Ring and pinion set up question

pbp1 · 02-21-2015, 09:05 PM

Moving the pinion in or out will not change the contact pattern from heel to toe, it will only move the pattern deeper into the root of the teeth or out toward the top edge of the tooth. Heel to toe is mostly affected by the cut of the gear and the alignment of the pinion bore machining to the carrier bearing bore. What you are looking for is the pattern to be centered between the root of the tooth and the edge of the tooth with a rounded edge on the pattern and not a pointed edge on the pattern.

Dana Fitzpatrick · 02-21-2015, 09:30 PM

Quote:

Originally Posted by pbp1

Moving the pinion in or out will not change the contact pattern from heel to toe, it will only move the pattern deeper into the root of the teeth or out toward the top edge of the tooth. Heel to toe is mostly affected by the cut of the gear and the alignment of the pinion bore machining to the carrier bearing bore. What you are looking for is the pattern to be centered between the root of the tooth and the edge of the tooth with a rounded edge on the pattern and not a pointed edge on the pattern.

The pattern does come to a point at the root side of the tooth. Not at all bullet shaped. I did increase the pinion shim to .022. It was .018, not .016. How do I get rid of the sharp point? Back lash is set at .008-.010. The ring gear is marked .008 from Motive.

Dragsinger · 02-21-2015, 09:35 PM

Dana, The Strange housing could indeed require a different shim. The above posted suggestions were for a factory GM housing.

You can search the web, even Youtube, for "rear gear setup patterns" might find some help.

Also, consider talking with Strange about a suggested shim thickness.

Did the housing have a gear set? If so, the original shim would be a good starting point.

Ed Wright · 02-21-2015, 11:26 PM

Gear sets typically come with an instruction sheet, with pictures of example patterns, and what is required to correct them. I would never do one without my old Zoom "gear setter", for measuring pinion depth. Puts them dead nuts. Good investment imho.

Dana Fitzpatrick · 02-21-2015, 11:47 PM

Looking at the Richmond instructions, it looks as though I have low tooth contact.According to the instructions, this is solved by increasing the pinion cone setting. Does this sound like I need to decrease the pinion shim thickness?

Ed Wright · 02-21-2015, 11:55 PM

You mean Pinion Depth? i've never heard the term Pinion Cone. More shim puts it deeper. I have never seen one require a shim as thin as you mentioned. I can't remember ever using a shim thinner than .028". As has been mentioned, .030" to .033" is very common.

Alan Roehrich · 02-22-2015, 12:17 AM

Try a 0.035" shim between the pinion gear and the pinion, and 0.008" to 0.010" back lash, as measured at the outside end of the ring gear teeth, measured 4-8 places around the ring gear. Make sure you're measuring the back lash with the dial indicator as close to perpendicular to the rotation of the gear as possible.

pbp1 · 02-23-2015, 01:24 AM

If the pattern comes to a point on the root side, you need to pull the pinion farther away from the ring gear, which in this case would mean removing some pinion shim. That being said, removing shim would move you outside the normal range on shim. I would make sure that the inner pinion race is fully seated in the housing bore as this would give you a false reading.

02-21-2015, 09:05 PM	#1
pbp1 Junior Member Join Date: Mar 2013 Posts: 80 Likes: 12 Liked 27 Times in 6 Posts	Re: Ring and pinion set up question Moving the pinion in or out will not change the contact pattern from heel to toe, it will only move the pattern deeper into the root of the teeth or out toward the top edge of the tooth. Heel to toe is mostly affected by the cut of the gear and the alignment of the pinion bore machining to the carrier bearing bore. What you are looking for is the pattern to be centered between the root of the tooth and the edge of the tooth with a rounded edge on the pattern and not a pointed edge on the pattern.

02-21-2015, 09:35 PM	#3
Dragsinger VIP Member Join Date: Jul 2008 Location: Liberty City [East Texas] Posts: 1,760 Likes: 5 Liked 99 Times in 60 Posts	Re: Ring and pinion set up question Dana, The Strange housing could indeed require a different shim. The above posted suggestions were for a factory GM housing. You can search the web, even Youtube, for "rear gear setup patterns" might find some help. Also, consider talking with Strange about a suggested shim thickness. Did the housing have a gear set? If so, the original shim would be a good starting point. __________________ Larry Woodfin 471W

02-21-2015, 11:26 PM	#4
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Ring and pinion set up question Gear sets typically come with an instruction sheet, with pictures of example patterns, and what is required to correct them. I would never do one without my old Zoom "gear setter", for measuring pinion depth. Puts them dead nuts. Good investment imho. __________________ Ed Wright 4156 SS/JA

02-21-2015, 11:47 PM	#5
Dana Fitzpatrick Member Join Date: May 2009 Posts: 148 Likes: 4 Liked 10 Times in 6 Posts	Re: Ring and pinion set up question Looking at the Richmond instructions, it looks as though I have low tooth contact.According to the instructions, this is solved by increasing the pinion cone setting. Does this sound like I need to decrease the pinion shim thickness?

02-21-2015, 11:55 PM	#6
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Ring and pinion set up question You mean Pinion Depth? i've never heard the term Pinion Cone. More shim puts it deeper. I have never seen one require a shim as thin as you mentioned. I can't remember ever using a shim thinner than .028". As has been mentioned, .030" to .033" is very common. __________________ Ed Wright 4156 SS/JA

02-22-2015, 12:17 AM	#7
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,105 Likes: 1,564 Liked 1,789 Times in 408 Posts	Re: Ring and pinion set up question Try a 0.035" shim between the pinion gear and the pinion, and 0.008" to 0.010" back lash, as measured at the outside end of the ring gear teeth, measured 4-8 places around the ring gear. Make sure you're measuring the back lash with the dial indicator as close to perpendicular to the rotation of the gear as possible. __________________ Alan Roehrich 212A G/S

02-23-2015, 01:24 AM	#8
pbp1 Junior Member Join Date: Mar 2013 Posts: 80 Likes: 12 Liked 27 Times in 6 Posts	Re: Ring and pinion set up question If the pattern comes to a point on the root side, you need to pull the pinion farther away from the ring gear, which in this case would mean removing some pinion shim. That being said, removing shim would move you outside the normal range on shim. I would make sure that the inner pinion race is fully seated in the housing bore as this would give you a false reading.