My rear end recently started acting up and I took it to a shop (I have absolutely NO experience with rear ends) and apparently, the ring and pinion is shot, as well as the bearings. I already bought a SLP posi unit because I knew the old one was broken. I would like to purchase 3.73 gears, but don't exactly know what else is needed to complete the job. Basically, the rear end is in need of a rebuild, and no previous threads really addressed this issue. Any input on what I need or if anybody can point me in the direction of a reputable dealer that sells complete kits for a reasonable price would be much appreciated. Thanks.

 

Any of your local parts suppliers should be able to sell you a bearing/installation kit or know where to pick one up.

3.73 gears will need a 3 series carrier unless they're designed to fit on a 2 series. I have no idea what series the SLP unit is. Does the SLP posi have the correct spline count for your car? What year is your car? I was under the impression that the SLP units were for 28 spline axles.

Once you have all the parts, take it to a proper shop it have everything installed. Changing bearings isn't always as easy as it sounds and setting up the pinion depth without proper measuring tools means you could be going through a few inner pinion bearings before it's correct.

Trying to do work yourself sometimes saves some money but without proper knowledge or tools, it can cost you more in the long run. If the shop that rebuilds your diff doesn't do a good job, they should have a warrenty on their work. You can't warrenty your own work.

 

Sorry, I should've mentioned my car. 1991 Formula 10 bolt 28 spline axle 3.23 drum rear. The posi unit I got was actually out of a 4th gen T/A. It is a series 3 carrier. The reason I am asking this is because the shop is wanting $520 for gears, bearings, and installation kit from what the guy said "high performance parts he got through Car Quest." I told him to hold off to see if I can find better parts at a better price.

 

From Summit

3.73 gears for 3 series carrier 7-1/2 - 7-5/8 $180
Installation kit including bearings - $96

The only other parts you need can be picked up from your local parts store
axle bearings - $36
axle seals - $4
plus about 3 quarts of gear oil. Spend the extra money for 75w90 synthetic instead or regular 80w90.

That $520 had better be including installation.

 

Nope, sadly, it's $943 with parts and labor. Looks like I'll be doing some shopping. Thanks a lot.

 

I don’t know that it’s that far out of line… remember that most shops can’t match Summit’s prices even at their jobber price (summit often undercuts the jobber price that businesses can get the parts for), and a shop will expect to make some profit on the parts. Depending on who their supplier is $350-450 + tax isn’t unreasonable for the parts (If you can get a set of bearings for $36 then more power to you, the last time I got some they were that much each…).

Labor… you’ll find places that will do the job for $150-250, but in most cases I’d avoid them. They are usually the ones that expect to pull the thing apart, slap all the new parts in with the original shims with no measuring and go. 5-6 hours will give a shop the time to mock it up and check clearances/pattern correctly and then do a final reassembly once they have that right. Around here labor runs $65-85/hr for a normal shop and about $75-120/hr for a performance shop, you do the math…

If you supplied your own parts (say shopped around on the net for the cheapest prices…) it’s not unreasonable/uncommon for the shop to 1- refuse to warranty any parts related issues with the install and 2- expect to mark the install up slightly to make up for some of the money that they would have made with the parts.

Nutshell, if you get away with under $800-850 from a shop that knows what they’re doing and does the job right you got a killer deal. I suppose temper that with whatever local labor rates go for and how desperate shops are for the business, and this time of year no one will be unless they don’t know that they’re doing, the racers are all desperate to get their last minute stuff done, people are getting their tax returns and itching to get their toys out and have some fun with them (mod them…)…

 

Jegs has ring and pinion set with new bearings. It also has instruction video. All this for around $300-$350. Installing gears is not that hard. Most people get scared when they think about setting up gears. If you can build a engine you can set up gears. There are alot more things to go wrong with an engine than a rear diff. Just get as much info as you can. Take your time. Olnly special tools you need is a hydralic press, micrometer, a torque wrench and a inch pound torque. Trust me if you know how to set up gears your friends won't leave you alone. Charge them $500 to set up thier gears to pay for yours. Hope my pep talk helped. Anyway good luck. Shop around because Car Quest parts are kind of cheap.