4.10s are in.. Slight problem... Experts step in

**SteelmanLS1** · 03-26-2008, 02:27 PM

Hi guys.. Here is the story 2 weeks ago I was playing around on the street an launched my car a couple of times and broke my carrier (lockrd) in half.. Well I got another out of a 2000 camaro that was a good rear end... I ordered 4.10's, t/a girdle.. We installed the gears and the backlash felt perfect, barely any slack, (we have set ring and pinions a hundred times).. It drives just perfect in a straight line, no pinion noise, nothing.. But when you turn a corner left (more often) or right, you can hear the tires screaking for a second (as if posi was 100% of the time not limited slip) and then all of a sudden Bang it will pop and drive fine and you could do circles all day long and no more banging... as soon as you put it in a straight line it does fine... next corner, Bang..

I put Royal purple 75w-90 in it for everyone who is going to ask me what kind of fluid I put in it... I Did Not put any limited slip additive in it becasue the royal purple bottle said it had it already.. I drove it about 40 miles (it banged probably 3-4 times, I was super easy on the corners)... I am letting it cool off and I picked up 2 bottles of limited slip additive from O'Reillys.. I am going to try and put them both in there and see if it stops becasue it sounds like the posi unit is locking up...

Guys help me! Is no additive my problem or is it more serious?

**bills98ta** · 03-26-2008, 04:06 PM

I'd try maybe 1/2 a bottle of the slip additive, the go to a lot, where you drive figure 8's to work it in. Hope that fixes it for you ! Add to much, it will slip to much...

**Toes** · 03-26-2008, 04:27 PM

if the additive dosent work go back to non syn diff oil w/slip additive

**SteelmanLS1** · 03-26-2008, 04:43 PM

I did a half a bottle of additive.. No luck, tried the full bottle no luck.. Still clunks.. I am going to try some just regular 80-90 lucas tomorrow.. if not I am going to take it to a GM dealership for new clutchs and stuff

**bills98ta** · 03-26-2008, 04:45 PM

You might find some ring gear teeth sticking to the magnet... Bummer...

**SteelmanLS1** · 03-26-2008, 05:04 PM

Originally Posted by bills98ta

You might find some ring gear teeth sticking to the magnet... Bummer...

Does fine in a straight line... So it wouldn't be ring and pinion.. Its only turning, so the clutch's in the spider gears are broken or even a spring offset or broken.. Something to that nature

**bills98ta** · 03-26-2008, 05:28 PM

You might be right... More work... There's always a bright side, at least you won't be bored !

**SteelmanLS1** · 03-26-2008, 07:23 PM

Originally Posted by bills98ta

You might be right... More work... There's always a bright side, at least you won't be bored !

Damn im dizzy... My uncle told me to go do figure 8's for about 20 minutes with a variety of speeds because that differential had been setting for a good while unused and it had to be "broke" in again... anyways I did figuer 8's for like 30-40 mintues and it has stopped... drove home no problems.. Odd too me but I will keep you guys updated

**RacerBob** · 03-27-2008, 09:30 AM

I hope someone replies to this thread that can explain how the figure eights worked.

**SteelmanLS1** · 03-27-2008, 09:44 AM

Originally Posted by RacerBob

I hope someone replies to this thread that can explain how the figure eights worked.

The carrier (differential) had been setting unused, unoiled in the shop for over a year... The spider gears and clutch plates got tighter, It had been washed with mineral spirits (solvent) and then set there, so everything was real super dry and tight... Even the GM dealership lets their new carrier's soak in limited slip additive for like 5 hours before they install... Just takes a little bit to break in a new carrier, or a used one that has been setting awhile.. Thats my theory and the techs I know at my local GM dealerships theory..

**RacerBob** · 03-27-2008, 09:47 AM

Thanks for explaining.

**sixpack_2_go** · 03-27-2008, 09:50 AM

save for a 9" i put a lot of cash into a new 4.10 ring & pinion and moser diff cover. after breaking 3 rearends i figured out that putting money into a a 10bolt is the worst mistake i ever made. i now have a moser 9" and i am happy knowing i don't have to worry any more. also, if you don't run slicks or drag radials don't run 4.10's. they actually made my 1/4 mile times a lot worse cause i couldnt get traction until 4th gear.

**bills98ta** · 03-27-2008, 03:51 PM

I rebuilt mine 4 times before I installed a moser rear ! The figure 8 slips the clutches clockwise, then counter clockwise to work in the additives ! Easiest way I can explain it ! Good luck on the rear !