How to Install a 4L80E into 1967 - 72 C10 / C20

[bry593]

Here's a video with some pointers on how to swap a 4L80E into your C10 or C20 truck.

https://www.youtube.com/watch?v=3yOop3td7Rc

If you have a C20, you probably have a 4.10 or 4.57 geared rear axle. You really can't hang with modern traffic unless you want to wind your engine up to 3000+ rpm. The 4L80E allows you to cruise 75 mph at a comfortable 2300ish rpm, reducing fuel consumption and improving usability. As an added bonus, it's a heavy duty transmission so no problem using your truck as a truck.

[Accelo]

The only reason this transmission is not used more is the cost of the controller as only fully electronic versions were manufactured. The stand alone controller can cost close to a grand. If you are transplanting an LS motor using a computer it can be used to run the transmission for a lot less money. It's covered in the video but without cost information.
The speedometer is also electronic and requires some type of conversion to work with the stock speedometer. It will connect to the aftermarket speedometers directly.

[tdangle]

I looked into it when I was going to take the 2004r I was running out. By the time everything was said and done, you were looking at close to $5K best I could figure and its still only a 4 speed. I ended up going with a built 7004r from Bowtie Overdrives and am very happy with it.

[bry593]

Originally Posted by Accelo

The speedometer is also electronic and requires some type of conversion to work with the stock speedometer. It will connect to the aftermarket speedometers directly.

Well hell.... I knew I was forgetting something. Yes, I had T56CableSpeedometer.com convert the tailhousing to a drive bullet. The guy does nice work and the conversion has been problem free.

As for cost, it's less than a Gear Vendor's Overdrive. I paid $650 for the trans with converter from a local salvage. It was a 100k trans and the oil was clean, so all I did was install new solenoids and a filter ($100). Trans fluid was about $60. Driveshaft was $350 shortened, new joints and balanced. Speedo drive was $350. Flexplate and crossmember mount around $100. Lines and fittings about $75. The EZ-TCU bought on special for $650ish. Altogether was right at $2400 total.

Mind you, I did the conversion over Christmas of 2019, before the world went off the rails. I'd guess if parts are still available, expect 20-30% inflation.

[Accelo]

bry593;
Thanks for the cost rundown. I am always interested in the true-costs.
I did my own machining and added the speedometer drive to my 4l60E tail shaft.
One of the few inexpensive conversions I could do myself.

[bry593]

Nice work on the conversion! That's how T56 Speedo does it as well. He basically bores the tail housing at a center distance matching the TH350/700R4. Then an aluminum insert is epoxied into the bore. The insert holds a typical TH350 pencil gear housing. The final trick is a drive gear lathed from steel bar. This is set screwed to the 4L80E output shaft.

$350 is reasonable considering the parts and labor involved. Not to mention, this is still more cost effective and more reliable than an electric drive.

[Accelo]

I purchased a metric set collar and pinned the factory plastic gear to it.
I have manufactured two of these. One for a friend with a LS3 in a 68 Camaro.

[MARKDTN]

Originally Posted by Accelo

bry593;
Thanks for the cost rundown. I am always interested in the true-costs.
I did my own machining and added the speedometer drive to my 4l60E tail shaft.
One of the few inexpensive conversions I could do myself.

For a 4L60E can't you just use a 700R4 tail housing to get a speedo gear? Or is there an early/late case difference?

And 4L80E was used in some 1990ish diesel pickups that had a stand alone controller. Yet I never see anybody do it that way. Is it because the controllers are hard to find or don't interchange with later transmissions or why?

[Accelo]

GM changed the tail housing from a 4 bolt style to a 6 bolt style on the removable bell-housing 4L60E transmissions. That's why you can't retrofit the eariler tail shafts to the late transmission.
BTW, you need to retain the electronic sensor when using modern computer controls.
This allows the computer to read the vehicle speed and can use that along with throttle opening to determine the required shift points.
You can see the hole for the second electronic sensor, in one of the pictures, I included in the prior post. It's installed on the opposite side and has the hall effect sensor connected to the wiring harness. The WOT shift points can be programed for each gear i.e different rpm shifts for different gears. Darn cool what you can do with the controls.
The program also delays shifts when it's cold out for better drivability. If you drive hard or have a trailer the computer will compensate by upping the line pressure to keep the shift times consistent. Tricks that are impossible with a non-electronic transmission.
If I was using a motor that required an ECM I would also use the electronic transmission. When the tuner modified the ECM, on my truck, he also changed the shift points to 6000 rpm in second and third and 4800 into OD.
Works flawlessly.
Stand alone controllers, for 4l80's, are over $900. That's why you don't see many. If you have to run a ECM you most likely have the controller built in. Some GM vehicles require a ECM and a transmission controller. That's for another day.
Cheers.

[special-K]

Originally Posted by tdangle

I looked into it when I was going to take the 2004r I was running out. By the time everything was said and done, you were looking at close to $5K best I could figure and its still only a 4 speed. I ended up going with a built 7004r from Bowtie Overdrives and am very happy with it.

Nothing wrong with a 3spd + overdrive. Especially in a such a superior transmission. My trucks have never needed gears between gears. The 4L80E is a tough old goat tough as a TH400. 700r4 can't touch that.

[jimijam00]

I've have HGM's COMPUSHIFT controller running a 4L80E.

A guy could do a manual valve body, or even a stand alone manual shift conversion for $100 if he didn't want a computer and shift the stick without the left knee/foot exercise.

[HO455]

Originally Posted by bry593

Well hell.... I knew I was forgetting something. Yes, I had T56CableSpeedometer.com convert the tailhousing to a drive bullet. The guy does nice work and the conversion has been problem free.

As for cost, it's less than a Gear Vendor's Overdrive. I paid $650 for the trans with converter from a local salvage. It was a 100k trans and the oil was clean, so all I did was install new solenoids and a filter ($100). Trans fluid was about $60. Driveshaft was $350 shortened, new joints and balanced. Speedo drive was $350. Flexplate and crossmember mount around $100. Lines and fittings about $75. The EZ-TCU bought on special for $650ish. Altogether was right at $2400 total.

Mind you, I did the conversion over Christmas of 2019, before the world went off the rails. I'd guess if parts are still available, expect 20-30% inflation.

How about an apples to apples comparison. Used GV to used 4L80 installation.

I bought my gear vendors with a T350 for $650. Sold the T350 for $100. Had a T350C built for $1200. New drive line $329. Add $100 for fluids, drain plug for transmission pan, and a new transmission mount. Done for $2200 in May of 2020. Overdrive with a lock up converter

[Accelo]

HO455;
You killed it as the current price for a Gear Vendor OD is $3,595.00.
Cheers.

[HO455]

Originally Posted by Accelo

HO455;
You killed it as the current price for a Gear Vendor OD is $3,595.00.
Cheers.

I picked up a very used one last year for $50 with a T400 adapter. It's my "on the shelf spare". They show up on Craigslist regularly. I've bought 3 of them over the years.

[bry593]

Originally Posted by HO455

I picked up a very used one last year for $50 with a T400 adapter. It's my "on the shelf spare". They show up on Craigslist regularly. I've bought 3 of them over the years.

Be aware that GVO will not sell parts unless a record of direct purchase exists. They keep that tight so as not to dilute their profits. This makes buying used more problematic as it must be exact to your application.

[bry593]

Originally Posted by Accelo

I purchased a metric set collar and pinned the factory plastic gear to it.
I have manufactured two of these. One for a friend with a LS3 in a 68 Camaro.

Great idea! Hard to beat OE design. I was a little worried the custom steel drive gear might wear out the plastic pencil, but so far, so good.

[Accelo]

Yesterday I confirmed the accuracy of my speedometer and it was right on according to my phone's GPS application. I was very happy with the results and it works even when you don't have satellite access because of trees or hills. LOL.

[bry593]

Originally Posted by Accelo

Yesterday I confirmed the accuracy of my speedometer and it was right on according to my phone's GPS application. I was very happy with the results and it works even when you don't have satellite access because of trees or hills. LOL.

Sounds a bit like my GPS. Just an old school AirGuide compass screwed to the dash. It works great so long as the key is turned off. It is mounted too close to the switch, so current in the wires puts off a magnetic field and rotates the compass ball about an 1/8 rotation. Oh well, I still like the way it looks...

[steves1967]

Thats a great video, I used the lokar shift linkage and the indents are really close together. Park is in the right location but, reverse and neutral are before the "R" and the OD is where the "N" is....

[May70]

Im putting a 6.0/4l80 in my truck now

[Speedracer39]

I’m starting to consider a 400 to a 4l80e swap and I think my big block will love me for it.

[bry593]

Originally Posted by steves1967

Thats a great video, I used the lokar shift linkage and the indents are really close together. Park is in the right location but, reverse and neutral are before the "R" and the OD is where the "N" is....

Thanks, appreciate it!

[Accelo]

Move the rod attachment point more to the outside. It will change the ratiio and give you more room between gears.
Then readjust for length to match up the gears.

[Extended Power]

Picked up a used 2006 4L85e today with the wife.
Came with the converter, but no slip yoke.
Also was able to scoop up a BNIB US Quick Shift 2 controller.

I’m concerned about how I can still use the Lokar shift linkage I have now to shift the transmission.
Another issue is the electronic speedmeter, but I found a vendor that has the mechanical speedometer tailshaft housing available and will set the gear ratio for your rear gears/tire height.

The ‘ol T400 is acting like I’m driving a snowmobile.

[72c20customcamper]

I was looking into getting a 4l80 or 6l80 for my 72 . Problem is they want big money for them around here . Same with LS motors making it cost prohibitive for me . I am leaning towards the GV unit for it $3400 for a new unit then I just need to get the driveshaft done . Been looking for a used unit but no luck .