Need gear pattern feedback

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

MtBraun

Full Access Member
Joined
Sep 27, 2017
Posts
455
Reaction score
306
Location
South Dakota
First Name
Matt
Truck Year
1984
Truck Model
K10
Engine Size
632
Setting up my first diff, front D44 on this build. First pattern, (not pictured) showed contact angled across the root and coast side was centered. I removed pinion depth shims because that pattern suggested pinion was too deep. Now I am having a really hard time making a drive side pattern. It is very faint despite putting all the resistance I can with one hand while turning with the other. You can see in the pic how the marking compound is “peeling” towards the valley in the drive side gear. The last tooth though appears to be high, which suggests I may need to add pinion depth shim.

Backlash is a little high at .009 but within spec.

I am reusing gears and am confident it wasn’t set up correctly to begin with, so is it possible incorrect gear wear is affecting the pattern? I would appreciate the experienced and critical eye. Thanks.
 

Attachments

  • 0D90D91F-5BA7-4F77-87FC-0619F0E6AFA8.jpeg
    0D90D91F-5BA7-4F77-87FC-0619F0E6AFA8.jpeg
    100.1 KB · Views: 49
  • FFD0530A-EE85-4EDD-9101-A0EAF0158091.jpeg
    FFD0530A-EE85-4EDD-9101-A0EAF0158091.jpeg
    99.4 KB · Views: 55
  • 88140BBE-DE8F-4D3A-B711-CBDC3565BCCF.jpeg
    88140BBE-DE8F-4D3A-B711-CBDC3565BCCF.jpeg
    115.8 KB · Views: 53

nvrenuf

Full Access Member
Joined
Jul 30, 2010
Posts
1,682
Reaction score
1,866
Location
Mobile, Al.
First Name
John
Truck Year
1991
Truck Model
K5
Engine Size
454
Imo, it’s too faint to read well. I’d suggest rerunning the pattern but apply a fair amount of resistance to the ring gear while turning so it imprints better.
 

MtBraun

Full Access Member
Joined
Sep 27, 2017
Posts
455
Reaction score
306
Location
South Dakota
First Name
Matt
Truck Year
1984
Truck Model
K10
Engine Size
632
Imo, it’s too faint to read well. I’d suggest rerunning the pattern but apply a fair amount of resistance to the ring gear while turning so it imprints better.
Any suggestions on resistance? I'm turning with the yoke holder and using my other hand with a glove to provide resistance against the ring. Holding as tight as I can. Seems like it should be enough resistance based off what I've seen others do.
 

nvrenuf

Full Access Member
Joined
Jul 30, 2010
Posts
1,682
Reaction score
1,866
Location
Mobile, Al.
First Name
John
Truck Year
1991
Truck Model
K5
Engine Size
454
I’ve helped a friend a few times and he will have me apply a lot of pressure to the ring (glove, shop rag in hand, etc) while he turns the pinion. With 2 people you are free to put more pressure on it, make sure the paint is wet too.
 

CalSgt

Full Access Member
Joined
Oct 3, 2021
Posts
1,466
Reaction score
3,046
Location
CA
First Name
Casey
Truck Year
1980
Truck Model
Chevy K-10 Custom Deluxe
Engine Size
350
I tap a chisel between the ring gear (or edge of carrier) and diff housing then move it to the opposite side to pattern the other direction. The ring gear pulls the chisel in tighter as you rotate the yoke, rotating back the other way while pulling the chisel lets it free.

I’ve seen people use a wooden hammer handle and other things to lever against the assembly too.

I’ve also had better results by thinning the pattern paint down by stirring in a few drops of oil or atf.

ETA: You need to have enough resistance to wipe the pattern paint clean in the center of the contact patch. The edges of the pattern won’t show otherwise, the edges should feather out gradually and not have a sharp abrupt line.

You must be registered for see images attach
 
Last edited:

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
28,956
Reaction score
23,466
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
Keep in mind, the front axle spends most of it's time running with pressure on the coast side.
 

MtBraun

Full Access Member
Joined
Sep 27, 2017
Posts
455
Reaction score
306
Location
South Dakota
First Name
Matt
Truck Year
1984
Truck Model
K10
Engine Size
632
Keep in mind, the front axle spends most of it's time running with pressure on the coast side.
With that in mind, how does the coast pattern look? I think it’s pretty close.
 

MtBraun

Full Access Member
Joined
Sep 27, 2017
Posts
455
Reaction score
306
Location
South Dakota
First Name
Matt
Truck Year
1984
Truck Model
K10
Engine Size
632
I was able to get more resistance and a better pattern. High on the drive side, good on the coast side. I think pinion need to come in deeper against the ring gear (add pinion shims). Thoughts?
 

Attachments

  • 525C3BB5-B3A8-4035-A585-77C24EA501E1.jpeg
    525C3BB5-B3A8-4035-A585-77C24EA501E1.jpeg
    89.1 KB · Views: 48
  • 0E50C831-D0C9-461B-93FF-370A2872325E.jpeg
    0E50C831-D0C9-461B-93FF-370A2872325E.jpeg
    97.3 KB · Views: 44

CalSgt

Full Access Member
Joined
Oct 3, 2021
Posts
1,466
Reaction score
3,046
Location
CA
First Name
Casey
Truck Year
1980
Truck Model
Chevy K-10 Custom Deluxe
Engine Size
350
How’s your backlash?

Moving the pinion towards the ring gear will probably tighten the backlash a little.

If backlash is on the tight end of the spec you may need to move the carrier towards the ring gear a bit when you move the pinion.
 

MtBraun

Full Access Member
Joined
Sep 27, 2017
Posts
455
Reaction score
306
Location
South Dakota
First Name
Matt
Truck Year
1984
Truck Model
K10
Engine Size
632
How’s your backlash?

Moving the pinion towards the ring gear will probably tighten the backlash a little.

If backlash is on the tight end of the spec you may need to move the carrier towards the ring gear a bit when you move the pinion.
Backlash was at .009. I ended up adding a .005 pinion shim and it patterned well. That did decrease backlash to .006 but since it was still in spec left it alone.

Overall I had a lot of fun with this. I used the SIU video on Youtube. It's a fantastic resource and you really can't screw this up based on that video.
 

Forum statistics

Threads
41,850
Posts
903,456
Members
33,362
Latest member
Dhatch84
Top