4L60E Information Thread (Includes 4L65/70/75)

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kkgp81

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lol I’m a sucker for a possible good deal at the summit outlet ($750). I was trying to find a trans that would fit the NP241c I have and it fit the bill. originally I was going to stuff it behind my 2022 5.3 LT engine but lost interest in the swap. Im less than $1700 into it with controller/torque converter by checking the outlet every time I roll by summit.

Putting it behind a ATK HP31 engine now that come out of there also which is a roller TBI setup.

I think it’s going to be a smidge of a hassle over just going with a 700r4 but when it gets rolling should be worth it. I still have a ways to go before I need to worry about it too much as I still have the wiring harness to install and about everything else.

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NickTransmissions

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lol I’m a sucker for a possible good deal at the summit outlet ($750). I was trying to find a trans that would fit the NP241c I have and it fit the bill. originally I was going to stuff it behind my 2022 5.3 LT engine but lost interest in the swap. Im less than $1700 into it with controller/torque converter by checking the outlet every time I roll by summit.

Putting it behind a ATK HP31 engine now that come out of there also which is a roller TBI setup.

I think it’s going to be a smidge of a hassle over just going with a 700r4 but when it gets rolling should be worth it. I still have a ways to go before I need to worry about it too much as I still have the wiring harness to install and about everything else.
Yes, lots of folks are suckers for good deals, and unfortunately, they are rarely actually good. All too many folks leap before they look when it comes to transmissions, simply because they don't know any better. I could have laid it all out for you insofar as what to do and how to build the trans but maybe next. time.

Only $750 for a 4L60E is flat rate prices so I'd be concerned about how that thing was built and what parts were actually used. I'd send it back and the adaptor kit and get the correct 4L60E for your application. For $750, at least with the correct version of 4L60E for your application, you can open it up and add and/or swap out substandard parts (if found) for better stuff).
 

AuroraGirl

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Yes, lots of folks are suckers for good deals, and unfortunately, they are rarely actually good. All too many folks leap before they look when it comes to transmissions, simply because they don't know any better. I could have laid it all out for you insofar as what to do and how to build the trans but maybe next. time.

Only $750 for a 4L60E is flat rate prices so I'd be concerned about how that thing was built and what parts were actually used. I'd send it back and the adaptor kit and get the correct 4L60E for your application. For $750, at least with the correct version of 4L60E for your application, you can open it up and add and/or swap out substandard parts (if found) for better stuff).
you know its a good idea when an expert in the subject is suggesting something that could be in his own best interest (say, you paying him to build you the trans) but is offering the advice because he wants to see you get the best performing 4l60e with the amount you have into it or possibly less.

Basically, if you have any ambition @kkgp81 id recommend going with what nick says, because if you can get your money back you wouldnt have to worry about things. Although, Im not sure if that will affect your NP241 plans or not?
 

kkgp81

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I get what you are saying but I don’t think you understand what the Summit outlet is. Scratch/dent and some returns but it’s a scratch/dent unit as the pan had a damaged corner resulting in a good discount. It’s the exact unit posted in the link above. And as far as look/leap it would/will work with my original intentions but went another way with the motor side and it will still work. I’ll post back if it gets going, worst case I have to roll back one generation to a single piece case setup if the adapter doesn’t come in by the time I’m ready to roll it.
 

NickTransmissions

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I get what you are saying but I don’t think you understand what the Summit outlet is. Scratch/dent and some returns but it’s a scratch/dent unit as the pan had a damaged corner resulting in a good discount. It’s the exact unit posted in the link above. And as far as look/leap it would/will work with my original intentions but went another way with the motor side and it will still work. I’ll post back if it gets going, worst case I have to roll back one generation to a single piece case setup if the adapter doesn’t come in by the time I’m ready to roll it.
Lol, you'd be thinking wrong. I get what summit outlet is, it sells blems that aren't impactful to the functionality of the unit - I've done this a few times myself and beefed up the unit for whatever purpose or vehicle. What I'm saying is that you should have purchased a Gen1 SBC-compatible 4L60E off of Summit's outlet page and saved yourself some funds and time but do what you want as it's your project.
 

Camar068

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NickTransmissions

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Can do another post if you like Nick. What's your thoughts on the 2.84 ratio input carrier available by Sonnax for the 4L60e? I like it except the price....hate the long 2nd gear in stock.

https://www.sonnax.com/parts/3734-2-84-ratio-input-carrier-kit

Thanks In Advance
I'd do it if you're racing/street-stip and the like...Keeps you in the power band and accelerating nicely during the 2nd gear shift vs bleeding so much of it going off before you finally recover before shifting into 3rd...As you said, the pain is all in the price but buy once, cry once (hopefully just once, haha).
 

Camar068

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I'd do it if you're racing/street-stip and the like...Keeps you in the power band and accelerating nicely during the 2nd gear shift vs bleeding so much of it going off before you finally recover before shifting into 3rd...As you said, the pain is all in the price but buy once, cry once (hopefully just once, haha).
Thx, after reading more again.....for at least the 3rd time, I was about to reply that it's a daily but I do like to take off fast....but not barking the tires. Getting on the interstate is one of the funnest parts of driving my truck. Actually had a trooper start to chase me until I let off at 10 over once I got on the interstate....he "carried on" lol.
 

kkgp81

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A little update on my situation for those that might be interested. Sure I could have just bought the LT based unit (single piece case) and moved on by shelving this unit but lets accept the challenge.

You will need a dust cover- Chev Perf part # 19332783 (this is listed as a manual trans setup but fits perfect for the lower exposed area.
I dropped a flex plate off to have the holes drilled for the LS torque converter pattern. This method will require spacers and longer bolts.
You will need bellhousing spacers- the CP one is 3/8"
This one is 3/8"- https://www.summitracing.com/parts/icb-551835-375fl
This one is 1/4"- https://www.summitracing.com/parts/icb-551820-250
This one is 1/8"- https://www.summitracing.com/parts/icb-551820-125


You can also buy the Chevy Performance Torque converter that is setup to mate a LS based 4L60E to a Small/Big block chevy. Chevy Perf makes a kit that has a flex/spacer/and cover but no idea when it will ever be in stock again but it you add the cost of that plus a torque converter this $1000 torque converter is the same price as going that way (kit+TC). https://www.summitracing.com/parts/nal-19299800



This is the chevy kit with flex/space/cover, I am still trying to track down the part number for the flex plate which will be a SBC bolt pattern with the torque converter pattern for LS based units- https://www.summitracing.com/parts/nal-19154766


I will have pics of this sooner or later when we pull the trans back to install the spacer. Currently its bolted up and honestly would work as you can spin the torque converter by hand with it installed but going to work out the spacing to make it mostly right until I can get hands on the right flex plate.






Spent some time this afternoon converting my mechanical speedo 241C to a VSS style. The whole thing will get sent to be rebuilt before being fully put into service.

img_2870-jpeg.347226


img_2869-jpeg.347227
 

NickTransmissions

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A little update on my situation for those that might be interested. Sure I could have just bought the LT based unit (single piece case) and moved on by shelving this unit but lets accept the challenge.

You will need a dust cover- Chev Perf part # 19332783 (this is listed as a manual trans setup but fits perfect for the lower exposed area.
I dropped a flex plate off to have the holes drilled for the LS torque converter pattern. This method will require spacers and longer bolts.
You will need bellhousing spacers- the CP one is 3/8"
This one is 3/8"- https://www.summitracing.com/parts/icb-551835-375fl
This one is 1/4"- https://www.summitracing.com/parts/icb-551820-250
This one is 1/8"- https://www.summitracing.com/parts/icb-551820-125


You can also buy the Chevy Performance Torque converter that is setup to mate a LS based 4L60E to a Small/Big block chevy. Chevy Perf makes a kit that has a flex/spacer/and cover but no idea when it will ever be in stock again but it you add the cost of that plus a torque converter this $1000 torque converter is the same price as going that way (kit+TC). https://www.summitracing.com/parts/nal-19299800



This is the chevy kit with flex/space/cover, I am still trying to track down the part number for the flex plate which will be a SBC bolt pattern with the torque converter pattern for LS based units- https://www.summitracing.com/parts/nal-19154766


I will have pics of this sooner or later when we pull the trans back to install the spacer. Currently its bolted up and honestly would work as you can spin the torque converter by hand with it installed but going to work out the spacing to make it mostly right until I can get hands on the right flex plate.
This is good information for folks looking to swap a 4L65/70/75E, as an alternative to a 4L80E, into a classic hot rod, resto-mod or other vehicle (Squarebody) with a built Gen 1 SBC or big block. Please update with the flex plate part number as that would complete the information chain needed to do the swap...Thank you for sharing.
 

macr0w

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I put a 2 piece 4l60e behind my mid 90's, 1 piece rear seal 350 with no adapter kit or spacers or anything.
It's been in for a year or so and runs great.
Which engine/transmission combos need an adapter? :shrug:
 

NickTransmissions

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I put a 2 piece 4l60e behind my mid 90's, 1 piece rear seal 350 with no adapter kit or spacers or anything.
It's been in for a year or so and runs great.
Which engine/transmission combos need an adapter? :shrug:
Do you have a picture of the front of that two-piece 4L60E by chance?

My guess is that it was a Gen1 SBC two-piece case, those were produced for pass cars and trucks between 1998-E2000, had the Gen1 SBC bell housing bolt pattern (no engine-bell bolt hole location at the 12'oclock position), shallower bell housing (relative to the LS 4L60/65/70Es), 298mm input shaft with corresponding pump assembly.
 

NickTransmissions

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Yep - that's the Gen1-compatible two-piece case 4L60E - note the lack of a 12 oclock bolt hole, compared to the LS/Gen3 SBC 4L60/65/70s, example shown below...Compare the input shaft on yours to the one in the pics below.
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macr0w

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I see. :cool:
 

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