Contemplating The Purchase of a C5500

[USSkoval]

So here's the deal. My boss is going to unload an '05 C5500 (Ex U-Haul) with the 8.1L and an automatic. It's currently slated for auction. It has around 160k on it, iirc. I'm thinking about offering to buy it before it goes to auction. These things have still been going down in value, correct? I know what he paid for it several years ago, and we've never used the truck for the purpose it was purchased, so it has just basically sat and moved from time to time.

I mostly just want it for the engine and trans, plus several parts that I can use on my van. Then potentially sell off the rest of the parts over time. There's the thought of building a ramp truck out of it, but that would cost me money, rather than the potential of saving me money on a powertrain swap. That and I've always wanted a crew cab ramp truck, not a single cab.

Y'all think I would be better off just letting it go and looking for a complete 8.1 pullout? Or is having the complete donor vehicle a better option?

Here's the rig in question:

 

[Wes Harden]

that rig has the correct fan belt high mount ac for a square body swap. maybe convert it to fuel return system for the swap.

 

[USSkoval]

that rig has the correct fan belt high mount ac for a square body swap. maybe convert it to fuel return system for the swap.

Yeah, the AC is up top.

I'm also wondering what's involved in swapping the Allison into a 4x4, but I haven't read up on that yet.

 

[muddybuddy]

Divorce tcase w/ 2wd trans and give you flexibility with driveshaft lengths

 

[Wes Harden]

Might need a body lift. Avalanche and suburban didn't get Alisons because the don't fit in the trans tunnel

 

[USSkoval]

Might need a body lift. Avalanche and suburban didn't get Alisons because the don't fit in the trans tunnel

Right, and neither did the vans. That was one thought I had... put the combo into my '00 Van, but I think that would require a lot of dog house fabrication.

 

[ZooMad75]

G-vans got 8.1’s for a couple of years. Would have been longer but somebody got a finger pinched on the assembly line and the UAW threw a fit and were partly responsible for the demise of the 8.1 in the vans.

The vans used a 4L80e with the 8.1 and not the ally. One big point to note on the medium duty accessory brackets. While the ac compressor is up high and all on one belt, the p/s pump is a much larger ZF unit and would require notching the frame on a squarebody to make it fit. In other words it’s Huuuuuge!


As far as buying the 5500 for a powertrain source I’d look for another rig. The 8.1 would be fine but not much carry’s over for a swap. The Allison would be a costly mess to convert to 4wd not to mention require a big body lift or floor surgery to make it fit. Selling other parts off the 5500 may not be lucrative as there isn’t a ton of demand for them that I know of.

 

[fourwheelerjeff]

I have one: https://ck5.com/forums/threads/2005-gmc-c5500.348751/
I bought it to put a truck camper on the front, a buggy behind it and pull my Jeep. But it is just something else to insure and register. so 1 day I want to keep it and 1 day I want to sell it.

 

[kennyw]

Yeah, the AC is up top.

I'm also wondering what's involved in swapping the Allison into a 4x4, but I haven't read up on that yet.

It already has the GM bellhousing and there are 4x4 Allision output shafts in the Duramax trucks in the wrecking yards. Although, you can probably just buy a good 4x4 GM Allision transmission for less than a rebuild to swap the output shaft.

 

[sweetk30]

It already has the GM bellhousing and there are 4x4 Allision output shafts in the Duramax trucks in the wrecking yards. Although, you can probably just buy a good 4x4 GM Allision transmission for less than a rebuild to swap the output shaft.

Motor yes . . Trans in these is a 2000 model and SAE bellhousing . They get a gm to SAE adapter in the mix . I have one in my shop from a 8.1 c5500 truck . They also got a tail shaft parking brake on them . Share a bunch with the 1000 model yes . And from what i have been told you can swap just the back over from 2wd to 4wd . But best to do trans sitting up on its bellhousing .

 

[kennyw]

Motor yes . . Trans in these is a 2000 model and SAE bellhousing . They get a gm to SAE adapter in the mix . I have one in my shop from a 8.1 c5500 truck . They also got a tail shaft parking brake on them . Share a bunch with the 1000 model yes . And from what i have been told you can swap just the back over from 2wd to 4wd . But best to do trans sitting up on its bellhousing .

If it has a 2000 model, then no chance that is fitting in a firewall tunnel without chopping... I'm in the process of rounding up SAE 3 adapters to put a GM 1000 behind a 5.9L Cummins. It drives me nuts how many adapters came from the factory to do such a simple job.

 

[USSkoval]

I have never paid too much attention to which transmissions are in our 4500's and 5500's (this is the only 8.1 rig and I have never crawled under it) but the trans sure seems like a smaller unit than what's in our 6500's, which have some variation of the 2000 series.

The trans does have a Park position though.

 

[USSkoval]

So I'll ask this as well:

What's the ballpark, going rate of a complete and good running 8.1 with harness and accessories? If it's anything like what people are getting for a complete 6.0 pull-out, I think I could probably do pretty ok on the deal if I end up only using the engine and some of the other parts, then letting the rest go cheap.

 

[USSkoval]

Well, I don't know if I paid too much or not, but I bought the thing. I paid a decent amount less than my boss did though.

I would like to use the 8.1 in my '78 C20 Burb, when I also finally do a 4x4 conversion. I've got an SM465 for it, along with an aluminum top and shifter, a Ranger overdrive and a pair of m1008 axles for it too.

I'd like to use the doors and tach cluster on my '00 van.

Maybe one day I'll use the frame and running gear for a '60-'66 C60 body swap and a 6V71 Detroit.

I guess I'll try to find a buyer for the Allison, or maybe sell it back to my boss for use if a trans fails in one of the other trucks.

That's my current thoughts anyway.

 

[JoshHefnerX]

Those allisons are the 5spd - sae housing?

 

[sweetk30]

Those allisons are the 5spd - sae housing?

Should be . I have one here in my shop with the gm to sae adaptor plate .

If trans has park/neutral switch on shifter shaft outside trans = 5speed .

 

[JoshHefnerX]

Was just thinking there's a company making adapters to put them on the 7.3 psd's to replace their 4spd - which is the weak link in that truck.

 

[USSkoval]

Should be . I have one here in my shop with the gm to sae adaptor plate .

If trans has park/neutral switch on shifter shaft outside trans = 5speed .

Going off of memory, I do believe that's what it is.

 

[sweetk30]

Going off of memory, I do believe that's what it is.

What i was told by a allison swap company .

 

[USSkoval]

It's larger than what I remembered, but it appears to be the same trans as what's in our other 4500/5500 trucks. 5 speeds and has a park/neutral switch on the side.