posi/spool - 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
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 10-13-2004, 05:22 AM
New Member
Join Date: Oct 2004
Location: houston
Age: 32
Posts: 26
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts

I know next to nothing about components in the drivetrain, just the basics. Could someone please explaine the difference and pros/cons of a rear with poistractions vs. spool? Thanks.

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 10-13-2004, 12:03 PM
OneMoreTime's Avatar
Hotrodders.com moderator
Last wiki edit: Health and safety in the shop or garage
Last journal entry: Yard Dog pic
Last photo:
Join Date: Jul 2004
Location: Washington State
Age: 72
Posts: 8,841
Wiki Edits: 3

Thanks: 220
Thanked 459 Times in 410 Posts

Well I will try and explain it..a bit..

A spool locks the rear end completely and does not give any differential action at all when cornering or parking..any of the things we do in a street car..We use spools in dirt racing and in some 1/4 mile cars to give a direct drive to both wheels..

A posi allows differential action so the car can corner and a posi only locks up when one of the tires spin..much beter on a street car or a pavement roundy round car..

Posi tracs are used in street driven pickups to help with extra traction when off in the mud and such..

Open rear will send power to the tire that has the least traction..what one gets on ice and slicky when one wheel spins and the other one just sets still..Open rears allow differential action when cornering and parking..

So for the street car we use a posi if possible...

Does that help ya..??
I have tried most all of it and now do what is known to work..
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-13-2004, 02:42 PM
New Member
Join Date: Oct 2004
Location: houston
Age: 32
Posts: 26
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Yeah, that did help. Thank you.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-13-2004, 05:03 PM
Registered User
Last wiki edit: Mopar tapered axle rear brake conversion
Last journal entry: What I'm doing now...
Last photo:
Join Date: Jan 2002
Posts: 4,263
Wiki Edits: 49

Thanks: 0
Thanked 8 Times in 7 Posts
To expand just a little bit..... When you go around a corner the inside wheel will turn less revolutions than the outside wheel. This happens simply because the outside wheel has to travel further than the inside wheel. A spool will not allow this to happen. When turning a corner the inside wheel will try to turn the same as the outside wheel which puts great strain on the axles as well as causes excess tire wear. Posi units allow traction to both tires when needed but allow this "differential" action when cornering. Spools are also very dangerous on a street car in the rain for the reasons stated above.

Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


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

All times are GMT -6. The time now is 06:44 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.