Very Limited Wrenching Knowledge. Too Big of A Project?

[ambull01]

Hello all,

Hope this is the right place for this question, I saw how dead the CTS-V forum seems to be so decided to post here. My apologies if it's not the right place.

I have very limited wrenching/mechanic experience. I can do basic stuff like change oil, brake pads, flush brake fluid, replace rotors, replace bolt on things, etc. I've always wanted to try and rebuild an engine and transmission. I have a 2004 CTS-V with about 140k miles. I don't drive it anymore, it's just sitting in my garage. I was going to sell it and my wife really wants me to but I've had it for about 8 years now and I want to keep it.

The second gear went out on it a while ago, it grinds when I try to shift it to 2nd so I just skipped over it. I'm guessing it's the synchro from what I've read. It's an LS6 CTS-V which I hear isn't as good as the LS2 but I don't really care about trying to squeeze a ton of HP out of it.

Do you think someone with limited auto knowledge would be able to pull the engine; add in some go-fast things like a cam, replace/upgrade internal things, rebuild the transmission, etc.? I was thinking about making it my long term hobby since I don't need it on the road. I'm not sure what the stock WHP is on the LS6 CTS-V's but I was hoping for something in the neighborhood of 450-500 if possible. I'm not sure what kind of expense that would amount to though.

Sorry, kind of long post. Basically can someone with limited mechanic knowledge be able to pull an engine, add in some cool parts, and rebuild a T56 6 speed trans?

I also found this site. Looks great because it breaks down everything I should/could do to the LS6 to make it more of a beast: https://www.onallcylinders.com/2018/...e-performance/

Thanks for any and all advice.

[SMWS6TA]

Unless you have the specialty tools I HIGHLY encourage you to have the transmission done by professionals. Manuals are a major PITA to rebuilt, much harder than an auto.

Engine wise depending on what you're planning you may not have to pull the motor nor need special tools beyond torque wrench and some other stuff.

[ambull01]

Unless you have the specialty tools I HIGHLY encourage you to have the transmission done by professionals. Manuals are a major PITA to rebuilt, much harder than an auto.

Engine wise depending on what you're planning you may not have to pull the motor nor need special tools beyond torque wrench and some other stuff.

Yeah I've heard that a lot about manual transmissions lol. I may do that since I'll already have my hands full with the engine and other upgrades/fixes I want to do.

You have a TON of mods to the engine in your T/A! I'm kind of jealous, that thing must be a beast.

[SMWS6TA]

At this point it's become quite tame. 450 to the wheels. My biggest hold back is my heads, I ran out of money and just wanted the car back after sitting for almost 19 months. Plus rebuilding the engine twice due to a rod bolt failure on start up. Very angry few months during that time period. I did 11.67 in 1/4 mile on street tires.


I built my engine, rear (minus the finish welding). The transmission I sent to Tick Performance. I did try to do it with someone helping me and it worked till the fluid that I was told was ok to run it with killed it.

Check with what fluid your trans uses because the T56's of 97-02 like Dextron III ATF vs VI. IV is synthetic and for some reason the early T56's do not like them. When I got mine back from Tick I made sure they confirmed what fluid to use.

[ambull01]

450 to the wheels with all those mods? Maybe I'm being too optimistic/hopeful with my goals then lol. How the hell did you learn how to do this kind of stuff (i.e. building/rebuilding an engine/rear/trans)?

Yeah I found Tick Performance online. I think they could rebuild/send me a T56 for about $1,600 or so the last I checked. I think that's the way I'm going to go, I just want a near bulletproof trans so I don't have to worry with it.

Maybe I'll sell this CTS-V and just get those older Trans Am, I always like the way they looked. Especially the WS6 (I think that's what they're called). Could you recommend some manuals/books about rebuilding/upgrading and engine? Looking to get started on this long-term project soon. Maybe I should just get an LS3 or one of those truck based L92 type engines to begin with.

[SMWS6TA]

My heads and cam greatly hold back the potential. Plus a conservative tune.


Mostly self taught, Been working as a hobby for many years. I worked on all my vehicles that I was assigned to in the Army so that gave me some practice. There's a couple of how to books on Amazon on how to build/rebuild LS engines. I used it as a guide plus this site helped a ton while I was working on it. Back then we had a lot more activity and ppl on board that had already been down the road and gave some great pointers.


If the CTS-V is paid for I would look at super charging it. There are plenty of used factory units out there that with supporting parts and tune will get you a long way in building power. Something someone told me a couple of things about mod'ing your car and they make solid points.

1 - Cheap, Reliable, Fast = you get to pick 2.

Very, very, very rare can you get all 3 things when part shopping as well as getting a solid tuner that knows these cars and engines.

2 - Plan, Research, research again, plan again, research, be prepare to change your plan again.

Simply put. Figure out what you want. Street, Strip, AutoX, Drift, Rally, Show,Solid Daily. Each have their pros/cons. You can combine them all but not all go together well. For example, suspension - depending on it's setup it can be excellant for Street/Daily but horrible for track and vice versa. Max effort engine build = less street manners and mpg. Figuring out what you want, research it to see if you can afford it, then plan for it.

Make a plan but be prepare for changes and set backs. I made a tracking spreadsheet to keep it all tracked. Setbacks will happen. I originally built me 6liter block as a basic engine swap but on test drive a rod bolt snapped and corkscrewed the stock crank. So 6 months later, with new pistons, crank and rods for a stroker build, take 2...

3 - Whenever you increase the performance of the vehicle engine you need to address the other stuff. It will find the next weakest point in the drive train. I'm not to familiar with CTS-V platforms but IIRC the rear is IRS and their weak points are always the half-shafts. My point being is you'll need to think about suspension and rear as well. Safety....



LS3/L92 blocks - they run on a 58x reluctor wheel and you have a 24x system. That means you can't just drop in and expect it to run. As well as they are also set up for fuel management system (they shut off fuel to cylinders to get better mpg) You will need to do a few more things to make them work.

IMHO the cheapest way is to break open the bottom in, purchase a 24x wheel from Summit and have a shop press it on OR if you're going to stroke the motor anyways, just order the 24x for the crank and it will already be pressed on when it ships. This way lets you use your ecm and harness. You may have to reroute a few connectors and change the crank and cam sensor for 24x but that's easy (just swap over from your block). All the accessories and trans will bolt right up. You will also need to get a AFM delete kit as well as a new cam, cam plate, and IIRC a front cover as well to delete the AFM.

The hard and expensive way is either getting a 58x to 24x control box which will let you use your stock ecm and harness but they are prone to fail and cost a shit ton of $$$. The other option is convert your ecm and harness over to 58x. This is more of the expensive route then it is the hard and painful route. Wire harness run about $500-1500 depending on if your having your harness repin and converted to buying a new one. ECM's avg $150-700 and that's not including a tune.


Tuning - Find a great tuner, no an average or I do it myself tuner. You live in VA I would look for Frost Tuning. He does a lot of mail in tunes for basic mods but does do full tuning as well. Depending on what you do will depend on what kind of tune you need. Basic mods like headers and intake = mail in, Heads/Cam/Intake/Stroker/Boost = full tune. Avg price is $500-800.


Hope this helps

[pajeff02]

Best advice -- practice on someone else's car! Just kidding.

It clearly sounds like you have the interest and the ability, you just need experience. Honest answer, for just about anything you need to do on a car there are books (downloadable), videos and web forums like this one. The key to it all is to take your time, ensure that you have the correct tools (many can be rented if you do not want to make the purchase investment), a good work space is a must with adequate lighting, and you need to document your work by taking pics with your phone (if your are going deep). Patience and the ability to walk away for a bit if things don't seem to go right are a must. I will differ from Scott's advice just a bit - I find manual transmissions to be pretty simple for the most part. As you disassemble, lay the parts out in the order they were removed being careful to maintain the correct alignment (which side faced in which direction). You can always mark the parts, but have to be extra careful when cleaning them that you do not remove your markings.