What is a safe change-out time for Richmond R&P in a 8 3/4?
I heard second-hand that Richmond recommends 300 passes but haven't been able to confirm it. I have changed mine at 300 passes twice now but have stepped up to a trans brake and have more power than before. It's a '742 case with M/W cap and arp cap studs. Thanks in advance BUT I'm not ready for a Dana yet and will never put a 9 inch in my car.

Dave

I guess it would depend on a lot of variables, there can't be one number for everyone. You would probably be best to pull the third member every so often and visually inspect the gears if you are concerned.


A Ford 9" is a lot like the Small Block Chevy - they are pretty reliable if you change every single piece to a beefed up aftermarket part.

Will depend on the weight of the car.... I have well
over 300 passes but my car is light with the 742 alum
center

Dave,

You are already getting about 298 runs more than we did before we switched.

I think you are the only one that will be able to answer this question.

The track(s) that you run on can make a big difference as well. Our home track used to have a little dip and going through that small dip is where ours would spit one out.

Good Luck,
Bill

If I was you I wouldn't make any more than 100 passes on the Richmonds, especially with the trans. brake now. Did you install a backbrace on your housing yet? If not it will need with the transbrake I'm a diehard 8 3/4 lover, I've used them in a lot of cars over the years, I have broken them also Axles, ring and pinons (a bunch), stock caps, posi units and posi side gears, I severaly twisted the 8 3/4 housing(not back braced ) up in my street car, 1971 duster that had ran 10:34 ET at 128.6 MPH on ET Street Radials corked up on Oregon pump gas motor only. That car has a cut down 3/4 ton Dana 60 in it now, Best thing I've done to the drivetrain in that car besides installing ladder bars and coil over rear suspension

Well the 3.91 gears in my old cuda let go friday at the track during testing. Made a 1.45 60' 6.50 pass at 105 mph, the next pass was a 6.78 at 98 mph, took the teeth of the ring gear im sure...Im telling my buddy its time to put a Dana in the car.....Phill

I forgot to add, It has a back brace and syn fluid.