First time setting up rear end. - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 01-17-2013, 11:54 AM
Registered User
 
Last photo:
Join Date: Dec 2012
Posts: 17
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
First time setting up rear end.

Hey guys! Im trying to get my rear end squared away so I can get it bolted back under the truck (47 Dodge). The rear end in question is a 8.5 10 bolt with Detroit True Trac and Richmond 3.73s.

I have been messing around with pinion shims and backlash for about 5 hours now and got a pattern that looks decent....to me!? I want to get some professionals opinions on it to make sure Im on the right track since this is my first time messing with this.

The drive side pattern is the first photo below and the coast is the second:

any help is greatly appreciated! Im going at this semi-blind so I could use some help. Thanks!
Attached Thumbnails
Click image for larger version

Name:	IMG_20130117_122912.jpg
Views:	116
Size:	896.2 KB
ID:	70671   Click image for larger version

Name:	IMG_20130117_122926.jpg
Views:	105
Size:	972.0 KB
ID:	70672  

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-17-2013, 01:00 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,117
Wiki Edits: 0

Thanks: 25
Thanked 266 Times in 249 Posts
Try this Precision Gear - PG Tech - Contact Patterns
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-17-2013, 01:33 PM
big gear head's Avatar
High Performance Rear Ends
 
Last photo:
Join Date: Nov 2009
Location: Central City, KY
Posts: 2,046
Wiki Edits: 0

Thanks: 10
Thanked 411 Times in 354 Posts
Looks like the pinion needs to go a little deeper. Try adding about .003 to the pinion shim.

Use an axle to turn everything when checking the pattern. Be sure that you have the pinion bearing preload set correctly each time you check it. If you are not consistant with the bearing preload then the pattern changes will be confusing. Add a drop of oil to the marking compound to thin it slightly and make several revolutions with the ring gear in both directions to wipe away the compound enough to make the pattern clear and easy to read.
Reply With Quote Quick reply to this message
The Following User Says Thank You to big gear head For This Useful Post:
Crosley (05-10-2013)
  #4 (permalink)  
Old 01-18-2013, 12:37 PM
Registered User
 
Last photo:
Join Date: Dec 2012
Posts: 17
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks guys!

Gear head I went with your suggestions and Im now running a .035" shim under my pinion with .010" backlash (on the first pattern I posted I had a .032" shim and .012 backlash)

This is the pattern I have now (pictured below: 1st pic-drive pattern, 2nd pic-coast)

Thanks again!
Attached Thumbnails
Click image for larger version

Name:	drive pattern5.jpg
Views:	84
Size:	918.5 KB
ID:	70710   Click image for larger version

Name:	coast pattern5.jpg
Views:	72
Size:	998.5 KB
ID:	70711  
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-18-2013, 01:16 PM
big gear head's Avatar
High Performance Rear Ends
 
Last photo:
Join Date: Nov 2009
Location: Central City, KY
Posts: 2,046
Wiki Edits: 0

Thanks: 10
Thanked 411 Times in 354 Posts
Yes, that is better. Look at the drive pattern in the first post. Notice that it favors the face of the tooth and the root is curved and not as long as the face. In the second set the pattern is about equal at the face and root of the tooth, which is what you are looking for. Many people get hung up on heel to toe, when root to face is what is most important. You probably will not be able to move this pattern off of the toe, so I wouldn't worry about that. Notice that your coast pattern is still favoring the face a little. You might try adding about .002 to .003 more to the pinion shim and see if it moves the coast side closer to the root without messing up the drive side.
Reply With Quote Quick reply to this message
The Following User Says Thank You to big gear head For This Useful Post:
Crosley (05-10-2013)
  #6 (permalink)  
Old 01-18-2013, 03:44 PM
Registered User
 
Last photo:
Join Date: Dec 2012
Posts: 17
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks again gear head!!

Here is the set up with .038" shim under pinion, .008" backlash and between 15-20 in/lbs of preload on the pinion nut. Let me know what you think.

drive pattern-1st pic, coast-2nd pic
Attached Thumbnails
Click image for larger version

Name:	drive pattern4.jpg
Views:	71
Size:	913.3 KB
ID:	70713   Click image for larger version

Name:	coast pattern4.jpg
Views:	66
Size:	886.6 KB
ID:	70714  
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-18-2013, 04:07 PM
big gear head's Avatar
High Performance Rear Ends
 
Last photo:
Join Date: Nov 2009
Location: Central City, KY
Posts: 2,046
Wiki Edits: 0

Thanks: 10
Thanked 411 Times in 354 Posts
The coast side looks much better, but the drive side looked a little better before. Try increasing the backlash by about .002 and see what happens to the drive side.
Reply With Quote Quick reply to this message
The Following User Says Thank You to big gear head For This Useful Post:
Crosley (05-10-2013)
  #8 (permalink)  
Old 01-18-2013, 05:38 PM
Registered User
 
Last photo:
Join Date: Dec 2012
Posts: 17
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by big gear head View Post
The coast side looks much better, but the drive side looked a little better before. Try increasing the backlash by about .002 and see what happens to the drive side.
Ok will do! Im gonna take .005 off of one side and add it to the other to increase the backlash and see what that looks like. Ill post the pictures when I get the pattern. Thanks for all your help! Ive heard that reading a pattern correctly is more of an art than a science, so it has helped having someone who knows what to look for. Thanks bud!
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 01-18-2013, 06:59 PM
Registered User
 
Last photo:
Join Date: Dec 2012
Posts: 17
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Gear head,
I was only able to adjust the backlash in .005" increments since thats what shims came with my richmond kit. I adjusted the pinion shim to .038" and adjusted the carrier by .005" and the backlash ended up at .012".

Personally, Id like to stay at .010" or lower, but not sure if the allowance works both ways. Ive found through research that .008"-.010" (.010 is stamped on my gears) is where you want to run it, so not sure if .012" would fly?

If I went up to .040" would this tighten up the backlash if I left the carrier shims the way they are? Or should I just run with the .035" pinion shim and take everything back to the way I had it in my second pattern I posted?
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 01-18-2013, 07:51 PM
big gear head's Avatar
High Performance Rear Ends
 
Last photo:
Join Date: Nov 2009
Location: Central City, KY
Posts: 2,046
Wiki Edits: 0

Thanks: 10
Thanked 411 Times in 354 Posts
The pattern is probably better with the .038 shim. If you can get the backlash to .010 it would move the drive pattern a little more to the heel and possibly make it look right. Increasing the backlash moves the pattern toward the heel. Closing the backlash moves the pattern toward the toe. Increasing the pinion shim moves the pattern toward the root and taking shim out of the pinion moves the pattern toward the face. Don't try to make up for backlash by changing the pinion depth.

If you can add some shim to the right side without taking anything out of the left side it might move the backlash .002. Do you have the shims tight enough that youc an not pull the differential out by hand? If you can't get the backlash to .010 then stay with .008 and .038 pinion shim.
Reply With Quote Quick reply to this message
The Following User Says Thank You to big gear head For This Useful Post:
Crosley (05-10-2013)
  #11 (permalink)  
Old 01-18-2013, 08:18 PM
Registered User
 
Last photo:
Join Date: Dec 2012
Posts: 17
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ok sounds good! I will mess with it and see what I can come up with. Ill post back and let you know what I find out. Thanks for the quick response!

Right now my carrier is pretty snug and with just the carrier in place it has drag and can spin almost one full turn. To get it out I have to use a pry bar and cant get it out by hand alone, so I believe my shims are good? At least for set up, I may add .005" to each side to preload them on final assembly?
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 01-19-2013, 05:51 AM
big gear head's Avatar
High Performance Rear Ends
 
Last photo:
Join Date: Nov 2009
Location: Central City, KY
Posts: 2,046
Wiki Edits: 0

Thanks: 10
Thanked 411 Times in 354 Posts
I wouldn't try adding .005 to each side if it's already that tight. You will probably damage your shims if you try that. Maybe just try adding .005 to the right side to open up the backlash just a little.

I know that this is a little late, but if you decide to do another gear sometime don't get a Richmond installation kit, or a Ratech kit or anything else that Jeg's or Summit sell. The kits that DTS, Tom's Differentials and Randy's Ring & Pinion sell have the super shim sets in them. You can make much more accurate backlash adjustments with these, and they are much easier to use. The shims in the other kits are just not good enough.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 01-19-2013, 07:40 AM
Registered User
 
Last photo:
Join Date: Dec 2012
Posts: 17
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Yea, I thought that this kit would come with the adjustable shim stacks that adjust by smaller increments but it didnt and another lesson is learned!

I will still try to add a little to the right side to open the .008 to .010 and see what it reads.

So do you think the .038 pinion shim is the more ideal pattern if i can get the backlash squared away?

Thanks gear head!
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 01-19-2013, 08:27 AM
big gear head's Avatar
High Performance Rear Ends
 
Last photo:
Join Date: Nov 2009
Location: Central City, KY
Posts: 2,046
Wiki Edits: 0

Thanks: 10
Thanked 411 Times in 354 Posts
If you can get the backlash to .010 we will see what the pattern looks like. You may need to go back a little on the pinion shim if the drive pattern doesn't look better. If you could take the pinion shim to .037 it might help. I've got a few thousand shims, so making small adjustments is no problem for me. For the guy who only has about 10 shims from one installation kit it's a little harder.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 01-19-2013, 09:18 AM
Registered User
 
Last photo:
Join Date: Dec 2012
Posts: 17
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I was able to get the backlash to .009" by adding a .005" shim to the right side carrier. My pinion shim measures .038" and this is the pattern I was able to obtain. Let me know what you think?

This looks way better than my very first pattern that I started with and its been awesome adjusting it and being able to see how the pattern changes. Im glad I didnt call it good enough with the original!?
Attached Thumbnails
Click image for larger version

Name:	drive pattern6.jpg
Views:	106
Size:	875.7 KB
ID:	70724   Click image for larger version

Name:	coast pattern6.jpg
Views:	93
Size:	882.0 KB
ID:	70725  
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
need help setting mechanical advance(my first time) xzero117 Hotrodding Basics 1 10-04-2012 12:42 PM
setting up a 4baron a 9in ford rear end in a 32 fo show off Suspension - Brakes - Steering 3 03-03-2012 12:43 PM
first time rear-end rebuild biscuitville Transmission - Rearend 4 02-24-2010 09:12 PM
Ford 9" rear end vs stock 89 chevy truck rear end jimmy p Transmission - Rearend 2 12-07-2005 03:28 AM
Tranny + Rear End going out at same time? 94silverado4x4 Transmission - Rearend 3 03-31-2004 03:38 PM


All times are GMT -6. The time now is 08:48 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.