Cutting a case for an aftermarket bell housing

390168847Well, you could say i have prepped a few 400 cases for the jw performance ultrabell. it is pretty straight forward, and the kit comes with instructions and hardware. this is pretty much how i have found to be the quickest way to get the job done.

The installation to me is done in two parts: 1- remove the bulk of the housing 2-grind the edges for an flush true fit. To remove the bulk portion of the housing, i like to use my 4 1/2″ milwaukee grinder with a cut off disc rather than a sawzall. 390168894 On a lot of cases like the one shown, there is usually some kind of impression left from years of oil pan gasket contact. use this as a guide and make your first two cuts above this mark….cutting through to the thin part of the bell. I then basically make a circle cut around the housing above or even with the top of the oil pump flange. keep in mind we want to remove a large portion of the bell to get it out of the way.

390168856390168859Here in the two pictures to the left, you can see the housing with the bulk of the bell removed. Also noticed i am pointing to two of the 8 bolt bosses needed to attach the case to the bell. Not all housings can accept the ultrabell. if your case does not have both of these bosses, don’t even bother cutting it. you need all 8 bolt bosses for the case to stay attached properly. the pump is no big deal however, just flip the pump over and drill out two holes to turn a 6 bolt pump to an 8 bolt pump. A lot of the ultrabell failures are due to two things happening, either not enough clearance when it was cut to fit the housing or not all 8 bolts were used because the case was cheap shitted. i have tore down ultrabell trannys from other builders where the housing ripped off……and find that it only had 6 bolts holding it on rather than 8, and they simply put a nut on the back side to make it look like it had 8 bolts in the case!!!! 390168849 At this point it is time to switch wheels and finish fitting the housing. i use a flap wheel style grinding wheel to knock the material off the housing. It doesn’t plug with aluminum like a metal griding wheel would, and removes material rapidly. wear your safety gear with this too cause it throws a lot of material all over. pull the wife’s car out of the garage first and save an arguement!!!

390168896390168868First thing you do is knock the 3 casting ears off so the bell sits flush. you then set your pump in the case….or what i do is use a tore up piece a shit as a dummy plug…..then set the bell housing down on the pump using two bolts as alignment dowels through the works. Now if you have a working tranny with a busted bell and just want to fit the housing, they say removal is necessary to install the bell housing. Although i have never done it, i think if you are careful you can do it without removal. i always cut for fitting during a rebuild. Basically at this point you take your flap wheel and keep knocking down the edges until the bell housing sits completely flush to the face of the pump. Basically trial and error fitting. You have the case clearanced correctly to the bell housing when you can hold it flush and still wiggle it against the bolts slightly. the only point you have to worry about taking down too far is getting into the oil pan gasket.390168903 You don’t want any part of the case touching the bell housing- just the face of the pump. Remember to refer to your instructions or call JW performance with questions. the picture to the right is a bottom view of a properly clearanced bell housing where it meets the oil pan.

after clean up and final installation, you then install the 8- grade 8 bolts provided. the o-rings go between the bell housing and the pump face to prevent leaks. i torque them to 18-20 ft/lbs. DO NOT OVER TORQUE these things. it is just aluminum. the bolts that come with the bell housing are actually a special length as well and thread into the case beyond a stock fastener. these bell housings may seam like they aren’t worth a shit, but they do work! i just wish you could run something bigger than an 11″ torque converter!!

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