Ground the burr off the inside of the drive shaft tube where it was hitting the locking collar and filed some burrs off the surface on differential where the ring gear is bolted down. After sorting through a box of steel thrust washers I had previously measured I assembled two with a new bronze washer and got this reading. I measured in several places and on both the ring and pinion and got .015 +/- .002 I'm ok with that.
From the contact pattern that is showing in the picture, you are heavy bearing on the toe of the ring gear. My suggestion is to move the ring gear away from the pinion and increase the pinion depth to move the contact pattern more to the center of the gear teeth. the toe is the weakest part of the gear tooth and it is not advisable to run them in this condition. You can also see the toe bearing on the tips of the pinion teeth. To start, move the pinion in which will reduce your backlash, but you will see an improvement in contact pattern. then move the ring gear away to adjust the backlash. Have fun! Dan
Thanks for your input Dan. The pre-occupation with backlash setting overlooks the need for a good contact pattern between the two gears. Your explanation of how to alter the engagement of the gears is most welcome.
Allan from down under.
You may like the results if you coat the teeth with white lead grease. I use cam assembly lube. This is a Jeep Liberty front differential I did last week.
White lead is the best marking compound but its kinda hard to get these days. Oil base artist paint in tubes works well. Mix it with a little lube oil and it wont harden/dry. Use a color that gives good contrast against your gear teeth. A very light coat is all you need to see the contact pattern- too much and you can't see what's going on. I use an acid brush to apply it and just dab it on in the tooth space of the ring gear. You don't need to keep adding it for subsequent indications- just respread it to remove the last contact pattern and re roll the mesh after an adjustment. Remember- you want pressure on the load side of the gear teeth- ie: turn the ring gear backward while applying drag to the driveshaft.
I needed this.
Back to the drawing board for me.
Mine looked about the same as Mark's a couple days ago before I raised the ring ten thou to lower the clearance. I'd imagine it'll be the same now. Closed spool axle and parts is my only difference.
Dan, any approximations on how much to move the pinion in (closer) to the carrier? I tried to get an adjustable FP kit but couldn't.
Can a fella use just arbor shims or some-such between the pinion and the tapered bearing to get the pinion depth prettier for a better contact pattern?
Sorry for the hijack Mark but we may as well fix 'em.
Off to find some marking goop.
No problem. So you mean you "closed" the clearance between the ring and pinion by putting a .010 shim under the ring gear. Here I thought .015 backlash was in the middle of the sweet spot for many people. But I guess we are assuming that my teeth are not meshing fully across the full length which is really the issue here.
My pinion is already pretty far into the ring gear and starting to show on the other side. So, not sure I can go much farther towards the differential. I'm not moving anything until I have something to mark the teeth and really check the contact. What is seen on my gears above was from previous putzing with the various parts. If I find that contact really is heavy on ring gear "toe" contact as Dan suspects ... then I'll have to rethink. Another thing is that my steel thrust washers are shy of the full .090 ... they're .086. Not sure if new washers might make all the difference. I think a .010 shim under the ring may place it closer than what I want.
Dan, the white stuff I use is Comp Cams part number 104. I ordered it through the local auto parts store, but it's available online. The stuff supplied with most modern differential bearing and seal kits is junk.
An alternative marker is bearing blue. I brush it on with a stiff bristle artist's brush. Just re-brush it when an adjustment is made to give a new impression.
Hope this helps.
Allan from down under.
Mark, Use Prushen Blueing to show were the contact patch is. Than you can adjust accordingly. If you need some most auto parts stores have It in stock or stop buy and I can loan you some.
I get ya about waiting to see the contact pattern first. I was only trying for a nicer clearance between the gears when I raised the ring.
The ring gear mounting/mating surface on mine had been trued up before I got it so I wasn't feeling bad about using a shim but now I'm... Unsure.
I had completely forgotten about contact patterns.
I tried some anti-seize as a marking aid a little while ago.
Shoot, this discussion is as old as time itself in internet years. See this one if you have time. I just went thru it and am still unsure which one to move. :-)
One forum member asked about alignment.
Yet, if we move one part, something else could be affected, especially on the drive shaft. Sorry. I'll shut up now.
Being able to adjust the differential carrier within the housing to set the gear mesh is one reason why I always make the two bronze thrust washers some .015" different in thickness. This allows more juggling of the steel thrust washers and bronze washers to move the diff within the housing. I have yet to have to resort to a shim under the ring gear.
Hope this helps.
Allan from down under.
The best way to do it is to put it together like Ford says, and forget all that crap!
Larry, if you're using all Ford parts, you're absolutely right. Dad's instructors in the Army during WWII were old men from Packard. Dad asked them about model A Ford rear ends while he was being taught ring and pinion set-up. Their response was that Fords are precision machined. Bolt them up and go.
I remember the saying we were taught at Technical School in relation to mesh readings on the Crown Wheel & Pinion set
Face and Flank, you move the crank
Toe or heel, move the wheel.
Interpreted, if the contact is on the face of flank of the C/wheel you move the Pinion in or out And
If the contact is on the toe or heel of the C/wheel you move the wheel (crown Wheel) via the brass thrust washers.
Just a piece of useless information!
Alan in Western Australia