Space between cab bottom and frame? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

AirSpeed · 02-20-2010, 01:28 AM

I am repainting my short/fleetside 72 GMC 4 wheel drive and it looks like the cab has sunk in the rear. I looked at the body mounts and they look like they have been recently replaced. If I raise the rear of the cab up to make the space between the bed and the rear of the cab parallel the body lines will be above the lines on the bed by about an inch. I can see a definite dip in the middle of the truck, it looks like it is bent down in the middle, The frame is perfectly straight. Am I going to have to raise the front of the bed and rear of the cab to get it straight? Has anyone ran into an issue like this before?
If one of you has a similar truck and wouldnt mind, could you measure the distance between the frame and the bottom of the cab where the rear body mount sits? I think this will give me a good starting point to figuring this out. Thanks for any suggestion! Aaron

Diablo de la Noche · 02-20-2010, 03:04 AM

I just took the rubber mounts out of my 67 yesterday. Mine were pretty much shot, and the new ones haven't come in yet. But, the old ones seem to be different sizes, maybe because they were rotten. Try swapping the front and back and see how that works. It is really easy. WD-40 and a breaker bar might not be necessary. The bolts are different diameters, but the sleeves may not be. Not a big help, but might work!

Leviticus · 02-20-2010, 03:05 AM

PO may have put the wrong body mount bushings/mounts in or they are missing or worn. Does anything look obviously bent? Also check the bed is sitting on the frame all the way back and the PO didn't put some type of bushing, spacer or ? in between the bed and frame.

May get lucky and its just the bed playin tricks on your eyes...hopefully.

Good luck man.

OARNGESI · 02-20-2010, 03:47 AM

Was there any rush in that area of the cab

PanelDeland · 02-20-2010, 07:57 AM

Also check to be sure you have the correct body mounts.There are some differences.I know 2wd is different from 4 wd.The mounts are the same but core support mounts are different 67-68 is different from 69-72.I have seen people have alighnment issues from the wrong core mounts.It's just a thought but could cause the problem.

**chevy71super** · 02-20-2010, 10:42 AM

Can you take a picture of what you are describing? I can then measure the area you are referring to. Doug

AirSpeed · 02-20-2010, 10:57 AM

Quote:

Originally Posted by chevy71super

Can you take a picture of what you are describing? I can then measure the area you are referring to. Doug

I will take a pic afterwhile, it is the rear cab mount at the underside rear corner of cab, if you look you can see a 2 inch diameter rubber bushing that the cab rests on, the measurement I am looking for is between the frame and the cab where this bushing rests, the length of the rubber itself. Thankyou!

**Stocker** · 02-20-2010, 02:26 PM

My rubber mounts are just a couple years old, cab & bed appear to be perfectly straight. Driver's side gap measures 1 1/2", passenger side is 1 5/8".

AirSpeed · 02-20-2010, 06:46 PM

Quote:

Originally Posted by Stocker

My rubber mounts are just a couple years old, cab & bed appear to be perfectly straight. Driver's side gap measures 1 1/2", passenger side is 1 5/8".

That's odd, mine measure 2 1/2", I wonder why there's such a difference? Is yours a 4x4? Did you measure the rear mounts?
Thanks!

**Stocker** · 02-20-2010, 09:12 PM

Yup, mine is a 4x4 (K20 in my sig) and yes, I measured the frame - to - body gap at the rear corners of the cab next to the cab mount bushings, just like you said.

Very odd there is an inch difference from my truck to yours.

EDIT: This really had me wondering, so I went back out & measured again. My measurements were correct from the frame to the body. However, re-reading your posts, I realized that's not what you were after. You want the height of the bushing (installed), from the mounting bracket (on the frame) to the bottom of the body.

Mine measures 2 1/2", same as yours. Sorry for the confusion.

With that out of the way, the question remains -- why does your truck look like it's sagging in the middle? Is it somehow possible that the front of your cab is sitting too high above the frame?

Shyguy · 02-20-2010, 09:17 PM

4 wheel drive and 3/4 ton trucks have thicker rubber bushing in the back than 1/2 ton trucks.

The 1/2 ton bushings may have been put in instead of the thicker bushings.

Danny

AirSpeed · 02-21-2010, 10:51 AM

I looked at the front bushings and they look correct as well. From Stocker's measurements it sounds like I have the correct mounts, there is no rust anywhere near the cab mounts and everything looks solid and parallel with the frame, the frame looks straight as well. If all else fails I guess I can put some spacers between the front bed mounts and the frame.

**chevy71super** · 02-21-2010, 01:17 PM

Here are a few pictures. Hopefully these will help. Doug

Leviticus · 02-21-2010, 02:10 PM

Well I am at a loss for what you have going on, but I have to say you have one clean truck underneath lol.

dazza · 03-02-2010, 04:45 AM

any luck AirSpeed?

02-20-2010, 01:28 AM	#1
AirSpeed Registered User Join Date: Jul 2007 Location: Fall River California Posts: 2,026	Space between cab bottom and frame? I am repainting my short/fleetside 72 GMC 4 wheel drive and it looks like the cab has sunk in the rear. I looked at the body mounts and they look like they have been recently replaced. If I raise the rear of the cab up to make the space between the bed and the rear of the cab parallel the body lines will be above the lines on the bed by about an inch. I can see a definite dip in the middle of the truck, it looks like it is bent down in the middle, The frame is perfectly straight. Am I going to have to raise the front of the bed and rear of the cab to get it straight? Has anyone ran into an issue like this before? If one of you has a similar truck and wouldnt mind, could you measure the distance between the frame and the bottom of the cab where the rear body mount sits? I think this will give me a good starting point to figuring this out. Thanks for any suggestion! Aaron

02-20-2010, 03:04 AM	#2
Diablo de la Noche Registered User Join Date: Jul 2009 Location: El Paso, Texas Posts: 142	Re: Space between cab bottom and frame? I just took the rubber mounts out of my 67 yesterday. Mine were pretty much shot, and the new ones haven't come in yet. But, the old ones seem to be different sizes, maybe because they were rotten. Try swapping the front and back and see how that works. It is really easy. WD-40 and a breaker bar might not be necessary. The bolts are different diameters, but the sleeves may not be. Not a big help, but might work! __________________ www.coolmoodart.com

02-20-2010, 03:05 AM	#3
Leviticus Shake and Bake! Join Date: Feb 2010 Location: Central Coast, CA Posts: 609	Re: Space between cab bottom and frame? PO may have put the wrong body mount bushings/mounts in or they are missing or worn. Does anything look obviously bent? Also check the bed is sitting on the frame all the way back and the PO didn't put some type of bushing, spacer or ? in between the bed and frame. May get lucky and its just the bed playin tricks on your eyes...hopefully. Good luck man. __________________ "All tyranny needs to gain a foothold is for people of good conscience to remain silent." Thomas Jefferson "You are remembered for the rules you break." General Douglas MacArthur "Support Our Troops And The NRA"

02-20-2010, 03:47 AM	#4
OARNGESI Registered User Join Date: Sep 2008 Location: CASA GRANDE AZ Posts: 4,276	Re: Space between cab bottom and frame? Was there any rush in that area of the cab __________________ 70 SWB STEPSIDE 70 BLAZER 09 challenger

02-20-2010, 07:57 AM	#5
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Re: Space between cab bottom and frame? Also check to be sure you have the correct body mounts.There are some differences.I know 2wd is different from 4 wd.The mounts are the same but core support mounts are different 67-68 is different from 69-72.I have seen people have alighnment issues from the wrong core mounts.It's just a thought but could cause the problem. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

02-20-2010, 10:42 AM	#6
chevy71super Registered User Join Date: Jan 2002 Location: So Cal Posts: 658	Re: Space between cab bottom and frame? Can you take a picture of what you are describing? I can then measure the area you are referring to. Doug __________________ 71 Cheyenne Super 4X4 SB 72 Cheyenne Super 4X4 SB 72 Cheyenne 4X4 SB

02-20-2010, 02:26 PM	#8
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,689	Re: Space between cab bottom and frame? My rubber mounts are just a couple years old, cab & bed appear to be perfectly straight. Driver's side gap measures 1 1/2", passenger side is 1 5/8". __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

02-20-2010, 09:12 PM	#10
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,689	Re: Space between cab bottom and frame? Yup, mine is a 4x4 (K20 in my sig) and yes, I measured the frame - to - body gap at the rear corners of the cab next to the cab mount bushings, just like you said. Very odd there is an inch difference from my truck to yours. EDIT: This really had me wondering, so I went back out & measured again. My measurements were correct from the frame to the body. However, re-reading your posts, I realized that's not what you were after. You want the height of the bushing (installed), from the mounting bracket (on the frame) to the bottom of the body. Mine measures 2 1/2", same as yours. Sorry for the confusion. With that out of the way, the question remains -- why does your truck look like it's sagging in the middle? Is it somehow possible that the front of your cab is sitting too high above the frame? __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 02-20-2010 at 09:33 PM.

02-20-2010, 09:17 PM	#11
Shyguy Junior Member Join Date: Dec 2006 Location: Southeast Missouri Posts: 2,436	Re: Space between cab bottom and frame? 4 wheel drive and 3/4 ton trucks have thicker rubber bushing in the back than 1/2 ton trucks. The 1/2 ton bushings may have been put in instead of the thicker bushings. Danny __________________ '67 Chevy C-20 short stepper - build complete, 454/SM-465. '75 C-30 Single Cab DRW-350 small block/NP-435. '77 GMC-6500 Dump Truck, 427 Tall Deck. '92 GMC K-3500 Duallie, 454/4L80E.

02-21-2010, 10:51 AM	#12
AirSpeed Registered User Join Date: Jul 2007 Location: Fall River California Posts: 2,026	Re: Space between cab bottom and frame? I looked at the front bushings and they look correct as well. From Stocker's measurements it sounds like I have the correct mounts, there is no rust anywhere near the cab mounts and everything looks solid and parallel with the frame, the frame looks straight as well. If all else fails I guess I can put some spacers between the front bed mounts and the frame.

02-21-2010, 01:17 PM	#13
chevy71super Registered User Join Date: Jan 2002 Location: So Cal Posts: 658	Re: Space between cab bottom and frame? Here are a few pictures. Hopefully these will help. Doug __________________ 71 Cheyenne Super 4X4 SB 72 Cheyenne Super 4X4 SB 72 Cheyenne 4X4 SB

02-21-2010, 02:10 PM	#14
Leviticus Shake and Bake! Join Date: Feb 2010 Location: Central Coast, CA Posts: 609	Re: Space between cab bottom and frame? Well I am at a loss for what you have going on, but I have to say you have one clean truck underneath lol. __________________ "All tyranny needs to gain a foothold is for people of good conscience to remain silent." Thomas Jefferson "You are remembered for the rules you break." General Douglas MacArthur "Support Our Troops And The NRA"

03-02-2010, 04:45 AM	#15
dazza Registered User Join Date: Aug 2002 Location: California Posts: 971	Re: Space between cab bottom and frame? any luck AirSpeed? __________________ --------------------------------------------------------- I'm not crazy, I'm chosen, there's a difference. ---------------------------- '72 K10 SWB, 350, sm465/np205 ---- ----



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