9" Limited Slip noise.

[Keith Stevens]

I have about 2,000 miles on my rebuilt 9" SPEC cased factory Trac Loc.  When I turn from driveways or make a bit tighter turn it feels like It's dragging a tire and there is bearing noise.  I did use the correct gear oil and additive. Is this common with the Trac Lock units? I removed my Detroit locker because of noise and harsh engagement at times.

[My427stang]

They can snap and pop when immediately installed with new clutches, especially  if the right additive isn't used, but pretty much silent after a few slow tight turns

Certainly no reason for bearing noise associated with them, I'd go back inside

[JimNolan]

I drag raced my Tru-Trac for a couple of years plus put a lot of cruising miles on it. It started doing what you're talking about and then on a trip from MS it started making a bearing noise constantly. I trailered it home and pulled it. The gears seemed OK but the pinion bearing sounded like broken glass. I installed an early model Equi-loc I had and just set the Tru-trac with it's 31 spline axles in the corner. It still works fantastic with no noise after 60 years. The Tru-Trac was 2 years old.

[gdaddy01]

 .

[gt350hr]

      This has nothing to do with the crush sleeve as the diff has a solid spacer because of the Daytona retainer. It more likely that the traction lock case cover has broken. This is very common on traction lock units. So much so that billet steel replacement covers are available for repair. "I" would pull the diff and look for the issue . It won't go away.
    Randy

[pbf777]

I have about 2,000 miles on my rebuilt 9" SPEC cased factory Trac Loc.  When I turn from driveways or make a bit tighter turn it feels like It's dragging a tire and there is bearing noise.

     Are you saying that it has been making this noise 'since' the rebuild?  Or that after the rebuild and 2,000 miles it has started making this noise?   

     Scott.

     

[My427stang]

Randy brings up a great point, and I am ashamed I didn't bring it up

The clutch cover on a Traction Lock also holds one side bearing.  They often crack over time, or even at assembly if the cover isn't drawn down evenly, especially the ones with the vent/view hole.

This not only can cause a loss of posi  or clutch noise, but depending how it broke, could change bearing alignment and preload, making bearing noise.

Go in....good thing is, it's not to expensive to replace with a billet cover through Currie and others and then good to go

[gt350hr]

    Ross ,
        I buy the whole billet case and save the retrofit hassle ( truing and drilling /tapping the 1/4 screws). I have seen the "bell side" break too

[Keith Stevens]

Thank you for the heads up. I was concerned that may be an issue.  I had planned on pulling it to change from the 389s that were supposed to be 350s to 318s I have.  Joy. Does anyone have a cover if I need one? I might as well line up my ducks in a row so this doesn't turn into a 1,000.00 project.

[gt350hr]

   Ebay. but seriously look at the complete empty case OR one complete new one ready to go for $310.
    Randy

[Nightmist66]

I will add my own experience. I went through two different "Ebay special" tracion loks and one of the Summit brand units when setting up a 31 spline setup a while back. Every one of the three units showed exactly .007" runout on the back of the ring gear. After the first "Ebay special", they sent me the case halves to swap. No change. That's when I bought the Summit brand.

I thought I was losing my mind. I started with a brand new ring and pinion from Quick Performance which is a Richmond gear set. I did the usual blueprinting like stoning the back side of the ring gear and the surface of the traction lok, deburring all the teeth, thread chasing, etc. Anyway, I spoke with the gentleman at Quick Performance about the situation since I had quite a few small items from them already. He suggested I try their Yukon traction lok and even offered me a little bit of a deal on it. Just upon visual inspection out of the box, the quality seemed far better than the first three. I installed a fourth set of side bearings and checked again. This time I had a max runout of just under .001" with the same ring gear and all. I was very happy.

I then took it all apart and soaked the clutches in a mix of gear lube and Motorcraft friction modifier overnight. Reassembled everything and when I finally got it driving again I couldn't have been happier. No noise, vibration, or chatter. I beat on it for a while on the street and only a couple passes at the track with drag radials. No issues at all. This was the old clapped out 390. I removed the entire setup when I built the new engine because I needed to upgrade and I wanted a spool.

[wayne]

If you use a ford tool to check clutch pack shims it makes a difference no two are the same. Look in a shop manual it shows you how. You can get a tool off ebay i got mine from otc years ago but they no longer sell them.

[Gaugster]

I went with a set of Richmond gears and a Powertrax spiral gear posi for my 9". 31 spline Moser axles. Fingers crossed....

[Keith Stevens]

I haven't heard much positive about Richmond in the last few years. The gears installed were new Richmonds. I don't remember if the ford additive was used during the re-install. It may have just been the lube with additive in it. The axle bearings were just replaced two months ago.
It does remind me of a bearing whine. I know those were new too.

To answer Scott's question. No, it wasn't nearly this noisy initially.

[pbf777]

To answer Scott's question. No, it wasn't nearly this noisy initially.

     Generally in my experience if the issue were with the clutch pack being too tight or wrong lube , or a combination of, including the fact that the clutches & plates might be new and fuzzy, the complaint would be most notable when newly assembled and degrade with use (though the exception being in application of the friction modifier directly to the plates at assembly and then the wrong lube utilized on the fill).  The solution recommended by Ford in the day when experiencing a Trac-loc that was overly effective causing excessive noise and/or suspension or steering lurching or excessive tire drag was to find a parking lot and execute tight figure eights for ten minutes to "wear-in" (wear-out! ) the friction plates.   

     Now I have seen instances where excessive 'one-wheel-peel' or 'off-road' experiences have damaged the plates by warping, folding, welding and even breaking them, all this causing them to bind in attempted intentional slip, and make noise.  And as Randy said, breaking of the Trac-Loc case wouldn't be anything new; and the cover can be broken in the typical fashion and remain engaged adequately to function for a period (as long as only grandma is driving! ), but once separated thoroughly generally one will note ring & pinion howling as it's proper relationship will be lost, and with greater loads or if it's the cone side, all rolls to a stop pretty quickly, with a really bad noise.   

     It is your observation of the noise only in turning that would lead one to suspect, at least at first, only those items that are put into motion at that time, whereas most other items in the differential already in motion in the straight line functioning don't really react consequently greatly because of the turning event.   

     Probably as stated previously, removal and inspection is the best course of action, particularly before something really does go wrong and damages your SPEC case,.........that'll cost ya! 

     Scott.