Rearend Ratio

[racert22]

I just took a car in on trade and it has a Bulldog Dmi rearend.. the guy said he thinks it a 4.11 but wasn't 100% is they a way I can find out by looking or will it have to be an experiment type deal with gears at the track?

[TheJet-09]

Should be a tag on the top of the center section with a serial number. If so, I'm sure you could call them and they'll tell you. Otherwise, if it's together (got axles/hubs), put a set of known gears (ratio) in and and just turn the pinion by hand until the hub makes one full turn. It should get you close as there's a pretty good difference between final ratios of the same gear set in a 4.11 versus a 4.86. I certainly wouldn't go to the track without knowing what's in it first.

[Matt49]

I agree...know before you go or you'll either be gear bound or blow up a motor.
What Jet described will work but you can do it without any QC gears in it too. Take the QC cover off and make a mark on your upper shaft. Rotate the hubs 360* and count the rotations of the shaft. If it's a little more than 4, 4.11 it is. A little less than 5, 4.86 it is.

[billetbirdcage]

I just took a car in on trade and it has a Bulldog Dmi rearend.. the guy said he thinks it a 4.11 but wasn't 100% is they a way I can find out by looking or will it have to be an experiment type deal with gears at the track?

Just take the Q/C gears out and turn the upper shaft which is the pinion and count how many turns to turn the axle/hub one turn. Either gonna be slightly over a turn for a 4.11 or real close to 5 turns for a 4.86

[racert22]

I took the gears out and turned the hub/pinion a full turn. It turned about 4 & 3/4s of a turn. So will that be a 4.86?

[Matt49]

I took the gears out and turned the hub/pinion a full turn. It turned about 4 & 3/4s of a turn. So will that be a 4.86?

Should be. If you want to be really sure, give the hub 3 full turns. A 4.86 will get you to right at 14.5 and 4.11 will get you to just under 12.5. Harder mess up if you check it this way.