stdyhand

Still undecided on the 373 or 410 gears but this is my next project and will be getting done very soon. Can someone point me to a how to guide for swapping the rear end gears? I've never touched a rear differential before so I'd like to gather all the info I can now.

Also, what all do I need to replace while I'm at it? I read somewhere the pinion bearing should be replaced with the ring and pinion gear. Anything else?

Is there anything I should know in advance? I'd like to learn from others problems ahead of time to save myself a headache.

95Five-ohh

http://www.americanmuscle.com/differ...r-install.html
that should answer a majority of your questions

sn95_331_GT_ yellow

not exactly a job you should tackle if you havent done anything like it before honestly...

mustangGT86_05

With you having never touched a rear end and planning to install your own stuff, i STRONGLY suggest finding someone who has done it before. It is not exactly a do it yourself project, it takes a LOT of measuring and precision. For one, when you install the pinion, yes there is a bearing AND race you will want to replace, there is also a crush sleeve that sets your pre-load. You are also suppose to measure for the pinion gear but I cant remember exactly what for. Installing the ring gear to the carrier is easy, however installing and shimming the carrier back into place is not so easy. You put in 2 shims, then find the shim that just slips in the rest of the space just enough that you can do it by hand, then you go a few sizes bigger than that. You must also use some crap on the teeth of the gears to determine where your pinion teeth hit on your ring gear to make sure you have those set properly for reduced noise as well as long life. And finally to tighten the pinion back up you will need a needle? style torque wrench to measure for rotational torque which sets the crush sleeve.

This is just a quick explanation of how its done, Im giving you an idea of what you're in for, it is no where near an easy thing to do especially for someone who has absolutely no experience. Again, I STRONGLY recommend having some assistance from someone who has messed with them before, not that the site provided cant assistance, its still can't tell you exactly everything and if you don't have it right you will have a lot of heartache

*edit* if possible, find an axle with the set up you want already installed, you will be glad you did

stdyhand

I understand the caution very well. But if you had ever met half the mechanics around here you'd also understand why I do all my own work. I recently took my car in to get the ebrake fixed because it was constantly raining and I didn't want to lay on the wet ground to run new brake cables. One of the mechanics saw the full length subframe connectors under the car and said "what are those things attached to the bottom of your car".

Needless to say it doesn't give you a very comforting feeling.

I don't know any shops that do this kind of work and that I would trust. I'm not new to working on cars, just new to the differential. I think I could do it but like to gather the info ahead of time and find out what kind of special tools I might need. That is usually my biggest problem. I always find theres a tool I don't have

Anyhow, thanks for the link to the write up. It does sound complicated but doesn't sound any worse than I've had to do before.

mjr46

you need a inch lb torque wrench that measures rotational drag, dial indicator to measure back lash, bearing press and removal tool, set of long punches to knock out old pinion races if replacing, three finger puller to remove flange, shim driver, flange holding tool (I used a 3 ft flat piece of steel with holes drilled in proper location) =used to hold flange when setting preload and your normal hand tools and air tools to remove the unit...I have the OEM ford tool for measuring pinion shim needed= 800.00 dollar tool (now most don't have this tool so they guess then run the pattern and change shim accordingly) me I don't have to guess!!...all in all I have some of the best tools to do the job and total cost minus bearing press ran me close to 1300-1500 .... now I know there will be some ******* that'll say..," you don't need all them tools"....so be it...I don't half azz installs or take short cuts....some will also say you can reuse the old shims if you buy ford racing gears,....true sometimes and others not....gee..wonder how I know that??..anyway, with all the right tools I usually spend 4-5 hrs on and install.

sn95_331_GT_ yellow

^^ truth

i have everything except the pinion depth too and it took me about 10 hrs the 1st time to do mine, my neighbors car took around 8 and my buddies 98 took about 6.5

















mike, WHERE THE HELL DID YOU GET YOU PINION DEPTH TOOL!??!?!?!?!

I WANT ONE SOOOOOOOOOOOO BAD!!!!!!!!!!!!

nitrous_bob

heres the best (and really only) way to know what gears are best for you and your cars setup.

1) are you scared to go fast ?

if yes, get 3.73's, if no... get 4.10's

Venomantidote95

This OS also a great time to consider upgrading your axles.

mjr46

our mac tool man was a ford tech for 25 years.......got it through him...OTC makes them........I use the tool as a guide, mainly because if you understand how the tool works, I feel it doesn't account for differences in the machined hieght of the pinion, I use a micrometer to measure the highth of the pinion head I'm removing, then compare it to the ford racing one and in most instances where I have installed ford racing gears the tolerances have been with in .001 to .002 and then I use the depth tool to check for the needed shim and most of the time the needed shim is the same as what was on the old pinion. google master housing depth method for 8.8's...this will explain the theroy/assumption better fyi, the tool is not cheap, I'm not kidding when I say all the pieces needed, cost me 800.00