Hi guy's, since day one I'v been getting a noise while turning and backing up, it's like a low pulsing growl.... bad bearing type noise and ya can feel it in the steering. I thought it was coming from the front but everything is new and upgraded except for the steering box. I got a 9 Inch trac-lok rear end, could the clutch's be causing the noise? Going straight is ok, only happens while turning. Thanks

 

Did you add limited slip additive? It will chatter and growl if you don't. Even if you fill it with oil that say's it's for limited slip rear ends you need to add it.

Scott

 

yup, put in a bottle of that stuff. From what I've read, locker rear ends can chatter when turning......... I have no noise Issues when cruising down the road.
Thanks Scott

 

I've had a couple trac-Locs and they kind of growled or rumbled in turns when they were first built. Quieted down once additive went to work. My lockers click loudly when they ratchet around corners. As long as it isn't generating metal its normal

 

Let's not confuse locking rear ends, which use gears that ratchet (and can be noisy when locking and unlocking) with clutch-type limited slip diffs, like Ford's Traction-Loc®. They should operate quiet and smooth under normal conditions. I don't know what kind of additive you used, but it may be worth changing the diff fluid and getting a bottle of friction modifier from Ford to use. I've tried the over-the-counter modifier before with poor results, and as Scotty said the oils that say they have it built in, don't. The factory stuff works better. My 2c.

 

Wayne nailed it. The actual Ford stuff makes a difference. Usually quiets down in a few miles of driving. Smells awful, works great.

 

Yea, add the Ford Friction Modifier before you try anything else.

 

Wayne is correct. There are several types of limited slip differentials but the old Ford Traction-Lok used an additive to buffer slippage between the spring loaded clutches. When there is no additive or it wears out the condition is called "slip-stick" where the unit transfers power and then slips. It is often evident on cornering. This type of differential is described here as "Fixed Value". It would only transfer up to 275 ft. lbs. of torque and then slip. They gave the most amount of traction transfer when you needed it the least and the least amount when you needed it the most. As you can see from the above link there are many newer types of limited slip differentials that are far better.

Originally the additive used was based upon whale oil but when we ran out of whales and hunting was banned in most countries lube manufacturers tried to find a substitute. They were unsuccessful for many years. The quality and durability varies greatly. And there are as many choices these days as leaves on a tree . . . and an equal number of opinions about each one. If your budget permits you might want to consider, while you have things torn down, switching to a better unit.

 

1969/72 F100 9" Traction-Lok:

 

I used the Ford friction modifier, during the rebuild I soaked the clutches & steels with the stuff for a day or so before assembly, then added a bottle along with the gear oil. Yesterday I was talking to a mechanic about this "noise" he said it's normal for rear ends with limited slip differentials to make some noise as the clutches slip while turning so I'm not too concerned about it. Thanks for all the advice you guy's!

 

It really isn't "normal" as designed. But without whale oil I don't know which of the additives is best these days. If you used the old clutches and plates they tend to make it worse. You usually can see the chatter marks on the old separator plate surfaces. Sorry to tell you but the condition will probably worsen over time. You could do some research and and try some of the various modern additives.

One other thing that we used to do is to go to an empty parking lot with a hard surface and drive in tight figure 8s until the condition lessened. It always helped but it was a temporary fix.

 

I throw this in the mix: Friction modifier was Ford's answer to customer complaints about noise in turns. All the friction modifier does is allow the clutches to slip easier. Slipping clutches equals quicker wear.

I don't add the friction modifier to my T-loks. Some make more noise than others. Some make almost no noise...those are usually older. If you pull the "quiet" ones apart, you'll find that the grooves in the clutch disks have 'rounded' edges on the channels. The 'noisy' ones still have sharp edges.

Noise = new, strong, well-gripping clutches.
Quiet = slipping clutches and increased wear.

Still, even with the friction modifier, you'd have to put many miles on to 'hurt' it or decrease your limit slip capability. All clutch-type limited slips are a compromise; real racers use ratchets or spools. Limited slip rears were simply another rung on the ladder between street car and race car becoming very prevalent during the HP wars of the '60s.

They work well for what they are. And if you want it quiet - put the Ford friction modifier in.