Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic
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> Is a 7.5" rear worth the hop ups?
User Name
Password
lost password?   |   register now

Thread: Is a 7.5" rear worth the hop ups? Reply to Thread
Title:
  
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :

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.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
08-03-2007 09:50 PM
biggeazy-e
Quote:
Originally Posted by ericnova72
Yes, that's an Auburn. They seem to work good with street tires, but add Slicks or Drag Radials and a 400+hp engine and they tend to "hunt" or "wander"--switching back and forth from right tire to left tire in very rapid succession, which eats up the clutch cones. This is pretty much a dragstrip- only problem as you can't hook solid enough on the street. Auburn says they have fixed this with the Pro version, but I haven't been around one yet.
IMO an Auburn is a big risk thru EBAY and I only look for Eaton style because the Auburn can't be rebuilt.
If you are within its limit I wouldn't be afraid of an Auburn at the right price.
Thanks for the info, will continue my search for parts....... If I could find one for cheap enough, I'd like to pick up a posi and gears for my 7.5 10 bolt until I finish building the 8.5/ford 9" (whichever I start working on first)..... May put those plans on hold and get into a good set of heads before the winter hits.....
08-02-2007 08:40 PM
runn141 has anyone used the richmond powertrax streetable locker for a long period of time?
08-02-2007 08:36 PM
ericnova72
7.5 worthless

Yes, that's an Auburn. They seem to work good with street tires, but add Slicks or Drag Radials and a 400+hp engine and they tend to "hunt" or "wander"--switching back and forth from right tire to left tire in very rapid succession, which eats up the clutch cones. This is pretty much a dragstrip- only problem as you can't hook solid enough on the street. Auburn says they have fixed this with the Pro version, but I haven't been around one yet.
IMO an Auburn is a big risk thru EBAY and I only look for Eaton style because the Auburn can't be rebuilt.
If you are within its limit I wouldn't be afraid of an Auburn at the right price.
08-02-2007 08:13 AM
biggeazy-e
Quote:
Originally Posted by ericnova72
8.5 rear diff with an s-shaped spring is an Eaton and is rebuildable. Of the two-plate-and-coil springs versions, there are two types. If the case is a one-piece forging, then it is updated or aftermarket Eaton version- also rebuildable. If the case has a bolt-on end cap on the pass. end then it is Auburn and has cone clutches and is NOT rebuildable.
Other things to watch out for are whether case is two series or three series(2.56 and down or 2.73 and up) and axle spline count(28 or 30)
Auburn non rebuildable- seen a few on eBay that seem fairly cheap brand new, are these quality units??



thanks for the info...
08-01-2007 06:16 PM
biggeazy-e
Quote:
Originally Posted by lumberjacknooj
Easy-e, I don't think you should have a problem with a used locker. As long as it's not damaged, or in need of rebuild- then you should be fine, assuming proper installation.

Nooj
I'm hoping so.. I have a ford 9 and an 8.5 10 bolt sitting here waiting for me to get off my......

Actually, I just missed out on a set of Richmond 3.42's and a Posi for my 8.5 brand new at a swap meet a few weeks ago for pretty cheap... hopefully they'll still have it next time the meet comes around, and hopefully it'll match my rear..
08-01-2007 04:33 PM
RPM Look at a Dana 60 as was mentioned the parts cost the same and it is bullet proof. Also cheaper to build than a 9" Ford.
08-01-2007 02:39 PM
lumberjacknooj
Quote:
if you worry about it breaking, it probably will. if you dont give a schit wether it does or not, it will last forever.
Haha! In that case- I don't give a dang It probably won't see much track time anyways (no dang tracks around here... that I know of). So, a beefed up 7.5 should hold up.

What about just shortening a stock 12 bolt? Would that be any more cost efficient than building a puny rear end into something substantial??

Easy-e, I don't think you should have a problem with a used locker. As long as it's not damaged, or in need of rebuild- then you should be fine, assuming proper installation.

Nooj
08-01-2007 12:48 PM
ericnova72
7.5 rear

8.5 rear diff with an s-shaped spring is an Eaton and is rebuildable. Of the two-plate-and-coil springs versions, there are two types. If the case is a one-piece forging, then it is updated or aftermarket Eaton version- also rebuildable. If the case has a bolt-on end cap on the pass. end then it is Auburn and has cone clutches and is NOT rebuildable.
Other things to watch out for are whether case is two series or three series(2.56 and down or 2.73 and up) and axle spline count(28 or 30)
08-01-2007 12:29 PM
biggeazy-e
Quote:
Originally Posted by ericnova72
Easy-- that photo you posted is the one to stay away from. They frag the shaft with the flyweights on it, usually at its driven point.
Thanks for the tip, how about the stock type ones(S "spring") vs the coil spring loaded?
08-01-2007 11:39 AM
ericnova72
7.5 rear

Easy-- that photo you posted is the one to stay away from. They frag the shaft with the flyweights on it, usually at its driven point.
08-01-2007 07:33 AM
biggeazy-e
Quote:
Originally Posted by ericnova72
Stay away from what is known as a Gov-Lock differential in the 8.5 rear, seems like they explode just by looking at them. Easy to identify by the big square block between the side gears, where a normal Posi has two plates w/ several springs between them.



any more info on buying a used locker/posi???
08-01-2007 12:52 AM
ericnova72
7.5 rear worthless

Stay away from what is known as a Gov-Lock differential in the 8.5 rear, seems like they explode just by looking at them. Easy to identify by the big square block between the side gears, where a normal Posi has two plates w/ several springs between them.
07-31-2007 09:14 PM
biggeazy-e Some pretty good info in here... I'm also looking for a little advice..

What do you guys think about used lockers/posi's???? (8.5 10 bolt)
Seen a bunch on eBay, and just missed out on a cheap brand new posi at a swap meeet, and I'm looking to start building my 8.5 soon....

What to look for? What to avoid???....
thanks

eazy
07-31-2007 08:45 PM
jimfulco The hop-up parts for the 7.5" will cost the same as ones for the 8.5", and it will break a lot sooner. A used 8.5 might cost you a hundred or so, and after you spend a few hundred more on it, you won't have to worry nearly as much about having to walk home.

GM used the 7.5" rear behind the anemic 2-bbl 305 for only one year in Novas, then went back to the 8.5" from then on. What does that say about the durability of a 7.5" rear?
07-31-2007 01:10 PM
killerformula Its pretty widely held amongst hotrodders that the 7.5 rear is not a great choice for any performance vehicle. I've personally seen several of them grenade behind motors that weren't that wild (sub 450 horse motors). Sure, it depends on hook-up etc. I don't know what you intend to do with this car, but for my money a rear end is kinda worthless if its killing your 60' times because you can't afford to put the coals to it until you're already rolling.

I'd also say that the "wait and see" philosophy isn't a really good choice. You can break a rear end and be lucky, the best that happens is you have a little unexpected work and some expense. Of course, you could also grenade the thing and lose control of your vehicle, or get some damage to your car.

A more stout rear isn't a huge investment. In all honesty it would probably be the first thing I'd get for any performance vehicle. No sense in doing work twice or risking safety-

K
This thread has more than 15 replies. Click here to review the whole thread.

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


All times are GMT -6. The time now is 06:29 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.