Well, after breaking a tooth of a side gear in the Eaton posi in my Moser 12 bolt after only 2 runs, i'm seriously considering a spool. Any advice you guys can give me? Wondering how they drive on the street. My car doesn't see tons of street time, but it sees more street then track. I know I won't have the benefit of a limited slip when turning anymore, but was wondering how bad is a spool on the street? How much stronger is a spool then a posi? I wouldn't guess I would break it. I have 33 spline axles now. Can I retain my ABS with a spool? Thinking about picking up one from Moser. What else do I need to know about spools. Any help would be appreciated. Thanks.

Ken R.

 

you will eventually wear out the splines in the spool since it is the softest part in the axle and if you launch hard you might put it into the wall. i've seen a couple of guys drive them on the street, the only time you'll notice it is when turning slowly it will either hop the inside tire or if you have a soft wall tire you will be on the gas cause it just loads up the tires. if you do use a spool i would check everything every season, ie. check the slop between the axles and spool for wear.

 

You need to do a search on this, there are many (myself included) who would never consider a spool for a street car. As far as your problem with the side gears on an Eaton, there was a bad batch of these gears some time ago. The first one I had broke the second time I had it at the track. The replacement (which Moser sent under warranty) has lasted thousands of miles and hundreds of runs (with evne mor hp). Maybe some of these bad gears are still around?

Rich

 

I have some spool time on the street. I broke a side gear in my Eaton also so I went to a spool. It's not great. The car pushes hard in the turns and the steering wheel feels a lot heavier. Parking lot maneuvers (sp) are god aweful. I get serious drivetrain chatter in parking lots. Softer tires help this but they'll wear out fast. Oh yea, don't drive in the rain. I only put about 1000 miles per year on the street so I live with it.

Steve

 

I think that's a pretty reasonable assesment of a spool on the street. I would strongly recommend trying a car with one prior to installing it in your own.

Rich

 

I've got a spool in my 9inch. About 95 percent of my street driving is hyway and don't notice the spool. But like said above, trying to maneuver the car around a parking lot is a pain, the car doesn't want to turn and there is alot of drivetrain chatter. If I did more street driving that required alot of short turns it wouldn't be much fun.

 

Ok. Think i'll stick with my Eaton. Too many cons vs pros for my situation. Rich, was there any way Moser or Eaton could pin point which batch of gears were bad? Don't know if they have any numbers stamped on them. It would be nice to know if I have a good pair second time around. I was kinda stunned that I broke that after only 2 passes. When your at the track, how do you launch your car? What rpm, what kind of tires, on the bottle, etc... Thanks for all the input guys. Much appreciated.

Ken R.

 

I'd like to ask, what HP you're at, how hard are you launching, ie what RPM, andwhat tires you're using? I've seen 12 bolts hold a lot, but they are still weaker than the 9in. So if you're running some relitively high HP #'s you may want to talk with moser about swapping to the 9in. and see what they say. I know it eats more HP to turn it, but it is stronger. And It's not the first time I've heard of a 12 Eaton biting it. Maybe you should contact Strange about one of their Super Strength units. I have yet to see one of those break, But if Moser will warranty your Eaton, then It can't hurt. I've also heard of set-up issues in the all the moser rearends. So I would get someone who knows their stuff to setup you new center section.

Just some opinions
Chris

 

My eaton crapped out on me as well, and I put a spool in just so I could make a my track rental. I kept it all summer (no $$$$ for another eaton) and it's the most awful thing in the world. I almost makes me not want to drive the car for the same reasons listed above. Only use a spool for drag racing, everything else you need a posi.

 

No, they never said anything other than "we know it's a problem and will send a replacement". When I had the M6 I launched at ~4,500 on the bottle. With the TH400 it's at 4,200 off the brake and on the bottle.

Rich

 

crash4cyl, I'm probably pushing close to 400hp at the wheels. Maybe somewhere between 375 and 400. ET streets launching off the bottle at about 3500rpm. It's an M6 with a Street Twin. On all 4 runs I made that day, all my 60ft times were in the 1.6 range, even with the broken posi, which wasn't known at the time. Seems like Rich was pounding his posi harder when he had his M6 and appears to have held up. I'm hoping I just got a bad apple, but am starting to hear of other Eatons breaking hear and there. So what is actually the true killer in the rear? What is most likely to cause a break? High rpm launch and a good hook up? Just wondering if coming out of the hole at a lower rpm but still hooked up would be as hard on the parts in the posi. I know it would hurt the ET, but just curious. My guess would be a high rpm hard hooking launch.

Ken R.

 

yes but no. I launched an M6 car with a bolt on motor and a strange at 4500-5K on an Nitto and an ET street. Limiting factor was actually the tires. They'd hook and pull the front end, but then they'd spin....can you say fast and the furious??? Yet he still cut 1.6's all day long. But I don't think the strange super strength is an Eaton unit. I would put money on the diff. not being able handle the shock. I'd almost say to get your money back for the diff. and go buy a SS unit from Strange. I have yet to see one of those break. That's also easier for me to say being 30 min. from Strange. But yeah the launch and the grip has got to be killing the limited slip, but It shouldn't be with a fairly new rearend.

Chris