01firechicken

Yes this should probably go under axles and gears but nobody seems to respond. I had my car on the lift yesterday trying to find out what's going on in the rearend (vibrations at 70-85mph). It looks like the spider gears are going out, good amount of metal shavings This is my question, I need to decide which is best for road racing and auto-x. I'll be stationed here in Germany for another 2 years so it'll have to with stand repeated 150-160mph autobahn runs(daily) I'm not worried about the weight differences between the 2 but duribility, I drive it like I stole it (gotta show the Germans cars that AMERICAN MUSCLE )!! Thanks for your help!!!!!!!!!!
Val

99HOSS

... either one, just a price preference. All the NASCAR boys run the 9" for a 'few' miles under power, and there are a lot of those that run the 12 bolt for durability.

Have to ask, you do change the rear gear fluid a lot more often than those of us that don't get to drive the Autoban at 150 mph daily, right?

sawedoff

iTrader: (3)

You'd actually be better off using a Ford 8.8" rear. They're sold by the sae companies that sell the 12's & 9's. You'd reduce the unsprung weight of the car, reduce parasitic power loss by using a better rear end.

01firechicken

99HOSS,
Yes all the fluids get changed alot more often whether it needs it or not. I keep going through brakes pads like there candy.
Sawedoff,
Thanks for the info!
Val

2001CamaroGuy

iTrader: (6)

I always said a Moser aluminum 9" (aluminum housing) with an aluminum center section would be KILLER for road racing

It would cost a good bit (compared to the standard version) but think of the weight savings....and it’s a 9"...indestructible....

mitchntx

iTrader: (14)

Are the 9" and similar diffs set up for 3 channel ABS? Or are they just 4 channel?

sawedoff

iTrader: (3)

If you just have your heart set on a 9", Speedway Engineering offers a lightweight housing and case. My reasoning on the 9" is, because I don't drag, why use a thirty year old design that has alot of power robbing characteristics, when I can use a more up to date version such as the 8.8" that offers the same strenght with reduced weight and it won't rob as much power as a 9". If I were a drag racer, the 8.8" can definitely take the abuse. The Ford guys have proven that. Let me know if you need anymore info on Speedway Engineering and their lightweight case.

NataSS Inc

iTrader: (9)

I just had my moser 9inch with nodular center section, 31 spline axles, daytona pinion support, 1350 yolk, richmond 3.40 gears, etc etc etc put in. On Wed. I had the car at the race track. The rear end is alot heavier so make sure that the suspension is up to snuff to handle the added unsprung weight. The rearend handled flawlessly the whole time on the race track and I was punding on the car pretty hard over 3 lapping sessions.

I would recommend the 9inch to you for a couple reasons. 1)It is a bulletproof rearend. 2)It makes changing gears a breeze in comparison to the 12 bolt. If you go with a 9inch, one thing you might want to add to it if you plan on making freaquent 150mph blasts down the autobahn is a "puke tank" mounted inside the car somewhere. I have a Canton catch can mounted where the drivers rear passengers back would be (no interior car). I dont recommend venting the rear end just out into the air. At high speeds you WILL blow fluid out of the rear end and you dont want it cover the car or blowing all over the road for the next guy to find.

One thing though, alot of people are talking about using lightweight housings and center sections, DO NOT USE THEM. In you case where cruising the autobahn at high speed happens alot, you will end up replacing gears often, not to mention blowing out pinion selas left and right. What happens is that the aluminum center section will heat unevenly in comparison to the housing.and cause flexing inside the center section. when everything starts felxing the gears get at bad angles and destroy them selves. Lightweight stuff is great if you have a track only car and a budget to buy gears on a regular basis. But for a street car that runs at high speeds for an extended period of time I would seriously steer you away from any lightweight parts. Even the NASCAR boys use the nodular iron center sections.

Cheatin' Chad

iTrader: (3)

The 12 bolt is more efficient which mean another 1-2% power to the ground.
I think it is lighter than a iron 9" as well.
Both have a good selection of gears and carriers.
You can get 12 bolts without c-clips
aluminum cases flex and accelerate gear wear.
you can swap gears alot easier with a 9in

Personally I like to keep my vehicles all GM if possible.I would go with a 12bolt.

Silver TT

NataSS - Damn dude....you have some awesome pics on that link in your sig. Those Nevada runs must be a lot of fun. So you fully gutted your car and put the cage in huh? Looks like you did a nice job.

I just did my first road race last weekend and I am totally hooked. So now I want to buy a race car, but I am still trying to find a race/street car. I am hopeful, but I guess there really is no such thing.

The car I am considering has a Moser 12 bolt with 4.10s. How will that do on an open road course? How will it compare to the stock differential in the way of driveability and realiability on the open road tracks?

Thanks,

Dan

Louis

iTrader: (7)

9" any day over the 12 bolts, 8.8s, ect.

Why you ask?

Nascar would run another rear end if they thought the weight savings/power gain/ availability was better than the 9".

The 12 bolt have no diff options. Eaton Posi, or spool. Take your pick.

A properly setup 9" will be lighter than a 10 bolt

01firechicken

Thanks for all the responses it has made my decision alot easier!
G2 LS1,
I've been trying to get ahold of you directly for some information reguarding a 9in and I few other items for my T/A. I can't seem to get you and the calls from Germany are $$$.
Going racing with the Porsche Club tommorow wish me luck (hopefully the 10 bolt will hold together for the last run of the season).

1LEThumper

I'm still lookin for a 3channel setup myself.

http://web.camaross.com/forums/showt...hreadid=165168

However one of these guys seems to think you can get a locker for a 12 bolt but I have yet to find anyone using one. So hopefully a 3 channel ABS 9" will be around shortly

EdmontonSS

Correct me if I'm wrong, but...
Doesn't NASCAR set a minimum weight for the cars? In that case wouldn't the cars be set-up with the weight as low as possible in the chassis? Perhaps this is why they use the heavier iron case 9"? With the rules in NASCAR, it might be the only legitamite legal rear-end anyway.

Cal

iTrader: (1)

I have the Moser 9" with aluminum center section in my '01 SS. I weighed both it and the stock 10 bolt while I had them out. To my surprise, the 9 inch was only 10 lbs heavier than the 10 bolt!! And I think most of that was due to the very heavy duty torque arm bracket supplied by Moser. Oh and BTW, it only cost about $200 more than the cast iron version; well worth it IMO!

01firechicken

Cal,
I thought that the weights of the 10bolt and 9in would be pretty close with the Alum center. I ordered mine Friday night, hopefully it'll be here to me in Germany within 2 weeks. Are there any tricks or tips when installing and breaking in?? Question for you; Did you have to do anything special to hook up the rear sway bar. I ask because Thunder Racing has 2 different sway bar mounts for the 9in. I couldn't get a complete answer on that question.

Cal

iTrader: (1)

01firechicken, sorry for being so slow to get back to you. Not much to breaking it in; it tells you how in the instructions, but I think you just run it for a couple of minutes on jack stands. Installation was pretty much a bolt-in except for the sway bar, the driveshaft U-joint, and the wheel bearings! The 9 inch uses a bigger yoke than the 10 bolt, so you will need a conversion U-joint back there. It's a standard item from NAPA Autoparts, but it might be a PITA to get a hold of one in Germany, so better order it now. You will have to have a good tranny shop press it on for you; with an aluminum driveshaft it has to done carefully! The 9 inch has larger diameter axle tubes, so you will need bigger U-bolts to re-attach your sway bar. These are a standard muffler shop item, I believe the size made to fit a 3" tail pipe. The other sway bar problem is one of the bolt bosses for the torque arm mount is in the way; you can either torch about a third of it off or take your die-grinder to it (the time consuming way.) You will need to salvage the caliper mount plates from your old 10 bolt and slide them over each axle shaft BEFORE you press the wheel bearing on! Also, make damn sure you have them turned the right way, or you will have to cut the bearings off to turn them around! Ask me how I know! $80 for a new taper bearing/oil seal/press block assembly! BTW, I hope you are getting the sealed-ball bearing option, not the tapered rollers like I got! Oh and another thing, that ultra-heavy duty torque arm mount they give you is going to smack the floor pan right behind the rear seat. I solved this problem by cutting out a 3"x3" square of the floor pan with a sawsall. I then MIG welded a steel box over the hole. The box is about 0.75" deep. It's not even noticeable once you throw the carpet back over it. I think most people just live the banging since it doesn't happen that often, but my car is lowered so I bottom the suspension a lot. Besides I'm a perfectionist and have to have everything working to my satisfaction, or I just start cutting and welding!

Good luck and let my know if you have any other questions . . . this time I'll make this a
Favorite Thread."

01firechicken

CAL,
THANKS! That's what I needed!! My 9in is sitting on my living room floor right now I read the breakin instructions and it's very simple like you said! I got the sway bar kit for the 9in along with the conversion u-joint. It came with the sealed-ball bearings. Thanks for the caliper mounting plates tip!! I can see already that I'm going to have fun with that HEAVY-DUTY torque arm mount ( mine already bumps the floor pan once in awhile). How did you attach all the brake line brackets to the housing?? Did you have any problems with the stock driveshaft length?? I'm hoping to put it all in next week (going to POR15 it this weekend). Thanks again for all the info!!!!
Val

Cal

iTrader: (1)

Hey Val sounds like you're all set! I coated mine with POR15 before installation also, that paint is simply amazing. No problems with driveshaft length, came out perfect. The only problem with the driveshaft is pressing out the old U-joint and pressing in the new one; must be done just right to not break the aluminum shaft end. You can't just beat the hell out of it with a BFH like we used to do on the steel ones! As far as the brake line brackets, I didn't even use most of them; used giant sized nylon zip ties instead. For the center bracket, I tried a couple different orientations before I got something that worked well. If you want I can snap a some pics and post them; would be real easy right now with it up on jackstands. Oh and the vent nipple stripped out so I just glued it in with JB Weld. Another thing, they didn't have the drain-plug option when I got mine, so I did that mod myself; that would be a lot easier to do now before you put the axle in the car. Hey, do they still use those cheezy T-bolts to hold the brake plates on? They're so damn short you can't use washers so the nut chews up the brake plate instead of getting tight. Also, the T-bolts are an SAE size yet you have metric sized holes that are a little too big in your brake plates making the problem even worse. I hope they've redesigned that by now, but if not I can tell you how I modified mine. BTW I did the whole install myself without any help; just put the car on jackstands and used a floor jack to lower the old axle and raise the new one. I even pressed the bearings on myself by using the autoshop press here at Hill Air Force Base; you may have a shop like that at your base also.

01firechicken

Cal,
Pics would be COOL! I planned on taking it to the autoshop here and doing it. They've got all the good tools and lifts. The Germans don't believe on working on their cars in their driveways. As for the drain plug option, I just made my own instead of paying the $25. Yes it still comes with the cheezy T-bolts. It also came with the studs for the center section, but no nuts. Do you know how hard it is to find a set of nuts to fit those studs over here. I finally found a place and bought 36 of them just in case. OK, this is going to sound REALLY stupid but I just have to ask. In the box that the axles came in in contained the bearings (w/rubber o-rings), axle press rings, and 2 seals. After reading the instructions repeatedly it says nothing about those 2 seals. Do they go in the axle tube? I'd put money on itbut wanted to ask first.