bggrnchvy

I have a 97 K1500, with the stock L31 5.7L(255hp) motor. It is wheeled decently and has swapped in 1 ton solid axles that have been geared for a slightly overstock final driveratio with 38" tires.

The stock 163k mile old 4L60e is on its last legs. It slips in OD and has a metallic rattling coming from the tranny hump while coasting in 3rd.

I plan to swap in an LQ4 with just a tune and some bolt ons when this motor dies. Ive been told I could expect 300-330rwhp with this setup.

Ive talked to my local tranny builder and he suggested getting a performance tranny from someone else as he can't build one for less and won't warranty a performance transmission. I don't think I require a build on par with an FTP level 4 or 5, so what are my options?

I see TCI has 3 different stages of trannies, but they seem to be geared for super snappy shifts and car straight line performance. I need firm shifts, but can't deal with hard shifts for fear of shockloading the drivetrain in a high stress enviroment.

A 4L80e swap is out as well because of the tall 1st gear, deeper OD, extra power it drains and more modifications to front and rear drivelines I just finally got setup.

I have an idea of what needs to go in the tranny(parts acquired from others knowledge), but Ive never even pulled one to look in it.

These include:
Transgo HD2 shift kit
Transgo Vacume Modulator
Sonnax pinless forward accumulator pistons
Beast Sunshell
29 Element Sprag
13 vane pump upgrade
Corvette Servo
Servo Release Check Valve
Heavy Duty Reaction Carrier Shaft

Raybestos Blue plate 3-4 band 7 clutch pack
Red Alto standard wide 2-4

I understand that some of these may not be needed, but can anyone help me try to figure out what I should do with this situation?

LT1PWRD

iTrader: (2)

I definately like your selection of parts. I would also do a low stall 10.5-11" converter built by a reputable builder. That 4L60E will handle your application fine. We build these all the time for trucks also,and they last with HD use. A couple things i would add to your list. "GM" 5 pinion planets for sure,this will add about $500-$600 to the build but, they have a much higher load capacity and are standard equip in 4L65E trannys. A billet 4TH servo cover with a larger piston. The corv. servo is fine for 2ND. This will give you more apply press on the band in 4TH under a heavy load so it's less likely to slip. Also i use and highly reccomend the Z-PAK for the 3-4 clutch pack. Much higher load capacity and twice the friction to steel surfaces(single sided frictions). The options for firmness are in the kit so don't worry bout it being too "snappy",just diff. mods for feel. Can be made firm but not abusive. There's 3 accum pistons alltogether,pinless is fine,just get the aluminum updated one for the forward accum in the valve body also cuz they are plastic from the factory and can/will crack. you'll loose forward and burn clutches. Oh,also,get all moulded pistons for the input drum to replace the alum/lip seal style pistons. I'm prob forgettin other mods right now but...this is the bulk of the mods we do to our builds plus more as we build. Oh,wait,some more just came to me,A new stator shaft,unbreakable pump rings,an epc sol,.500 press reg valve. etc,etc.

bggrnchvy

Thank you for the in depth input on parts.

I had heard about the 5 pinion planets from the 4L65e's but had also heard that they are starved for oil at high rpm's and the extra load handling was a tradeoff in that respect. Add in the additional cost I was informed they were not worth it on a 4L60e with 4 pinion planets intact. What is your take on that info?

I did fully rebuild the front and rear axles and Im sure given time and the full ATSM manual I could rebuild the 4L60e with all these parts. Unfortunatly I don't think at this point I can afford the downtime and I know I don't have the room to do it in a clean envirement like I did for the axles.

So for that reason I ask for recomendations on where to order a tranny that is tough enough to stand up to the mentioned vehicle, but not overly built as to just drain the wallet.

Sorry for the long winded posts and thank you all again for the help. I just want to make sure all the facts are in the open so there are no suprises

LT1PWRD

iTrader: (2)

As far as the 5 pinion planets being starved,thats never been an issue that we have seen in the shop. The prob with using the stock 4 pinion planets in ur trans are the captured torrington bearing has a tendancy to fail,(especially the rear). It cannot be changed w/o expensive equipment. Although not real often,it does happen. So....i say why put a used planet in ur trans that may fail?
This has bitten us twice,so we now use a new rear planet in every build. And depending on customer needs/wants a new front. You can also buy those planets urself online and get em cheaper than i said and save some $$.
But,to get to your point about who to build a trans for you,i'm sorry,but i don't trust anyone but me/us. And i'm not a sponsor so i'm not gonna step on any toes of the quality people to the right of this box. There are guys that have had good luck,maybe try a search to see what comes up.

bggrnchvy

It has been brought to my attention that FLT makes a level 3 transmission. I am seriously considering going this route, possibly iwth a vacume modulator if they will put one in it like they offer for the level 4 and 5. Seems like a cost effective solution for the level of power and the use of it. With a 24,000gvw cooler and a trans temp gauge I think I can keep it cool and happy. Any thoughts?

LT1PWRD

iTrader: (2)

That sounds good. is it in ur price range? The vac. modulator along with the other HD mods and the cooler will def. keep up with ur veh. application. Any warranty w/this?