is it expensive???

[garymunson]

If it's two separate noises, I'd suspect the clunk means you need to lube the drive shaft slip joint.

[LiftedBronco93]

ok yeah ill check that out... thanks

and yeah it 2 different noises the whining/ grinding is constant usually when it shifts into 2nd gear and so on at about 1500 to 2000 rpms is when it starts and then the clunk sounds like something popping in and out of place but doesn't really do it to often...

[4NIC8R]

Could be a lot of things. You're driving a spooled rear end on the road as a daily driver? Wow.

See how much play you have in the rear end to try and eliminate pinion bearings. Put it in neutral and see how much you can turn the driveline.

Could also be the transfer case

[LiftedBronco93]

Yeah i know shit happened and i got stuck with my wheeler as a daily.

I will try that tomorrow in the light and let you guys know how it goes

[LiftedBronco93]

i know the front drive line will spin now in park of course because the front axle is gutted, and tried the rear drive line while in park and it does not move at all

[garymunson]

r.e. the clunk....I suspect you'll find the boot around the slip joint torn. BGraveyard has been the only source I could find for them $30 something shipped.

[4NIC8R]

Try the driveline in neutral. Check the U-Joints and slip joints. Are you sure you're hearing it from the rear end? If the drive line is in good order, then check the pinion. If that is ok then I'd look at the transfer case. They are famous for going out.

As for the grinding sound, it could be that the pump-stay arm in the tcase broke off and it's randomly kissing the gears inside it. That's how mine did me dirty.