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MY OWN TRUCK is a 1999 Silverado Z71 LS 5.3l 4L60E with 195,000 miles, and it always starts, always runs, gets me down the road, and the job done, without fail.

Paid $1800 two years ago, with a bad rear end. Installed new water pump, starter, alternator, new brakes all around, and rebuilt the rear-end myself. Wasn't at all easy, or cheap, but it was worth it.


Now, my transmission needs to be either rebuilt, repaired, or replaced; neither of which will be at all cheap, or easy for me I know, but I have somehow managed to have a potential swap fall in my lap, and it was free.


The replacement tranny is a 4L60E out of a 1999 Escalade 5.7l AWD, that's only got 90,000 miles on it. Things been sitting for about a year, is complete, and has (had) no known issues.


Lacking the means, knowledge, and/or financial resources to make repairs (Sun Shell thing broke) or to pay someone else to fix it, or rebuild it, or the time to wait until a busy shop can get to it, I'm preparing to make the swap myself, but with the assistance of a few buddies, some of their tools, and hopefully a collective of experience and knowledge to do the  job properly.


What I'm asking for here is a little help with the particulars, and I could definitely use any and all the help I could get in the way of advice, direction, caution, tips, pointers, hints, do's and don'ts, and a few nuggets of wisdom.


Steps, or some order of operation, would be nice, but first I was hoping for a confirmation on interchange fitment, relative suitability, difficulty in completing the swap, should the swap be less than a good fit, but perhaps still do-able. So.. 


First, is my OKXD swap compatible? I've done quite a bit of research, but still haven't got a simple, definitive "Yes" what I was hoping for. Is it even possible to keep my PCM with a tranny from a 5.7? The Bell Housing has a bolt hole top-center (I was told that  was for diesel motor engine application) and the Torque Converter TMBX 242-4393 has three holes for bolting up to my Drive Plate. Both are two-piece (Bell Housing to Gear Box), and both include 4WD/AWD coupler 15724744-YDC-5 to Transfer Case (Transfer Cases are the same? My truck came equipped with Automatic 4WD) so are there any issues with this swap?


Second, if compatible/interchangeable, what should I do first, besides drop the driveshafts, transfer case, crossmember, and pull plug-in connector, linkage, etc? Is there any prep I need to do to ready the replacement unit? It has been sitting somewhere in a guy's garage, gathering dust, dirty, a little crusty, does it need to be flushed, primed? Should it be checked to make sure the electronics are not friend, switches operable?


Third and last, what are my odds to complete this swap, by myself, the first time, and still be able to drive my truck another 100,000 miles?


Any input, comment, criticism would be much appreciated, thanks!

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1) Swap instructions:   Buy a Chilton repair manual and follow the transmission replacement instructions to the letter. Easy to do if you follow the instructions. 


2) As for the interchange, go on eBay and find the exact same transmission for sale. Then plug in your vehicle info and see if the compatibility is there. 


3) As for how many miles the transmission will go: Who knows man.... Its anyone's guess. 






Take your time, don't rush it. 

Make sure you use the correct fluid 

Flush your trans cooler, or use an after market one. 

Make VERY sure your vehicle is supported on jack stands properly 

Plan on taking several days to complete the job

Replace the trans filter, pan gasket, input and output seals prior to installation

Put a large magnet in the trans pan 

Consider installing an inline trans filter on one of the cooler lines 





Edited by starman8tdc
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You may have to pull the intake manifold to get to the top bolts on the bell housing.  When I pulled my engine, I don't think I could have gotten those top bolts from the bottom, or with the manifold in place.  First step, disconnect the battery.


If you have any leaks at the rear of the engine, the best time to address these is when the trans is out.

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Okay, so I decided I'm not scared of this thing, and I'm not gonna worry too much about all the little things, and just dig in and get dirty. I'm gonna go ahead and do it myself. If in fact this really IS a (more, or less) simple straight up swap without any mods, I think I've got a pretty good handle on it, at least the basics anyway.


I will take my time, put together my list, have all parts, supplies on-hand, and just deal with any issues that may come along as necessary. I've done all my own work on this truck til now, doesn't seem to be outside my abilities. I know that I'm no mechanic, but I'm pretty smart, pretty good with my hands. I feel like if I take my time and do it right every step of the way, I'll be alright.


Thanks for the advice, much appreciated. Im not quite ready to drop the bad one yet, but when I begin, I'd like to post updates, images along the way, if that's alright. Is there some other place for me to do that, or should I just keep this going with this thread or topic, whatever?


Thanks again guys.

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Updates and pics would be cool.


The first time I swapped a transmission,  it was on a 1978 K5 Blazer. I did it by myself in a grass field with no repair manual and limited tools. I was 16 and had absolutely no idea what I was doing. It took 2 to 3 days. If I could do it, you can do it. 


I would not try rebuilding one, but I don't mind swapping them at all. 








4L60E side section.png


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  • 3 weeks later...

Dang! Thanks a bunch!

Yeah, I fully intend on taking photographs of everything throughout the process, and I know I shouldn't take something like this, and dangle it out there too long, without keeping it moving, fresh...


I've been trying to get everything together; the time I need, at the right time, and place, and I've pretty much got all that, but times have been hard lately, and honestly, I just can't muster up the cash to be able to purchase the Dexron III, filter, gasket, gasket maker/sealer, everything else I need to get going on this. I lost phone service on the 1st, didn't get it back til the 8th; someone (maybe more than one) stole a bunch of tools from me, right from the bed of my truck! Top it off, as I had eluded, got a place to hole up for a couple days, if necessary, to make a mess, on a promise. Just like the Trans Dolly, which I was also just promised...


Used to be I made my money with my truck, doing handyman work, hauling/putting in, pulling out boats, running up hills to anchor points to secure floating docks, and a little shadetree when I could get it (parts changer, mostly) but without my truck in good working condition, and without all my tools intact, work is getting harder and harder to find...


That's my update. Wish I had more good, productive, positive stuff, but that's where I'm at right now.


But I just wanna say thanks right about now, for all of your help, tips, advice, and interest. You all make me wanna get this done for you guys, more than for myself (almost)!


More to come, as they happen!

(with pics;)

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