Hi, I'm getting ready to install my new torque converter, and while i'm in there i figure i might as well replace my front pump since it is the only thing i didn't replace when i completely rebuilt the tranny. In searching around online for a good deal on one, however, i found a post at one of the message boards where a guy said that if the front pump was not professionally installed it would cause major damage to the transmission. My question is, what's so difficult about the front pump? I plan on buying a whole new pump w/ stator, and i've installed them before, but is there any trick or any particular things to note while installing it? Is it just the "rings" on the stator that i have to worry about? Thanks!
C4 Front Pump There is not a problem installing the pump if you have the right equipt. to do the job correctly. Being you have already rebuilt the trans I think you know pretty much the procedure. First of all you need to check the lateral movement of the gear train before removing the old pump. Place a dial indicator on the end of the input shaft and with a screwdriver, pry the foward clutch pack towards the pump. The valve body must be removed to do this, if the movement is more than .045 a change in the two selective thrust washers on the pump is required to get the lateral back in specs. I like to set mine up tighter than recommened(.008-.010), this is for racing purposes, gives a little quicker engagement because the excess movement is reduced in the clutch packs. Normally the factory specs are the one's to follow in your case. Before removing the old pump, tighten the fornt band up to hold the internal assy. in place when pulling the pump out. Installing is just a reversal of the procedure, I use two studs in the case to line up the pump going into the case, should not force it but a little persuasion is required. If you needed to chge. the two washers, they are available in various thicknesses to get your lateral movement back in spec.(most trans shops have them). Vaseline holds them in place as with the gasket. Tighten a couple of bolts and then recheck the dial indicator reading. I assume you have a good rebuild manual and most of this is all in there, the rest is just torqueing and replacing valve body etc. Hope this sheds some light on things. One thing though, both pump washers must be replaced not just one, and they must be the same thickness. The large one is plastic material and the small one on the end of the stator is brass, There are shims available too for these but not needed in most cases.
