Which do you prefer rubber or poly cab bushings and why?

[HeavyHauler]

I am getting ready to replace my cab,bed and front radiator mount bushings in my 1968 Chevy C10.

I am wondering if I should go polyurethane or rubber like the factory used. The poly of course sounds good in that I would not need to replace them again but I am wondering how much that would change the ride quality of the truck or is that more a function of quality shocks?

Which did you install and could you give me your input as it is appreciated and thanks!

[jimijam00]

Rubber is quieter and absorbs more NVH. I recommend that.

[Accelo]

I see no advantage to polyurethane as a cab support.
There are no bed supports, it is bolted directly to the frame.
I just replace my cab supports. The replacements were a harder durometer than the stock mounts.
I had to add almost 3/8" of spacing to get the crease on the bed and cab to match up.
If I had to do it over again, I would have made new hardware and reused the rubber.
90 percent of the aftermarket parts require reworking to be serviceable. The mounts are not an exception. I would be interested in others experiences with cab mounts.
I am unsure how vendors get by with this but I guess we have few options in most cases. Or there are nice parts and most don't know where to get them.
I certainly would have paid more and not had to spend the day machining spacers. I think we give away out time without thinking about it. Off my box!
Pictured is a worn, and obviously sightly collapsed rubber next to a new POS replacement.

[Richard]

I used rubber mounts myself from Classic Heartbeat, a forum vender. There have been several mentions of LMC cab mounts not being correct on the forum, myself included. I would avoid them for this if possible. 1/4" rubber spacers are readily available to shim the bed if needed.

[special-K]

Rubber. Why, because that is what has worked so well to cushion the body since it was new. Just imagine how much better brand new ones will e compared to the 50 year old ones you are replacing. Like putting new tires on or motor mounts, etc.

I don't know why anyone would want poly body cushions. They are called cushions for a reason. Something you wouldn't want to be stiff, for comfort or for being the part engineered to absorb stresses that could damage other parts of the truck. The energy not absorbed there can find another place to impact. Suspension cushions? Sure, if you want to firm up the suspension for better handling at the expense of losing some comfort.

People make the mistake of comparing worn deteriorated 50 year old rubber cushions to brand new poly cushions without considering the improvement brand new rubber cushions will bring

[CUSTOM/10]

I use rubber for all the body mounts and all urethane for the suspension.

[Palf70Step]

Rubber for body/cab, poly for suspension. I have seen quite a few vehicles with poly body/cab mounts that the sheet metal cracked after a while because of the lack of flex.

[sick472]

There's no good reason to go poly UNLESS you are trying to build a very responsive truck with respect to racing. There's nothing wrong with the poly's on a serious street vehicle given some added beef at the mount locations, but it will be a bit more of a rough ride. The difference would be minimal to the average driver, but if you're really in tune with the truck...a difference will be noticed in how it handles and how it rides. You give up some for the other.

I tend to lean towards Palf's suggestion on my builds...poly on the suspension for tight handling and longevity, and rubber for the body mounts for ride.

[Dieselwrencher]

I went poly on my 72 because I didn't want the cab flexing as much. I have a lot of tight tolerances on it. Then I boxed the frame so I guess it is a moot point. I've done a lot of things with that truck and had it on severe inclines and declines/sides of steep hills with a gooseneck and heavy loads and the body doesn't squeak and the floor or cab hasn't cracked. I'm doing a 72 K20 now and I went with rubber but it is a stockish type build.

[MikeB]

I'm with DieselWrencher.

I installed some brand new GM cab bushings under my 69 C10 sometime around 1990. By the mid-90s they were already shot and causing a door alignment problem. (Maybe they were very old NOS!)

Ended up installing name-brand poly bushings (Prothane or Energy Suspension). More than 25 years later, they still look like new. As far as ride and vibration goes, I didn't notice a difference. But, hey, it's a truck with STEEL A-arm bushings, not a Cadillac!

[Accelo]

But, hey, it's a truck with STEEL A-arm bushings, not a Cadillac!

So true. That said I do wish they had at least made them the same height. Even the steel washers were 1/2 the thickness of the stock ones.

So I wrote the manufacture and complained. They said they made them thinner to make the truck faster.

That's a marketing joke. You can tell because I got an answer!

[toolboxchev]

Originally Posted by Palf70Step

Rubber for body/cab, poly for suspension. I have seen quite a few vehicles with poly body/cab mounts that the sheet metal cracked after a while because of the lack of flex.

That is EYE OPENING! I have a set of poly bushings if anyone wants them!