Differential Pattern Help/Check?

[bandit25]

Installing ARB lockers front and rear in my 96 FZJ80. Working on the rear now. New pinion and carrier bearings (if that makes a difference) on original pinion shims.

How does this pattern look? My coast pattern is really faint and I'm not sure how to make it more pronounced.

This is my first differential work so I don't want to mess it up. If I understand it correctly, it looks like my drive and coast are too deep and need a thinner shim? The only issue is that cruiser outfitters sent a shim pack that goes under the race and not between the pinion and bearing, and getting that race out is very difficult (the aftermarket Koyo bearings provided by cruiser outfitters have practically 0 lip to punch out. I figured this out the hard way after basically destroying my brass drifts and filling the differential housing with brass flakes in the process!).

Anyway. Thoughts?

 

[maxamillion2345]

Too far in on toe. Sounds like you need setup bearings

Edit: sorry I was backwards, toe*

 

[bandit25]

Am I correct in understanding that heal/toe position is just a backlash correction? Where as face/flank depth is a pinion height (shim) correction?

 

[Cruiserdrew]

I think it's too deep. You can confirm by looking at the pinion, which the pattern should appear shallow.

It's a reiterative process. Get your pinion the right depth, set backlash to spec, test pattern. THen adjust again as needed.

 

[bandit25]

Any recommendations on how to punch out the aftermarket Koyo race? Last time took me 45 minutes and ate through my brass punches..

 

[Cruiserdrew]

You are in Arizona. Ken Francisco in Chandler is your guy. He'll also have the under pinion head shims to make this easier.

Toyota gear Install

ZUK shares many close-up good pics of Toyota gear installs

gearinstalls.com

 

[bandit25]

I used a few of his builds as guides actually. I'll try and get in touch with him, thank you!

 

[Rifleman]

You are in Arizona. Ken Francisco in Chandler is your guy. He'll also have the under pinion head shims to make this easier.

Toyota gear Install

ZUK shares many close-up good pics of Toyota gear installs

gearinstalls.com

The OP really should follow the advice provided by Cruiserdrew's above , box it up, make the 2 hour drive to Phoenix, and have Zuk do it for you. After everythings said and done, you'll be glad you did.

 

[nukegoat]

You're right - it's too deep. You can order some pinion shims if you want to keep DIY.

 

[nukegoat]

The OP really should follow the advice provided by Cruiserdrew's above , box it up, make the 2 hour drive to Phoenix, and have Zuk do it for you. After everythings said and done, you'll be glad you did.

I don't disagree with @gearinstalls.com being preferable, but since the OP is this far, he can probably finish

 

[maxamillion2345]

Ideally a clamshell bearing puller tool and a press. Even more ideally you have set up bearings.

I kind of agree with taking it to Zuk, while I commend you for your efforts, this will be a quick job for Zuk and save you a lot of headache and possible failure. These are not the easiest to set up yourself, but since it's a removable 3rd its easy to take to someone so you have that going for you.

 

[maxamillion2345]

To some extent yes, I would say maybe backlash to tight but at some point you're fighting to keep it in spec and get the right pattern. I think maybe a little more backlash but also a little less pinion depth, I think...

 

[bulhas]

if its used gears they dont mark for s***, you have to look at wet paint transfer not the initial contact, if you want better paint contact youll need to shim your ring gear tighter to the pinion

whats your backlash and runout at??? it could come up a hair on depth but try wet paint transfer first

 

[cruisermatt]

Did you check the pattern before you took the third apart? You said you used the same shim height as original so I can't imagine the depth is very different from Toyota's setup.

 

[Rifleman]

I don't disagree with @gearinstalls.com being preferable, but since the OP is this far, he can probably finish

Back in the late 70's i worked for Air Research running Gleason Gear generators that made Hypoid ring and pinion gears used in the reduction gear box of the Garrett TPE331 aircraft Turbo prop engine.

I remember fighting to get the gear contact pattern just right, by adjusting the pattern from heel to toe, and face to flank, so the gear set didn't leave the factory with an out of spec contact pattern. I've got to tell you It's not really a good thing to have gears making metal in an aircraft engine at 30 thousand feet.

So this is just my opinion, if he's never done this type of work before, his cost in wasted time if it starts to make noise, or the possible wear damage to the gears if their set up wrong will far outweigh his one time cost of paying someone like Zok to do it for him. YMMV

 

[BILT4ME]

Back in the late 70's i worked for Air Research running Gleason Gear generators that made Hypoid ring and pinion gears used in the reduction gear box of the Garrett TPE331 aircraft Turbo prop engine.

I remember fighting to get the gear contact pattern just right, by adjusting the pattern from heel to toe, and face to flank, so the gear set didn't leave the factory with an out of spec contact pattern. I've got to tell you It's not really a good thing to have gears making metal in an aircraft engine at 30 thousand feet.

So this is just my opinion, if he's never done this type of work before, his cost in wasted time if it starts to make noise, or the possible wear damage to the gears if their set up wrong will far outweigh his one time cost of paying someone like Zok to do it for him. YMMV

I have done a few setups in my time. I own all the tools to do it.

If I have to do the ones in my 80, I will ship them to Zuk to complete. It is NOT worth my time and frustration to do another set and go through exactly what the OP is doing here. Putting it together, taking it apart, multiple times is a HUGE PITA.

I guess with age comes wisdom, and this is one of those wisdom things.

Then again, I gained wisdom by doing it myself to learn what NOT to do.......

So...carry on! Read the FSM for the correct pattern!

Good Luck!

 

[nukegoat]

Back in the late 70's i worked for Air Research running Gleason Gear generators that made Hypoid ring and pinion gears used in the reduction gear box of the Garrett TPE331 aircraft Turbo prop engine.

I remember fighting to get the gear contact pattern just right, by adjusting the pattern from heel to toe, and face to flank, so the gear set didn't leave the factory with an out of spec contact pattern. I've got to tell you It's not really a good thing to have gears making metal in an aircraft engine at 30 thousand feet.

So this is just my opinion, if he's never done this type of work before, his cost in wasted time if it starts to make noise, or the possible wear damage to the gears if their set up wrong will far outweigh his one time cost of paying someone like Zok to do it for him. YMMV

Well, this isn't an aircraft

 

[bandit25]

I appreciate all the feedback, but I will continue doing this myself. The initial headache for me was understanding the ins and outs of the differential and how to do it correctly. So there really isn't any headache remaining. Sure it takes time going back and forth in order to get the depth just right, but I have plenty of time to spare, and the work isn't stressful to me.

The paint pattern is the only thing I'm not certain on, so once I get the pinion re-shimmed I'll post a picture of that new paint pattern (with all of my final measurements) just to make sure I'm good to go.

Thanks everyone!!

 

[BILT4ME]

I appreciate all the feedback, but I will continue doing this myself. The initial headache for me was understanding the ins and outs of the differential and how to do it correctly. So there really isn't any headache remaining. Sure it takes time going back and forth in order to get the depth just right, but I have plenty of time to spare, and the work isn't stressful to me.

The paint pattern is the only thing I'm not certain on, so once I get the pinion re-shimmed I'll post a picture of that new paint pattern (with all of my final measurements) just to make sure I'm good to go.

Thanks everyone!!

Do a search for some of the threads that reference Zuk or gearinstalls. There are LOTS of pics of the CORRECT tooth pattern from Zuk or others that have posted his work.

Knowing whether you install or remove a shim and what it's net effect on both will be is part of the "art" of doing this. I don't have the patience to do this in my stage of life, but when I was much younger, I did it to learn and understand.

You will have to read and search for some of your answers. Many of us just pay someone else to do it anymore.
Good Luck!