limited slip 7.25" Rear End?? - Ford Muscle Forums : Ford Muscle Cars Tech Forum
Reply
 
LinkBack Thread Tools
post #1 of 29 (permalink) Old 12-15-2010, 11:23 AM Thread Starter
Registered User
 
Join Date: Nov 2010
Posts: 6
limited slip 7.25" Rear End??

I recently switched my i6 to a 289 v8 in my 67 mustang and i find that at any hint of water on the road reduces my tracton to zero at my left rear wheel. I still have the 7.25" rear end in it because i dont have the money to swap rims and tires. Does anyone know of such a thing as a limited slip diffrental for a 7.25"? Or is a swap to an 8.8" my only hope?
Bongos444 is offline  
Sponsored Links
Advertisement
 
post #2 of 29 (permalink) Old 12-15-2010, 07:29 PM
Registered User
 
Join Date: Jul 2009
Location: orleans indiana
Posts: 1,343
Re: limited slip 7.25" Rear End??

I haven't heard or seen one for that rear. 8" and 9" are available and easier to get for your car. Which one will depend on the use of the car.
fordman460 is offline  
post #3 of 29 (permalink) Old 12-16-2010, 09:05 PM Thread Starter
Registered User
 
Join Date: Nov 2010
Posts: 6
Re: limited slip 7.25" Rear End??

is there any way to find 4 lug axals for that the 8" or 9" rear?
Bongos444 is offline  
 
post #4 of 29 (permalink) Old 12-24-2010, 07:07 PM
Registered User
 
Join Date: Dec 2010
Location: Grand Prairie,TEXAS
Posts: 171
Lightbulb Re: limited slip 7.25" Rear End??

Quote:
Originally Posted by Bongos444 View Post
I recently switched my i6 to a 289 v8 in my 67 mustang and i find that at any hint of water on the road reduces my tracton to zero at my left rear wheel. I still have the 7.25" rear end in it because i dont have the money to swap rims and tires. Does anyone know of such a thing as a limited slip diffrental for a 7.25"? Or is a swap to an 8.8" my only hope?
Where did you get that # from. I've never heard of a 7.25" rearend. Maybe I just wasn't paying attention. YEE-HAW!!!
2stangman is offline  
post #5 of 29 (permalink) Old 12-25-2010, 07:35 AM
Registered User
 
Join Date: Mar 2006
Posts: 2,187
Re: limited slip 7.25" Rear End??

Quote:
Originally Posted by 2stangman View Post
Where did you get that # from. I've never heard of a 7.25" rearend. Maybe I just wasn't paying attention. YEE-HAW!!!

Contrairy to what our friend from Texas mentions, I have one of the smaller dia (2.79 ratio) rear ends in my Ranchero. These seem to have been popular at one time as a way for six cylinder powered autos to get good fuel mileage.

I dunno as to where you are going to locate the L-S rear end at, for although listed, have not seen any out west.


Wm.

Old Ford owner
coosbaylumber is offline  
post #6 of 29 (permalink) Old 12-26-2010, 01:18 PM
Registered User
 
Join Date: Jan 2008
Location: Seattle, WA area
Posts: 10,295
Re: limited slip 7.25" Rear End??

The relatively weak 7.25 axle was only used behind the I6, and so has very limited aftermarket support as a performance item. Factory LSD (limited slip differentials) do exist, but are very rare. Even if you found one, re-fitting would be expensive if you're not doing the work yourself.

The 8.8 is not the only option, but likely the least expensive, as complete limited-slip assemblies are rather cheap on local listings and wrecking yards - at least as compared to the 8" and 9" versions. A couple local 'yards around here have limited-slip diff's for about $30 and complete rears (LSD or not) for about $60. Add some good CV or MkVII rear discs while you're at it for about $50 and miscellaneous parts to finish and you could be under $200-250 with careful shopping. Even a non-LSD axle and separate LSD to install would be nearly as cheap as doing the 7.25, with much better availability of gears, service parts, brake options, and such.

There are many options, but if your wallet is ruling the project like most are, do some local pricing and see where it all fits for you. Generally, cheaper means more work on your part, and you'll have to weigh that factor for yourself.

David

-=≡ If it was easy everyone would do it ≡=-
[size=1]HotShotsJava.com Hot Shots Java Coffeehouse, Poulsbo ,WA fair trade and 100% organic. Voted best espresso and coffee![/size]
PSIG is offline  
post #7 of 29 (permalink) Old 12-26-2010, 02:03 PM
Premium Member
 
Join Date: Sep 2004
Location: Sunny Arid Desolate Port Orchard WA
Posts: 34,851
Re: limited slip 7.25" Rear End??

Just keep a fat chick in the trunk of your car over the left rear wheel... Twinkies are cheap.
FEandGoingBroke is offline  
post #8 of 29 (permalink) Old 01-10-2011, 08:20 PM
Subscriber
 
Join Date: Jan 2008
Location: SW Iowa
Posts: 336
Re: limited slip 7.25" Rear End??

Quote:
Originally Posted by FEandGoingBroke View Post
Just keep a fat chick in the trunk of your car over the left rear wheel... Twinkies are cheap.
Quote of th'week raht therr!

I believe Mavericks had 4 lug 8 inchers for a couple years, but may be a bit narrow for a 67 Mustang. Best bet may be to get an Exploder axle. 9x-95 for drum brakes, 96-01 for disk. Most had 3.55 or 3.73 gears, many of which are limited slip- identifiable by the L, such as 3 L 73 if the diff tag is still there. There was even a 4.10 ratio available, but they werent too common. Just bite the bullet and step up to 5 lug and bigger brakes all the way around. 9" drums sucked on the back of a fox body mustang, let alone the front of a performance car.

-Eric
65 Comet wagon, 60% of the time it works every time.
decurion is offline  
post #9 of 29 (permalink) Old 11-15-2014, 04:25 PM
Registered User
 
Join Date: Nov 2014
Location: Australia
Posts: 13
Re: limited slip 7.25" Rear End??

Quote:
Originally Posted by Bongos444 View Post
I recently switched my i6 to a 289 v8 in my 67 mustang and i find that at any hint of water on the road reduces my tracton to zero at my left rear wheel. I still have the 7.25" rear end in it because i dont have the money to swap rims and tires. Does anyone know of such a thing as a limited slip diffrental for a 7.25"? Or is a swap to an 8.8" my only hope?
Grave dig I know, and I fear that Bongos444 has moved on but I have just purchased from a gent in Indiana a Equa-lok LSD that came out of a 7.25" Ford diff. It had 2.83 gears.( which I also have) The gent has reco'd it and I will be installing it in a '66 Australian round body. Not going to be pushing a lot of HP.

It will be installed in a 5 lug Ford utility diff ( Ranchero equivalent in the US)

These Equa-loks are rare as hen's teeth so I am fortunate to have purchased it.

cheers

BRuce



BJBOZ is offline  
post #10 of 29 (permalink) Old 11-16-2014, 12:57 AM
Registered User
 
Join Date: Mar 2013
Location: cologne, germany
Posts: 22
Re: limited slip 7.25" Rear End??

nice score!
i think i also read something about a detroit locker unit for the 7.25"
for my own 65 mustang, i swapped in a maverick 4-lug 8" rear end. a little more versatile in the end...
tody is offline  
post #11 of 29 (permalink) Old 11-16-2014, 03:12 AM
Registered User
 
Join Date: Nov 2014
Location: Australia
Posts: 13
Re: limited slip 7.25" Rear End??

Quote:
Originally Posted by tody View Post
nice score!
i think i also read something about a detroit locker unit for the 7.25"
for my own 65 mustang, i swapped in a maverick 4-lug 8" rear end. a little more versatile in the end...
Tody, thanks mate. The Maverick 8" units are being imported to Australia as well and are finding their way into the early Falcons, mainly for the better taller ratios and those that are running V8s ( all our early Falcons were 6 cylinders until mid '66 when the 289's were introduced.

Mine runs a 200 2v head, but I will be installing a 250 down the track with 2.83 gears in the diff. 5 stud wheels .

Not looking to drag it etc but the LSD should offer some better driving when the roads are wet.

The gent I purchased the LSD unit from has never had one of these 7.25" Equa-lok units so they must be very rare. I don't think there was any detroit lockers for the 7.25" diffs, as they are fairly light and not made for racing etc. 9" for certain...but would be a waste on a 7.25"

cheers

Bruce
BJBOZ is offline  
post #12 of 29 (permalink) Old 11-16-2014, 01:42 PM
Registered User
 
Join Date: Jan 2008
Location: Seattle, WA area
Posts: 10,295
Re: limited slip 7.25" Rear End??

Quote:
Originally Posted by BJBOZ View Post
Not looking to drag it etc but the LSD should offer some better driving when the roads are wet.
Careful with that thought. An LSD can help acceleration traction up to a point, but then becomes a potentially dangerous liability in slippery conditions. They help with acceleration, but can initiate sudden total loss of rear tire traction (especially in turns) that promotes fishtails or spin-outs if torque exceeds traction to one tire, affecting both. The points is, wet weather is not the place to look for better acceleration at the cost of lateral traction, and can become far more risky with an LSD/locker if you do. Been there - done that, and just sayin'.
Quote:
Originally Posted by BJBOZ View Post
The gent I purchased the LSD unit from has never had one of these 7.25" Equa-lok units so they must be very rare.
Actually, they are not all that rare, and I've found several especially in Aerostars and Rangers. I've passed them up as there is low demand, considering if you get all that extra traction from it, and your power is higher, the rear axle becomes its own weak link. In other words, by the time you have enough power to make a 7.5" LSD truly useful to make use of higher power, you are also looking towards an axle upgrade anyway. Double-edged sword there. Not trying to throw a wet towel on anything; but hoping you consider the potential consequences (good and bad) of all your mods.

David

-=≡ If it was easy everyone would do it ≡=-
[size=1]HotShotsJava.com Hot Shots Java Coffeehouse, Poulsbo ,WA fair trade and 100% organic. Voted best espresso and coffee![/size]
PSIG is offline  
post #13 of 29 (permalink) Old 11-16-2014, 02:54 PM
Registered User
 
Join Date: Nov 2014
Location: Australia
Posts: 13
Talking Re: limited slip 7.25" Rear End??

Quote:
Originally Posted by PSIG View Post
Careful with that thought. An LSD can help acceleration traction up to a point, but then becomes a potentially dangerous liability in slippery conditions. They help with acceleration, but can initiate sudden total loss of rear tire traction (especially in turns) that promotes fishtails or spin-outs if torque exceeds traction to one tire, affecting both. The points is, wet weather is not the place to look for better acceleration at the cost of lateral traction, and can become far more risky with an LSD/locker if you do. Been there - done that, and just sayin'.
Actually, they are not all that rare, and I've found several especially in Aerostars and Rangers. I've passed them up as there is low demand, considering if you get all that extra traction from it, and your power is higher, the rear axle becomes its own weak link. In other words, by the time you have enough power to make a 7.5" LSD truly useful to make use of higher power, you are also looking towards an axle upgrade anyway. Double-edged sword there. Not trying to throw a wet towel on anything; but hoping you consider the potential consequences (good and bad) of all your mods.

David
Thanks David, my first car with a LSD was a '76 Ford Falcon 5.8 litre and it was handful in the wet under hard acceleration so I tempered my driving skills on that beast. Most of my work vehicles over the last 20 years have been powerful performance vehicles equipped with LSD and now with the advent of Traction Control the cars are now more manageable. I must say that our turbo 4 litre Falcons can sometimes overwhelm the T/Control in the wet.

Re the Aerostars and Rangers, are you suggesting that their LSD's will install in the 7.25"??? diffs that were in the early Falcons and Comets? Also the E-L unti that I have purchased is 24 spline .

The other factor not mentioned as to fitting the early LSD is for bragging rights as I factor no one in our country will have one. ...and that just doesn't require any logic at all.

Bruce
BJBOZ is offline  
post #14 of 29 (permalink) Old 11-16-2014, 04:06 PM
Registered User
 
Join Date: Jan 2008
Location: Seattle, WA area
Posts: 10,295
Re: limited slip 7.25" Rear End??

OK, so you already know the tendencies of limited-slips and lockers in slippery conditions. Most folks do not, and most also don't have traction control here (though TC usually only engages after traction is lost), and end-up finding out the hard way. Yes, the carriers will work in either housing style, as long as either axles or side gears are matched to the other. Axles are generally easier, and a guy near me did his '62 Falcon with a Ranger carrier, using two junkyard 8.8" axles (the right ones just happened to be in 8.8" rears) of correct length. I do not recall the lengths, but that's easy to measure. Congrats you found an original early one as shown by the casting numbers. That makes it a bit simpler.

David

-=≡ If it was easy everyone would do it ≡=-
[size=1]HotShotsJava.com Hot Shots Java Coffeehouse, Poulsbo ,WA fair trade and 100% organic. Voted best espresso and coffee![/size]
PSIG is offline  
post #15 of 29 (permalink) Old 11-17-2014, 03:06 AM
Registered User
 
Join Date: Nov 2014
Location: Australia
Posts: 13
Re: limited slip 7.25" Rear End??


Last edited by BJBOZ; 11-17-2014 at 03:11 AM.
BJBOZ is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Muscle Forums : Ford Muscle Cars Tech Forum forums, you must first register.
Please enter your desired user 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:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
8" Trac-Lok or other limited slip SLCK64 Wanted 1 04-17-2009 02:24 PM
What cars had an 8" rear 3.25 gear (maybe with a limited slip if possible)? JoeD All Ford Techboard 16 02-06-2008 09:04 PM
anyone using a Limited Slip Diff.? jeff63390 Galaxie Pages 3 01-08-2004 02:52 PM
limited slip doesn't limit slip anymore Matte All Ford Techboard 4 09-01-2002 09:49 AM
Limited Slip 8" AZ65coupe All Ford Techboard 6 08-11-2002 03:15 PM

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

 
For the best viewing experience please update your browser to Google Chrome