Dave - I am obviously a little bit biased regarding this topic, but I'll have a go at it. The press-on pulleys rely on interference fit between the pulley and the water pump shaft to stay in position, and transmit the torque from the pulley into the pump. If the fit is just a little loose (by just a few ten thousandth's of an inch), the pulley can drift fore and aft on the shaft (affecting belt alignment), or slip on the shaft (affecting pump performance). Either of these scenarios, if left unattended, will result in wear on the shaft and eventual failure of the pump. This sensitivity of the fit between the parts is the main problem with the pressed-on pulley arrangement. Again, this is all my opinion. The bolt-on pulleys do not have this requirement for an interference fit. The torque is transmitted in shear through the four attachment bolts, which is a very efficient way to transmit torque. Our bolt-on pulleys happen to also be works of automotive art (a glistening jewel in the engine compartment). Our waterpumps (with the bolt-on pulley) come with a lifetime warranty. Toby Peterson VIN 2248 "Winged1" DeLorean Parts Northwest, LLC www.delorean-parts.com --- In dmcnews@xxxxxxxxxxxxxxx, "usndmc" <usndmc@xxxx> wrote: > > Group, > > I am going to get a new water pump soon, and I am curious as to > advantages/disadvantages of the 4-bolt on pulley style and the > original press-on pulley style. Is there anything besides ease of > removal of the pulley? Just looking for a little enlightenment as to > the differences. Thanks everyone, happy holidays! > > Dave > #5968 > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/