Need help with gear swap issues

[ShaneMK]

Hey y’all, I just got finished working on my Jeep today and I have a few questions. I’ve tried to get the gear marking right a few times and I can’t seem to get it right, I was real close but it was slightly too deep so I pulled a shim from behind the pinion race and put in one that was just a little thinner. Well I went to put it all back together no snags or anything. I DID over tighten the pinion but just a little and my preload was 30 (previously it was 20 in/lbs every time) but I figured it would be good enough just to see what my pattern would look like. I ran my pattern and on the drive side it was on the heel and the coast was on the toe (right before I did that shim adjustment they were perfectly in the middle just a little too deep).

My main question is what do I need to adjust to get it back twords the middle of the ring gear.
By the way this is a Dana 30, I’m installing 4.88 gears.

 

[ShaneMK]

From what I understand this means I have to decrease the pinion depth shim, is this correct? This is the contact pattern interpreter I’ve been using.

 

[someguysjeep]

every change (unless super minute) is/can be x2. if you move the pinion depth you likely need to adjust the backlash as well, they work in tandem.

if the pinion moves away the gear moves toward center to maintain the backlash spec.

looks like heel/toe #2, and says the pinion needs pulled back some.

any pics of the 1st set?
pull 5 thou out of the pinion stack and try that.
are you using set up bearings on the carrier? you have the ability to change those shims?

@hosejockey61 < he's more familiar with this.

 

[ShaneMK]

every change (unless super minute) is/can be x2. if you move the pinion depth you likely need to adjust the backlash as well, they work in tandem.

if the pinion moves away the gear moves toward center to maintain the backlash spec.

looks like heel/toe #2, and says the pinion needs pulled back some.

any pics of the 1st set?
pull 5 thou out of the pinion stack and try that.
are you using set up bearings on the carrier? you have the ability to change those shims?

@hosejockey61 < he's more familiar with this.

Yeah that’s what it was looking like to me, I’ll pull some more off the pinion. And yes I am using set up bearings so any adjustments that I need to make can be made quickly. About to start on it again today, ill update when I get some pinion shims pulled and try and get that pattern in the middle. I’ve just been having a hard time getting it it the middle and having good contact with the ring gear, usually when I get it in the middle it’s either biting too deep in the ring gear or it’s too shallow. Let me try this again.

 

[someguysjeep]

hosejockey61 is pretty good with this stuff hopefully he'll chime in on the next set for ya.

i got my front axle in like 3 sets. the rear took me like 12 to get it right , be patient and make calculated moves.

 

[ShaneMK]

hosejockey61 is pretty good with this stuff hopefully he'll chime in on the next set for ya.

i got my front axle in like 3 sets. the rear took me like 12 to get it right , be patient and make calculated moves.

Yeah absolutely, I haven’t started to put my rear back together at all, but this is my 6th attempt on the front, taking it back out now going to pull a few tho hopefully that’ll get it right where I want it.

 

[ShaneMK]

So I’ve pulled everything 4 times since my last message and removed shims every time. I’ve ended up with no shims behind the pinion race and I have a similar heel/toe pattern pictured in #2, but now it’s contacting more of the crown of the ring gear and appears to be too shallow.

Any opinions on what to do would be a huge help, can’t seem to get this to work well at all

 

[ShaneMK]

Any help or advice would help a lot.

 

[someguysjeep]

your bringing the backlash back in range at every change of the pinion depth?

do you know what existed under the original pinion ? go to that bring the backlash to spec and see what you get.

 

[ShaneMK]

your bringing the backlash back in range at every change of the pinion depth?

do you know what existed under the original pinion ? go to that bring the backlash to spec and see what you get.

Yes I’ve adjusted backlash every time I’ve changed pinion depth. Originally there was no shims behind the pinion race.

 

[ShaneMK]

My process has been pull everything out carefully. Unbolt the carrier and set it down, then unbolt the pinion and set it down then remove the inner pinion race, change the shims. Then put the pinion back in and put the nut back on and tighten it until I get 20 in/lbs of preload. (I did over tighten it once to 30 in/lbs, and as I said before that’s when I started getting these weird readings, but even if I had crushed the bearings it would make the pinion farther away not closer. Plus the bearings looks fine visually.) then I pop the carrier in, bolt it down and torque it to 70 ft/lbs and then check my backlash. I try to keep it around 5-6 tho. If it’s not in spec then I pull it out and adjust shims accordingly (pulling from one side and putting it on the other). Then I put on my marking paste and put as much force as I can on the ring gear using a leather gloved hand. Then I put a drill on the pinion nut and spin it at a reasonable speed, then reverse the drill and then check the pattern.

Anything inherently wrong with this setup? If so please let me know. Spinning the pinion nut with a drill was something I got from a YouTube video and it seemed to work fine for him.

 

[hosejockey61]

My process has been pull everything out carefully. Unbolt the carrier and set it down, then unbolt the pinion and set it down then remove the inner pinion race, change the shims. Then put the pinion back in and put the nut back on and tighten it until I get 20 in/lbs of preload. (I did over tighten it once to 30 in/lbs, and as I said before that’s when I started getting these weird readings, but even if I had crushed the bearings it would make the pinion farther away not closer. Plus the bearings looks fine visually.) then I pop the carrier in, bolt it down and torque it to 70 ft/lbs and then check my backlash. I try to keep it around 5-6 tho. If it’s not in spec then I pull it out and adjust shims accordingly (pulling from one side and putting it on the other). Then I put on my marking paste and put as much force as I can on the ring gear using a leather gloved hand. Then I put a drill on the pinion nut and spin it at a reasonable speed, then reverse the drill and then check the pattern.

Anything inherently wrong with this setup? If so please let me know. Spinning the pinion nut with a drill was something I got from a YouTube video and it seemed to work fine for him.

I always tell everyone who is learning to set up gears.... Take it too deep and then bring it back too shallow. Then you have it bracketed and can start focusing on getting it perfect. I would be surprised if that's your pattern without a single shim...

 

[ShaneMK]

I always tell everyone who is learning to set up gears.... Take it too deep and then bring it back too shallow. Then you have it bracketed and can start focusing on getting it perfect. I would be surprised if that's your pattern without a single shim...

This was the pattern with no shims behind the inner pinion race, I still have the oil slinger one (not the stock one but the one that came with the kit, it was about half the thickness).

 

[hosejockey61]

This was the pattern with no shims behind the inner pinion race, I still have the oil slinger one (not the stock one but the one that came with the kit, it was about half the thickness).

View attachment 263376

View attachment 263377

Ok. So that slinger is also a shim, how thick? Make BIG changes so you can see what it's doing. I would add 10-15 thou and see what your pattern does.

 

[ShaneMK]

I always tell everyone who is learning to set up gears.... Take it too deep and then bring it back too shallow. Then you have it bracketed and can start focusing on getting it perfect. I would be surprised if that's your pattern without a single shim...

But I ran into something very interesting, not exactly sure how it helped, but I ended up adding a few shims (can’t remember the exact numbers, I have to pull it out again soon so I’ll measure then). I added a few shims behind the pinion race and it centered the pattern on the ring gear but it’s also too deep in the ring gear IMO. But whenever I remove any of the shims from behind the pinion race it does bring the bite up higher on the ring gear but it spreads it out more and more until it’s similar to the pattern with no shims.

The following pics are of the pattern with a few shims behind the pinion race.

 

[ShaneMK]

Ok. So that slinger is also a shim, how thick? Make BIG changes so you can see what it's doing. I would add 10-15 thou and see what your pattern does.

Hey sorry took me a few to send the last message. Yeah I think I added somewhere around 10-15 tho and I was able to get it centered but it looks like it’s biting too deep in that ring gear. Yes the oil slinger is also a shim. I’m not sure if there is an adjustment I can make to get that pattern higher up on the ring gear without pulling any shims from behind the pinion race (when I pull shims from behind the race it makes that pattern space out further like it was with no shims).

 

[1904-06LJR]

The below pic grab is from the Billa Vista write up. Your last pattern above appears acceptable.

Figure 29 – Acceptable drive pattern.

Pattern is centered between top and root and between heel and toe with diffuse edges. Note the thin strip of yellow compound indicating the required clearance between pattern and top of tooth

 

[ShaneMK]

The below pic grab is from the Billa Vista write up. Your last pattern above appears acceptable.

View attachment 263395
Figure 29 – Acceptable drive pattern.

Pattern is centered between top and root and between heel and toe with diffuse edges. Note the thin strip of yellow compound indicating the required clearance between pattern and top of tooth

Well the reason I was worried about the last pattern I showed was it has a real sharp edge on the bottom. Maybe I’m misreading it but I’d rather take it out a few times than messing it up. Posting a better pic of that “sharp” bottom edge on the marking
Its centered up in the gear nice but just appears to have that sharp edge on the bottom.
Drive

Coast

If it’s okay to run with that sharp edge on the bottom then good but everything that I’ve read it should be a bit closer to the crown of the ring gear.

 

[someguysjeep]

looks like your a bit deep into the root, but more in the ballpark now.
whats the backlash? does it have room to open ? your range is .006-.010, yes?

 

[ShaneMK]

looks like your a bit deep into the root, but more in the ballpark now.
whats the backlash? does it have room to open ? your range is .006-.010, yes?

Yeah that’s what I was thinking, and everything I’ve read about being too deep in the root means I need to remove a few tho in pinion shim, but when I do that I get that spread out pattern and that also seems to be bad. And yes every adjustment I do to the pinion shims I adjust backlash accordingly, I keep it around 5-7 tho that way it doesn't open up too far once everything starts breaking in.