How to pick a rear?

[pajeff02]

Ok... I recently bought a pile of UMI suspension pieces for the back of our car. Since I have to do the work anyway, seems like upgrading the rear now would be the thing to do. Winter is setting in and I need projects like this to get me through until we can drive our car again in late March or early April.

I have been reading up on the available F-body bolt in rears -- 9", 12 bolt and the Strange Dana 60 (which looks damn nice!). I know the basic differences between each of these, and understand that with traction control I would need the 4 channel upgrade on whatever I go with.

A lot of you have already upgraded, so my question is how did you choose from these rears? The Dana is obviously the beast of the bunch, but it also results in a substantial weight addition. The 12 bolt is nice as it has the c-clips eliminated and you also have easy access if there ever is a problem. The 9" is tried and true, but I believe I have read about fitment and ride height issues in other threads. Anything else I should be considering?

For reference, the car will be a bolt-on project for at least the next year. The future may have in store a H/C upgrade. As it is an A4, the rear will most likely be ordered with 3.73's.

[Hi-Po]

Ok... I recently bought a pile of UMI suspension pieces for the back of our car. Since I have to do the work anyway, seems like upgrading the rear now would be the thing to do. Winter is setting in and I need projects like this to get me through until we can drive our car again in late March or early April.

I have been reading up on the available F-body bolt in rears -- 9", 12 bolt and the Strange Dana 60 (which looks damn nice!). I know the basic differences between each of these, and understand that with traction control I would need the 4 channel upgrade on whatever I go with.

A lot of you have already upgraded, so my question is how did you choose from these rears? The Dana is obviously the beast of the bunch, but it also results in a substantial weight addition. The 12 bolt is nice as it has the c-clips eliminated and you also have easy access if there ever is a problem. The 9" is tried and true, but I believe I have read about fitment and ride height issues in other threads. Anything else I should be considering?

For reference, the car will be a bolt-on project for at least the next year. The future may have in store a H/C upgrade. As it is an A4, the rear will most likely be ordered with 3.73's.

Being an auto, Either 12 bolt or 9" will do fine. The Dana would be massive over kill IMO.

I had a DTS 12 bolt with Moser internals. It whined pretty severe. If you go with a 12 bolt, check out the Strange 12 bolts. I love a 9", but the Tru Trac is a toss up for me at the moment. Its hard to get information from certain dealers. They all say the best is what they sell. 373 is a great ratio for most autos.

Even with my stroke of bad luck recently... I would still recommend a 9". Mark at kyspeed.com (sponsor) can get you a deal on a 9" or 12 bolt. Being an auto, you can go wrong with either really. Others will chime in with an opinion.

[ntimid8r]

For an A4, 3.73 gears work out best for running 1/4 mile. For the rear end...pretty much what Hi-Po posted is true. My only change to that would be a recommendation for the midwest chassis 9". I wish those were around when I did my rear end upgrade. I went with the Strange 12 bolt, I mainly street drive and from what I read from others that the abs system can sometimes have problems with sensors not aligned properly with the 9" rears. I wanted to keep all my abs/tcs equipment. But I believe that alignment issue is no longer an issue. I helped a buddy install the midwest chassis 9" and wow...that thing is sweet. A little more pricey than a 12 bolt but you get a much stronger (and lighter) unit.

There's lots of things to consider for a rearend but take in all the opinions, do your research and find what fits your use and budget.

[Hi-Po]

For an A4, 3.73 gears work out best for running 1/4 mile. For the rear end...pretty much what Hi-Po posted is true. My only change to that would be a recommendation for the midwest chassis 9". I wish those were around when I did my rear end upgrade. I went with the Strange 12 bolt, I mainly street drive and from what I read from others that the abs system can sometimes have problems with sensors not aligned properly with the 9" rears. I wanted to keep all my abs/tcs equipment. But I believe that alignment issue is no longer an issue. I helped a buddy install the midwest chassis 9" and wow...that thing is sweet. A little more pricey than a 12 bolt but you get a much stronger (and lighter) unit.

There's lots of things to consider for a rearend but take in all the opinions, do your research and find what fits your use and budget.

Yea, I forgot some things. The MWC fabbed 9" is nothing short of beautiful. Great piece, but it is costly. ABS was a no brainer to delete for me, but I can understand people wanting to keep things like they were.

[ntimid8r]

Yea, I forgot some things. The MWC fabbed 9" is nothing short of beautiful. Great piece, but it is costly. ABS was a no brainer to delete for me, but I can understand people wanting to keep things like they were.

Yeah, the abs/tcs was a thing for me. I remember Nino got a moser 9" and kept the abs/tcs.....boy did he have problems with it. Most guys deleted it when they upgraded. So far my buddy with the midwest unit has been more than pleased with how well it's working. Makes me want to post my 12 bolt up for sale.

[Hi-Po]

Yeah, the abs/tcs was a thing for me. I remember Nino got a moser 9" and kept the abs/tcs.....boy did he have problems with it. Most guys deleted it when they upgraded. So far my buddy with the midwest unit has been more than pleased with how well it's working. Makes me want to post my 12 bolt up for sale.

I'm willing to bet that the Moser 9" have sorted out most of the problems with the ABS/TCS. But, whenever you add electronics back there, it stands a chance of fighting you.

Whats your budget Jeff?

[pajeff02]

I'm willing to bet that the Moser 9" have sorted out most of the problems with the ABS/TCS. But, whenever you add electronics back there, it stands a chance of fighting you.

Whats your budget Jeff?

Any of the rears are within budget. I agree the Dana is overkill for my application, so choosing between the 9" and 12 bolt is probably the real question. I'm glad you guys are including sources as well in the responses. Other than the electronics, any other concerns?

[35th-ANV-SS]

Any of the rears are within budget. I agree the Dana is overkill for my application, so choosing between the 9" and 12 bolt is probably the real question. I'm glad you guys are including sources as well in the responses. Other than the electronics, any other concerns?

Not so sure it is a "concern", but both Ron and I have had axle leaks on our Moser 9". I had my seal replaced only for it to start leaking again almost immediately (within the week). RTV seems to make it go away. Haven't yet got it fixed the second time around.

Other than that, I got the 4-chan option with mine to keep my ABS and TCS functional. No issues thus far.

[pajeff02]

Not so sure it is a "concern", but both Ron and I have had axle leaks on our Moser 9". I had my seal replaced only for it to start leaking again almost immediately (within the week). RTV seems to make it go away. Haven't yet got it fixed the second time around.

Other than that, I got the 4-chan option with mine to keep my ABS and TCS functional. No issues thus far.

That's interesting. I already have a weepy 10 bolt. Wonder if it is a seal or housing issue that is causing this?

[ntimid8r]

Any of the rears are within budget. I agree the Dana is overkill for my application, so choosing between the 9" and 12 bolt is probably the real question. I'm glad you guys are including sources as well in the responses. Other than the electronics, any other concerns?

If the midwest chassis 9" is in the budget....go for it. You'll never have to worry about making the wrong decision going with it. You can call their shop and talk to Eric, the owner. He's a very cool guy and can talk you through any concerns. I called him before about upgrading my procharger to F1a....he's a procharger dealer and has some experience with F1a units...and answered all my questions and then some. So I gained alot of confidence in his work.

[35th-ANV-SS]

I think on the 10 bolts they are notorious for leaking at the seal.

As far as my 9", the axle seal is what the problem is. Put the new one in and it seemed seated just fine, but few days later it was leaking again.

This time around I will be using black seal/silicon around it to make sure I won't ever have to mess with it again.

More annoying than anything really. Damn gear oil all over the wheel, tire, rotors, brake pads, etc. Not the easiest stuff to clean off...

[ntimid8r]

That's interesting. I already have a weepy 10 bolt. Wonder if it is a seal or housing issue that is causing this?

One reason I went with Strange and not Moser....I read a few negative posts/threads about Moser. Now I don't have any personal experience with them and am not condemning their product, I know Strange had their issues in the past as well. But Moser quality was the main reason I didn't go with them. But seals do go bad so it could be just normal wear and tear. Maybe have it all checked out by a rear end specialist that for sure knows what he's talking about.

[Z28Thunder]

One reason I went with Strange and not Moser....I read a few negative posts/threads about Moser. Now I don't have any personal experience with them and am not condemning their product, I know Strange had their issues in the past as well. But Moser quality was the main reason I didn't go with them. But seals do go bad so it could be just normal wear and tear. Maybe have it all checked out by a rear end specialist that for sure knows what he's talking about.

I went Moser (and before this gets to that thread). I can not say enough about their customer service. I had some bolts back out on my backing plate. Not their fault MINE 100 %. Now this was just recent and I bought mine over 3 years ago. I called Moser got treated like I just bought it yesterday. Looked my purchase up asap. Then they sent 8 new bolts to me at no cost period. Again I can not say enough about Moser!!

[0rion]

when I picked mine out I wanted something that was plug and play. I didn't want to have to screw around with it so that immediately made me look at 12 bolts. The way the moser 12 bolt mounts the torque arm really turned me off..... I read thread after thread after thread of people having those torque arm bolts back out even with loctite on them. Since I was an auto car and only make a few passes a year the 12 bolt seemed like enough for me so I went with a strange 12 bolt. I had a leaking axle seal out of the box but they fixed it under warranty. Other than that I've been pretty happy with it. I forget who I even bought it through but they no longer carry them.

[Y2KPewterSS]

This is something that is gonna be down the road for me, but it will be the next major thing I do to the Camaro. I am on the fence about Moser/Strange also, read positive and negative about both of them. The torque arm mounting really concerns me with the Moser but its not like I beat on my Camaro either, so it probably shouldn't be a concern for me realistically. Definitely good reading so far in this thread, hope to see more personal experiences posted up, might help me make my decision as well.

Jeff, I agree the Dana 60 is probably overkill for your what you want. What rear suspension components have you purchased so far?

[pajeff02]

I have LCA's, relocation brackets and a panhard bar. Really want to go with something I can install without issues. Plus, not having problems down the road would be good too. All of the above information is great as I am putting a lot of thought into this one.

I looked at both the Moser and Strange Engineering's websites before I posted the initial question. That's where I realized I would need some guidance from those of you that have done this. Unless I missed something, KY Speed did not have a link to rears on their site. I understand the Dana requires a shortened driveshaft -- any such concerns with the 9" or 12 bolt?

[Y2KPewterSS]

I have LCA's, relocation brackets and a panhard bar. Really want to go with something I can install without issues. Plus, not having problems down the road would be good too. All of the above information is great as I am putting a lot of thought into this one.

I looked at both the Moser and Strange Engineering's websites before I posted the initial question. That's where I realized I would need some guidance from those of you that have done this. Unless I missed something, KY Speed did not have a link to rears on their site. I understand the Dana requires a shortened driveshaft -- any such concerns with the 9" or 12 bolt?

Keep in mind the rear sway bar too, certain rear ends won't allow for the stocker sway to fit IIRC.

[pajeff02]

Keep in mind the rear sway bar too, certain rear ends won't allow for the stocker sway to fit IIRC.

Now that would be an issue.

[35th-ANV-SS]

The OEM rear sway bar will fit around the 9", but it is pretty tight.

[allbaugh_04]

Based on what I've read, I'll be doing a 12-bolt as well. It's sufficient for an Auto after what I've read. Especially since mine will not be a track car. I won't bother with it till it breaks.

Mine was replaced under warranty and it makes no noise.