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Starting the 8-lug swap

Old 02-16-2016, 05:19 PM
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Almost done. Just have to get shock mounts welded.



Almost done.

New shoes
Old 02-16-2016, 08:55 PM
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Wow those H2 tires are a huge jump in surface area. Let us know how the ride/handling changes.
Old 02-16-2016, 10:07 PM
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For starters I can say the shifts are brutal now. I had been driving around doing high pressure shifts for a while on the old suspension...I guess the old trackbars were bending and eating the shift lol.

The big difference is the Hummer wheel is pretty much a 17x9 low offset (it's called 17x8.5 but it's really a 8.75") wheel so using very wide tires shouldn't cause handling issues. As it stands the fit is perfect.

Last edited by Suburbazine; 02-16-2016 at 11:48 PM.
Old 02-16-2016, 10:08 PM
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Is that your RCF. If so, the pcm has been cracked and can be tuned.

http://www.clublexus.com/forums/cl-vendor-products-for-is-f/811160-tuning-tech-fs-lexus-is-tuner.html


My ISF with cheap wheels and snow tires.
Starting the 8-lug swap-xqkvska.jpg


No more from me on this. I can't wait to see the dually setup!
Old 02-16-2016, 11:36 PM
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Yes, the 2016 RC-F is the other money pit haha. Good to hear on the tuning, put it up on the dyno last week and watched the PCM choke the life out of the engine one step at a time. Still fast, but clearly has a large sum of power being held back.

Old 02-24-2016, 11:27 PM
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Finally finished up, got the shock mounts welded on and the axle shaft replaced. The truck is much more confident when tackling corners compared the narrower original axle. Now I just need to find some very beefy shocks to keep the body from flopping around on bumps and takeoff. The panhard bar just ever so barely clears the diff cover...I think an aftermarket cover is out of the question now.


Old 02-24-2016, 11:35 PM
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What did you have to change for the shock mounts?

I though the hummer 14 bolt rear end was a bolt in deal?
Old 02-24-2016, 11:43 PM
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Originally Posted by 1FastBrick
What did you have to change for the shock mounts?

I though the hummer 14 bolt rear end was a bolt in deal?
Everything but the shock mounts are the same. The H2 uses offset, angled shocks, whereas the Tahoe uses vertical shocks. So on an H2 axle the shock mounts are mounted 6" outboard (near the brake), angled 25 degrees to put the top of the shock on the inside of the frame rail. Theoretically I could get spherical shock ends, but after much searching I couldn't find anything of the sort that wasn't for prerunners with very long travel.

Here's the comparison:

Old 02-24-2016, 11:47 PM
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Interesting... Thanks for sharing!

I have never worked on one of those swaps so I didn't know.
Old 02-25-2016, 02:23 AM
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Originally Posted by 1FastBrick
Interesting... Thanks for sharing!

I have never worked on one of those swaps so I didn't know.
yeah, this was my first swap. Took me nearly 2 months to complete

I wound up having to change plans a few times along the way, there are similar swaps on the internet but none of them specified exactly what was needed (or it was incorrect). I spent 2 weeks trying to figure out how to measure for the correct conversion u-joint, then an old fellow who's been building driveshafts for decades said "forget everything you read, get this part" and solved my woes in a single look lol.

Then I had to swap out all the trackbars and panhard bar (Spohn is a fantastic performance upgrade over the stock parts, fyi).

I wound up paying someone else to do the welding and swapping of the bent axle shaft (too messy for my taste lol). I got a new axle from Nitro-Gear ($200 vs $800 for GM axle, better quality axle to boot LOL), shouldn't be able to bend the flange on this one. Apparently Nitro-Gear sources most of their stuff from American Axle and Manufacturing, which makes their North American market stuff in-house (USA made! hooray!), instead of using Chinese tooling.

Last edited by Suburbazine; 02-25-2016 at 02:29 AM.

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