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View Full Version : early ford rear id help! Not to beat a dead horse.

Pete
11-08-2003, 05:35 PM
Iv got a 48 Ford truck open drive banjo rear end with 9-34 stamped on it, anybody know how to find the gear ratio??


The 9-34 is stamped on the bottom rib. I have the street rodder article on how to identify the different rears but it doesnt actually give you any formula.

Pete-
286merc
11-08-2003, 05:38 PM
Try some basic division and you wind up with a 3.78
Pete
11-08-2003, 05:43 PM
Wow, thanks zero rust man, that really makes perfect sense....smack smack.

Pete-
voodoo
11-08-2003, 09:04 PM
9 teeth on the pinion and 34 on the ring. I just got a 9 37 last weekend. 4.11 ratio. It's going behind my Merc flatty in the RPU.
Pete
11-08-2003, 10:30 PM
Voodoo,

I just removed the 3.78 from my modified roadster. The car has a 55 Chevy 235 with a 2 speedpowerglide, the damn thing would barely break 55 on the highway and that was really winding the motor up.

Pete-
FencePost
11-09-2003, 11:48 AM
OK so is it 3:78 or 4:11 ?? Math says 3:78 Voodoo said his was a 4:11. Now Pete how do we figure out the others...
I'll call you Mon or Tues on the 5 winda....

Doug
Fortyfordguy
11-10-2003, 05:25 PM
3:78 is correct.....per the markings on the housing. HOWEVER, if someone replaced the ring and pinion with 4:11's then you'll only know by rotating the axle/hub 360 degrees and counting the revolutions of the pinion. You'll have to make a reference point and do a little "by guess and by golly" to get the actual ratio, but it should be close enough to find out w/o opening the rear end and counting the actual teeth.
Jimv
11-10-2003, 05:51 PM
Pete said his rear was marked "9 34"(3.78), someone else said theres was "9 37"(4.11).a litle confusing !! but we're pretty sharp people here on the hAMB!!lol http://www.jalopyjournal.com/ubbthreads/images/graemlins/tongue.gif
286merc
11-10-2003, 05:57 PM
The 3.78 should give you a comfortable 60-65 Pete but I would suspect that Glide has some slippage to add to the woes. And how accurate is your speedo?
You can always go with some 6.50/7.00 x 17 rubber out back to keep the revs lower.

Note that Voodo has a different tooth count for his 4.10. You arent going to find better gears unless you blow a bundle at Speedway for 3.54's.
voodoo
11-10-2003, 06:43 PM
Pete I also have a 3 speed od tranny that came with the '51 Merc motor. So I should be OK on the highway. If not then I'll drop a T-5 behind it.