Leveling the cab

[72Mountaineer]

Are the rear cab mounts supposed to be flexible? I'm in the process of mocking up stuff, and noticed there are uneven gaps between the running board and the bottom of the cab at the rear mounts. Do you just get the sides even and tighten up the bolts where the bushings are? The assembly manual gives a dimension of 3/4" between the frame and cab floor, mine will be closer to 1"plus in order keep the gap between the cab and running board close from front to back. By the way, its a '53 3100.

[MARTINSR]

The rear mounts are like a spring shackle and I have to imagine would sag quite a bit if the rubbers were shot in that shackle.

Brian

[72Mountaineer]

The rubber bushings are new. Should they be greased? So you're saying that they should move, or rotate, as a shackle.

[dsraven]

if the rubbers are new then look for something bent or attached wrong possibly. just because you assemble it like you took it apart doesn't mean it was right when you started. haha.
default to the assembly manual dimensions. if it is not right then look for the cause. out of adjustment or just sagged/bent from years of service. it doesn't matter which as long as you get it right in the end. I have heard of some guys modifying a newer style rubber mount like a hockey puck. that would take some time though as well as not be stock if that is what you are trying for. the cab basically sits on the front cab mount like metal on metal correct? the rear is that spring shackle affair? the rad support also sits on a rubber bushing set correct? just saying that if you don't get the dimension right then the whole thing is going to be a bugger to get the body set up because the inner fenders attach to the cab and the rad support. hood gaps will be hard to achieve as well.

[vintovka]

Mine is on a k10 chassis . I finally gave up on the archaic shackles and went with pads made of synthetic decking between frame and cab. 3" washers above and a 1" square tubing across cab bottom seems to work well.

[dsraven]

could you use a urethane mount with the steel dowel inside to prevent compressing too much? it may transmit less vibration and noise than a more stiff mount.just not sure how much movement the stock style has in comparison. wouldn't want to stress the body and cause cracking.

[mr48chev]

Here is the factory assembly manual

I'd say pretty much all stock frame and suspension leave the shackles as they work as the engineers designed. Boxed frame or partially boxed frame with an independent front end you could get away with some mount tabs on the side of the frame and some suitable body mounts.

[vintovka]

Originally Posted by dsraven

could you use a urethane mount with the steel dowel inside to prevent compressing too much? it may transmit less vibration and noise than a more stiff mount.just not sure how much movement the stock style has in comparison. wouldn't want to stress the body and cause cracking.

The synthetic decking material (choicedek) sees
to act like urethane in damping and ride qualities. It won't degrade or swell. Not sure about the dowel but a half inch grade 8 thru bolt seems to work and hasn't loosened any. my spacers are 3 layers for a total of 3". My front cab mounts are on recycled HD padded machine mounts on L mounts.

[Jemezcrusher]

I put corner mounts on my 47 cab which was originally a center rear mount. I measured several different trucks and all were right at 1" from bottom of cab to the top of the frame rail. Guess it does not matter much of all the sheet metal lines up

[dsraven]

it doesn't really matter what you do as long as you end up with that frame to cab dimension. if you want to keep it by the numbers then use the stock stuff for sure.
they didn't have urethane in the main stream back then like it is now or they may have used plastic for the mounts in the first place.

[Haasman]

I would add never to use any petroleum based lubes on rubber. Only use silicone. Grease etc will make the rubber degrade over time.

Had a friend who rebuilt a suspension and lubed all the rubber with axel grease. About 8 months later he had to do it all again as the rubber pieces split and failed.

[mr48chev]

It shouldn't need any lube unless it squeaks or acts like it is binding up.

Other than that read post 11 a couple of times over before doing any lubing. I replaced a lot of oil soaked rubber bushings during the years I was doing front end work daily.

[vintovka]

I have used 2" urethane blocks as risers for my bed so it aligns properly with the cab. . They have been in service for nearly 20 years despite weather from 120 down to zero, oil grease, deer and mice. They are "as new" despite heavy loads and other abuse. Now Painting and re using them again. Stuff is bullet-proof (literally). Choicedeck synthetic decking is a close second in durability. The decking can be cut or stacked to form spacers almost as good as urethane and much cheaper. It also has a very low coefficient of friction negating the need for lube.

[my56chevytruck]

Like others that have already posted, look for any misalignment or bent components, and never grease rubber, it will most definitely break down over time and grease will hold onto any dirt/dust and can lead to a noisey ride thereafter.