I didn't know it was a GMT800......Performance Automatic makes a custom crossmember.
The 800 with a 4L60 has a crossmember bolted in between the frame rails. However
the 800 with a 4L80 has the crossmember bolted on the lower edge of the rail, so check
the salvage yards for a 4L80 crossmember.

TCI part number 277501 has been ordered. Due in date is 17 June. As soon as it arrives it gets slapped onto a crate and shipped to FLT.

UPDATE:

The new gearset is in. These gears will give me a 2.75 first gear ratio and a 1.57 second gear ratio instead of the factory 2.48 first and 1.48 second. Too bad there's no option for a 0.67 overdrive. Maybe the next rebuild.





Monday, my next day off, I'll be packing these gears onto a pallet along with my extra transfer case for shipment up to FLT Transmissions. Shortly after that, I should be getting a bulletproof setup back. I'll also not have to rush the job as I've got a spare POS to drive in the meantime. The 'ol lady will be driving my Buick while I've got her truck apart.

Incidentally, now that I've ordered my parts I see there is a new gearset, just out, part numbers 279700 and 279701, which are 6 pinion low gear sets. I'm going to stick with the ones I have though, as these are about 450 dollars more than the ones I did order, part number 277501. 277500 is the other gearset depending on year of transmission.

What a beauty! I saw the 2.97's the other day when I was on TCI's web site and was wondering what you went with, the 2.57's or 2.97's. I'm curious to get your impressions of your new tranny when you get it installed. I like the 3.06 of my 4Lpos60e and has been my hold up. I've got 3.42's and 20's on all wheel drive. Changing out two ring and pinons with bearings etc. makes the tranny gear set a serious consideration since I have to be in there anyway and there is nothing wrong with my current diff's. Now that they have the 2.97's I really think they hit the mark and they will fly off the shelf with 80e conversions.

With the 80e's relative low cost and decent availability. Spending the extra $$ for the 2.97's and refresh with the rest of stock stuff you get a stellar trans. You can spend $3,500 easily for a working 4lpos60e, but just $1,800 for a rebuilt 80e and toss in the $1,200 gear set, your still $500 ahead!!!!

The 2.97's are a game changer....

These are the 2.75s that I got. The 2.97 were something like 2200 dollars where these were a few hundred. I figure I'll make up the acceleration difference under the hood. With the cash difference between the 2.75 and the 2.97 I could almost supercharge the engine.

Are these the ones with only a 500hp rating or are they an upgrade over stock being that they are a 6 pinion gear set....Assuming the stock is probably a 5pinion?

According to TCI, they are rated for 17 percent more power than stock.

4L80E 6-Pinion Planetary Set
(1997-Newer 2.75 1st/1.57 2nd Gear Ratios)

• 6-pinion planetary sets improve acceleration & gear transitions
in GM 4L80E street/strip or towing applications
• Lowers 1st & 2nd gear ratios to improve take-off while also
improving rpm drop between gears
• 6-pinion rear/5-pinion front planetary & CNC-machined
billet construction provide 17 percent increase in load capacity
& improve long term reliability

I don't forsee any problems, as a 4L80E will more than handle anything I plan to throw at it in stock form. 17 percent stronger, all the better. I would rather have had the 2.97 first gear, but I'm doing good coming up with the money I am as it is. My cars aren't the only thing I have that drains the funds.

Conversion crossmember prototype has arrived.





Things are still looking good for shipping my extra transfer case along with the 1-2 gear conversion set to FLT on Monday. I'll be loading the parts in the back of the truck later today, and will be enroute to the shipping company first AM tomorrow.

Transfer case and gears are on their way now. Tick tock tick tock tick tock...

Crossmember looks excellent

Thanks Howard, just wish I could take credit for actually making it.

I maybe jumping on this wagon pretty soon. It would be nice to have a short 1st gear instead of 1st taking me to 60mph..... I believe the tires wouldn't stay on my truck long though:P
is there any progress to speak of yet?

Not yet, waiting on FLT to get the rebuild done. They have the gearset and my transfer case, and when they are done the next step takes place. They are going to be using a 4L80E output shaft, and the transfer case will be modified to accept the 4L80E. Once Chuck at FLT finishes the trans and ships it back, the fun begins.

Speeder wrote:

Totally based off this transmission, which is supposed to be an actual 4L80E with extra gears. I don't know much on how transmissions work, always treated them like a single unit before so I'm not ashamed to admit ignorance on what may or may not work.

Here is a little video about the TCI 6 speed auto.

http://video.streetlegaltv.com/video_detail.php?mId=7726



peace
Hog

Hog wrote:

Speeder wrote:

Totally based off this transmission, which is supposed to be an actual 4L80E with extra gears. I don't know much on how transmissions work, always treated them like a single unit before so I'm not ashamed to admit ignorance on what may or may not work.

Here is a little video about the TCI 6 speed auto.

http://video.streetlegaltv.com/video_detail.php?mId=7726



peace
Hog

TCI 6x

Designed for GM SBC, BBC and LS applications, as well as Fords and Chryslers, the 4L80E-based TCI® 6x Six-Speed Automatic Transmission is a fully programmable transmission that gives you six forward gears (2.97, 2.23, 1.57, 1.18, 1.00, 0.75) for quicker acceleration and increased fuel economy at cruising speeds and is capable of handling up to 850 horsepower.

Wonder if you can use their computer on a tranny that had the modified gear set?

CrazyHoe wrote:

...
Wonder if you can use their computer on a tranny that had the modified gear set?

Yes! Both their new controller and the previous version I used to run with the Tahoe have user configurable gear ratios. (OEM PCM allows that too)

I was really hoping that video would have been in-car. Every time I've ever seen one of these transmissions it's been on a bench or stand just looking pretty.

James B. wrote:

I used to run with the Tahoe have user configurable gear ratios. (OEM PCM allows that too)

What would it take to have the 0411 change gears like the TCI computer?

CrazyHoe wrote:

James B. wrote:

I used to run with the Tahoe have user configurable gear ratios. (OEM PCM allows that too)

What would it take to have the 0411 change gears like the TCI computer?

I would have to be custom-programmed and timed right. The reason a 6-speed 4L80-E is possible is because it has three planetary gear set unlike most four-speeds which only have two. The 4L80-E in stock form shifts with only a single mechanical clutch event for each gear change, so no precise timing or synchronization is required and that's why these things feel like they shift so solidly.
The way TCI is doing this is by engaging the Overdrive planet between each gear.

First gear = forward clutch engaged (same engagement as OEM first gear)
(overdrive engages)
Second gear = forward clutch and overdrive clutch engaged
(overdrive disengages, intermediate clutch engages)
Third gear = intermediate clutch engaged (same engagement as stock second gear)
(overdrive clutch engages)
Fourth gear = intermediate clutch and overdrive clutch engaged
(overdrive disengages, direct clutch engages)
Fifth gear = direct clutch engaged (same engagement as OEM third gear)
(overdrive clutch engages)
Sixth gear = direct clutch and overdrive clutch engaged (same engagement as OEM fourth gear)

So, the 2-3 and 4-5 become two mechanical events that have to either perfectly overlap or favor a slightly delayed OD disengagement to prevent flare up and engine overspeed from a moment of the previous gear ratio.

In short, it's COMPLICATED!

how much were the gear sets?

james8997 wrote:

how much were the gear sets?

761 bucks.

Incidentally, there was a bit of a delay. Chuck got married and went on a honeymoon. He's working on the trans and transfer case this week.