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I will like to upgrade my tranny. With a shift kit and boost valve and stuff. I searched a lot here but a lot of you's are using different parts and ones more than others. So Maybe we should make a list of items we need and the link where it can be purchased from. Then we can make this a sticky.

I wonder if a company makes a whole kit to upgrade this tranny?

Also I live on Long Island NY. Whats a Good Performance Tranny place out here?
 

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2003 chevy trailblazer_ls
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Most of the good upgrade parts are manufactured by Sonnax. You can purchase them from any number of sources, including your local transmission rebuilder shop. They all know about Sonnax.

As for the parts needed, the sky is the limit -- how much horsepower do you want to push through it, and is this for towing, drag racing, or street duty -- it makes a BIG difference in how you build -- hence the different builds you'll see on the site.

For firmer shifts, a .490 boost valve, and a Corvette servo will take care of business. Add a PCM program and increase internal pressures electronically via the solenoids in the valve body. Pinless aluminum accumulator valves help longevity and shifts a bit.

For heavy-duty use, replace the shell with "The Beast" (requires some special fitting) and the planetary with a 6-gear model. Also replace individual valves in the valve body with steel-sleeved versions that have fitted pistons.

Clutch packs can be upgraded with higher quality friction material, and the jury is out as to the best. Some like this, some that. Just remember that the super grabby material might not be best for street use. There are even modifications that increase the number of clutch plates. Same for bands. There are bands with kevlar, carbon fiber, etc., that all grab harder, but make sure that is what you want!

Shift kits are old school with the new electronic valve body controls, but they still work, and can dramatically increase shift pressures, quicken shift times, change shift points, etc.

The torque converter is the next cog in the machine, and to get a good launch, a higher stall converter is needed. Ours kick in right above idle for the best possible economy (means that as soon as the engine rpm lifts above idle, the torque converter starts to move the transmission input). Higher stall speeds (engine can rpm to 2000 or more rpm before starting to move the input shaft) is similar to revving up the engine and dumping the clutch. More violent start and lots of action (do the heavy duty race mods in the transmission or it turns to little bitty pieces!). This is for racing only. Stall converters increase heat dramatically and you need to run a big cooler, which is a good idea in any case. Same with external filtering, which does a much better job of removing the fine particles from clutch and band wear than the stock pick-up screen/filter, which is mostly for big chips, not the fines.

After all this, you can have a transmission that shifts SO hard with each shift (or is only manually controlled) that it will break the tires loose whether you want that or not. Make sure ALL the other parts of the vehicle can take that sort of violent reaction.

The final modification is to repalce the entire unit with a custom built model. There are several builders that re-manufacture the 4L60E to withstand over 1000 hp, and they can build to race specs. The same transmission is used behind the Corvette, and it is in essence the 700R4, which has a long history behind Firebirds, Vettes, Camaros, and pick-up trucks. Most of the parts interchange between the 700R4 and the 4L60E, so builders have a lot to work with.

Oh, and be prepared to get your credit card dirty... Mods like this can run over $4000 for a fully-built unit with all the possible goodies. It is capable of wheelstanding a TrailVoy sized vehicle if you have the motor to push it -- but the cost goes well above what most guys can handle -- or stand to drive more than 1/4 mile at a time. :D
 

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This is an older thread, but I am looking to upgrade my transmission for towing. I want to tow a camper across country next year, will be a pop up style around 3500-4000. I want to get the parts to take to the shop before I go.

Thanks for any help.

Brian
 

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This is an older thread, but I am looking to upgrade my transmission for towing. I want to tow a camper across country next year, will be a pop up style around 3500-4000. I want to get the parts to take to the shop before I go.

Thanks for any help.

Brian
If your looking to tow under 4000 lbs, I don't think you need to mechanically change components of the trans. A heavy duty inline aux trans cooler would be a must suggested by most members. Also, maybe a PCM tune for your towing objectives. I've towed cross country with my I6 Rainier without the trans cooler. It performed flawlessly. Now (as a more educated member) I wish I hadn't... But hindsight is always 20/20.
 

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Sounds great. I will be getting PCMforless Cooler before I start towing, I like there kit. I just got the tune in last night and love it. Thanks for the info.

Brian
 

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DO NOT INCREASE LINE PRESSURE!

A good clutch pack (Alto Red Eagle), kolene steels, billet servos, shift kit (I think the transgo HD2 now comes with a .500 or .510 boost valve), beast sunshell, No yoyo unbreakable pump vane rings with a heavy duty pump slide spring, and borg warner 29 element dual cage sprag. This will be damn near bullet proof if the clutch packs are set up tighter than factory specs.

The input clutch drum is aluminum and when you increase the line pressure, you also increase the chances of damaging the input clutch drum. I am unsure which pump comes in the Trailblazers, but if it's not a 13 vane, there's another upgrade.
 

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I dont think I increased line pressures. If you are talking about the tune, I put down that I would be towing more than 1500 lbs. That was the only option I saw.

Thanks
Brian
 

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For heavy-duty use, replace ... the planetary with a 6-gear model.
This caught my attention. What is the purpose of this? Surely it can't be that easy to convert our transmissions to a 6-speed? I've been thinking that with an extra gear, it should provide more ranges to help with towing heavy loads at lower speeds, but without sacrificing the final highway gearing and MPG under normal driving.
 

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I believe he's referring to the more robust 5-pinion planetary from the 4l65E (never heard of a 6-pinion version:undecided).

4L60Es come with 4-pinion planetaries and the 5-pinion version is a drop-in replacement. It's an extra pinion gear within the planetary stage, not an extra gear for the transmission. I wouldn't tear down the trans just to swap but if you're that deep into it anyway you might as well upgrade.
 

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I will like to upgrade my tranny. With a shift kit and boost valve and stuff. I searched a lot here but a lot of you's are using different parts and ones more than others. So Maybe we should make a list of items we need and the link where it can be purchased from. Then we can make this a sticky.

I wonder if a company makes a whole kit to upgrade this tranny?

Also I live on Long Island NY. Whats a Good Performance Tranny place out here?
http://www.transmissioncenter.net/4l60e.htm

As others have mentioned before you start - know what you want to get out of the mod's.

If you want a trans that is more durable and are not planning on major HP increases then I suggest the following:

transgo SK4l60 shift kit
corvette servo (or billet if you want more load capacity e.g. towing near rated load)
replace the 3/4 & fwd accumulator pistons with aluminum ones.
No need to drop the trans to do these. Valve body has to come out and you must have an in/pound torque wrench to put it back in.
 
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