Gear Change 9.5" 12 bolt

hemipowered22z · January 12, 2015

I talked to Yukon a few days ago. They are working on a new ring and pinion for the new rear end. They did not have a time frame but was told it should be by the end of the year. It will make the gear change much more affordable once they release it.

CAtaylor · January 12, 2015

I talked to Yukon a few days ago. They are working on a new ring and pinion for the new rear end. They did not have a time frame but was told it should be by the end of the year. It will make the gear change much more affordable once they release it.

It doesn't look like they are in too much of a hurry, a guy was running their prototype in march of last year. They must have run into issues.

hemipowered22z · January 30, 2015

Figures. I dont mind waiting as long as it is worth the wait and all the bugs are worked out. they have a pretty good reputation so i expect the product will be right whenever it finally is released.

joeglock40 · May 4, 2015

Any updates? ??

Kerrslight · May 6, 2015

I have 3.08 as well and really looking to re-gear at some point. Gets pretty decent mileage, but downshifts all over the place. Drives me crazy! Hoping Yukon comes out with something around the same time I get my 33's!

On another note, those of you with the Diablo tuners, can you do a flash for a regear? Just want clarification on that.

Mike1220 · May 8, 2015

I have 3.08 as well and really looking to re-gear at some point. Gets pretty decent mileage, but downshifts all over the place. Drives me crazy! Hoping Yukon comes out with something around the same time I get my 33's!

On another note, those of you with the Diablo tuners, can you do a flash for a regear? Just want clarification on that.

Yes with a Diablo Intune I-1000 you can reprogram for new gears, tires, and more.

joeglock40 · May 8, 2015

I sent email to yukon n the sales manager is slowly talking to me so we'll see what he says. ..ill keep yall up to date on it

44Bogger · May 14, 2015

Want to share my experience to maybe help others. Long story but some might want to know.

I very recently bought a 2014 1500 Z71 with 3.08 gears and did not like the way it was constantly searching for gears. I regularly pull a 2000 lb trailer. First time I hooked up to it the shifting was worse and I could not get the truck to stay in 6th gear at 70 mph. No the tow/haul button was not engaged. 2000 lbs is not really "towing". I could put the transmission shifter in M and shift to 6th but it would go straight back to 5th when shifting to drive.

So I started googling and found this thread amongst a few others but this one has the most information. Yes I could have had them order a max-tow truck but I think I still came out ahead because I got such a good deal on my 2014. I researched and researched. Called East Coast Gear a few times too. But ended up ordering from Randy's. Randy's happened to have a front and rear set of Yukon 3.73 gears that were "used" for a very low price. Yes I put used gears in a new truck.

The salesman assured me that the gears had not been installed but for some reason they could not be sold as new. So I took a chance and got em. He also assured me I didn't need a new rear carrier. This truck will rarely leave the highway but I will occasionally need 4wd. The Gov-Loc will suit me fine. The salesman told me I needed a new front carrier and master install kit for it but said I only needed a mini kit for the rear. This was incorrect. The mechanic broke some of the ring gear bolts on the rear due to what he described as massive amounts of fresh loc-tite. So I had to order ring gear bolts that would have been in the master kit. Well the same day the ring gear bolts came in they slapped the carrier back in to find out there weren't enough shims in the mini kit. None to be found locally. Had to order a shim kit. I had printed out the how-to instructions from East Coast Gear and told him the factory carrier might not fit with the new gears. It did just fine. No I didn't need a diff cover spacer. Those have nothing to do with new gears. They are required for aftermarket carriers as apparently they are "meatier". And no machining of the brake caliper.

As stated earlier you must buy a new pinion yoke. I chose the Yukon strap type that uses the factory u-joint. Also you can't use the pinion seal in the install kit. But Randy's gives you a part number for a aftermarket seal. That seal is designed as a rear main seal. Not a pinion seal. The OEM seal is what you want. Of course the factory seal will be ruined during install. Just go to the dealership and order a new one. Mine was $47 after tax.

My mechanic was very thorough in the installation. He checked the pre-load several times with an inch-lb torque wrench. He got the truck back together on a Friday at 5:15. I was there and elated. Thought I was going to get my truck back for the weekend. .......wrong. I knew it would need break-in but he wanted to do it himself. The next Monday he let the truck run in idle for a couple hours on the rack in gear. Then he drove it 20 miles and let cool down 3 times. After all that he let me have it. Told me to come back in 500-1000 miles and he would change the diff fluid to factory specified oil. I think he put some generic 85w in it at install. No gear whine whatsoever. Charged $1,100 for the install. I purchased all the parts myself.

After getting the truck back it drove GREAT!!! Transmission goes into 6th at 45mph and stays there. RPM's are at 1970 at 70 MPH in 6th. With the 3.08's the RPM's were at over 2100 at 70 mph in 5th gear.

Now about the speedometer. Before I bought anything I asked the service manager at the dealership if he would get a VCI number for me and correct my speedometer after the change. He said they would try. This should be possible as 3.73's were a factory option. After I got my truck back from mechanic I went to dealership.....had to make an appointment for the following week. When that day came I had the truck there. But was a waste. Technician simply told me it couldn't be done. I didn't push the issue as I will be using them for any warranty work that might be needed. Ordered a Hypertech that day and programmed two days later......which was last night.

Speedometer is now correct and I don't know if it is in my head but the truck seems to be shifting even better than before programming.

Truck stay's in V4 mode almost the whole time in city now. As other's have reported better mileage in town as well. I'll report back actual mileage after a few tanks.

Edited May 14, 2015 by 44Bogger

fataslp · May 14, 2015

Can you post a full list of part numbers?

44Bogger · May 14, 2015

ZK GM8.25IFS-B Front install kit

YC G26018131 Front carrier

YG GM8.25-373R Front gears

ZK GM9.5-B - USA Standard Gear Rear install kit

YG GM9.5-373 - Yukon Gear Ring & Pinion Sets Rear gears

YY GM19256396 - Yukon Gear & Axle Rear yoke

And the factory rear pinion seal. I think that is it.

If you want to put a locker or limited-slip in it you can, you will just have to "dent" out your factory diff cover or buy the spacer from East Coast Gears.

Mike1220 · May 14, 2015

Anybody have any updates on a direct fit 4.10 gear swap?

joeglock40 · May 14, 2015

Nothin direct yet from word i got, but the conversion cost approx the same if your changing to a better locker anyway , i wouldn't trust the g80 with 4.10s if your getting good traction from a launch anyway, they don't have a great rep

07Softail · May 14, 2015

ZK GM8.25IFS-B Front install kit

YC G26018131 Front carrier

YG GM8.25-373R Front gears

ZK GM9.5-B - USA Standard Gear Rear install kit

YG GM9.5-373 - Yukon Gear Ring & Pinion Sets Rear gears

YY GM19256396 - Yukon Gear & Axle Rear yoke

And the factory rear pinion seal. I think that is it.

If you want to put a locker or limited-slip in it you can, you will just have to "dent" out your factory diff cover or buy the spacer from East Coast Gears.

So the rear Ring and Pinion set is the same part number from the old gear sets all the way back to late 97-current.

RT

SouthernSilveradoGuy85 · May 14, 2015

Does anybody know if anybody has made 3.73s for the 9.5" 12 bolt yet? Last I saw there was only 3.08, 3.42 and then 4.10. I believe there's a 3.73 for the front diff since I don't think that changed, just curious more on the rear 9.5" 12 bolt diff.