02firehawkT/A

iTrader: (2)

What's up guys.. After the past winter up here in NY I've seriously been considering trading in the T/A after the summer's over and getting something I can drive all year round as a DD. Right now I use a Nissan as a DD which..well.. it's a Nissan . I want to stay with an LS car, and I've noticed how inexpensive used GXP's are these days and I love the way they look (I'm sure they drive awesome too, I've never got to drive one yet though). What would you guys think would be a fair price to pay for a 9/10 condition GXP with between 40-70k on the clock? Also, how easy are these cars to mod and what is the aftermarket support like for the LS4? I definitely know that after going from my f-body to a GXP I'm going to be itching for more power, so I'm wondering how the aftermarket treats the LS4 and how expensive they are to mod. And most importantly, is there anyone here with a high mileage LS4 than can report on reliability?


Cliff notes: Basically, I'm asking for the shakedown of what the GXP is all about. How easy/cost effective is it to mod (what would a stout LS4 put out in terms of power?) what's a fair price for a GXP, and how reliable are they under DD circumstances. Thanks!

lemons12

iTrader: (71)

From what I hear low 13s are only a few inexpensive mods away, while not having quite the trap your current car does, it would be comparable.

99FormulaM6r

iTrader: (2)

Beware of the transmissions! Kind of like the f-body and the 10 bolt....not suitable for that kind of power.

Besides that, my sister had one for a few years, they definitely have some get-up-and-go, plus they're comfortable to boot (stock Bilsteins are also a bonus), minus the rear seats if you're tall or have kids that want to look out of the windows, lol.

LS1 Racing

iTrader: (15)

I'd say our trannys are much worse than the F-body/10-bolt issue.

As far as overall reliability, I would classify any LS4 car as "not very reliable."

DP 08 GXP

iTrader: (3)

you can buy mine for $18k

https://ls1tech.com/forums/vehicle-c...-18-000-a.html

vroom_vroom

iTrader: (5)

every car has its issues ours is the trans i have 82k on my stock trans had a bit of an issue when i got it but was fixed my not leting the dealer near it, copy and past the trans pressure table for tap to d , and get a trans cooler if u get one i wouldn't hesitate to drive it any where

02firehawkT/A

iTrader: (2)

that sucks. I just read thru the sticky at the top about the trannys. Can't believe that many people are having problems. It doesn't seem like something you can just slap a tranny cooler on either and be ok.. Thanks for the input

Sick GXP. I think for a little more $$ I'd look for an 04/05 CTS-V though

what was wrong with yours? Did you mean you wouldn't let the dealer fix it?

Sadden

Heres the thing with the transmissions...
Yes they break , you KNOW its going to happen

So you buy a used car with a good trans?
You can beat the **** out of it and throw more power at it with solid set of bolt-ons.

Or you can pull it into the garage stick a transgo shift kit in it with a good cooler and a tcm module from overkill as soon as you get home , then slowly save up for a full on rebuild with good parts and then worry about performance.

If you KNOW the trans is a weak spot why throw more power at an already insuffecient transmission?

It doesnt make sense
But everyone does it
And everyone bitches about these transmissions.

My second mod was a cooler with a shiftkit
It should have been my first.
I beat the **** out of my car on a daily basis.
And the trans still feels great , But i started making upgrades to that tranny less than 2 months after buying the vehicle , and i am going to continue to upgrade it as i go.






Its an LS motor you can make as much power as you want if your pockets deep enough.

DavidGXP

iTrader: (14)

All of this weak *** tranny talk is crap! I have beat the living **** out of my trans since day one, and I have thrown tons of money into mods. I only have 52k on it, and it will fail eventually, as well other stuff. If I can get anything over 100K I'll be jumping for joy. Autos aren't know to last past 150k. I have had my trans tuned with HP tuners and the tuner pasted the tapshift table to the drive table and made a few other tweaks. I have also installed a transgo shift kit and change the fluid and filter every 20k.
As far as I know, the trans doesn't break... Something like the converter goes out or the the fluid heats up and the clutches get burned up. Trans temps are 180-240 without a cooler, due to our excessive and most awesome stall (2200-2400)
Having this trans is like raising a wild animal or a pitbull. You never know if or when it might snap.

GXP are very nice cars and well built. They are great family cars with bilstein shocks, 18" wheels, big brakes (stock pads suck!) super turning radius and agressive styling. It is not a race car but begs to be driven like one. Mod for mod the T/A is the better option.

Take it for a test drive and try it out for yourself.

I'd recommend (in order)
Trans cooler
Shift kit
Ceramic front brake pads
275/40/18 front tires
Front and rear STB's
3" downpipe with highflow cat
Magnaflow exhaust kit
CAI
Header wrap (for the crossover pipe)
Tune

You could always add a LS1/LS6 intake and cam in the future for gobs of power.

HENRYGXP

my GXP has 65000 miles. Completely stock. Rarely beaten. Trans is complete junk

monte_with_a_LS4

iTrader: (4)

i think the gxps are good cars. If i were to do it all over again i probably would have went with a rear wheel drive car but i love my monte and itll be here for a while. My trans hasnt given me any issues yet with the mods i have so far but i believe if you take care of it itll take care of you lol.

HENRYGXP

my GXP has 65000 miles. Completely stock. Rarely beaten. Trans is complete junk

Brian396

iTrader: (3)

Only one expensive mod for 12’s. Well maybe two, I think somebody said something about the trannys being weak?

LS1 Racing

iTrader: (15)

You're a lucky man, David.

That is the odd thing about this whole trans situation. MOST of the failures don't involve something "breaking". Yet, the trans is only rated to handle 280 lb-ft of torque at the crank, and our motors are rated at 323 lb-ft. We SHOULD be experiencing more hard part (input shaft, etc.) failures than we are. Perhaps, the compromises made in the design of our trans protects it from these types of things while causing the problems we DO have.

This is the case for most things, but not OUR transmissions. I respectfully disagree with you, and I'm sure a large number of the other 129 people on this site who didn't beat on their car but still had problems feel the same way.

For the record, my '87 Grand National has 166,000 miles on it. The trans is original and stock, with only a big trans cooler and no shift kit. At least 500 of the above miles was done a quarter at a time , with dozens of passes in the high-elevens. The car only gets about 8,000 miles per year now, and I change the trans fluid every spring, just to be safe. It still works fine, and I know how to take care of my cars.

My point is, any stock trans should be able to get 100k miles without problems. Unfortunately, I've had more trans changes in our Impala than I've had fluid changes. I can't seem to get one to last the 30,000 miles at which I would do a fluid change, and this is on a car that gets 99% highway miles at 65 MPH, as driven by my wife.
The trans IS a problem, and any buyer should be be acutely aware that they have AT LEAST a 1 in 3 (and probably more like 1 in 2) chance of having a problem by 60,000 miles.

94ss06gxp

iTrader: (5)

if i were you OP i would just bite the bullet and get a CTS-v, going from an Fbody to GXP you probably will hate the FWD, also one thing to consider is your T/A is prolly getting better mpg's than the GXP's will. I mean any car with a nice set of snow tires can be good in winter. Make sure you really think thru your decision

SSCoop

Stay with the T/A or like 94ss06GXP said go with a Caddy CTS-V.

DavidGXP

iTrader: (14)

I think our trans is rated for more then 280lb/ft at the crank. That rating is for the V6's I bet. GM added a few upgrades to the LS4 4t65e as we all know. I'm sure we're pushing it though..
Just sucks that that when It does decide to go, it's not cheap or easy to replace.

+3 on the CTS-V

02firehawkT/A

iTrader: (2)

I hear ya. The appealing thing about the GXP to me at least is the FWD for the winter and the automatic. It would be hard to justify getting a RWD 6 speed Daily Driver like the CTS-V . Plus, I love the T-56 as much as anyone here, but the commuting I do is mostly city miles with stop and go traffic everywhere. I'd be pulling my hair out after 1k mi with that car. I'm not totally opposed to getting a CTS-V, but even the 04's with heavy miles are a little too pricey IMO


What the ****! was GM thinking putting this tranny in there? From the way it sounds it's the biggest hunk of **** ever assembled.. You would think by around 06 they would've learned how to build a tranny..unbelieveable

LS1 Racing

iTrader: (15)

Surprisingly, there are no torque ratings available anywhere for the 4T65-HD used in the LS4 cars.

When one of the users on this site, RKO, asked GM that question specifically, they refused to answer. They also would not provide any information on failure rates, due to a pending NHTSA investigation.

The trans in the V6 does have a different valve body and is calibrated differently, but aside from our thicker half-shafts, hardened gear train and case-mounted starter, it's pretty much the same transmission that went into the L67 cars. The thing is, this trans was inadequate for the S/C3800's, too.

94ss06gxp

iTrader: (5)

my gxp sucks in winter (with the stock tires) i hate FWD in snow IMO, have no turning control in corners, id rather be able to swing the *** end around if i need to that hit the gas and keep going straight, if i were you i would look into the Trailblazer SS in 2WD, but get a nice set of snowtires and add some wieght in the back and your set,