4l80e Swap

So I just ordered a 4l80E transmission for my 1971 GS 455. Extreme Transmission in Amelia (Cincinnati) Ohio is building it. I selected an early model valve body, Adapter plate with a Reid bell housing, custom made converter (2500 ish stall) U.S. Shifter quick 4 electronics. I will get the G Force cross member that is for the A body conversion. also have an Aluminum deep sump pan w/fins for it.
I have finally decided to replace the "wont stop leaking no matter what" TH400 and get the O.D. I want with the 355 gears I have. The question is; What am I missing, forgetting, or don't know? Kind of a pricey swap, but after a few years of pondering it, this seems like the best option. I don't race it. Just cruising, car shows and an end goal of a power tour.

 

Will you need a throttle position sensor with that, or does one of the things you ordered come with it?

Very cool BTW. Looking forward to seeing more about your conversion.

 

I believe the U.S. Shifter quick 4 is stand alone electronic system. How it does that, I don't actually know...yet.

 

They built my 400 for my racecar, haven't got to use it yet, going in this winter. They are buick ppl at heart, they have a gs there that isn't buick powered but crazy fast turbo car.

I'm sure they can help you with what u need for the conversion but you will need a tps and maybe a map it needs these inputs to determine load

 

Thanks, Larry. I read those at one time. Need to review them. I am staying with an automatic shift vs. manual. I believe the U.S. Shift Quick4 is an rpm driven shifter, but fully adjustable. Should be able to dial it in and be good enough for most driving conditions. I think it wouldn't be ideal for low E.T.s. I really like their billet adapter plate.

 

Hey Gary, you are forgetting driveshaft, the yoke is different and the length shortening. Though, some HD version (non buick as I understand) THM400 did have a larger yoke that could work.

 

The guy I have installing the transmission has that covered. I have no idea which yoke it uses, but they do. I am a little concerned about the pinion angle, but the G-Force cross member is supposed to get that right.

 

You are correct! U.S. Shifter sells a TPS seperate from the Quick 4 that you need for the installation.

 

FYI to anyone interested in the US shift quick 4 I have the complete set up along with a TPS to go along with the Holley sniper in the for sale section along with a 4L 80 E transmission and converter. Willing to separate $500 for the Us quick 4 thanks, Tom.

 

Generally a trans has needed a vacuum modulator or some type
of throttle position sensor (like a cable). Does the 4L80E use
both? I have considered the vacuum modulator more responsive
esp at low rpm where little throttle is used.

Good project. Bruce Roe

 

Bruce, I am not sure which (vacuum or cable) system U.S. Shift uses. I imagine it is a cable, like a 200r4. Honestly, I know very little about how the newer stuff actually works. I gotta rely on the guys I hired to get it right. Hopefully, I learn something in the process.

 

The 4l80e uses neither, it's all electronic. It uses the tps as the cable, and in stk applications uses rpm and map for load like vacuum.

Same basic input functionality just a different way to get there

 

So the transmission is built, and all of the problems seem to be solved except the Speedometer. Is there a conversion from electric to cable for these applications? Wondering what the best solution is. I do have cruise control, so I would like to keep the cable. (vs converting the speedometer to electric)

 

Bowler transmissions and a few others make tail-shaft replacement kits that convert to a mechanical speedometer drive. 7-800 bucks though. I run a Dakota Digital Cruise control on both my 60 Electra and my 64 Riviera in place of the factory mechanical cruise. Its more accurate, smoother, etc and uses a speed sensor instead of a mechanical drive. So you could retain the cruise that way, and convert to an electronic speedometer unless your trying to preserve the original gauges of course.
https://shop.bowlertransmissions.com/products/4l80e-4l85e-mechanical-speedometer-conversion

 

I followed your leads and Dakota Digital does have a digital to cable converter. I have to ponder where to mount that, but it will work. Thanks!

 

Do both maybe? I don't have cruise and don't care so I retrofitted my original speedo with an electronic speedometer. To the common person and even riv owners it would be hard to tell. Can you still have a vss to run an electric speedo and still accommodate a speedo cable out in your configuration? Again since I don't have cruise I am thinking that that system is cable driven but vacuum modulated for the throttle.

 

Or.. do that and get rid of the cruise. I rarely have ever used cruise control in any vehicle.

 

Good info^^

 

If you want to keep the cable speedo simple. Did this on my 4L60E. The US Shifter is a nice controller. TPS options are on their website. Word of caution, if there isn’t a sensor built into the trans to monitor slipping don’t check those boxes in the software.

http://t56cablespeedometer.com/

Ray