I installed a 9" last week and did some driving around town, but this is the first time I've had a chance to run it any any sort of speed. When above 50mph, the gears whine when loaded (on the gas).

This rear is a Moser 9" with 3.70 gears, detroit locker, and 35 spline axles.

Those guys with 9" rears, how's your gear whine on a scale of 1-5 with 5 being annoyingly loud?

 

yea some gear whine is normal.. but if you feel its excessive.. you might wanna have it looked at or at least listened to someone.. and get a 2nd opinion..

 

They are gonna whine. Just get used to it.

 

i run a 4.30 us strange gear and my car goes mid 9's and it's quieter that my everyday driver. you might want to change you gear oil, yours might have broke down from the run in. i use wolfs head 80-90w in all of my gear installs.

 

I voted noticeable but not bad. I could care less about the slight wine from mone, its the Detroit locker in mine that I cant take. That along with the M6 is annoying. I dont know how anyone could daily drive a car with one. I didnt have a choice when I bought the rear since I got a great deal on a complete one used. I've got almost the same rear setup as you, Moser 9", 3.89's, 35 spline axles and the locker. Anyone know how well the Powertrax locker/differentials work? They claim to be much more streetable than the Detroit locker, I'd like to swap this out for one this winter.

 

It's not the fluid. The fluid has about 10 miles on it. The previous owner drained it on removal and I filled it on installation.

You're right about the M6 + detroit locker. I didn't realize how little there was in the 35 spline world for carriers. I'm half tempted to trade someone straight up for a 31 spline setup.

I have an aluminum center section and some 4.30 gears sitting here. I was thinking about putting together a powertrax setup... Since the powertrax just replaces the guts of an open diff, do you happen to know if any open diff would take the powertrax 35 spline locker? If not, I'd need to find an open diff from either '75-'86 F150 or '60-'83 F100 pickups to put it in.

 

the jacka.. who sold the package should have known about a manual trans and a detroit locker combo dont go together. have you had it down the drag strip with slicks? i bet it was a hell of a ride.

 

Why can't you combine manual trans and detroit lockers? Heck they were factory installed combo's back in 69-70. At least you could order Fords with Detroit lockers and 4 spds.

Roadie...if you find out the problem thats causing your whine let me know. My 8.8 only makes noise above 50mph with a load on them too. I assume its incorrect gear setup but i wonder if something else could cause the problem also.

 

Yeah, a friend of mines Dad has an original 69 GT 350 Mustang with a 428, a 9" with a detroit locker AND - a factory installed freaking rollbar! I couldnt believe they factory installed that combo in a car back then, that is just sick!

The M6 and locker is certainly driveable, but those along with the Spohn body mount TA and SPEC 4 clutch I just installed makes for some brutally hard shifts. The locker just has too much play in it, it really bangs hard between shifts. I had my wife for a ride in it this weekend and she couldnt beleive it was supposed to do that, she thought the car was broken, and I was trying to take it easy I really want to try the Powertrax diff this winter, that is the only other option I know of with 35 spline axles.

 

Right. It's not that they don't go together. It's that the slip in the detroit locker makes unloading and reloading the rear very harsh. A friend of mine broke a solid-body 1350 u-joint on the dyno because of the "slack" or "play" in the locker.

I haven't taken my wife for a ride in it yet because she'll tell me it is broken.

If you get it done before me, definitely post up your results. I started my search for a 35 spline open diff already.

 

Yeah, I dont recommend it, mine was a little scared. At one point she asks if I have my cell phone on me in case we get stuck. I tried to tell her those sounds were "normal" for this kind of rear, she still couldnt believe it.

Let me know if you find anything else for a diff, if not I will be swapping the locker for the powertrax later this year. I'll definitely post up how it works.

 

If its a 428 car it would be a GT500 if its "original". Check my sig on the second page you'll see why i know a little bit about stangs. He is lucky to have a Shelby with the Drag pack option. I wish my car was a SCJ car.

 

Your Mustang looked nice. I'm not real up on classic Mustang info, it was a big block car I know, maybe it was a 429? I know the model was a GT350 though, it has the shaker hood, the factory race package, 9" with the locker, and a rollbar with a 5 point seatbelt harness. It an unrestored original car in extremely good condition too, his dad has owned it for over 20 years and it has sat most of that time. Pretty wild to think that all came factory at one time.

 

They are cool cars. It would have to be a 428. The 429 was only available in bosses in 1969. If its a shelby shakers weren't available on them. If its a GT350 the only thing available for them was 351 windsors if its original. Thats enough Ford talk i'm sure its a cool car.