--This is going to be a lengthy post, I'm sorry in advance. I have a 1997 F-150, 107k miles, with a REAR Limited slip 3.55gear 9.75" differential. Whenever I drive the truck, at any speed, any conditions, etc., there is a metal sounding "click" that clicks seemingly once per rotation of the rear tires. I opened the diff. cover and drained all the fluid out. No pieces of metal or anything serious. For curiosity purposes, I put the truck in drive and let everything do its job. No noise. I then stopped one tire from moving, and it sounded like I was trying to shift gears with no clutch. Just a roar with frequent pulses of forward pressure on the tire I was holding. So much for the limited slip...? Filled the diff. back up and put everything back together, full synthetic 75w140 lube w/ friction mod. Held the tire again, same noise. Drove it. Same noise. - This has been happening for almost a year now, but money has was a big issue, so I just let it go... may have made things worse.
--One note to add to this that seems odd (possibly). It never clicks when I'm on the throttle, accelerating or just cruising (with constant throttle pressure), but once I start drifting, decelerating or hit the brakes, CLICK CLICK CLICK; noise starts. From reading as many posts as I could about this before posting, I think my clutch packs are going, but could it be as simple as bad wheel bearings?
--So here are the basic questions
1. What do you think the problem is?
2. Will my rear end seize and shoot axles, gears, and splines like a grenade?
3. "IF" it is the clutch packs, whats the cost and should I just buy a re manned rear axle like this? - F150 3.55 Ratio 9.75 Complete Rear Axle Assembly

--Thank you for your time. If you have any questions regarding specific details I may have left out, just post them and I will try and respond ASAP!

 

Maybe you have a bad u joint?

I also get the "roaring" when my truck does a 1 tire fire, im assuming that this noise is the wornout clutch pack slipping. I would check the u joints and the brakes to see if you find anything

That rear end wont work in your truck, it is for the 04+ trucks. They had different mounting points for shocks.

 

Wow, that was a quick response, especially near 5am... Anyways... The Re Manned rear end I posted is just a reference to show what I would buy, I know that rear end wont fit my truck, but many thanks for bringing that up in case I was not aware. That would be a returned shipping cost disaster... =(

*^*One thing I didn't add but will now. When the truck is off, in neutral, rear end raised... If I start rotating either of the tires, I get the slow "click click click" I don't know the count for sure, but its like 8-12 clicks per 1 full rotation of the tire. but previously posted, it seems like 1 click per one rotation when I'm driving...

I don't believe it's my brakes making noise because the noise happens with or without the brakes engaged, and as previously posted, goes away with acceleration... Plus I have had the brakes done in the past year and the noise was there before and after the brake job. But thank you for that also... I wont rule it out though.

A U-Joint is also something I have taken into consideration, I personally replaced the 3 U-Joints in the drive shaft not too long ago, but maybe I did something wrong. That would make a lot of sense not hearing the noise under acceleration. But why would it still click when I did the above test I put "*^*" in front of?

 

The clutches in the limitied slip differential are shot. You should not be able to hold one rear wheel stationary with the truck in drive. Good luck!

 

Okay. Excellent. Thank You. One last question. Can i continue to drive the truck with the clutch packs shot or is something going to seize or break or something along those lines? If the truck just clicks, and spins up one wheel, i couldn't really care less at this point in the trucks life and what I use it for. So keep on truckin' or get ready for a breakdown?

 

I don't see why you can't keep driving it at is as long as you can put up with the noise.

 

Nah it shouldnt hurt anything.. just the more its drove, the more it will wear out and act like a open diff.

 

Sorry for bumping this topic to the top again; I though I had all the answers I needed, but one other thing. When it comes to these clutch packs... Does anyone have a estimated price on getting them fixed? What would be the cheapest route? I know so little about axles. Could I just throw in a locking differential for less or is that even possible? Or should I buy a whole new axle? They are like a grand or so from what I've seen, and I would get all new brakes and seals obviously with a new axle... So any input? Thanks again

 

Swapping axles would be the most expensive and time consuming route. A new LS shouldn't be more than a few hundred bucks for the Kit.

 

I was having some noises with my 01, but nothing like what you're describing. Take a look on ebay and look under Ford Limited Slip. There are some guys on there that sell the clutch packs. I believe you need a special tool to get the spring in there to compress the clutch packs to get them into the carrier.
Regards
Rich