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Author Topic:   Transmission and rear question.
TRAP
Dirt Full Roller

Total posts: 34
posted June 24, 2002 06:04 PM
I am trying to find out what the 2nd gear size and the rear end size on a totally stock 82 mustang with a 2.3 Liter. I am trying to avoid taking the tranny apart and think that If I do I could not get it back together in a timely manner. I am a one man race team and do all the work myself and am not a professional mechanic. I know there are probably some different ways of telling and I am all ears on this one. Thanks in advance for any help .

TRAP the budget racer

hs
Dirt Full Roller

Total posts: 37
posted June 24, 2002 10:03 PM
iam the same has you are trap, do mostly everything myself with the help of girlfriend. you can count the tranny and rear end. stick it in 2nd gear and turn the input shaft 10 times and count how many times the output turned ,i believe thats correct its been awhile. i know there are 2.1 and 2.5 2nd gears, think theres also 1.9 but not sure on that one. hope it helps

KWTracer
Dirt Freak

Total posts: 233
posted June 24, 2002 10:33 PM
Turning the shaft and counting is the best way to tell, but if it is an 82 model and has the origional trans, it should be a SROD 4 speed. The ratios for this trans are as follows. 1st=3.07; 2nd=1.72; 3rd=1.00; 4th=0.70. There are lots of possibilities on the rear end. I would pull the cover and count it. Or you may find a tag we could cross. Gl

TRAP
Dirt Full Roller

Total posts: 34
posted June 25, 2002 06:21 PM
I looked for a tag and found a broken piece attached to the bolts on the casing. I guess it is time to open it up to see. Is there a way to check final drive physically with everything still in tact?

I am told by some of the local boys that race the same track that I should shoot for a final drive of 6.0 for a .4 mile dirt track. I should probably question the accuracy of this but I feel like these guys are pretty straight shooters and are really trying to help. Is this information accurate?? Im obviously working over my head but I guess that is the only way to learn.

TRAP

KWTracer
Dirt Freak

Total posts: 233
posted June 26, 2002 12:37 AM
Ok, All you need to do on the rear end is pull the cover, and wipe off the ring and pinion. Get the oil puddle out of the bottom of the housing. You don't have to take anything out. Get a paint pen or soap stone, or something to mark a tooth on the ring and then mark a tooth on the pinion. Turn the gearset and count the teeth on each gear. Divide the number of teeth on the ring gear by the number of teeth on the pinion and that will give you your rear end ratio. I'm thinking 6.00 final will get will get you pretty close depending on what your tire runout is and your motor. So, with a 6.00 final and a 1.72 2nd you'll need a 3.48 gear. If you have the 7.5 rear end, you should be able to use the 3.45 gear. That will give you a 5.93 final. Good Luck.

TRAP
Dirt Full Roller

Total posts: 34
posted June 27, 2002 05:28 PM
KTWracer,
Again you have been a big help to a beginner low budget racer. I am learning more and more about it every time I come on here and read the questions and responses and some of the terms used are foreign to me. You are able to bring it down to my level and I appreciate it.

Thanks again

TRAP

KWTracer
Dirt Freak

Total posts: 233
posted June 27, 2002 11:00 PM
Thats what this forum is for. I needed it when I started, and now I'm happy to help anyway I can. Good Luck.

rickmiller48
Dirt Newbie

Total posts: 1
posted July 02, 2002 08:37 AM
If the tranny is in the car (and you have a helper), you can jack up the rear end, line up the timing marks on the engine, put it in 2nd gear, and turn the driveshaft exactly 1 turn (use a marker to make sure it is exactly 1 turn), then you go by how many times the crank turned. Just shy of 2 turns is a 1.99 or 1.98, 2 turns plus 30 degrees or so is a 2.14, 2 1/2 turns plus a little is like a 2.60 or something, you get the idea. You can do the same for the rear, if the driveshaft turns just past 3 times for 1 turn of the tires, it's a 3.08, 3 and a quarter turns is a 3.27, 3 and a half is a 3.45 (or something), 3 and 3 quarters is a 3.73, and just past four is a 4.10 or 4.11 or whatever. The rear is real hard to do if it isn't locked. If it isn't you have to actually roll the car so the wheels turn 1 time and watch the driveshaft unless you can get both back wheels to turn together in the air.

This is the quick lazy way of doing it.

Sorry for the long post, hope I helped.

Rick Miller
#8 Mustang (Trail-way Speedway)

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