Installing GMT900 rear Cab mounts in a GMT400

MIHELA said:

Those look nice, where would one acquire those?

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Believe it or not.. the shocks are made by Monroe... I don't have a part number right off hand... when I get into work , I'll look it up.. not sure if you can get just the plates....

any thoughts onto whether or not these mounts would improve the ride of a suburban?

Any idea how many body mounts are under the 2 door tahoes? Will be trying this soon, will post results.

jfletch said:

Any idea how many body mounts are under the 2 door tahoes? Will be trying this soon, will post results.

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http://www.lmctruck.com/icatalog/csd/full.aspx?Page=10
says 8 body to frame mounts & 2 rad support to frame mounts

Hi everyone, saw this was stickied, wanted to ask if anyone here has done this swap on their GMT400 truck. And if you were able to directly swap the entire bushing and mounting hardware from the GMT900 to the GMT400 platform without any modifications.

Edit: This is from Aloicious's write up in 2011 on this swap, it's probably what I am looking for:

I had some rust that was preventing the new mount from sliding in very well, and the paint on the mount itself was also pretty thick and preventing it from seating, with a small grinding tool, like a dremel, I cleaned the hole in the frame, and removed some of the paint from the mount itself, it was still not going in well, so I clearanced the hole just a tiny bit, it’s likely you will need to do the same, just be aware not to take too much material off, you want the mount to fit snugly in the hole. Here you can see the upper mount fitting through the frame hole correctly:



My guess is the hole was actually just smaller than the intended holes on GMT900 frames.

The mounts that I want to put in are from S&B Filters, they're silicone rubber. They're supposed to have the ride quality of brand new OEM rubber or better, and last the lifetime of the vehicle. I don't want to go with Daystar/Energy Suspension/Prothane and have the truck rattle like a SOB and the rubber options from Dorman and LMC have longevity problems from what I've read on the forums. These S&B mounts are not cheap, but I love one and done solutions that work and work for a long time.

S&B let me know the frame holes on our GMT400s are smaller than the later vehicles and that they advised not to alter the frame holes to make their bushings fit. Looks like they were spot on. Not sure what I'll do in the interim. The mounts aren't 100% shot yet but I'm taking the cab off soon.

mars2878 said:

any thoughts onto whether or not these mounts would improve the ride of a suburban?

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On my 99' suburban I replaced the body mounts that are about under the front doors w/ the GMT900 rear cab mounts and I think it made the ride worse.

My body mounts look ok, but after 270k I'm assuming they are shot. In an effort to get back some ride quality I rebuilt the front suspension which helped a bit. I then put in the GMT900 mounts and it still feels like a canoe down a wood pile over railroad tracks and pot holes.

My plan is to try GMT900 Suburban/Escalade mounts this summer. I'm pretty sure they will fit and happy to be the guinea pig here.

coomer said:

The mounts that I want to put in are from S&B Filters, they're silicone rubber. They're supposed to have the ride quality of brand new OEM rubber or better, and last the lifetime of the vehicle. I don't want to go with Daystar/Energy Suspension/Prothane and have the truck rattle like a SOB and the rubber options from Dorman and LMC have longevity problems from what I've read on the forums. These S&B mounts are not cheap, but I love one and done solutions that work and work for a long time.

S&B let me know the frame holes on our GMT400s are smaller than the later vehicles and that they advised not to alter the frame holes to make their bushings fit. Looks like they were spot on. Not sure what I'll do in the interim. The mounts aren't 100% shot yet but I'm taking the cab off soon.

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I've been intrigued by the S&B silicone mounts since the Ford super duty owners really seem to like them. I did see on a forum somewhere (cannot find it now) that on the Chevys they are actually a little harsher than stock. If you go down that road, please let us know how it goes!

The more I read on this forum, the more parts I end up buying. I am going to give this a try on my truck.

Aloicious said:

Hey guys, so I just did a write up about installing GMT900 rear cab mounts onto my '96 c1500 to help with the ride quality. There was another guy on here that I remember mentioning the swap which got me interested in it, but I can't for the life of me find that thread anymore...so whoever you were, thanks for the suggestion...

its apparently a fairly common swap among the GMT800 diesel guys, but thought y'all might be interested in it, since I haven't heard of many GMT400's that have done it. here's my write up on it:
http://www.gmtruckcentral.com/articles/bodymounts.html

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Link Doen't work

ForeverFalcon40 said:

Link Doen't work

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Still does not work