cheven

Have my cover off and was wondering what ratio I have? Please don't tell me to count the teeth and do all kinds of math ....I missed that day.

Its a 12 bolt NON posi, can you tell by the numbers on the gear? (here they are )


oh, and where "should" the axle info and or numbers be on the tube ?

1969 cutlass 2 door sedan 350 V8 2bbl with air auto THM 350

Thanks in advance for the help !!

RandyS

The code is on the back of the axle tube on the passenger side. Figuring your ratio by counting the teeth is very easy. # of teeth on ring gear divided by the number of teeth on the pinion gear. Example - Ring gear 39 teeth, pinion gear 10 teeth, 39/10 = 3.90. Use a calculator...........

1969w3155

Really? Make an effort. Get a paint pen (any hobby store) wipe the grease away form one tooth on the ring gear, and one on the pinion, that can be your starting point, number 1, count the teeth on the pinion while rotating the tires (off the ground), count the teeth on the ring gear, divide the pinion number into the ring number, for example: 39 teeth on the ring gear, divided by 9 teeth on the pinion gear = 4.33 gears. The number of teeth will also be stamped on each gear, i.e. "39" and "9". On the axle tube, with you facing the rear of the differential, it should be to the right and upside down, use scotch brite or something similar to scuff the axle.

1969w3155

Randy, you type faster!

Bob Kelso

Looking at the numbers it is a 2:56 ratio and it was made in October of 1968 . Divide the 16 in to the 41 and you have it . 10- 68 is the build date . That is the std ratio for the 2 bl engines .

joe_padavano

X2 (hundred!)

Geeze, even if you can't do simple division, both the computer you are typing on and your phone have calculator apps built in. Is this country really in that bad a shape?

oldsmobiledave

Wow. Really? You already have the cover off & can't figure out how to count the teeth on each gear & divide one by the other?


Sorry but this is just sad. I am embarrassed for you.

z11375ss

They didn't say there would be math.

Fun71

Counting teeth is totally unnecessary as the numbers of teeth on the ring and pinion gears are clearly marked on the edge of the ring gear as shown in the first picture. Also, counting pinion teeth can be a PITA.

This is by far the simplest method:

cheven

Thanks Kelso ....you have a grasp of the dates and code, I'm still a little lost on the dating system on some parts.....the dates do coincide with my mid 69 build. I did the tooth count and you're right ....2.56 !! and yep, car "was" 2bbl ...B-4 that was hacked up too. I knew someone had the #'s. At some point the cover was off and looks like nothing else was changed ....how do I know? nothing else is WRONG !! The cover had no gasket ...silicone only .....and the U-joint that was replaced was missing the clips on the loose caps, glad I caught that. (the u-bolts don't have stops)

Fun71

I thought there were stops on the pinion flange.

I have 4 different styles of Olds rears so it is possible I may be confusing your early O-type with one of the others.

cheven

I thought so too ? but when I was trying to put the icing on my axle project ....the drive shaft just slid back and forth as I tried to center it ....I was most perplexed as this isn't the first drive shaft I have installed (was R&R guy at trans shop in the 80's) The "U" bolts are smooth with no stops and so is the pinion yoke ......how the thing wasn't hopping down the road like Perter Cotton Tail is beyond me? I know I have a couple of loose clips ...someplace?

Fun71

I checked my axles and all of them (68 HD O-Type, 70 O-Type, and 71 10 bolt) have smooth pinion flanges with no stops. I guess I was remembering the stops on the Jeep driveshafts.