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Discussion Starter · #1 ·
Ok, question.....I cant' really afford to have my gears installed right now, but a lot of guys have been telling me how easy it is, as long as I get the right number of shims and the bearing installed. Well I bought some used FMS 3.73 that have about 600 miles on them, and since they are used out of a similar year mustang with an 8.8, the pinion already has the bearing and shims installed. A friend of mine who has done this in a mustang before said to re-use the crush sleeve and install the pinion and ring gear since it was formally installed in the same rearend anyways. I've heard of people using .030" shims as a standard when installing FMS 3.73 gears....Any comments on this?? So if my used pinion DOES in fact have a .030" shim already installed, and the bearing is already on there, its just a really simple swap, right??
 

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There is no set size of shim for a particular gearset. You need to measure backlash and check for correct wear pattern. DO NOT re-use crush washer. Wait and get them done correctly. No offense, but it doesn't sound like you or your friend should be attempting this project. Shop around and get a good price for installing them.
 

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YOU DO NOT RE-USE A CRUSH SLEEVE. It does not "uncrush" when you unload it. The pinion bearing should not be reused. Since it is out of the car buy a new pinion bearing (it will come with a new race), get it to a shop. Have the old bearing removed and the new one installed. That race is installed inside the rearend housing.

It's in there hard, too. They can develope a wear pattern over a lot of miles in some cases. You're best bet is to have a shop remove the old race from the hpusing and put the new one in. Do yourself a favor. Do not rush to get the gears in just because you have them now. You will be causing yourself a lot of headaches and money if you don't get the 8.8 worked on right the first time.
 

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Discussion Starter · #5 ·
Oh come on people. I know I've seen threads on here of people doing gears themselves without any insanely expensive tools and nothing bad happened.....so where are those people??
 

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Discussion Starter · #6 ·
oh and here's another problem with paying somebody to do it..............none of the shops in tucson want to install used gears. they downright REFUSE to.
 

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Reuse everything, crush collar and all, I know of a reputable shop that ha ssome very fast cars that re-uses everything (you guys know them to I just dont wanna say their name)

They dont check shim sizes or nothing
 

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Discussion Starter · #8 ·
I'm going to give it a shot this Saturday morning. Have been reading up on it all night, looks like the majority of people who have never seen a rearend with the cover off say that is in an impossible extremely techinical job and it can't be done by the average joe, but then the few people that have actually tried it have all said its a piece of cake. I'm going to try it and report back.
 

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Discussion Starter · #9 ·
ttt
 

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hey, i found this thread in the search engine and just wanted to see how your gears are holding up afterabout a month or so of driving. i'm in the process of installing some used 3.73's myself right now and this is my first time working on gears, aside from re-building the limited slip clutch packs,
 

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Its not that hard or technical.there's a guy here who does them in no time.Its all about having the right tools for the job.Changing oil i real easy when you got the right wrench. Try changing your oil with just a screwdriver.A lot of guys say just throw the used stuff in with the same shims that came out of your rear.If i was goin to attempt it myself i would at least use new bearings and crush collar.But your better off finding somebody who knows what they're doin and has the right tools.
 

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Discussion Starter · #13 ·
Hey guys, just an update: I've been driving on these gears for over a month now. They still have absolutely NO gear whine, no noticable play, they are perfect like factory installed gears. I installed them by re-using the crush sleeve, bearing, and shims, so to all nay-sayers, I guess either I"m really lucky, or maybe it is possible to install gears yourself by re-using all the measured parts like the shims and bearing to acheive the same gear mesh.
 
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