4.56 Gear Install

[Hawaiian Brokechanic]

I decided it was time to swap gears up to 4.56's.  My Silverado is lifted 15" on 37" tires with stock 3.42 gears.  I did a few mods squeeze a few more horse power and torque, but after towing my travel trailer for a few months I realized it's time for an upgrade.   These are 4.56 Nitro Gears from Summit Racing... I will be installing these myself this weekend. 

[dieselfan1]

Subscribed

Stepping up to 38's from 37's.

I know I should do this too.

 

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[WSFD6107]

On my wish list as well. I'm on 35's with 3.42's, and my trans downshifts at the slightest hill on the highways.

[Frankielozano214]

Also subscribing to this thread, I don’t do no towing but I have 37s.

[mitchely03]

Gonna do it yourself? Very interested,  because I would def buy some 4.11s if i can install my self.

[Hawaiian Brokechanic]

16 hours ago, mitchely03 said:

Gonna do it yourself? Very interested,  because I would def buy some 4.11s if i can install my self.

I've done all the work on my Silverado from the simple engine mods to the suspension lift.  The gear swap is the largest project by far that I've undertaken.  I'm like one of  many true do it yourselfers that are on this forum... Knowledge is power and its saves me $$$.  I will post picks here shortly.  Just a quick note:  Gear Swap is not so easy like these YouTube Videos make it out to be...  If you are an experienced Mechanic or have ton's of life experience wrenching autos, then you'll know the work arounds. If you're like me, it's more on the (intermediate)  life experience side of the spectrum.   I don't have the latest and greatest gadgets to make the install easy, but I was able to get the disassembly done.  I will put together a short YouTube video highlighting the project...

Edited March 20, 2021 by Kailua Knight
Bad Grammar...lol

[Hawaiian Brokechanic]

[dieselfan1]

I'll be paying someone for this job.
Good for you to have the skills for a job like this.
I may have the skills but I don't have the balls to go in that deep

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[Blk2015gmc]

You'll absolutely love them. I have 37's and threw 4.56's in as soon as I could. I can spin the tires no problem. 

[dieselfan1]

Kailua Knight,

Did you get it put back together?

 

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[Hawaiian Brokechanic]

On 3/24/2021 at 7:43 AM, dieselfan1 said:

Kailua Knight,

Did you get it put back together?

 

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Yes I did....and it wasn't easy.  I ran into a few obstacles with the install.  I got the rear diff done over the weekend and worked on the front over the course of 2 days after I got off of work.  I am putting a non-instructional video just highlight a few things.  There are so many Youtube videos out there with step by step instructions, but they don't show and tell you the difficulties you'll encounter during the install.  If you're not mechanically inclined, take it to a shop.  

[Hawaiian Brokechanic]

Disassembling the rear diff was pretty straight forward.  It was challenging by myself, but I got it done...

[Hawaiian Brokechanic]

The issues I ran into was trying to install the races without damaging the carrier housing.  I had Macgyver a race installer and this is what I came up with....and it worked!

 

[Hawaiian Brokechanic]

Final assembly was also challenging... It took me three tries to set the gear pattern to where it was acceptable.  That step entailed assembling, disassembling carrier, pinion shaft and shimming.   Pinion pre-load was also a pain, the yoke just didn't slip on.  These steps were repeated for the front diff.

[Hawaiian Brokechanic]

Hello All,  just a quick update... Just passed the 500 mile break in period and so far so good.  I will tow my trailer (7000lbs) next week and I will update y'all on how the truck did with the new gears.  I didn't smoke the tires yet and I may never...lol, but I did notice better gas mileage and acceleration.  So I have attached a link to the YouTube video I put together documenting the install.  DISCLAIMER:  The video is not an instructional video that shows the step by step instructions.  But feel free to ask me questions and I'll try to answer them  I wasn't able to video me setting the gear patterns and pinion pre-load on both differentials, but rest assured I did set those to spec.  If you're thinking of doing this yourself, be sure you have extra bearings just in case.  This is a can do D.I.Y. project...just don't rush the install.  With that said, good luck on your projects!