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Rear End Upgrade Advice for 1983 Mustang GT

  • Thread starter Thread starter EBW83
  • Start date Start date Nov 29, 2019

EBW83

Member
Jul 10, 2017
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Nov 29, 2019
#1
  • Nov 29, 2019
  • #1
I am considering a moderate upgrade to my 3.08 7.5” Traction-Lok rear end. My initial thought was to “simply” swap out the gear set (to 3.55 or 3.73) but there are other considerations:
  • This rear end is original and has around 230k miles on it. I’d bet that there are other items which should be serviced such as the Traction-Lok clutches and bearings and/or bearing seals. Currently, this rear end seems to be working fine and doesn't leak but I have put more HP to the rear end with some engine performance upgrades.
  • Experience level required. I have the 1983 Ford shop manual set which has detailed instructions but have limited experience doing something like this. There are a number of specialty tools (dial indicator, pinion depth gauge, shims, gauge blocks and depth tools) and calibrations (bearing preload, ring gear backlash, ring gear runout) required. I was hoping to get a high-level recommendation of the job and then assess whether or not I should tackle it myself.
  • Can this be done without removing the rear end? It looks like the gear set swap out could be done without removing the housing assembly from the car. I’d be doing this using jacks and jack stands while laying on my back.
  • Availability of 7.5” rebuild parts and/or kits (carrier, bearings, seals, etc.).
Any insight or advice is appreciated.
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
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#2
  • Nov 29, 2019
  • #2
I think for the time, effort and money involved in rebuilding the 7.5 including new gears and all, your better bet would be to swap out the 7.5 for an 8.8 out of a later year foxbody. With a little patience you can find one with the gears you want. Then just swap the whole rear end.
 
Reactions: rgsauger

revhead347

Apparently my ex-husband made that mistake.
20+ Year Stangneter
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Nov 29, 2019
#3
  • Nov 29, 2019
  • #3
You can do gear swaps with marking compound instead of special tools. It just takes longer; it's more of a trial and effort process. If you have a factory engine, or near factory power, and you aren't running sticky tires, the 7.5" rear end will probably be fine. If you intend to do anything with the car power wise, I would go ahead and upgrade to an 8.8" rear end. Last I checked, MPS sold a Fox 8.8" for about $250, and an SN 8.8" (5 lug with disk brakes) for about $550. It really depends on how far you want to go with the car.

Kurt
 
R

rgsauger

Member
Aug 8, 2018
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Houston
Nov 30, 2019
#4
  • Nov 30, 2019
  • #4
You can also pull the diff and take it to a shop that does gears. Very simple to set up on a bench. Will not be much $.

Or check eBay and Craig's for a differential with your desired gears and limited slip already.
 

EBW83

Member
Jul 10, 2017
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Nov 30, 2019
#5
  • Nov 30, 2019
  • #5
Thanks guys for the inputs. I have upped the rear wheel HP by 80-90 and have wider, stickier tires on it. It seems I've outgrown the 7.5" so I will pursue the 8.8" rear end option. This also gives me a good excuse to replace the rear end control arm bushings.
 
Reactions: General karthief

General karthief

wonder how much it would cost to ship you a pair
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#6
  • Nov 30, 2019
  • #6
Where are you located?
 

EBW83

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Jul 10, 2017
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Nov 30, 2019
#7
  • Nov 30, 2019
  • #7
Dallas, TX.
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,944
10,582
203
polk county florida
Nov 30, 2019
#8
  • Nov 30, 2019
  • #8
That's too far away, I got a 8.8 in a parts car.
8.8 is the way to go, shop around, you may even find one with a gear you like.
 

JD1964

there is enough sticking out to grab on to
15 Year Member
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Nov 30, 2019
#9
  • Nov 30, 2019
  • #9
rgsauger said:
You can also pull the diff and take it to a shop that does gears. Very simple to set up on a bench. Will not be much $.
Click to expand...

In order to set the pinion depth and backlash, the housing would also need to be onsite.
 
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