redwolf3

Hey Guys-
It's my first time doing a differential gear install, and I'm having some issues right now, or feel like I'm going the wrong direction.

I'm installing some 4.88 gears into my 4 Cylinder 3rd Member. The gears appear to be "Genuine" (Yes, I know, cheap, but money was tight at the time, now I wish I had gone with something better). In any case, I have gotten things mostly setup, but I'm having a hell of a time getting the pattern where I want it to be. I have spent a lot of time reading up on Zuk's site, but what I'm seeing here just doesn't quite seem to make sense.

If someone with more experience wouldn't mind reading the pattern below and tell me what you think. This pattern was obtained with about .006" of Backlash, and .064" of pinion shimming.

Drive Pattern


Coast Pattern


From what I have read, it seems like the pattern I am getting is indicative of crappy Genuine gears. The way I read it, I need less backlash, and the pattern still looks a bit too deep. I started out around .088" of pinion shim, and the pattern has moved a little, but it's such an odd looking pattern, I'm not sure.

Any help would be greatly appreciated.

rokblok

iTrader: (1)

I have seen a similar pattern with another brand of gears. I wont say the name, but they were NOT yukon, sierra, richmond, etc... Anyway, it appeared to be due to the machining of the teeth. No matter how deep, shallow, tight or loose we made them, it had a funky "scratched" looking contact pattern. It WOULD NOT mesh smoothly and move all the paint off the face or the back of the teeth.

I wound up getting Sierras, and never used that BrandX again. So I cannot tell you how to fix it, other than getting diff brand. Trail Gear uses US Gear I believe, which is the maker of Yukon if I'm not mistaken....

redwolf3

Buying different, better known gears is one of the options I am contemplating. I'm not quite there yet, but given the trouble I have had so far, it's looking like a viable option. But, I'd like to give it the old college try first, if possible.

Anyone else?

MudHippy

You need a thicker pinion shim and/or less backlash. Try less backlash and see what happens. Then try adding thicker shim. You can get it close enough if you keep fiddling with it. Not rocket science...

justdifferentials

That's what us diff guys call the mark of Zoro! as in the pattern looks like a Z left by zoro more than a contact pattern. Although a couple of the teeth look like a "Pacman" head. Judging by the pattern it is hard to say. What is the backlash at? Pinion depth shim? shouldve held out a bit to get some quality gears, whoops. this install guide will be of much more help to you. Ignore heel to toe. Set by Face to flank

http://www.nitro-gear.com/installation-guides/

BigBluePile

iTrader: (3)

Looks like you need more pinion shim...


www.gearinstalls.com

redwolf3

Backlash is at .006" in that picture. I tried tightening up all the way to .004", but it didn't seem to make any real noticeable difference.

.064" currently. It started at .084", then I went up to .094" which seemed to move it more to the heel, so I started going down. The pattern seems to be more at the toe now... but it was such an odd pattern, I wasn't quite sure what to make of it.

The general consensus seems to be that I need more shim. I know I read one install on Zuk's site that said with the Genuine (Jen-u-wine?) gears he had to start at close to .110" shim in one set, so maybe that's the way I am going to go.

I have actually ordered a new set of Quality gears now, and I'm just waiting for those. In the meantime, I'm going to keep playing with these, just to try and get a feel for how best to adjust them.

Any feedback is still greatly appreciated, as I like to learn as much as I can about this sort of stuff, regardless of if I really need it now or not.

redwolf3

Ya, I've been living on Zuk's site for about 2 or 3 weeks. the problem is, I wasn't seeing anything that quite looked like what I was seeing, that's why I came here. It's possible I'm just not paying attention to the correct part of the pattern at this time though to properly interpret and relay it to Zuk's site.

ZUK

iTrader: (1)

That is one of those Genuines that will never give a good pattern...time for a new gear.

rokblok

iTrader: (1)

What is the best brand in your experience Zuk? For Toyotas. I used Sierra alot when I worked at a shop in Utah.

justdifferentials

Nitro Gear for sure.

redwolf3

Well, I went ahead and ordered some higher quality gears. This time I went with some Trail-Gear Trail Creeper gears. From all my research these were high quality gears, often times they are the same as Yukons.

In my case, I received a set of Yukon gears, so we should be good to go.

So far, I have done one pass of setup. The pattern I received this first pass were leaps and bounds better than what I received with the other gears. Nice, wide pattern. First pass tonight was too shallow, but it looks like I will be able to set it much better now.

I will post updated pictures with patterns with the new gears once I'm done, just so others who have similar issues can see the difference in the patterns.

Thanks a gain guys for your help and guidance.

MudHippy

Nice link.


What's the word? Oh yeah, biased. As in, your statement is a little biased. Don't ya think?

BTW, OEM gears FTW!!!

justdifferentials

Totallly, Yes I am biased, because I am also very experienced