3.73 pinion depth??

[trailblazr81]

Can someone tell me the pinion depth for a set of Ford OE 3.73 gears? I plan to install some 3.73's in great shape from another vehicle into my 85 Mustang. Ive paid to have gears installed on 3 different vehicles. So now I wanna start doing it myself. I'll buy an install kit, get a inch/pound torque wrench, and probably the Proform #66516 pinion depth tool. I own a 12 ton press and 2, 3 jaw pullers. Gear installs and front end alignment are the only things Ive paid to have done to my "fun" cars. So its time to learn. I plan to take my time since this isnt a daily driver, and read anything and everything I can find on the subject. So any tips will be welcome. Thanks!!

 

[cobradvm]

I've done my rear end - its really not that hard if you take your time. I did not use a pinion depth tool to figure out the pinion shim thickness - instead I reused the stock pinion shim when I installed my 373s. Worked like a charm - they weren't 100% quiet - you could hear a slight noise at exactly 2000 rpms on acceleration in 4th gear only. Other than that they were silent and if the window was open or the radio was on, you couldn't hear anything. I came across a cheap pinion depth tool somewhere but forget where it was. If I was doing another set of gears I would do it the same way again but bear in mind this only works if you are using FRPP gears.

 

[93 LX]

I would think that because you are using used gears you would need to set the pinion to the depth of the previous wear patterns. Mind you i have not done a rear gear myself so this is just from a general knowledge stand point.

Allen

 

[Aryan15]

I checked mine before gear change and after gear change with a depth mic using the factory shims and it was within thousandths. That was a 2.73 to 3.73 gear change.

 

[trailblazr81]

Ya these are not a ford racing performance parts gear set, its a gear set from another vehicle, probll a Ranger. So Im not sure if I could get away with just using the same shim. I'll try when I set 'em up but I will check everything before I drive it. Any easy tips for carrier shims??

 

[FSTNG]

If you want a quiet gearset you have to do it right and check the backlash after shimming it with your best guess (old shim to start with is a good idea). Then you use gear marking compound to check the mesh pattern and adjust the carrier and pinion depth to compensate. This is why a gear change is such a pain, you have to keep pulling the pinion and re-shimming until you get it right.

I haven't done a gear swap on a Ford axle yet but from past experience it is probably the job I would least want to do out of anything on a vehicle. It is very time consuming.

Also, like the guy above mentioned, when you use a used gearset you want to set the pattern to the previous wear instead of dialing it in perfectly to spec. If this axle uses a pinion crush sleeve as I'm assuming it would, you will not want to use the new one while you are setting up the gear pattern, use the old one or a spacer while setting up the gears. Good luck and I'm sure somebody who has done an 8.8 will chime in. I'll be watching this thread as well because I'm planning on doing a swap on mine soon.


PS -- If you're not anal about gear noise and setting them up exactly to spec like I am, you CAN get away with just throwing them together with the original shim and probably get the pattern close enough to work ok. Also when I've done it in the past, it's been a good idea to set the backlash tighter than suggested especially with new bearings. I set my last axle up at .003".