[gw1626]

my rear end was making a whining noise when i was at a steady speed and a little on acceleration in high gear. it had royal purple 75w-90 max-gear synthetic oil. when i ck back lash it was .007. i put white grease on the gears they appear to in the center. was going to loose up to 12 thousands and use castrol hypoy c85w-140 oil. hoping this would quiet it down.should i get posi additive from ford? i had a shop put new bearings in last year. (aprox 300 miles ago). when i spin the tires both wheels turn in the same direction does this mean i have a posi? the gears are 37 & 9 is this a 411. case has a #c4aw 4025-g. just want to know what i have. thanks for any help.
Butch

[gw1626]

hereb are bsome pictures.

[eloc431962]

Yes i would put some skunk oil in it if it were me. Here's what i use it's recomended for ford posi units. But there are other brands out there.
This is just what i have alway's used in mine.
JMO

Cole

[gw1626]

here are some pictures.

[big gear head]

Looks like a standard differential to me. It's pretty comon for the 9 inch Ford to weld the pinion gears to the cross shaft when someone does one wheel burnouts. I've had several of them that were like that. It's also possible that you have one of the 2 pinion limited slip differentials. You don't have the 4 pinion Traction Lock.

Using the limited slip oil additive will not help the gear noise. Some people have claimed that the Lucaqs oil helped, but I haven't tried it. I don't know how you can tell what the pattern looks like with that grease. I can't tell anything from the pictures.

[eloc431962]

My bad i had a "BRAIN FART" wasen't thinking about the whine in the gears .
Additive will not help with that usually a replacement of the gears will fix that problem.JMO


Cole

[302 Z28]

IMHO the only traction additive to use in a Ford Traction Loc is Ford additive. I have tried CRC and it does not work, and I have tried Royal Purple that is supposed to have it and it did not work either. The Ford additive got rid of the clutch shudder going around corners none of the others did. I would be very wary of the Lucas product and I had a very bad expensive problem happen when I recommended it's use.

Fwiw, do not buy a Richmond Gear if your trying ro get rid of a whine.

Vince

[eloc431962]

Originally Posted by 302 Z28

IMHO the only traction additive to use in a Ford Traction Loc is Ford additive. I have tried CRC and it does not work, and I have tried Royal Purple that is supposed to have it and it did not work either. The Ford additive got rid of the clutch shudder going around corners none of the others did. I would be very wary of the Lucas product and I had a very bad expensive problem happen when I recommended it's use.

Fwiw, do not buy a Richmond Gear if your trying ro get rid of a whine.
Vince

Yep the motorcraft additive i posted in the pic is the only one i have ever use in a ford unit. And it does work like you said Vince.


Cole

[oldschool hero]

That is not a posi unit.Don't set the back lash @.012 thats way too much and it will whine even louder.Std. 90 wt.gear oil is all you need for lubing.Nothing you add will quieten it down unless you put in sawdust and banana peels.I set mine between .004 and .007 max

[gw1626]

>how do i tell if i have limited slip? i am in the process of putting a tremec tko 600 in this car and a set 26 x 10 inch slicks. was going to go to the track to see how fast it will go. most of the time it will be street driven. if i need to change the gears get get rid of the noise. was thinking of a lower gear. 456 488 ? the tko is the .63 5th gear. or is this rear end a waste of time? also how come i cant see my post? i have log out to see them.

[bentwings]

If you are going to go with a deep gears and big slicks I wouldn't mess with any Ford "posi" unit. I'd go with a Detroit Locker in a heartbeat. End of trouble. Beginning of enjoyment. No additives required. I have one and it works great on the street. It's really cool when leaving the local drive in to just step on it lightly and shift gears. You get an automatic little bark from the tires.

You don't really show the pattern on the gears. The one tooth that can barely be seen looks like heavy 'toe' contact on the drive side. Run the gears thru what ever is on there and let us see the mesh pattern. You probably won't be able to do much about the noise from this used set. Once you break it in it's what will be. Richmon seem to be noted for noise. I have them in mine but they make a little noise. I had one of the best patterns I ever had so like I said it's what will be.

Check this rear end out I just finished last week. It's basically a 9" Ford with the large pinion and race gears. It a Strange Eng top loader for funnycar. You can see the next victim in the FC chassis in the background

[big gear head]

I think you need to toss that chunk and start over with good parts. You will break that thing. Do you have the WAR or WAB case? If you do then you need to replace it. The '67 and later cases are better than the early cases. The nodular cases are best, but rare. I would also recommend replacing the standard pinion housing with a Daytona pinion housing. The stock differential is weak and should be replaced with an aftermarket differential. Even the 4 pinion Ford Traction Lock is no good. The Detroit Locker is great for drag racing, but a clutch type differential is smoother on the street. Yukon makes a good clutch type that is much stronger than the Ford TL. I replaced the Detroit Locker in my Camaro with the Yukon unit last summer and I haven't been able to break it yet with a 427 and a 4 speed with 15 inch wide tires.

People are always talking about how strong the 9 inch Ford is, but it isn't really very strong at all until you get the stock Ford parts out of it.

[bentwings]

I agree except for the locker. Each to their own.

For all the screwing around trying to get the right parts out of the salvage yards you are better off just going to the rear end co.s and purchasing the right stuff the first time. You can buy everything from one place and assemble it your self. If you don't "have the technology" just ask here.

[big gear head]

Originally Posted by bentwings

I agree except for the locker. Each to their own.

I like the locker too, and I believe that it is best for drag racing. I put the Yukon Duragrip in my car to test it and see if I could break it. I don't like to sell something that I don't trust. I'll probably put the locker back in mine sometime. I have another old nodular case that I'm probably going to put together with a different gear ratio, and I'll probably put the locker in that one.

[gw1626]

i took my center chunk down to my local hotrod barn. they think i have a mini spool. after getting marking compond. i have took some more pics. as i am running out of money for right now. i would like to use this rear end for a little while. i would like to shim it so that it ride in the center like it is suppose to. dont know if i should add shims or remove. thanks for all the info.
Butch