Speedometer conversion

[Lets Moparty!]

just swaped a set of original rallye / BFG 15's  to BFG 275/60R-15's - still on 15X7 rims -     Do I need new speedometer gear or cable?

[MEK-Dangerfield]

Well, if the originals were smaller than 275's, then yes, the speedo will be a bit slower. I didn't know you could get 275's on a 15X7. Anyway, your cable is fine, it's just a matter of a new gear.

  Mike

[GhettoPop]

sorry to butt in but what exactly is involved in changing the speedo gear?

[Chryco Psycho]

it is easy sort of , where th ecable hooked to the tranny there is a 1/2 " bolt , remoive this bolt & the forked clip that holds the adapter into the tranny & pull out the adapter BE WARNED tranny fluid will come out , the speedo gear is held in the adapter , it just sldies out & can be replaced with the correct gear , generally 3.23 geaars need 32 tooth , 3.55 need 35 tooth 4.10 need 41 tooth IF you are running a stock size tire , about 25" tall. This si the most difficult part , there are 3 groups of # on the adapter you need to line up the notch on the tranny housing with the groove that corresponds with the # of teeth on the gear , now reconnect the cable & refill the tranny
 Pix http://www.dodge-charger.com/Charger/index.php?board=4;action=display;threadid=38942

[GhettoPop]

thanks psycho, your always a great help, what speedo gear do i need:

4.30 gears
275/60R15

i belive this comes out to:

rear diameter/tire height :
27.99212598

[Chryco Psycho]

my chart doesn`t show that combo but I think you would be very close at 41 teeth