A Strange 12 bolt Install
Thread Starter
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
Nope, TrueTrac was a champ. I actually really liked it. I went spool because the TrueTrac was 28lbs and the spool is 8. At the end of the day, I shoulda saved the money and time and went spool out of the gate. But for some reason I error on the side of conservative and regret it later and double work myself 
Teching In
Joined: Dec 2012
Posts: 3
Likes: 0
From: Manassas, VA
I was looking to buy a strange 12 bolt just recently. I am assuming the can put the stock F-body backing plates on, as I am trying to do a c6 brake upgrade from flyinbye. But from previous comments, the 12 bolt is not recommended for manual transmissions. I don't want to do a 9" because of weight reasons. But why is that? I did a search and it wasn't clearly explained.
Thread Starter
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
Yes, you reuse your stock backing plates. The 12 bolt is a great rear end. The ones saying go 9 inch are saying that from the prospective that it doesnt have the pinion support bearing like a 9 inch does. That pinion support helps it stay very stable during very high rpm launches at a drag strip. When it comes to launching an m6 very hard, you should over build anything you can afford to. So that makes a 9 inch a shoe it, especially when price is similar. Other then that extreme example a 12 bolt will last you a lifetime.
Teching In
Joined: Dec 2012
Posts: 3
Likes: 0
From: Manassas, VA
Sounds like a glove then. I do have another question that probably sounds stupid, but will stock axles fit the 12 bolt? In other words, are the thickness of the axles the same or completely different? If they were the same, I was just going to get the center chunk and have a driveline shop around me fabricate the rest (welding the 10 bolt axle tubes to the 12 bolt housing, etc).
Teching In
Joined: Dec 2012
Posts: 3
Likes: 0
From: Manassas, VA
Thanks for all your help. And one last question. I think you said that the 12 bolt hits the upper panhard bar. Will a panhard relocation bar help out with that? I am going to get the new girdle as well and don't feel like dealing with any banging between panhard bare and rearend.
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Brett Foote Thread Starter
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
Youll have to install your cover and check clearance then go from there. I suspect a relocation will work because its a bar not a big flat piece like the stocker. Also, I realized my rear end was shifted to the rear so I bought adjustable lower arms and centered the tire which require pulling the rear end forward. That probably created some.clearance also.
Thread Starter
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
So I figured while I was doing a gear swap I'd freshen up a little bit. I've always hated the fact that I spray painted the rear end in this car. Money was tight when I ordered it so saving money was important, now I can go back and undue that mistake. So ordered up some Richmond 4.10s. Gonna hold onto the Motive 3.73s for now, they may end up going back in one day.
Got it pulled and hung up for full disassembly.
And off to the powder coat shop!
Going more low key this go round, went with gloss black.
And that little custom touch that makes it your own and unique.
All that hard work, lets relax by the BBQ grill with some LSX buddies.
Should have it reassembled this week, a few tuning tweaks, and off to the track March 11th weather permitting of course.
Got it pulled and hung up for full disassembly.
And off to the powder coat shop!
Going more low key this go round, went with gloss black.
And that little custom touch that makes it your own and unique.
All that hard work, lets relax by the BBQ grill with some LSX buddies.
Should have it reassembled this week, a few tuning tweaks, and off to the track March 11th weather permitting of course.
Thread Starter
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Got this thing back and it was an oily sandy mess inside. So I spent considerable time cleaning the inside. Now that it's clean it's ready to be reassembled.
Stopped at home depot and got some angle iron and some all thread. After all the rear ends ive built I'm finally building myself a case spreader.
The case has one 3/4 and one 1/2 hole for the case spreader to attach to, so I found some scraps that fit those dimensions. I did have to revise this design as it was blocking the bearing caps from going in. No big deal, we are learning.
Here it is set in place. You turn the buckles and the case spreads. Easy as pie.
And this is why you need a case spreader. I pulled this out during disassembly. No doubt it got bent during final carrier preloading last time when I swapped the spool in.
May not have this out again for a while so I decided to take some weights. This is the empty housing weight.
This is fully dressed weight. It has a spool, no brakes, aluminum rear cover.
I was an idiot to not powder coat this thing sooner. It looks very pimp now. Will reinstall this weekend. Stay tuned.
Stopped at home depot and got some angle iron and some all thread. After all the rear ends ive built I'm finally building myself a case spreader.
The case has one 3/4 and one 1/2 hole for the case spreader to attach to, so I found some scraps that fit those dimensions. I did have to revise this design as it was blocking the bearing caps from going in. No big deal, we are learning.
Here it is set in place. You turn the buckles and the case spreads. Easy as pie.
And this is why you need a case spreader. I pulled this out during disassembly. No doubt it got bent during final carrier preloading last time when I swapped the spool in.
May not have this out again for a while so I decided to take some weights. This is the empty housing weight.
This is fully dressed weight. It has a spool, no brakes, aluminum rear cover.
I was an idiot to not powder coat this thing sooner. It looks very pimp now. Will reinstall this weekend. Stay tuned.
Thread Starter
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
TECH Resident
Joined: Oct 2014
Posts: 898
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So tell us your thoughts on the spool vs the truetrac. Was there any difference at the track? How is the spool on the street?
Thinking about a strange 12 bolt with a spool with 3.90s for my Z. It's an A4 with a 4000 stall.
Thinking about a strange 12 bolt with a spool with 3.90s for my Z. It's an A4 with a 4000 stall.
Thread Starter
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
So far I love the spool. The Trutrac was very good, so no complaints, but I like the 20lb weight savings and having one less thing to break. The spool will buck just a little around tight corners but other then that you never know its there.
looks amazing! I had mine powder coated in silver, looks like yours when you first painted it. when you swapped out the true trac for the spool, did you have to reset your pinion depth? I'm getting to take my spool out for a wavetrac and was wondering since the diff is different if the center point would change.