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Watch a 4L80 swap video

B

Blazer79

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I just found a 15 minute video recorded from TNN I think. It shows two guys swapping a blown TH400 tranny for a new 4L80 tranny in a motorhome. Since the motorhome didn't have a computer, they installed a tranny computer that even has knobs for adjusting the shift feel and rpm points. Very interesting. They make it look so easy. I think the hardest part for my Blazer would be finding an adapter for my NP203 transfer case. Now I'll have to hunt a 4L80 tranny in the junkyards.

You'll need the Free Real Player to watch the video. Here' s the link to the page. <A target="_blank" HREF=http://www.autotransinc.com/eplaceview.html>http://www.autotransinc.com/eplaceview.html</A>. Just click on the picture.

I hope you like it.

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Soon a 454 K5!!</font color=black>
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That's the fellas from the Shadetree Mechanic show. I saw that episode. The tranny is expensive, but I seem to remember that the computer to run it was several hundred dollars. On gas powered rigs, the tranny is run by the same computer that runs the engine, so the computer won't work right unless it's also running the fuel injection. They used a tranny control computer from a GM diesel powered truck and a custom wiring harness.

BTW, that tranny is the 4L80E. There was a non-computer controlled version, the 4L80 for a couple of years. The E signifies electronic control of the trans.

<font color=black>HarryH3 - '75 K5</font color=black>
<A target="_blank" HREF=http://www.angelfire.com/super/ThunderTruck>http://www.angelfire.com/super/ThunderTruck</A>
It's a great day to be alive...
 
Harry,
Would that mean that the 4L80 wouldn't need a computer and could run right behind a non-EFI engine? This would still be the bullet-proof OD transmission right??? Just wondering, thanks.

It's not what you buy, it's what you build!
 
Yep, if you can find a 4L80 then it will bolt right up and work. It uses hydraulic shift logic. I think you just have to come up with a way to lock the torque converter, like you do with a 700R4.

<font color=black>HarryH3 - '75 K5</font color=black>
<A target="_blank" HREF=http://www.angelfire.com/super/ThunderTruck>http://www.angelfire.com/super/ThunderTruck</A>
It's a great day to be alive...
 
To the best of my knowledge there never was a 4L80 (visit http://www.v8s-series.freeservers.com/trans.htm). The 4L80E is electronic, there is no non-electronic version available. I believe there was a Motorhome version called the MT1 with different gear ratios, but still electric. There are at least 5 manufactures of aftermarket computerized controllers for these tranys that I have found. None of them require a fuel injected motor or the factory computer. The undisputed expert for GM overdrives (700R4, 4L60E, and 4L80E) is Steve Holmes at Bowtie in Hisperia? So. Cal.
http://bowtieoverdrives.com/index.htm Steve has a controller that is full programable with your Laptop and I would recommend it.

JET sell built 4L80Es and a controller, but I wouldn't recomend them for several reasons (they have to program it for you and they charge a arm and a leg to do it).

TCI has a good unit.
http://www.tciauto.com/electronics/index.htm

Premier Preformance has one.
http://www.findarticles.com/cf_offrd/m1185/n4_v31/19168103/p1/article.jhtml

Ramsey
 
Hmm, I thought they had made the 4L80 for a year or two. Maybe I'm thinking of the 4L60.
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<font color=black>HarryH3 - '75 K5</font color=black>
<A target="_blank" HREF=http://www.angelfire.com/super/ThunderTruck>http://www.angelfire.com/super/ThunderTruck</A>
It's a great day to be alive...
 
4L60 = 700R4, same thing
4L60E = Electronic version of the above

There never was a 4L80. The 4L80E came out in mid-1991 and is essentially an overdrive version of the TH 400 that it replaced.

Tim
'84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
 
Yep! You can run the 4L80E in a non-EFI engine. I have one behind my 502. I like the idea of the strenth of a TH400, but with the 4th gear overdrive at .70:1. Bought it from Jet Transmissions. However, I agree with Baja Blazer about Jet's ECU for the trans. Not as full-featured as the TCI ECU, which I will be running.

TCI's computer allows you to custom program just about anything you want with the 4L60E or 4L80E transmissions, and run either one without a computer-controlled engine. You can just program in your tire size, gear ratio and trans type and be on your way. Or, you can adjust things like full-throttle and part-throttle shift-points and check everything with full data-logging. Pretty cool.
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Robb
'73 GMC Suburban - 502DFI
<A target="_blank" HREF=http://community.webshots.com/user/robbrj>http://community.webshots.com/user/robbrj</A>
 
What kind of adapter are you using to connect your NP205 to the tranny? I guess that same adapter would work with my NP203, since both are 27 spline, right?

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Soon a 454 K5!!</font color=black>
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It's the same adapter that is used for the TH400 to NP205 combo. However, I had to change the NP205 input shaft to the longer version to get the proper engagement between the two pieces. Also had to machine the adapter to accept the o-ring seal from the 4L80E, and shave about 3/8" from the output shaft on the transmission so that it wouldn't bottom-out in the t-case input shaft.

As for your NP203, I'm not very familiar with them. If they use the same adapter as the TH400 to NP205 combo, then you would be in good shape.

Robb
'73 GMC Suburban - 502DFI
<A target="_blank" HREF=http://community.webshots.com/user/robbrj>http://community.webshots.com/user/robbrj</A>
 
Rob,

You should call Bowtie. Steve used to recomend the TCI unit but has recently started using a new one that I do not recall the manufacturer of, that he says is even better and I believe cheaper. Your 4L80E/205 combination sounds great I would like to hear more about it.

Ramsey
 
Ramsey,

Thanks for the tip on Bowtie. I'll give them a call. Until the money is spent, I'm always up to hearing about a possible better solution; especially when it comes to electronics. The improvements seem to come at such a rapid rate.
crazy.gif


I'd be happy to share any info I can about the trans/t-case combo. You can PM me, if you like, or just post any ?? you may have. Like most others here, I check this board at least once a day.
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Robb
'73 GMC Suburban - 502DFI
<A target="_blank" HREF=http://community.webshots.com/user/robbrj>http://community.webshots.com/user/robbrj</A>
 
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