Cab mount rubber question... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72gmcshorty · 04-12-2003, 07:45 PM

I have new rubber cab mounts and was wondering if it is necessary to put some kind of shim on top of the rubber? Plus, my kit came with 2 different sized rubber pucks. Do the small ones go in the front or the back.

Southpa · 04-12-2003, 08:16 PM

Typically, those kits NEVER come with instructions. The only way I managed was to try to remember the order everything came off. Luckily, there was still something left to make sense from, not the case for most other trucks,

. Here are pictures that might help, one of the old rear mounts...

Southpa · 04-12-2003, 08:17 PM

and old front left. (before)

Southpa · 04-12-2003, 08:24 PM

(after). As you can see the new rubber looks nothing like the old so you have to use your own discretion. The main idea is to keep that cab level. If its bowed up in the middle when you are done then something is wrong. Used to have a whole whack of pictures on MSN but I believe they've dumped my photo albums.

72gmcshorty · 04-12-2003, 09:05 PM

Did you end up putting any kind of shim over top of the rubber?

Southpa · 04-13-2003, 04:44 AM

The large washers are used to allow for even weight distribution over the entire surface of the rubber. If not then the mounting surfaces (cab rails in front and cab crossmember in rear) would cut the tops and the rubbers would fail. You shouldn't have to add anything else, ie. for shimming, so long as you have the right components in place.

jay-dawg · 04-13-2003, 05:20 AM

Southpa,
Is that the slip over style cab supports that you have on there? Any positives and negatives on going that route?

Thanks,
jay

Southpa · 04-13-2003, 03:53 PM

The front supports I installed are OE and my rears are slipons. At the time my supplier didn't have the rear OEs. The OE fronts are solid 12 ga. painted steel. The rear slipons are 14 ga. satin coat (fine galvanizing). The slipons are made slightly larger to cover over the original supports but I didn't like the idea of having any rot underneath. So I cut out all the bad metal, painted rust converter on what was left and then welded in the slipons. Slipons are OK, but slightly thinner metal. Just make sure there isn't any rust underneath. I also sprayed a heavy rubber-based undercoating on everything when I was done.

I had a ton of pics on MSN up until a few days ago. I guess I overstayed my welcome. I'll have to find another web hosting site for my pics. Any ideas?

**stllookn** · 04-13-2003, 07:21 PM

The PO put slip-ons on my '67 over the old cab mounts. The moisture got inside them...why would you expect otherwise and they rusted from the inside out. I took them off and they were filled with the rusted remains of the old cab supports. I would cut the old ones off and weld those slip-on's to the cab. Just my 0.02...of course I look for any excuse to weld something. Park your truck in my driveway for too long and it is likely to get the stake pockets shaved.

Dads72 · 04-13-2003, 08:28 PM

Cab mounts.
I checked out the pictures in several vendor's catalogs to see how they should go.
After installing the side trim and discovering that it was "off - I did the mounts again with several washers in there to make everything look right.
Metal is metal. I don't think those rubber spacers know if they are up against the frame or up against a metal washer.

04-12-2003, 07:45 PM	#1
72gmcshorty Registered User Join Date: Jul 2001 Location: North Delta, British Columbia Posts: 1,344	Cab mount rubber question... I have new rubber cab mounts and was wondering if it is necessary to put some kind of shim on top of the rubber? Plus, my kit came with 2 different sized rubber pucks. Do the small ones go in the front or the back. __________________ 1992 Gmc 2wd 1972 Chevy Blazer 2wd

04-12-2003, 08:16 PM	#2
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,410	Typically, those kits NEVER come with instructions. The only way I managed was to try to remember the order everything came off. Luckily, there was still something left to make sense from, not the case for most other trucks, . Here are pictures that might help, one of the old rear mounts... Attached Images __________________ 1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first. Last edited by Southpa; 04-12-2003 at 08:27 PM.

04-12-2003, 08:17 PM	#3
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,410	and old front left. (before) Attached Images __________________ 1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first.

04-12-2003, 08:24 PM	#4
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,410	(after). As you can see the new rubber looks nothing like the old so you have to use your own discretion. The main idea is to keep that cab level. If its bowed up in the middle when you are done then something is wrong. Used to have a whole whack of pictures on MSN but I believe they've dumped my photo albums. Attached Images __________________ 1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first.

04-12-2003, 09:05 PM	#5
72gmcshorty Registered User Join Date: Jul 2001 Location: North Delta, British Columbia Posts: 1,344	Did you end up putting any kind of shim over top of the rubber? __________________ 1992 Gmc 2wd 1972 Chevy Blazer 2wd

04-13-2003, 04:44 AM	#6
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,410	The large washers are used to allow for even weight distribution over the entire surface of the rubber. If not then the mounting surfaces (cab rails in front and cab crossmember in rear) would cut the tops and the rubbers would fail. You shouldn't have to add anything else, ie. for shimming, so long as you have the right components in place. __________________ 1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first. Last edited by Southpa; 04-13-2003 at 04:47 AM.

04-13-2003, 05:20 AM	#7
jay-dawg chevelito Join Date: Jun 2001 Location: Honolulu, HI USA Posts: 1,609	Southpa, Is that the slip over style cab supports that you have on there? Any positives and negatives on going that route? Thanks, jay __________________ New deadline...when my son can drive. Aloha from Honolulu, HI

04-13-2003, 03:53 PM	#8
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,410	The front supports I installed are OE and my rears are slipons. At the time my supplier didn't have the rear OEs. The OE fronts are solid 12 ga. painted steel. The rear slipons are 14 ga. satin coat (fine galvanizing). The slipons are made slightly larger to cover over the original supports but I didn't like the idea of having any rot underneath. So I cut out all the bad metal, painted rust converter on what was left and then welded in the slipons. Slipons are OK, but slightly thinner metal. Just make sure there isn't any rust underneath. I also sprayed a heavy rubber-based undercoating on everything when I was done. I had a ton of pics on MSN up until a few days ago. I guess I overstayed my welcome. I'll have to find another web hosting site for my pics. Any ideas? Attached Images __________________ 1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first.

04-13-2003, 07:21 PM	#9
stllookn Saving 1 truck at a time! Join Date: Aug 2001 Location: Kent, WA Posts: 6,463	The PO put slip-ons on my '67 over the old cab mounts. The moisture got inside them...why would you expect otherwise and they rusted from the inside out. I took them off and they were filled with the rusted remains of the old cab supports. I would cut the old ones off and weld those slip-on's to the cab. Just my 0.02...of course I look for any excuse to weld something. Park your truck in my driveway for too long and it is likely to get the stake pockets shaved. __________________ '68 C20 Longhorn 50th Anniversary 400/TH400 '68 C20 Longhorn 50th Anniversary 468/TH400w/buckets '72 C20 Halfhorn (Longhorn w/o cab and front clip) '69 Flxible Cruiser (look up ugly in the dictionary)

04-13-2003, 08:28 PM	#10
Dads72 Registered User Join Date: Nov 2002 Posts: 427	Cab mounts. I checked out the pictures in several vendor's catalogs to see how they should go. After installing the side trim and discovering that it was "off - I did the mounts again with several washers in there to make everything look right. Metal is metal. I don't think those rubber spacers know if they are up against the frame or up against a metal washer.



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