: wrong alternator

Harry Yarnell
09-17-08, 09:50 AM
This is the second time I've seen the wrong alternator on a Northstar, and they both are mid 90s. This is when the transition from the 4.9 to the 4.6 Northstar was happening, and when a 'mechanic' replaces the alternator, he gets the 4.9 one and not the one for the 4.6. The difference is in a 1/4" offset on the pulley. It WILL throw belts.
This has worked to my advantage, as I've been able to pick up a NICE '95 Eldo and a '96 Seville, cheap, because the mechanic has told the owners there was too much crank endplay and needed and engine overhaul, or they tried to replace idler pulleys, only to snap off the bolts in the block.
So when you replace the alternator, make sure the pulley is flush with the fan, and doesn't have the 1/4" spacer.

09-17-08, 11:28 AM
sounds exactly like what happened to me with the install of the wrong pulley on the right alternator...

10-13-08, 04:07 PM
does anyone happen to know what pulley size an alternator for 1998 deville uses, and perhaps where exactly to take the measurements? i know they come in 57mm or 62mm diamater. will either work? when you say quarter inch offset, i assume you are talking about where the pulley sits in line with the others?

Harry Yarnell
10-13-08, 05:49 PM
Yes, the 1/4" is axially; there's a 1/4" solid portion to the pulley before the six ribs.