Stock drivetrain/diff/axles for a newb...

**ls1fan74** · 04-15-2009, 02:13 PM

I want to know more about it-this is my first RWD car. So far I've learned the Camaro/Trans Am's have a solid rear, which is 1 axle bolted to both wheels, which is better for traction, yet doesnt handle as well? I know the GTO's have an independent rear, which has to do with suspension, but mostly that it has two halfshafts instead. So the diff is split, but its still a limited slip? I'm just trying to learn more- how strong is it stock? How often to change the fluid? (AND how difficult is it....can I do it myself with ramps/jackstands-I've always done oil, brakes, wheel hubs, a few transaxle fluid changes on a FWD...nothing major or bigger than that, & I have some tools)

Most input I've heard is the T56 is basically bulletproof as long as its not romped on or had too much power put through it. Truf? Also, I *think* the manual says it doesnt ever need fluid changing (manual ALSO says the Dex/cool only needs to be changed every 150,000 miles which is a load) Is there an easy way to check it, and at what mileage would you guys recommend changing it out? I've got an 04 with 56,000 miles I plan on keeping for a while

**GTO1_OHIO** · 04-15-2009, 02:59 PM

The stubs are the weak link.

**ls1fan74** · 04-15-2009, 06:17 PM

whats that mean

**GTO1_OHIO** · 04-15-2009, 06:29 PM

Originally Posted by ls1fan74

whats that mean

Here's a good example. They twist when ... ummm abused a little.

http://www.ls1gto.com/forums/showthr...ht=stubs+twist

**qwkgto** · 04-17-2009, 01:37 AM

even the bullet proof ones seems not to be for some people..lol

**mark21742** · 04-17-2009, 02:59 AM

so are you guys saying when I get the money I should go with a good quality, standard 355 tire under the rear of my goat and stay away from DRs?

**GTO1_OHIO** · 04-17-2009, 04:09 AM

It all depends on how much power you're putting down or if you have a M6. The M6s twist these when people launch from 5000+ RPMs. A4 guys don't launch that hard and have not see the kind of twisting the M6 guys do. I didn't upgrade to the 1000rwhp stu-to-hubs but only as a long term precaution...my OEM stubs were not twisted when I removed them.

**mark21742** · 04-17-2009, 04:24 AM

Originally Posted by GTO1_OHIO

It all depends on how much power you're putting down or if you have a M6. The M6s twist these when people launch from 5000+ RPMs. A4 guys don't launch that hard and have not see the kind of twisting the M6 guys do. I didn't upgrade to the 1000rwhp stu-to-hubs but only as a long term precaution...my OEM stubs were not twisted when I removed them.

a4 with a 3,000 stall here. so I can leave the stubs without worries for now, the way they are and upgrade the driveshaft, and tranny 1st?

**qwkgto** · 04-17-2009, 05:25 AM

by all means drag radials are the only tires to run,unless you want to spin on the street,if you a A4 dont worrie about the stubs unless your using slicks at the track,ive ran two seasons in the 10s with stock rear end ,altough I did break some of those 1000hp hub to stubs,went back to stock 05s and they lasted rest of season with MT 15inch drag radials and trans brake with a 3500 stall.I took them out again yesterday they still look prestine,so they are the backups again.Power is definite turning point that and leaving the line at a senceable rpm.

**qwkgto** · 04-17-2009, 05:26 AM

Originally Posted by mark21742

a4 with a 3,000 stall here. so I can leave the stubs without worries for now, the way they are and upgrade the driveshaft, and tranny 1st?

yes do shaft and wait on trans it will be the weakest link..

**mark21742** · 04-17-2009, 05:45 AM

Originally Posted by qwkgto

yes do shaft and wait on trans it will be the weakest link..

ok sounds like a plan....it will probably be a few years before I give it boost or stroker, but I'd like to have it ready to handle the power when I get it

**ls1fan74** · 04-17-2009, 04:46 PM

Can the stock driveshaft be replaced with a lighter one, at least to reduce rotating mass if not increase strength? I dont plan on making huge HP like you guys do at least for a while so I'm not immediately concerned w/ that but I'd like to make it lighter

**mark21742** · 04-17-2009, 05:13 PM

Originally Posted by ls1fan74

Can the stock driveshaft be replaced with a lighter one, at least to reduce rotating mass if not increase strength? I dont plan on making huge HP like you guys do at least for a while so I'm not immediately concerned w/ that but I'd like to make it lighter

yes there are a few different companies out there that make 1 piece driveshafts. I'd give you a few links, but I'm using my cell phone 300 miles from my home computer

**Tide** · 04-17-2009, 06:16 PM

Driveshaft is the first thing to be replaced. The stock piece one is a horrid piece of rancid shit. Your half shafts should be fine for a good long while. I would strongly recommend subframe connectors and a stronger strut tower brace . The GTO body is a bit twisty, and stronger strut tower brace combined with the subframe connectors go a long ways to allowing our cars suspensions to do its job. Which in a 'round about way leads to....

The single biggest problem with our cars (and just about any IRS car that is RWD) is axle hop. When the wheels start hopping, the risk of breaking something goes through the roof. I personally don't believe there is one magic setup cure all for it. It's a combination of driver technique, air pressure, drag bags, better bushings, ambient temp, tire temp, track/road temp, etc.

You just have to figure out what works best for you.

Anyway, I change my transmission (M6) and rear end fluid/dope (I still call it that...) about every 15,000 miles. But I spend alot of time at the track (300+ passes on a stock tranny and clutch before I did a slight rebuild this winter and put in a new clutch), and am generating some pretty good HP. I'm also increasingly anal retentive/obsessive compulsive about maintenance. But I made it to 65K miles before replacing the clutch/pressure plate/to bearing/flywheel, as a daily driver that sees significant track time - though I haven't been to the track this year. Yet. Itching to go, just haven't had the time.

**ls1fan74** · 04-17-2009, 06:53 PM

Originally Posted by Tide

Driveshaft is the first thing to be replaced. The stock piece one is a horrid piece of rancid shit. Your half shafts should be fine for a good long while. I would strongly recommend subframe connectors and a stronger strut tower brace . The GTO body is a bit twisty, and stronger strut tower brace combined with the subframe connectors go a long ways to allowing our cars suspensions to do its job. Which in a 'round about way leads to....

The single biggest problem with our cars (and just about any IRS car that is RWD) is axle hop. When the wheels start hopping, the risk of breaking something goes through the roof. I personally don't believe there is one magic setup cure all for it. It's a combination of driver technique, air pressure, drag bags, better bushings, ambient temp, tire temp, track/road temp, etc.

You just have to figure out what works best for you.

Anyway, I change my transmission (M6) and rear end fluid/dope (I still call it that...) about every 15,000 miles. But I spend alot of time at the track (300+ passes on a stock tranny and clutch before I did a slight rebuild this winter and put in a new clutch), and am generating some pretty good HP. I'm also increasingly anal retentive/obsessive compulsive about maintenance. But I made it to 65K miles before replacing the clutch/pressure plate/to bearing/flywheel, as a daily driver that sees significant track time - though I haven't been to the track this year. Yet. Itching to go, just haven't had the time.

thanks for the info, wow so you're supercharged with the stock trans/clutch all the way to 65k? Nice that makes me feel better about the drivetrain.....gotta look into the driveshaft though. How difficult is the fluid change? Called the dealer today just for kicks on my lunch break, said prob $65 for diff fluid, $90 for transmission chg

**mark21742** · 04-17-2009, 06:58 PM

I was shock when I climbed under the the car for the first time at just how small the driveshaft was.
SFCs are on my parts list for later this spring

**Tide** · 04-17-2009, 07:42 PM

Originally Posted by ls1fan74

thanks for the info, wow so you're supercharged with the stock trans/clutch all the way to 65k? Nice that makes me feel better about the drivetrain.....gotta look into the driveshaft though. How difficult is the fluid change? Called the dealer today just for kicks on my lunch break, said prob $65 for diff fluid, $90 for transmission chg

I put the blower on at about 55k miles, maybe a bit more.

I don't change it myself. I take it one of the local shops, guys I trust. It's just not worth it to me when I can get it done quickly and relatively cheaply.

Diff fluid is a breeze, however.