Author Topic: Cab bushing replacement  (Read 1960 times)

Offline 502Silverado

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Cab bushing replacement
« on: December 04, 2018, 11:16:58 PM »
I have an 87 2wd short bed that I have been working on.  I've repaired the core support and passenger side inner fender that was damaged from a leaking battery.  I removed the passenger side fender, hood and core support at one point but left the driver's side fender in place to have a 'square corner' to start from when putting everything back together.  I replaced the core support bushings and now the holes don't line up with the core support.  I have bought new cab bushings from a popular mail order company that has parts for our trucks (I'm assuming I can't mention the name for some reason).  The bushings need to be trimmed down so they will mate up with each other which I also had to do with the core support bushings. I'm ready to install the new bushings on the cab and would like to know if I can leave the driver's side fender attached to the cab and if the truck needs to be absolutely level when I go to replace the bushings.  The truck is parked in my garage and the floor is obviously sloped for water drainage.
I appreciate the help.  I know there has been threads on cab replacement and have read a few but I can't recall these issues being addressed.  Just for clarity, the core support is in place but not bolted down, both fenders and the hood are in place but not connected to the core support.

Offline 75gmck25

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  • 1975 GMC K25 Camper Special, 350/TH350/NP203
Re: Cab bushing replacement
« Reply #1 on: December 05, 2018, 08:44:40 AM »
I replaced cab bushings on my '75 several years ago, and the polyurethene bushing kit I purchased didn't require any trimming or adjustments to get it to work.  I greased the poly bushings in an effort to reduce squeaking, but it still made noise until they settled in.

The front two bushings under the radiator area were hard to reach and I had to buy a new type socket that was sized to fit, but that was the only issue.  IIRC, what I needed was a socket with a section around the neck that allowed you to turn it with a box end wrench, since there wasn't enough clearance for a standard socket and wrench to fit over the bolt.

I was parked in my driveway, and didn't really worry about leveling.  The frame is stiff enough that it should make the cab match its level point as you install the bushings.

Bruce

Online VileZambonie

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Re: Cab bushing replacement
« Reply #2 on: December 05, 2018, 04:07:53 PM »
You do not trim the bushings. I posted how to correct this in another thread recently. Try searching
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 502Silverado

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Re: Cab bushing replacement
« Reply #3 on: December 05, 2018, 06:37:58 PM »
Thanks for the replies.  I'm using rubber bushings as opposed to polyurethane.  I did search before posting this as well as before a previous post regarding the core support bushings not fitting together but got no replies.  If you could point me in the right direction I would appreciate it.

Online VileZambonie

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Re: Cab bushing replacement
« Reply #4 on: December 07, 2018, 04:29:14 AM »
Quick reply here,

Loosen all of the cab mount bolts and jack up the cab enough to allow for movement. Shim or space appropriately to allow for proper panel positioning. Align doors, fenders, core support and ensure all bolts are tight. Carefully lower the cab into position on its mounts and tighten them gradually, add shims as needed.
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 502Silverado

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Re: Cab bushing replacement
« Reply #5 on: December 07, 2018, 09:03:12 AM »
Thank you for the instructions. I was going to jack up the cab and do one side then the next.  Makes more sense your way.   What about trimming the cab bushings?  They do not fit inside one another like they are supposed to. I’ve tried everything from dish soap to silicone to get them to fit and they just don’t.