Hello All looking to change whells on my skylark from 14" to 15" anybody know what size the bolt pattern for a buick is? Thanks Jim
I don't know about what your friends Chevy was... but I can assure you that your 71 Skylark has a 4 3/4" bolt pattern. (Unless it's been modified somehow) :beer
:Smarty: As Rick said ............4 3/4 will do the job ! Wanna buy 4 weld racing brand wheels and tires ?? SWEET .........:Brow: :Brow:
4 3/4 is correct. You will find the 15x7 & 15x6 with that pattern came on the big Buicks..(land yachts) and sport wagons too I think. I found some even on a Monte Carlo
bolt pattern i believe that u will find that the big buicks of the 70's had 5" bolt patterns . i also believe that the early 80's lesabres had 4 3/4" patterns .
Don't want to hijack this thread, but I do have a related question. I moved from 14's to 15's a few years ago, and luckily haven't had more than 1 ticket from it. I had stock 14s (I think 215/75). I plan to put 245/60s on my 15" rims. What gear do I need to make the speedo correct?
The early 80's big cars still use a 5x5 pattern as they did in the 70's. The switch came along after 83 model year(I think).
speedometer gears Hi Truzi Could not find a reference in the BF Goodrich web site for a 215/75R14, but did find their 215/70R14 has a diameter of 25.4 inches and takes 819 revolutions to go a mile at 45 mph (slight changes at different speeds). The 245/60R15 has a diameter of 26.6 inches and takes 782 revs/mile at 45 mph. That is a 4.5 percent change. Since the new tire is takes less turns per mile your speedometer would read 57.3 mph when you are actually going 60. Therefore you would need to reduce the driven gear by one or two teeth to correct. (actually a tooth and a half was correct, but you need to round to the nearest integer) If you did have the 75% aspect ratio tires use one teeth less, as this tire will take less revolutions to traverse a mile. When we changed both the differential gearing and tire size in Shari's GS we took it down the interstate for 10 miles comparing the speedometer distance to the mile markers. We figured over the 10 mile distance the slight variation in mile marker placement (due to exits, mistakes etc) would even out. We took the difference to our transmission specialist (Jimmy's Transmission in Mundeline, IN) who carries the various driven gears who put in the correct driven gear. On the return drive we tested again and he had it correct. From: http://www.tciauto.com/tech_info/speedo_gears.htm Driven Gears For TH 350 34 teeth - light green 35 teeth - orange/pink 36 teeth - white 37 teeth - red 38 teeth - blue 39 teeth - brown 40 teeth - black 41 teeth - yellow 42 teeth - green 43 teeth - purple 44 teeth - dark gray 45 teeth - light blue Buick, Oldsmobile & Pontiac transmissions use a 2.078" diameter driven gear housing. Two housings, each made from either aluminum or plastic, are available for driven gears with 34 or more teeth. One fits gears from 34 - 39 teeth and the second one fits gears from 40 - 45 teeth. * * * * * * * * * * * * * Hope this helps . . .
Thanx for the detailed info. I thought it would be off more than that. I've always had 215s on the 14s, but I think the factory used 205s (I really have no idea).
