20" rims on a 1500HD does service msg apply

[krayniac]

does the service message about the 20" rims apply to the 1500HD crewcab? what is different between the 1500 and the 1500HD?

[USA1Fan]

The frame length, box size (the 1500 CC only has a 5'8" box, vs. the 6'5" box on the 1500HD), suspension, etc. The message concerning 20's and crew cabs only applies to the regular 1500's. There's at least one other topic around here somewhere that goes into a bit more detail about the why's, but if you have the HD you should be good to go.

[krayniac]

The frame length, box size (the 1500 CC only has a 5'8" box, vs. the 6'5" box on the 1500HD), suspension, etc.  The message concerning 20's and crew cabs only applies to the regular 1500's.  There's at least one other topic around here somewhere that goes into a bit more detail about the why's, but if you have the HD you should be good to go.

 

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USA1 thanks. i have called three dealerships, two say i have to take them off, they claim the frames are the same , just the axles and a few options are diff. the other stated i was fine but couldn't tell me the diff. between the two. again thanks

[v-tx]

The frame length, box size (the 1500 CC only has a 5'8" box, vs. the 6'5" box on the 1500HD), suspension, etc.  The message concerning 20's and crew cabs only applies to the regular 1500's.  There's at least one other topic around here somewhere that goes into a bit more detail about the why's, but if you have the HD you should be good to go.

 

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USA1 thanks. i have called three dealerships, two say i have to take them off, they claim the frames are the same , just the axles and a few options are diff. the other stated i was fine but couldn't tell me the diff. between the two. again thanks

 

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My point exactly, the frames are the same, length is the same just added two full doors on the rear and shortened the box. WHY can't we put 20" wheels on these crew cabs. GMC support is a joke and don't know a thing about what's going on. Hopefully someone will finally find out.

[silverado3500]

The frames on a 1500cc, and a 1500 hd are NOT the same, The 1500hd is essentially a crew cab 2500, and uses a heavier-duty suspension, stronger frame, and stronger gvwr. The 1500hd also runs only a 6.0/4l80e transmission, where the 1500cc runs with a 4l65e transmission and largest engine being the 5.3, and in a limited number of trucks the 6.0

 

Hope this helps.

 

[jeffbf89]

The frames on a 1500cc, and a 1500 hd are NOT the same,  The 1500hd is essentially a crew cab 2500, and uses a heavier-duty suspension, stronger frame, and stronger gvwr.  The 1500hd also runs only a 6.0/4l80e transmission, where the 1500cc runs with a 4l65e transmission and largest engine being the 5.3, and in a limited number of trucks the 6.0

 

Hope this helps.

 

 

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Is the 4L65E and option on the 1500CC?

[USA1Fan]

The 1500hd cc has a longer frame than the 1500cc (similar cabs, longer bed on the hd). The non-hd seems to be the same length as the ext cab, but from what I've read the frames are actually a bit different, including the way the rear suspension mounts up to the frame. Supposedly that's also the weak spot on the (current?) 1500cc's that caused the whole conundrum re: 20" wheels.

[MS3DALE]

The 1500hd cc has a longer frame than the 1500cc (similar cabs, longer bed on the hd).  The non-hd seems to be the same length as the ext cab, but from what I've read the frames are actually a bit different, including the way the rear suspension mounts up to the frame.  Supposedly that's also the weak spot on the (current?) 1500cc's that caused the whole conundrum re: 20" wheels.

 

 

 

 

 

Yep,Thats exactly right,The non HD 1500 crew-cabs are the same wheelbase as an ext.cab short-bed truck (143.5in) but the frames are different in the rear suspension mount and thats where the weak link is.

[v-tx]

MS3DALE

 

After all the calls to GM and they can't/won't tell me exactly what component would fail with the 20" tires on the 1500 and all I had to do is read it here. Interesting that its the rear supension and not the front that fails. I kept looking and looking for the diference in the crew cab and extended cab and could not find any difference in the way it was set up...now I know why. Or buy my truck back and give me the HD model. Well that won't work either, the bulletin says no 20" on any crew cab so I guess I'll have to settle for the extended cab plus $5,000 or so in difference.

I'm going to visit the GMC dealer and take a look at the differance and I'm still going to persue this matter with GM and demand a fix and/or recall in this matter.