Are shims still needed after cab mount replacement?

[Big Chip]

If your original mounts were completely blown out maybe the cab was sitting on metal. In that case then yes your poly mounts would feel better.

Maybe you missed the part about my mounts not being all blown out?

 

[waterpirate]

I was at work and missed the party, lol The porta power was used to correct a tweaked frame horn. It reared its ugly head when we tried to fit the hood. Took measurements and yup, its tweaked. My point was kinda like, I was the second owner of this truck and always thought it had been worked. This do over brought that to light, big time. For those who have rigs with multiple owners, you just never know. It looks good when you take it apart, swap some parts, replace some others, and now nothing fits. Regardless of the reasons, this $hit takes time and patience and is not for the short tempered or faint of heart. The process and procedures are all the same. Every rig is not.
Eric

 

[shiftpro]

What did you do with the porta power? It was required even with the bolts loose?

Normally, we would leave the radiator support loose, just sitting on the mounts. The LH fender would go on, sitting on the cab (on the designated* shim pack) and then drive the vertical rear bolt.

We would then open the door, drive the horizontal top rear bolt (tight) against it's designated* shim pack and then loosen the vertical bolt a bit, so it was no longer torqued down.

While all this is going on another guy would be driving the 7 (I think there were 7) nose bolts in the front of the fender to the radiator support.

After the LH rear guy was done he would then take a big stick and pry rearward on the dog leg portion of the fender, pulling it back towards a fixture to set the gap to the door, while the guy in the pit drove the bottom anchor bolt tight against his designated* shim pack.

We would leave everything loose assembled like this until after the hood was installed and fit (you should be able to slide the radiator support crosscar by hand, squaring the opening so the hood gaps are even). Then all remaining bolts got torqued down.

All this happened in about 45 seconds. All day. Every day.

While I was foreman on the line in this area I watched them do about 900,000 trucks (or 1.8 million fenders) over a six year period.

K

That's amazing really.. what a 'dance'.

 

[shiftpro]

Maybe you missed the part about my mounts not being all blown out?

What is your real issue here?

 

[ak4life]

Not necessarily.

Shims were used on the assembly line to help with fitment (trends).

Shims were also specified by engineering to vary the compression of mounts in specific locations, to increase the stiffness and help with certain vibrations or noise. Normal people would probably never notice the difference, but the N&V engineers (with their "dog ears" and "sandpaper a$$es" seemed to be able to tell the difference.



I've had the experience of removing front end sheet metal on my Chevelle a couple times, and I always record and re-install the shim packs exactly like they came off.

It has never worked. I always have to fine tune the fitment a little bit, using the original setup as a starting point.

K

Well thank you for the insight, i assume that they arent on every vehicle then from factory ? I mean they only added to a vehicle that seemed to need them ? im asking not being rude....lol. thank you.

 

[Keith Seymore]

Well thank you for the insight, i assume that they arent on every vehicle then from factory ? I mean they only added to a vehicle that seemed to need them ? im asking not being rude....lol. thank you.

Yes - correct.

If it was a "permanent" addition it would be added via an engineering change, and shown in the assembly manual.

Anything less permanent would be added via a temporary deviation, and would have a specific time limit.

K

 

[ak4life]

Yes - correct.

If it was a "permanent" addition it would be added via an engineering change, and shown in the assembly manual.

Anything less permanent would be added via a temporary deviation, and would have a specific time limit.

K

Thank you for clarifying

 

[Randy and Easton]

We’ll see, left them for now. When we get steering back in, we will tackle the front body panel alignment issues. Will be interesting to see how all that shakes out. Good thing is that its a 15 year olds restoration and it only has to look good enough at say 60 mph.. so I think if we are in the ballpark he will be happy! I will keep y’all updated

Randy and E

 

[SquareRoot]

Poly cab mounts are known to be haywagony although last time they are needed.

BS. I have them on mine. Better than the used rubber

 

[SquareRoot]

I used the term "designated" shim pack because we would not fit each individual truck. There simply wasn't time.

We built to "trends", that is, we got it pretty close and then ran every truck exactly that way, whether it needed it or not, until the repair foreman out back would call and demand we make another adjustment.

What we used to do for fender shims is tape a packet together, like 3 shims, and we would run those all day whether the truck we were currently building needed it or not.

Eventually the final repair supervisor would call back and say something encouraging, like "SEYMORE!! YOU IDIOT!! WTH ARE YOU THINKING?!?! ALL THESE FENDERS ARE RUNNING HIGH!! ARE YOU EVEN LOOKING AT THESE TRUCKS?!? TAKE A SHIM OUT BEFORE I COME BACK THERE AND SHOW YOU HOW TO DO THIS!!" I can just imagine the spittle flying into the phone mouthpiece.

So we would start running a new shim pack, like 2 shims, until he called again with his latest observation.

Basically it was to address "macro trends". You had about 45 seconds to complete the truck in front of you and move to the next one; that's not enough time to fit and re-fit each individual truck.

There was a repair station at the end of my area. There was also a short moving repair line (two, actually) at the end of final line. If they could fix them there while on the move then they would; otherwise it would be out to a stationary repair stall in "heavy repair" for the really bad ones.

I should add that most of the repairs did not consist of removing the bolt or adding/deleting shims. Often the repair consisted of bending, twisting or hammering while the line was moving.

K

AKA....the 20/80 phenomenon.

 

[AuroraGirl]

BS. I have them on mine. Better than the used rubber

Haywagony doesnt mean that they are bad or shouldnt be done. I was discussing the material in general and its something to be said about consistent matching unworn mounts compared to unmatched worn tired old rubber ones lol. New rubber ones vs new rubber poly id be curious to see, but im also someone who would say poly myself as I dont expect much a ride quality in a truck especially front leaf springs kind, so I would just prefer not have to do the job ever again if I replaced them

 

[AuroraGirl]

AKA....the 20/80 phenomenon.

You must be registered for see images attach

My first thought googling it was pacman!

But its meant to be a pie graph
About statistical relationships seemingly. but My thought was pacman!

 

[SquareRoot]

You must be registered for see images attach

My first thought googling it was pacman!

But its meant to be a pie graph
About statistical relationships seemingly. but My thought was pacman!

20% of a population cause 80% of the problems. It's fascinating how accurate it is. It's a lot like our population right now. It's just that the 20% make a LOT of noise so they tend to get their way despite being ignorant, snot nosed donkey dicks!