BM Tranny LSD Insert Installation

BM Tranny LSD Insert Install on a '99 Eclipse GS-T

Tools required-

The best time to do this install would be during a clutch replacement (which is what we were doing), as the transmission needs to be entirely removed to perform the install. Take the time to organize a nice clean area to work as there are a few pieces that will come loose and need to be set aside. Also, it's safer to work in a clean area as you don't want debris falling into the transmission. The smallest of items can cause catastrophic destruction! The numered links lead to some pretty high res photos. Most are about 220k. A lot of VFAQ's use smaller low-quality images that don't show the detail necessary.

First things first, get that transmission out of the car! (Picture 1)You can find instructions for this under any of the clutch replacement VFAQs. Pretty straightforward. Seeing as the transmission is already out, the fluid will be drained. Keep some rags handy as after you open it up, the parts will still be coated and some fluid may still be lingering in there ready to leak out. Also, you should remove the speedometer sensor and the reverse sensor at this point.

So now it's out of the car and you have it in your clean area, right? (Picture 2) This is what you should see. There are 7 bolts holding the end case to the transmission. Behind this case, you will find the 5th gear and intermedite gear. There are two large 36mm nuts holding these gears in place. (Picture 3). First thing to do is remove them. This can be easily accomplished by the use of a penny. If you look closely in the picture, you can actually see the mangled penny sitting there. What you do, is you feed the penny into between the gear teeth as you are turning them with the socket. You will get resistance when the gears try to eat the penny. Don't worry, you will not hurt the gears one bit by doing this. The copper in the penny is much softer than those gears. Once both nuts are removed, this is what you should see- (Picture 4). Before you can pull either of the gears off, the shift fork must be removed. If you look where the fork attaches to the rail, you will see a small roll pin that holds the fork in place. Use the punch and pop that roll pin out. It should be in there pretty tight so a little force getting it out may be necessary. (Picture 5) Once the pin is out, the fork will come off pretty easily. Set it aside along with that roll pin. You don't want to lose it. Next, get that gear puller and use it to remove the intermediate gear (the smaller one). Next, you want to remove the 5th gear assembly. It is best to try and remove it all in one piece as it makes putting it back together a much simpler task. Put the gears aside where they can't be knocked around or anything.

Using the various sockets, remove all the bolts on the case. Make sure you removed the reverse light switch. There are 4 bolts in particular that need special attention. The first 3 are these: (Picture 6). Remove them slowly. Behind each of them is a spring and a ball bearing. (Picture 7) The last of the 4 that needs to be removed is a Torx bolt that attaches to the reverse shaft in the transmission (Picture 8). This is a T-50. Remember, this install was performed on a '99. Some people I have talked to think that only the later model 2G's had the Torx bolt and others had a standard bolt. Once all the bolts are removed from the case, it's time to get inside the main case of the transmission. You may need to work the case off a little because of the factory RTV keeping it stuck together.

(Picture 8) This is what you should now be seeing. At this point, a couple things might have fallen out of the transmission. Most notably, the following parts- Shim (Picture 9). This piece acts a barrier between the transmission case and the bearings on the end of the shafts and differential. Race - (Picture 10). This is what the bearing spins inside of. This piece should be pressed into the case but that will be discussed further along when we discuss re-assembly. On our install, the shims and races fell off while the bearings remained pressed onto the shaft and differential (Picture 11).

By looking at this picture again (Picture 8), you can see differential just sitting in there. At this point, it can just be lifted out. (Picture 12) This is where you will need the impact wrench. There are 8 bolts holding the large ring gear to the differential. These bolts are in there TIGHT and there really is no way to get any torque on them. Save yourself the trouble and locate an impact wrench. We didn't have one but were lucky enough to have a shop down the street remove them for free for us :) Once the ring gear is removed, there is a small tapered pin that comes out TOWARDS the ring gear. It comes out very easily. Once that pin is removed, you can remove the LARGE center pin. This picture details what is going on- (Picture 13) Once the pins are both removed, it's time to put the LSD insert in. You will notice that it comes with 4 dowel pins and 2 plates on the end. Keep these on! With them on, slide the insert through the center of the differential so the large pin can slide back through it. When I say slide, I meant tap it with the rubber mallett. Simply pushing on it didn't get us anywhere. Once it is all the way in and the hole is lined up for the large pin to slide back through, put in the large pin and remove the two plates and the 4 pins on the insert (Picture 14). With the insert in, put the small tapered pin back in the same way it came out. Refer to picture with the diagram if you forgot. Re-attach the ring gear. You are now done with the "LSD Insert" installation.

Putting it all back together is naturally the reverse of the disassembly, but there are a few tips to follow. First, just drop the differential back in. Next, gather up the races and shims that came off while removing the case. Assembly goes like this (Picture 15)- race goes on the bearing, shim goes on the race. Although this may cause an issue as it did with us. We had to actually put the shim and race into the case rather than place it on the bearing. If thats the case for you, first, place the shim into the depression on the case, and then put the race in. We had to use a ball-peen hammer to bang the race into the shim (Picture 16). The race should be flush with the case. Here is a picture of all the shims and races back into the case- (Picture 17). Once that is done, apply a thin bead of RTV all along the bottom of the case. Give it a good 15-20mins to skin over. While it is skinning over, notice the 3 shift rails. Make sure the tranny is in neutral and that the rails are lined up. (Picture 18) The 5th/Reverse rail is the one that needs special attention. (Picture 19). Don't forget to reinstall the long black plastic oil guide that delivers gear oil to the 5th gear! It only goes in one way so you can't mess it up. Another tip, once the RTV is skinned over and you are ready to put the large case back on, line up the bolt hole that the Torx bolt goes into. Once that's all done, put the large case back on. Tighten it down with the numerous 14mm bolts that were removed. Replace the 3 bolts with the springs and ball bearings and the Torx bolt. Gather up your 5th gear parts. They just slide back on the same way they came off. You need to install the intermediate gear first! You will need to put the 5th gear on with the shift fork attached to it. Be careful not to move that shift rail! Slide the gear onto the rail easily and tap the roll pin back in. Using the penny method, tighten to the 2 36mm nuts back on. You may notice that there is a small wave spring (looks like one of the shims that is warped), just pop that onto the 5th gear cover. Apply another thin bead of RTV to the 5th gear cover mating surface, let it skin over, put on the cover, tighten it down and you are done!

Credits: A couple pictures were taken from: http://www.turbo4wd.com/TrannyApart/frontdiffchange.htm. Thanks to Jay (RavenX on the forums) for letting me tear apart his tranny and my fiancee Melissa for letting me do this in our bedroom!