4.10 Gear Change Questions (part nos., girdle fitment, etc.)...

[Professor]

I've found a good deal on Ford Racing Gears, so I've decided to go for it. But ... I want to make sure the part numbers are correct. The Ford Racing pinion & gear set (4.10) are part no. M-4209-G410A. Is that correct? I assume that I need the install kit (Part no. M-4210-B)? Also, I was going to replace the differential cover with a Ford Racing unit for some extra insurance. They make a low profile cover for the 05-08 Mustang (Ford Racing Part No. M-4033-G2). I like the look of the low profile cover ... will it work on our differentials, or should I go with the standard Ford Racing Cover (Part No. M-4033-G1).?

Anything else I need to get before making the install?

[Stranger in the Black Sedan]

solid pinion spacer kit. It's not worth re installing the inferior (and very difficult to install) crush sleeve.

Also, I don't know the part # off hand, and if that install kit has carrier shims. It probably does not. If it doesn't, you will need those. Ratech brand shims are horrible quality and I would not wish them on my worst enemies. I think their shims are stamped by children using soup cans and a hammer. Ratech does not deburr their shims (and I have used quite a few of their install kits) and they all have huge razor sharp burrs on the edges, that will hugely affect the stack up height, giving you a false reading. It takes forever to hand deburr 5 thou thick shims -- this is not something that you should ever, ever have to do.

The best aftermarket carrier shims you can buy are these:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&viewitem=&item=250236274874


They lock together and have very high quality machining. The shims are much much better quality parts than Ratech's (not difficult).

Are you installing the gears yourself? I bought a Rotunda pinion depth tool and it gets the pinion depth nearly dead on first try. There is some fine adjustment +/- a few thou from where it sets you, if you want to get a truly perfect pattern, but it saves a ton of time. If you are going to trial and error and eyeball it, plan on having the car down for at least the whole weekend. I have had my rear apart for several gear changes and constantly adjusting pinion depth and backlash simultaneously takes a long time.

[Stranger in the Black Sedan]

PS I forgot to ask, where are you located?

[Professor]

Located in Winterville, NC (coastal plains of eastern NC). I'll probably have a local Mustang shop do the install.

The Ford Racing install kit includes:

- pinion and carrier shims
- crush sleeve
- pinion seal
- pinion nut
- ring gear bolts
- pinion gear
- carrier bearings

Usually, the Ford Racing parts are better made than many aftermarket parts.

[Stranger in the Black Sedan]

Ok as long as it has the carrier shims it should be fine. THey won't be as easy to install as the locking type I used, but if you are not the one doing the install, that's not your problem

I would still throw out the crush sleeve and get a solid pinion spacer. It is much stronger and also easier to install.