529 US GEARS in Will's front IFS 7.5"
(29 low res pics loading)
DEC 6 2005

Will, all the way from Long Island, wants 529 gears in his IFS front-end. To speed things up, I happen to have a spare IFS assembly laying around that I can set the gears up in.

The rear cover and the stub axles have to come out, of course. On this side, the 4 bolts that clamp the long housing to the center section come out first.

The rear cover comes off and both stub axles rather easily come out by wedging a large screwdriver, as shown, between the cross-pin and axle end. Then hammer the screwdriver lightly and the stubs pop out.

The clip stays in the groove near the end of the axle. They seem to be re-useable.

I mark everything....I mark the bearing caps on both sides.

Removing the case is super easy with 2 tire irons.

I measured the thick factory shims on each side and documented it. These shims are available from the dealer for about $7 each.

Removing the 24mm pinion nut is also super easy with my electric impact.

Be careful about using a steel hammer to bang the pinion out. Too hard of a blow could leave chatter marks on the outer pinion race. I try to use a rubber mallet and if all else fails....

....I use the 10 ton press.

Then I use my seal removal tool....

I also noticed that the carrier bearing (cone) is the same part number as the larger 8" 4 cylinder 3rds. The race (cup) is different though.

The US GEAR ring and pinion came in a Yukon box. Made in Chicago.

I do everything possible to make sure the ring gear is on right....I file the clamping surfaces, clean the threads, loctite them, and tighten to 70+ pound/feet.

The old crush sleeve hits the garbage. No solid collar option is available for the front 7.5" 3rd yet. I am re-using all the bearings and the pinion shim, also.

The factory is using a pinion .098" shim here. Micrometers are a very cheap yet worthwhile investment.

Right now, I will load the pinion up less the crush...I'll oil the bearings up generously and establish about 5 inch/pound of pinion drag.

The case taps in with the same tension that it came out with. I will add more CBPL after I measure the backlash and determine which side I want to favor the extra shims on.

The backlash measures a little tight at 6 thou.....good enough for a paint check though.

Pinion depth is good. A little more BL will move the pattern off the toe end some.


These are Dana 44 pinion cup shims designed to fit behind the large pinion bearing cup to set pinion depth. They also happen to be the perfect size to Toyota front IFS carrier bearing shims. I decided I would add a .005" thin shim to case side carrier bearing shim (farthest from the ring gear) to estabish more CBPL and a wider BL value.

And, as expected, the pattern moved a little closer to center. BL is now at .008".

coast is good.

If we had a solid collar in there, I would not have to take it all apart....but I do here because I have to now add the crush sleeve in.

I assemblied the pinion end using a new seal at this point, also. The bearings are used so 5 in/lb was a good number.

I coated the pinion threads with blue Loctite and dimpled the nut with a modified chisel. The nut will never "loosen up"....on its own.

Last chance to add extra pre-load....so I added 3 thou to each side. This won't change the 8 thou backlash I wish to keep....but it will create the CBPL value I am looking for. It did take greater coaxing with the lead filled rubber hammer but it eventually went in. This gearset will run quiet and be very strong.

Now I lick the 48 dollar stamp for the trip back to NY. :)