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Author Topic:   How to find rear end gear (not final gear)
sleadhead44
Dirt Maniac

Total posts: 109
posted April 30, 2004 12:01 PM  
What is the best way to figure out what rear gears I have? '82 Cutlass 10 Bolt rear end. Driveshaft is not in. If I pull the cover, will I be able to see the teeth on the ring gear and the pinion gear? Never done this before so your help is appreciated.

sc1 racing
Dirt Freak

Total posts: 419
posted April 30, 2004 12:05 PM  
gm has the ring, and pinion numbers on the ring, rotate it till you see the numbers, then divide the highest into the smallest that will give you the gear ratio. most likely it will be a 2.41, 2.29, 2.73

sleadhead44
Dirt Maniac

Total posts: 109
posted April 30, 2004 03:04 PM  
Thank You SC1!

racer17j
Dirt Forum Champ
Total posts: 5390
posted April 30, 2004 05:24 PM  
It will probably be a 17-41 for a 2.41 ratio.

M1
Dirt Freak

Total posts: 257
posted May 01, 2004 09:44 AM  
I just pulled mine off for the first time and found 22 on the pinion and 47 on the ring. That would make a 2.13 or so.

ICK!!!!

That was in a 86 cutlass with a 307.

racer17j
Dirt Forum Champ
Total posts: 5390
posted May 01, 2004 01:36 PM  
i had a set of 2.23 in an 80 monte carlo once it was all we had, it took about 2 or 3 laps to get thatthing up to speed on the 3/8ths track we ran but as long as there were no cautions my old man used to haul with that thing. of course we were running a 331 in a field of 305s so that may have had something to do with it.tech wasn't really tough there at all. in theroy those gears never should ahve worked at all with the pg that was in the car and they only worked well at that one track. one of thosde freak things i think

sideways
Dirt Forum Champ
Total posts: 715
posted May 01, 2004 07:55 PM  
I have ended up with a couple 2:13 or so.One in a 305 monte 1978 and 83 cutlass with a 350 or could have been 307? Can you say"all passengers put there tables in the upright position and buckle up we are about to get this airplane off the ground with those gears folks"

[This message has been edited by sideways (edited May 01, 2004).]

M1
Dirt Freak

Total posts: 257
posted May 02, 2004 04:32 PM  
racer17j,

I was told that already by a few people. They laughed and said I better go recount them, so I did, and came up with those numbers again. One guy would NOT believe me, so I counted them while I was on the phone with him. Ive never heard of them until now, but they exsist, so beware...LOL

sleadhead44
Dirt Maniac

Total posts: 109
posted May 06, 2004 07:22 AM  
I pulled the cover off and cleaned it all out. On the ring gear it says 21:48. I used a paint pen to mark my starting spot and counted all the teeth, just to make sure I was looking at at the right numbers. Yep, 21 teeth on the pinion, and 48 teeth on the ring, so I have a 2:29 right??? That means with a Turbo 350 and 1st being 2.75 and 2nd being 1.52, that would give me a final gear of either 6.30 in 1st. and 3.48 in 2nd. So I better leave it in 1st when I finally get it to the track. Is this correct thinking everyone? Ok, now to close it back up, do you use just a gasket, just orange silicone, or both? And do you use 80/90 oil or something different. Thanks again everyone!

racerman707
Dirt Freak

Total posts: 374
posted May 06, 2004 09:31 AM  
You've got your math right.Gasket or sealer will work.Pay attention to your tire rollout too.

25JHenry
Dirt Full Roller

Total posts: 73
posted May 06, 2004 10:50 AM  
Another way to check the rear gear ratio is to put the car in neutral, jack one wheel off the ground and leave the other on the ground so it will not spin. Spin the wheel that is off the ground 2 complete turns while counting the number of times the pinion yoke turns. The number the pinion turns will be you ratio. When looking for a gear in the junk yard you can check several in only an hour.

sleadhead44
Dirt Maniac

Total posts: 109
posted May 06, 2004 12:34 PM  
Can you do that with a welded rear end?

[This message has been edited by sleadhead44 (edited May 06, 2004).]

racerman707
Dirt Freak

Total posts: 374
posted May 06, 2004 01:03 PM  
yes.

nate 11
Dirt Freak

Total posts: 316
posted May 06, 2004 03:04 PM  
wouldnt both wheels have to be off the ground?

WesternAuto17
Dirt Forum Champ
Total posts: 569
posted May 06, 2004 03:43 PM  
Yeah, both wheels would have to be off the ground if the carrier was welded.

racer17j
Dirt Forum Champ
Total posts: 5390
posted May 06, 2004 03:55 PM  
I don't see how you guys are coming up with the 2.28's and higher gears,around here they are 90% 2.41's.

sleadhead44
Dirt Maniac

Total posts: 109
posted May 07, 2004 02:06 PM  
Ok Thanks, I don't know how I came up with 2.75 for 1st gear. So a Turbo 350 in First gear is 2.52 and my rear end is 21:48 or, 2.29, so I come up with a final gear of 5.76.

racer17j
Dirt Forum Champ
Total posts: 5390
posted May 07, 2004 04:16 PM  
here what i have got all mine from reco
80 malibu v6 2.73
83 cutlas v6 3.23
84 regal v6 2.41
79 monte 305 2.29

    

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