what are my chances on this install

jhonda

Member
Jul 22, 2003
125
1
16
Huntersville NC
I got a ford 3.73 gear I want to install on my 91hatch. What are my chances of everything working good and without any noise from the rearend if I use the stock shims. I mean only changing the ring and pinion and puting all the orginal stuff back on bearings and everything. The car has 86000mile on it and was babied for about 70000miles
 
Have you changed gears before? I have only seen a few people do it, and you need a special tool I believe. I would just have a shop do it if this is your primary car, or at least have someone help you that has done it before.
 
Why take the chance? Install kits arent overly expensive. I would much rather have the good feeling that everything is nice and new than the gut feeling it could be noisy and not right ten minutes after its installed. Then unless you are doing it all yourself, it just cost you more money in parts and labor. Just my Opinion
 
If this is the first time you've swapped rear end gears I almost guarantee that it will fight you. First off your new gears may need to be shimmed differently than the gears that are currently in your car. So an install kit is a must. Their is also several things that could go wrong during your install. The pinion shaft has a tendency to get stuck. Especially if your car has been abused. When I did the gears on my Mustang it was so bad that I ended up taking the entire differential out so I could get the shaft out! Also the pinion shaft lockbolt can break off in which case you will probably have to cut the differential housing to get the bolt out! It hasn't happened to me but I have seen it happen. The crush sleeve can be a pain as well especially if this is your first one. Other than that you will want a dial indicator to check your ring gear for play. Experienced techs can do this by feel. I haven't done enough diffys to be that good.

IF you want to go ahead and tackle this project their are dozens of people on this site that will help you but I just want to let you know that it might not be as easy as you think.
 
got it installed

well I did my 3.73 gear install yesterday and everything went slow and frustrating. It took about 10hours worth of work and picking up tools and a pinion bearing but it works good. I saved 200 dollors. I used the orginal crush sleave, it only had about 8inch pounds of resistance on it before I took the orginal gear out so when I torqued it down with the new pinion bearing on it I put it at 24 inch pounds....I only get a little bit of howl when I am at a very slight acceleration like when your just maintaing speed.