My 3.73's were replaced with 4.56's on Thursday, 10/27 and today, I was finally able to "drive" the truck to get a feel for the new gears. First off, thanks to Wayne at diffsonly.com for GREAT pricing on Yukon gears and master install kits, and to Santa Clara Truck Wreckers for a one-day turnaround on the install. Initial break-in takes place in the first 100 miles after install so the last few days were spent driving around town, with slow speed take offs and just general grandma driving. Well today, I hit 96 miles so I decided to get on the freeway for a little road time. I was enjoying my truck so much that when I got back home from my test drive, I had put on an additional 60 miles!

Although I didn't floor it, acceleration was nice and strong and I could definitely feel the improvement over the old gears. There was no unusual noise or vibrations so I am really happy about that and I can't wait to get another few hundred miles on these gears before I really jump on it.

Thanks again to Wayne and SCTW and to Marc (msall150) for the heads up on both of them. My total out the door price for parts and labor was ~$1650.00 which is over $600 LESS than the average pricing I was finding locally. This upgrade was NOT cheap but I am so happy I finally got it done. As mods go, gear upgrades are the best and the most dramatic modification you can do to your vehicle (short of going super/turbo charged, of course), as well as the healthiest if you have oversized tires or tow.

I can't wait till the spring when I can take the boat out!

 

Congrats! I'll be glad whenever I finally get my gears done.

 

Glad it worked out! I have been enjoying the 4.56 gears as well. Did some solid hauling in the hills and the truck is much happier now. Not to mention that when offroad deer hunting in 4Lo on the steep remote logging roads, the low range ratio is retarded. It basically idle crawled up and over everything...

 

Can't go wrong with Wayne @ Diffsonly. He has the best prices on the Yukon stuff. I've been enjoying mine for a little over a year now! Nice truck too.

 

Love my 4.56s too. Sounds like you got a good price. I paid right at $1,600 total for mine. You'll really love them if you tow. I pulled my 10,000lb tractor with my truck and I was extremely impressed with how easy it was to stay at a constant 60-65mph without constant downshifting

 

1st off, nice truck!! I wouldn't mind seeing some of your mpgs after the install of your 4.56s. Those are what I'm going to be running if/whenever I re-gear. On the performance side of things how much easier does it get up and move under normal and hard accelaterion? Also, have you towed yet since the gears went in, just curious how much better driving it is with some better gears?

Thanks

 

congrats!! keep us updated on how the new gears perform!!

 

Been going to them for 15+ years, great, great, guys!

 

So over the past few days, I put another few hundred miles on them and got my foot into it a couple of times. As expected, take offs and around town driving is crazy as acceleration puts me back into my seat! But freeway driving is something I need to get used to again: At 75mph, my truck is doing about 400 more RPMs than the old 3.73s (from ~1850rpms to ~2250rpms in OD). Keep in mind that its been a LONG time since I had stock tires on my truck so this may be normal, but at those RPMs, the exhaust is louder which in turn makes it sound like the engine is working harder. But its just a few hundred RPMs more than I've been used to so there's no worry there, although MPGs may suffer a bit on long hauls. On that note, the Edge is reporting the tranny pan temps are 10* degrees cooler on average when cruising at ~75+ for extended periods. I will take 10* cooler any day!

Back in the day, I upgraded my '90 Mustang GT from 2.73s to 3.55s and my '95 Tahoe from 3.08s to 4.56's (WAY over done!) then back to 4.11's. After each gear swap, the vehicle just performed so much better and although this is the case with my F150, this is the first time I made tranny temps and towing the priority. I am very happy with this mod but I dont expect to tow till the spring. If you have ovesized tires and/or want better towing performance, this mod is a must have.

 

Mileage on the highway is still the same for me, but around town is definitely better since the tranny doesn't stick in gear to accelerate. Normal performance is so much better, definitely worth it if you tow/haul often or drive hills with oversized tires.

 

Nice truck. I'll be adding this mod to my list of things to do when I get my F-1

 

Glad u like them. I'm glad I did the swap too and I know ur gonna love the swap even more once u fully break them in.

 

Glad I found your post, I have 35's and have been thinking about 4.56 or 4.88 gears. Sounds like you are happy with the 4.56 gears did you ever wonder if you should have gone with the 4.88's instead?

 

The general consensus seems to be that 4.88's are a bit overkill for 35's. If you plan on running 37's one day you might want to consider them over 4.56's though.

 

No, 4.88's would throw my RPMs through the roof. I also know that I'm not going with a tire larger than 35". But it's you're truck and only you know what you got planned for it...