Happy Halloween from Mississippi! Hey I dis***embled a 9" Trac Lok two months ago & just now getting around to installing my new clutch kit. I can't remember which way the little wear guides go that fit around the Ears on the Steel Discs. They have a little Protrusion that I think goes "UP" when ***embling them into the case around the Ears. I see no use for the protrusion if they are ***embled with them in the down position. Looks like the protrusion would hold a steel plate higher in the case bore that way. But the few exploded pics I've been able to find seem to show them in the case before the clutches are being loaded. Pisser getting old And also I installed a new clutch side side gear as the splines were stripped on the old one. This gear is .020" thicker than the old one. When I ***emble the case the diff locks up & I am unable to bench test rotating torque. The old shim was .015" & I thought I wanted a thicker one but even if I remove the shim it won't rotate. I installed the old side gear & got it to "POP" turn a little but nothing like the Youtube vids that folks just rotate them with ease... I also measured the new clutch pack against the old one & they measure the same. I soaked the friction discs overnight & I think I'm doing everthing correct but I'm sure it's gonna be too tight. Thanks! Andy
The little tabs go to the outside of the case. If you install them towards the inside they come out.The diff should not be able to turn without some effort. Sounds like it's time for you to hand this project off.
Squirrel that's the photo I was referring to. It shows the guides with what I think is the tab away from the bore of the cover, on top of the plate tabs. I'm sure I have it correct. Bob I NEVER Hand off a Project! I'ma Too Hard Headed for that! I will Prevail! Thanks for the help boys!
If you can easily spin one axle in a Trac-loc, it is wore out. With out checking, I think the “ break away” torque from axle to axle is in the 150 ft lbs range for a Trac-loc in proper shape! Bones
I believe he was refering to the mating of the side gears and spider gears... they should spin pretty easily with finger tips. It would be wise if replacing the side gears, to replace the spider gears and thrust washers from the same kit. If, in fact he is refering to Youtube video of "turning with ease" meaning actual clutch slipage, it should not be easy to turn.
He refers to “ I ***embled the case” and cannot test the rotating torque. If he ***embled the case, it would have spring pressure on the clutch plates. I think his problem could be the .020 thicker side gear causing the gears to put pressure on the clutch pack. At this point there should only be spring pressure on the clutches and should be able to” break away” the clutch pac at around 150 Ft lbs. Edit. I went back and looked a Squirrel’s post with actual Ford tech book and it shows the break away torque is 100 to 250 ft lbs ! 250 ft lbs could give the indication of it being “ locked up”! Also the new side gear being .020 thicker may indicate that the Trac-loc might like a little more pressure. Maybe! Bones
I am surprised that the replacement side gear has that much indifference from the original. As far as clutch shims, I always start with no shims with new clutches. 1st test broke free easily, put .005 shim in and breakaway torq was 55-60 lbs, added another .005 totalling .010 shim and had clutch slippage at 140-150 lbs using a needle torq wrench. I could have added another .005 totaling .015 but don't want the tires chirping around corners on a 2500# car. Not every case is machined the same so, clutch shims will very some. All clutch disks were soaked with Motorcraft Friction Modifier. Stinks like hell.
The springs, just kinda get the Trac-loc working. The actual clamping force to make both axles spin at the same time comes from the side gears wanting to separate from the spider gears on hard acceleration. Usually the Trac-loc is not “positive” enough to chirp tires. It works fairly good if both tires have somewhat equal traction. But it will slip if power is put to tires on grossly different traction. It is usually a very soft traction enhancer. Bones
I made some "axle" tools to help measure breakaway torq. Just some old axle ends with 1/2" drive socket welded on the end. Have both 28 and 31 spline handy.
They also are good when you ****on up the case halves, you can use as an alignment tool for the clutch hub and side gear. Nothing is more fustrating that getting the pumpkin in the car and realize the axle won't go in all the way.
I haven't pulled many of those out that weren't broke on the clutch side. Some carriers are better than others.
Hey guys! I was gonna add that I can stick my finger into each of the 4 holes in the case & "Wiggle" the little pinion gears ever so slightly so as to see the axle gear wiggle a little also. So I'm sure the "Diff" proper is not bound up due to the extra thickness of that side gear on top the clutch hub. Thanks for the photo Big Deuce I have them installed correctly. At lunch time I watched a U Tuber for replacing 9" clutch packs & I'm sure that dude installed his upside down! Since the old & new clutch packs measured the same & I have only .002" added shim thickness over the old shim thickness I feel the unit should be OK, if maybe a little stiff to start. Don't know where it's gonna wind up. This diff has 3.50 gears & I have another 3.50 trac lok diff I've not looked at. I have a set 3.70 gears I'd kinda like to take the 4.10s outta son n laws Mustang & install one these but don't know what the spline count on his axles are yet, all these are 31s. Oh the Drama! Stay Tuned!
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