'99 Silverado 4.3 to 5.3 Swap with 4L80e bonus

[stutaeng]

That sucks, sorry to hear it.



You probably already know this, but just FYI there is a valve body relief mod that's recommended in the HD2 kit which has been found to do more harm than good. Better explanation here:

https://sites.google.com/site/sloppywiki/everything-ls/4l80e-info

The rest of the kit is fine, I would just avoid that one specific mod.

Thank you. I was not aware of this....can't access that link, something about administrator workplace...

I'll have to look into this. Do you know which mod this is? I was actually debating getting the Transgo shift kit, which is considered a high performance kit instead of the stock shift correction kit. I got the rebuild kit from tranmissionbench.com, and the training is superb. He shows both ways.

 

[df2x4]

Do you know which mod this is?

Basically it's drilling and installing a check ball from passage 14 into passage 47 of the valve body. Copy/pasted from the Sloppy Wiki link I posted... There's a picture there too.

"HD2 kit Update and caution

recently we had a discussion on the sloppy page and people pointed out to me to not perform this mod

"Grady Farrer: It's to solve over pressure conditions. It has you drill from 14 into 47. 47 is a void so it's easy to undo this mod if you've already done it

If torque signal fluid builds up too much pressure (tune. Worn valve. Epc, etc) then it will unseat the trans go ball and exhaust the fluid.

This way you don't build up too much pressure and blow out snap rings or seals etc.

It's a bad mod because if the transgo ball doesn't seal perfectly...or over time it wears out and leaks...or gets cocked sideways etc...then it leaks torque signal fluid and causes horribly LOW line pressure and cooks the trans

It doesn't really fix anything and there's a big risk to break ****. Moral of the story... don't do the relief mod"

 

[stutaeng]

Basically it's drilling and installing a check ball from passage 14 into passage 47 of the valve body. Copy/pasted from the Sloppy Wiki link I posted... There's a picture there too.

"HD2 kit Update and caution

recently we had a discussion on the sloppy page and people pointed out to me to not perform this mod

"Grady Farrer: It's to solve over pressure conditions. It has you drill from 14 into 47. 47 is a void so it's easy to undo this mod if you've already done it

If torque signal fluid builds up too much pressure (tune. Worn valve. Epc, etc) then it will unseat the trans go ball and exhaust the fluid.

This way you don't build up too much pressure and blow out snap rings or seals etc.

It's a bad mod because if the transgo ball doesn't seal perfectly...or over time it wears out and leaks...or gets cocked sideways etc...then it leaks torque signal fluid and causes horribly LOW line pressure and cooks the trans

It doesn't really fix anything and there's a big risk to break ****. Moral of the story... don't do the relief mod"

Ok, cool. It looks like it is Step 1 of the kit. This video talks about it. Around the 1:00 mark:

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I really like the smoothness of the 4L80e shifting. I don't really want to shift firmer. That's more like for racing, I think. I'll go with the softer of the 2 options.

 

[df2x4]

Ok, cool. It looks like it is Step 1 of the kit. This video talks about it. Around the 1:00 mark:

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I really like the smoothness of the 4L80e shifting. I don't really want to shift firmer. That's more like for racing, I think. I'll go with the softer of the 2 options.

Yup, that pressure relief valve he points out at 1:00 in the manual is exactly what's pictured on the sloppy wiki page.

 

[stutaeng]

Yikes, that's a lot of parts! LOL

You must be registered for see images attach

 

[stutaeng]

Old t-r-a-n-n-y is out. I can't seem to able to raise the truck high enough to clear the ****** on the t-r-a-n-n-y jack...raised the trucks far as my floor jack would go with 2 pieces of 2x. Still not high enough though.

Had to get t-r-a-n-n-y off the jack once I dropped it and drag it out.

 

[stutaeng]

I wound up just swapping another transmission. This one is an '06 model out of an 2500HD.

I had an "oh sh#$@t!" moment. I added ATF fluid to where it was showing ok. But it was on jackstands. When I lowered it and put in gear briefly it slipped a bit after shifting through all gears. When I checked fluid level it hardly registered anything! 5 quarts later it was back again to normal on the dipstick (bought all the 3 qts. of DEX 6 at O'Reilly, 1 qt. at WallyWorld and finally a full gallon at AAP!) think the fluid went into the TC when I lowered it.

Also got a new (old) hood painted to match!

 

[stutaeng]

I did flush the radiator ATF cooler with KoolerKlean.

And had to extend the rear lube line on the tranny. O'Reilly sells some brake fluid lines that work with compression fittings. Lines are 3/8". Just cut the brake lines fittings with tubing cutter and screw in compression fittings.

 

[stutaeng]

Next phase will be re-gearing...well, axle swapping really. I bought a 2015 Silverado "Hybrid" axle (I think also called AXN on the GMT 900 series trucks with 6.2 engine.) It's a 14 bolt 9.5" with bearings from the 6 lug axles. I got one with 3.73/G80, which is kinda rare ratio I believe. They also made a 9.76" ring gear of that axle. I think most are 3.08/3.42 because of the 8 and 10 speed trannies.

There's a bolt-on mod on these trucks where you can use 2020 Silverado front 4 piston calipers and matching larger rotors. But you have use like 18" wheels. But for the rear axle I don't believe this is the case. I'm keeping my 16" wheels for the time being.

 

[stutaeng]

Just took her for a spin. Got her on the freeway up to like 75. My speedometer is slower because my ECU got reflashed to 4.10s because that's what I wanted to run.

From taking off it doesn't feel too much different than before probably because of the 1st gear difference on the trannies. But above 2,000 RPM there's a significant difference in power. I think 3.73s are going to be a bit better than 3.42s.

I think I'm going to like the little 5.3!

The cluster I replaced it with has 469,000 miles! It came from a 02 Tahoe getting parted out. Truck "only" has 260,000 miles. Lol