Pinion offset? - 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 04-09-2013, 07:58 PM
Registered User
 

Last journal entry: Old guy's low cost Chev coup.
Last photo:
Join Date: Apr 2011
Location: Baytown, Texas
Posts: 68
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
Pinion offset?

Ran into one today that is blowing my mind. Got my driveshaft bolted in and it didn't look quite perpendicular to the rear end. Kind of looked like an angle tween the differential pinion shaft and the transmission output shaft. So did some measuring cause I obviously mismeasured when I made my transmission mount. So, unbolted everything forward of the rear end (1998 Camaro posi) and slid it over to where it all looked perpendicular (90 deg). This moved my eng and trans over to where it is two inches closer to the right frame rail thean the left. That can't be right ! conclusion is that the pinion shaft on rear end is not dead center, although it appears to be. I am measuring something rong here. What have I forgotten here? I thought maybe leaf spring backwards or something, but they all measure out ok and the center pins are ok and centered but seems that the Camaro pinion shaft is not centered and when squaring everything out to "square" it translates to moving engine and transmission over. Sorry for long explanation, but it has me baffled. Always thought that the front and rear universals and driveshaft were dead center on all cars. Is that what I get for thinking all by myself again? What have I missed here? Thank you, in advance, for any help on this. trans is th700 chevy behind 94 350, rear end again is 98 camaro. all in 39 chev coupe chassis. Thank you !

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 04-09-2013, 08:23 PM
Registered User
 
Last photo:
Join Date: Feb 2013
Posts: 88
Wiki Edits: 0

Thanks: 0
Thanked 16 Times in 16 Posts
I do rears for a living,almost all your rears are offset,most Chevys,1",most 9" Fords 2 1/2",some as much as 4",if you read up on driveshaft angles,you"ll find,if you line a driveshaft up perfectly,vertically,and horizontally,it will most likely vibrate,the offset on your Chevy rear is fine,make sure you have about 2 deg. difference between,trans./driveshaft and driveshaft/rear end,(up and down)and it will run smooth if everything else is good.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 04-09-2013, 08:56 PM
sedanbob's Avatar
Registered User
 
Last photo:
Join Date: Oct 2008
Location: St. Louis
Age: 66
Posts: 626
Wiki Edits: 0

Thanks: 61
Thanked 80 Times in 77 Posts
Side to side offset is just like vertical offset - you want some, and you want the angles at each end to be opposite. As long as your rear axle and transmission output shaft are perpendicular, you'll be fine.
Reply With Quote Quick reply to this message
The Following User Says Thank You to sedanbob For This Useful Post:
Crosley (04-09-2013)
  #4 (permalink)  
Old 04-09-2013, 10:02 PM
Registered User
 

Last journal entry: Old guy's low cost Chev coup.
Last photo:
Join Date: Apr 2011
Location: Baytown, Texas
Posts: 68
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
Actionjk and sedanbob, thank you for the information. Wow thought I had a real problem here and getting ready to fire up the torch to fix it. One thing I learn over again every day is: There is a whole lot more that I don't know than I do. Made my day, Thank you again. Been a great day till then, now still great day and learned something new. And got driveshaft fitted and pwr steering installed. Things coming together. Haven't yet tried figure the vertical angles on d/s as still have body off and only weight is in front. What's best (easiest) way to measure those angles? Someone mentioned laser pointer, but don't know how to do that.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 04-09-2013, 11:22 PM
sedanbob's Avatar
Registered User
 
Last photo:
Join Date: Oct 2008
Location: St. Louis
Age: 66
Posts: 626
Wiki Edits: 0

Thanks: 61
Thanked 80 Times in 77 Posts
Easiest is probably a magnetic angle finder - cheap and available at most hardware stores. Rotate the rear until the yoke is vertical to measure that end, and the end of the output shaft on the transmission.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 04-10-2013, 07:14 AM
big gear head's Avatar
High Performance Rear Ends
 
Last photo:
Join Date: Nov 2009
Location: Central City, KY
Posts: 2,168
Wiki Edits: 0

Thanks: 15
Thanked 525 Times in 442 Posts
All of the 12 bolt, 8.2, 8.5 and 7.5 Chevy car rear ends that I know of have the pinion offset 1/2 inch to the right. This makes the pinion 1 inch closer to the right side than the left.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 04-10-2013, 07:39 AM
Registered User
 
Last photo:
Join Date: Jul 2004
Location: At Speed
Age: 51
Posts: 1,399
Wiki Edits: 0

Thanks: 2
Thanked 41 Times in 39 Posts
Most all GM c-clip rears have the same length axle in both sides, meaning the diff cross pin is what is centered in the car.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 04-10-2013, 10:11 AM
Registered User
 

Last journal entry: Old guy's low cost Chev coup.
Last photo:
Join Date: Apr 2011
Location: Baytown, Texas
Posts: 68
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
Like I said before: each day is a reminder to me that what I know is nothing compared to what I don't. I appreciate the help. Can put it all back together now and tighten everything up. Will have to see what can find to figure the D/S angles, but doesn't sound that hard and have looked over what has been posted here on what to look for. I thank you all for the help on this and it has really taken a load off.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 04-10-2013, 08:55 PM
Cape Cod Bob's Avatar
Registered User
 
Last wiki edit: How to title a hot rod Last photo:
Join Date: Jul 2007
Location: MA
Posts: 1,141
Wiki Edits: 1

Thanks: 0
Thanked 30 Times in 20 Posts
Quote:
Originally Posted by fasteddy_1947 View Post
Like I said before: each day is a reminder to me that what I know is nothing compared to what I don't. I appreciate the help. Can put it all back together now and tighten everything up. Will have to see what can find to figure the D/S angles, but doesn't sound that hard and have looked over what has been posted here on what to look for. I thank you all for the help on this and it has really taken a load off.
Yes, put it together and tighten up. Don't weld the spring to axel brackets yet. Wait till all the weight is on then check the pinion angles. The driveshaft should be the last thing you make before getting on the road. IMHO
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 04-10-2013, 11:04 PM
Registered User
 

Last journal entry: Old guy's low cost Chev coup.
Last photo:
Join Date: Apr 2011
Location: Baytown, Texas
Posts: 68
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
Yes, I've read that here before. Going to be awhile before ready for that though. Extensive body work next, lots of rust (or holes, where there was rust before sandblasted body, kinda like Swiss cheeze). Was lucky with the frame as it pretty solid all way around. Thank you for heads up reminder on that.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 04-10-2013, 11:17 PM
evolvo's Avatar
Heathen
 
Last photo:
Join Date: Nov 2006
Location: Port Hadlock, Wa
Posts: 575
Wiki Edits: 0

Thanks: 49
Thanked 66 Times in 64 Posts
http://www2.dana.com/pdf/J3311-1-DSSP.pdf

http://www.iedls.com/asp/admin/getFi...&TID=28&FN=PDF

A little lite reading
Reply With Quote Quick reply to this message
The Following User Says Thank You to evolvo For This Useful Post:
fasteddy_1947 (04-16-2013)
  #12 (permalink)  
Old 04-16-2013, 07:36 PM
Registered User
 

Last journal entry: Old guy's low cost Chev coup.
Last photo:
Join Date: Apr 2011
Location: Baytown, Texas
Posts: 68
Wiki Edits: 0

Thanks: 2
Thanked 3 Times in 3 Posts
Just finished the 'light reading' you sent along. Takes a lot of the guess-work, and hope I aint really screwing this up-work out of the mix. Thank you for taking the time to send it along.
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:
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
Differentail pinion shaft offset ? supercab78 Hotrodding Basics 6 10-21-2012 07:03 PM
offset pinion???? GUNTHER19820 Transmission - Rearend 4 06-25-2009 01:53 PM
Offset rearend and pinion angle murrsue Transmission - Rearend 5 05-19-2007 06:51 PM
ford 9" pinion offset 85406 Transmission - Rearend 8 10-29-2004 07:46 PM
9 inch pinion offset ctb460 Transmission - Rearend 9 01-03-2003 03:48 PM


All times are GMT -6. The time now is 09:23 AM.


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.