6 sp weakness
Thread Starter
Instructor
Joined: Apr 2004
Posts: 132
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From: Rochester New York
6 sp weakness
I have a 2002 LS1 6sp convert. The engine has a lot of mods done to it that I won't get into too much detail but I'm putting out around 425 hp at the RW. My question is exactly what and where are the weak points on the transmission? I recently had a LS7 clutch assy installed and I'm thinking on installing a DTE differential strut brace. Now I don't race the car but I love getting on it every now and then ( after all it is a Corvette). I just want to know if there is something else that can be done just to cover more bases to avoid leaving something out that will reinforce the integrity of the drive train. Maybe axles??????
Race Director
Joined: Aug 2008
Posts: 15,560
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From: Long Island NY
St. Jude Donor '08-'09
question i my self have done several wheel hops, still learning the manual, is it just on high speed wheel hops, or low speed wheel hops that are dangerous, its usually me going into first gear, that it happens, what kind of damage are we talking about?
Safety Car
Joined: May 2006
Posts: 3,799
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From: Northern Virginia
St. Jude Donor '08
^^Wheel hops at any speed on bad. Damage - can take out tranny and/or differential. That is a lot of $$$
Race Director
Joined: Aug 2008
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From: Long Island NY
St. Jude Donor '08-'09
OK here goes, how do you prevent it, for me its being at a red light, and i guess over revving it , then letting the clutch go, here in LI we have very well i should say always in a hurry people, how can it be prevented, except for the basic, just take your time and dont worry about whos behind you i guess
Tech Contributor
Joined: Jan 2007
Posts: 19,360
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From: Dyer, IN
Wheel hop is killer. If you really want to be worry free, I'd focus on the differential more than the trans.....
Pro
Joined: Aug 2007
Posts: 619
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From: ATLANTA GA
The stamped steel slider keys inside the transmission are Known to break... I make the same hp you make
I did a downshift on the interstate and upshifted fast into 3rd and that was it, It wouldnt come out of 4th gear without double clutching real hard
I did a downshift on the interstate and upshifted fast into 3rd and that was it, It wouldnt come out of 4th gear without double clutching real hard
Tech Contributor
Joined: Jan 2007
Posts: 19,360
Likes: 1,127
From: Dyer, IN
How often do you powershift?
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Pro
Joined: Aug 2007
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From: ATLANTA GA
Race Director
Joined: Aug 2008
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From: Long Island NY
St. Jude Donor '08-'09
can you pm me the speeds you were doing, i also have sometimes problems, with going into third or 4 , i usually go right into fifth gear, very hard shifting, thanks
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
Meaning, i wouldn t keep the throttle floored between shifts and cram the gears like you re running from the FUZZ!!
Melting Slicks
Joined: Jul 2005
Posts: 2,586
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From: Bardstown Kentucky
641RWHP here with a stock tranny and diff. Been out to the track a few times and I must say I think shes on her way out. Last time out on the best launch the car has had the trans wouldnt go into 2nd. With that being said I think the transmissions in our cars are pretty tough as long as you treat them right. If you are planning on beating on the thing all the time then I think you should look into an upgrade. 
Melting Slicks
Joined: Feb 2006
Posts: 3,191
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From: Scottsdale Az
The rubber couplers on the torque tube wear out pretty fast with more hp. I tore up a tube because I didn't know that at the time, but some forum vendors make aluminum replacements that I put on the new tube to prevent it from happening again.
The tranny lasted 2 years with over 700rwhp and a lot of racing, but I don't power shift.
The tranny lasted 2 years with over 700rwhp and a lot of racing, but I don't power shift.
Pro
Joined: Aug 2007
Posts: 619
Likes: 1
From: ATLANTA GA
No, It doesnt.
I never keep the throttle open during shifts. There is no logical explination or a simple "dont do" list to keep things from happening.
A simple quick shift into a gear ar redline is all thats needed to break those keys.
For those who asked I was going arround 70 and I downs shifted into 3rd ran it out untill redline and shifted into 4th. 3rd and 4th is where my car pulls hard.
3/4 Is the Main weakness within the transmission. 4th gear is the very first gear in the gearbox to get his with all the power from the engine. Most people bend the 3/4 shift fork as well.
It broke those keys very easily. This is a very common failure on even STOCK ls1 powered cars. Do a search over on LS1 tech.
I never keep the throttle open during shifts. There is no logical explination or a simple "dont do" list to keep things from happening.
A simple quick shift into a gear ar redline is all thats needed to break those keys.
For those who asked I was going arround 70 and I downs shifted into 3rd ran it out untill redline and shifted into 4th. 3rd and 4th is where my car pulls hard.
3/4 Is the Main weakness within the transmission. 4th gear is the very first gear in the gearbox to get his with all the power from the engine. Most people bend the 3/4 shift fork as well.
It broke those keys very easily. This is a very common failure on even STOCK ls1 powered cars. Do a search over on LS1 tech.
Last edited by vettekidc5; Nov 19, 2008 at 01:40 PM.
Race Director
Joined: Dec 2004
Posts: 13,760
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From: Haymarket VA
I was talking with Rodney at RPM last year. He built my 3.90's a while ago and since my 403 is pushing over 525RWHP and lots of RWT through a Ram Dual Disk it seemend to me that the tranny is the weak link. He told me he would never pull a M6 if there was nothing wrong with it. He said his Stage transmissions will put up with more abuse than a stocker but the strockers are really pretty good. So far mine's fine but when/if I do need a new one, I know Rodney will be getting my business.
Le Mans Master
Joined: Aug 2005
Posts: 5,130
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From: Winter Park FL
I kick the crap out of my car. Chekc the sig pic, I'm not gentle. At 430rwhp and 2 years of beating on it at the track the stock trans is working perfectly w/ no signs of weakness.
If you are going to drag race it the ls7 will be your weakness. If you are just punching it from a roll there isn't much to worry about as long as you avoid wheel hop.
If you are going to drag race it the ls7 will be your weakness. If you are just punching it from a roll there isn't much to worry about as long as you avoid wheel hop.
Racer
Joined: Apr 2008
Posts: 265
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From: Wesley Chapel Florida
There is so much talk about wheel hop in this thread (and a lot of others) and I've never read anyone that can really say how to get rid of the wheel hop, did I miss something somewhere? My car (420rwhp) will do it whenever it feels like it, and I can't find a rhyme or reason to link a certain gear or action that causes it. First, second, third, whatever. Sometimes it acts perfectly nicely, but when she's mad, wheel hop, and I immediately get off of the gas. Hell, a hard 1-2 shift will make the tires seem like they are gonna come through the wheel wells sometimes. The tranny has 97k on her and there are no problems, and I have the LS7 clutch and other than the incredibly soft pedal, it works great at my power level. The tranny seems to hold up quite nicely, but the wheel hop scares the crap out of me.