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1/2-ton 4L80?

campfire

campfire

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Came across an interesting thing today, a 4L80 installed on a C1500, driving a standard 10-bolt. I've seen 4L60 trucks upgraded to 9.5" rear axles under various designations (like "heavy half"), but I haven't met a truck with a heavy tranny driving a 10-bolt. It seems a little backwards to me. :dunno:

@GWeakland620, @ZooMad75, @Babaganoosh, my understanding is that the M30 RPO code indicates that this truck should have come with a 4L60, am I reading that right?

20161030_160543.jpg

It is also cable-driven, another weird red flag.

20161030_160812.jpg



Anybody seen something like this?

And, if there was a factory configuration like this, anybody know when or why?
 
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What year is the truck?

Yes the m30 is a 4l60E...

2wd It looks like.. Engine?
 
1997 C1500, 5.7L engine. I mistyped K1500 above (corrected now). :doah:

Should either the 4L60E or 4L80E be using a cable like that? I thought they were completely electronically controlled by that point. :dunno:
 
95 up use cable to shift them . there just electric valve body control and line pressure and such . NOT full electric like new crap boxes .

and need better pic of pan to tell shape to verify 4l60-e or 4l80-e
 
No, they never went wireless, always cable.

What's the gvw of the truck? Door sticker..
 
According to the vin/rpo breakdown. It started it's life with a m30 4L60e. Can't tell it's a 4L80e from the side view you showed. The cable you see is for the shifter. I think 96 was the first year for the new steering column (away from the old round Saginaw unit we are all used too) which used a cable for shifting instead of the rod/linkage.

As the interchangeability goes, one could have swapped in a 4L80e to a half ton and being 2wd would have made it easy to do so.
 
ZooMad75 said:
According to the vin/rpo breakdown. It started it's life with a m30 4L60e. Can't tell it's a 4L80e from the side view you showed. The cable you see is for the shifter. I think 96 was the first year for the new steering column (away from the old round Saginaw unit we are all used too) which used a cable for shifting instead of the rod/linkage.

As the interchangeability goes, one could have swapped in a 4L80e to a half ton and being 2wd would have made it easy to do so.
Click to expand...

95 was the new column and cable shifter.
 
Way to go quick draw! We were probably all typing at the same time. Just couldn't remember when the column change happened. Thought it was the same year as the Vortec and OBD2, but I'm off by a year.
 
sweetk30 said:
95 up use cable to shift them . there just electric valve body control and line pressure and such . NOT full electric like new crap boxes .

and need better pic of pan to tell shape to verify 4l60-e or 4l80-e
Click to expand...

I will admit only having a brief moment under the truck to identify what I was looking at, so I didn't get decent pictures. I'm not very familiar with the 4L80E architecture, and I didn't have this diagram with me at the time.

stock-transmission-pans.png


But what I noted was that the bell housing was integrated instead of bolting on, the case was noticeably larger than my 700R4, it did not have the round servo cover on the passenger side like mine does, and that it had the elongated pan shape instead of the nearly square pan. Sounds like a 4L80 to me. :dunno:
 
beags86 said:
Back to the OP. Get a pic of the pan.
Click to expand...

I should have known that was coming. :doah:

It's not my truck, but I should be able to get another picture of it eventually. :dunno:


beags86 said:
No, they never went wireless, always cable.

What's the gvw of the truck? Door sticker..
Click to expand...

Honestly, I didn't even think about shifting, I saw the cable heading up toward the engine region and thought about the throttle body, that's the part that didn't make sense to me. I guess I should have looked at it for more than 30 seconds. :doah:


VIN says GVWR is between 6k and 7k pounds.
 
campfire said:
Came across an interesting thing today, a 4L80 installed on a C1500, driving a standard 10-bolt. I've seen 4L60 trucks upgraded to 9.5" rear axles under various designations (like "heavy half"), but I haven't met a truck with a heavy tranny driving a 10-bolt. It seems a little backwards to me. :dunno:
Click to expand...


Just a few notes, a heavy half was sold when emissions were coming out and trucks under 6,000 gvrw had to have cats. Trucks over 6100 gvrw were exempt from cats and emissions.
Heavy half's typically had more leaves out back and heavier shocks. But reports have been conflicting on how they were really optioned. I have heard some trucks were exactly the same, just a sticker and a title change.
1979-gmc-sierra-classic-heavy-half-low-mileage-original-4.JPG

GMT400-
The 9.5 ring 14 bolt you speak of was sold as a light duty 2500. You could buy those with 4L80E. I had one.
 
beags86 said:
Just a few notes, a heavy half was sold when emissions were coming out and trucks under 6,000 gvrw had to have cats. Trucks over 6100 gvrw were exempt from cats and emissions.
Heavy half's typically had more leaves out back and heavier shocks. But reports have been conflicting on how they were really optioned. I have heard some trucks were exactly the same, just a sticker and a title change.
View attachment 218400

GMT400-
The 9.5 ring 14 bolt you speak of was sold as a light duty 2500. You could buy those with 4L80E. I had one.
Click to expand...

The water seems to be murky here. My brother's K1500 has a 9.5" 14bsf in the rear (and a 4L60 up front). 6 lug, of course.
 
beags86 said:
You could buy those with 4L80E. I had one.
Click to expand...

campfire said:
The water seems to be murky here. My brother's K1500 has a 9.5" 14bsf in the rear (and a 4L60 up front). 6 lug, of course.
Click to expand...

Key thing is could. I have never seen another one myself, only seen a 6 lugger 2500 with a 4l60E.
The reason for this is my grandfather bought the truck brand new and ordered it with a the 80 trans for pulling farm implements. Hell maybe it was the only one ever built like that. I don't know.
He also had ordered it with cab clearance lights. Personally i have never seen that on a another light duty 2500 either.
 
beags86 said:
Key thing is could. I have never seen another one myself, only seen a 6 lugger 2500 with a 4l60E.
The reason for this is my grandfather bought the truck brand new and ordered it with a the 80 trans for pulling farm implements. Hell maybe it was the only one ever built like that. I don't know.
He also had ordered it with cab clearance lights. Personally i have never seen that on a another light duty 2500 either.
Click to expand...

Yeah, the many possible "could" options is why I felt like asking about it. I haven't encountered this combination, but it looks like Gus has.

The odd part is my buddy bought this truck at 80k miles and was not informed of the 4L80. So he has assumed it is factory (why would someone have replaced/upgraded a tranny on a sub-80k mile truck and not have touted it as a selling point?).

I don't think we'll ever know, but with that RPO sheet it does look swapped in. :dunno:
 
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