The 4.88 mega thread!!

That's the full icon leaf pack replacement vs the 3 lead add a leaf

 

I currently have a block under my springs with airbags. I asked for deavers and they recommended the icon add a leaf. Maybe becuase the airbags?

 

I believe the diff is always passively turning and the power is applied through the t-case when 4x4 is selected.
I've been told that a few easy 4x4 trips are important for breaking in the front diff.
Something to think about is the front clamshell holds 1.6 quarts of oil vs the rear (8.75") which holds 4.2 quarts so the front clamshell will heat up allot faster given the same load.

 

I got the same setup and got the truck back today. Stopped 5 times in 45 miles going up hill a 2000' climb overall. I checked the heat with a IR gun, the hottest was 186, cooled to 130 at stops. No speed over 55 most at 45-50 mph so I could not map it at 70 mph. I tow too and live in the hills so this should be interesting. Nice to see higher RPM in 4 gear. I am running the Shift Sense Pro so working on which profile to use. The 3rd profile for more aggressive seems too much. Moved it to the 2nd profile to try tomorrow.

 

Speedometer discovery
I installed the calibration unit to adjust for tires and checked it against GPS and it is real close.
Did the 4.88 and expected to make another adjustment but not necessary. Speedometer is still accurate sooo I think the speedometer is using the ABS sensor system and not the transmission. That is good as this will feed many systems and now my real error factor is just the 1" tire size change.

 

Have you checked to see if the odometer it's still accurate as well?

 

Yes odometer is accurate too.

 

Hey guys, lots of good info I just read here. I'm running 33's on my M/T OR and was wondering if you think it's worth the change from 4.3 to 4.88. From what I'm reading, it sounds like a pretty damn good upgrade but most of you guys have the 3.9 A/T. I'm waiting to hear back from a shop on a quote but I know it's gonna be expensive in Canada so I'm not sure if its worth it. I've added a decent amount of weight with a bumper, winch as well as a couple hundred pounds in the back at all times. I know it would help and I want to do it but it just seems like quite a small difference vs the cost.

 

4.88 first 100 miles
My setup- 265/75r16 k2 tires so one size larger at 31.65" I also have the Sense Shift Pro v2 with 3 shifting profiles.

Off the line the torque improvement is very big. It blast through the first 2 gears as you come up on speed quickly. I now feel like I can match most cars now if I want.

Most people do the gear mod for big tires, 33"- 35 tires. The result brings the truck back to normal.

I did this for performance or improved torque applied to the ground. There is no change in engine HP or the torque that the engine puts out.

To get more torque you need to do two things. Get the engine to run at a higher RPM before shifting and change the diff gear which I did. The stock shift pattern causes you to shift around 2200 rpms most of the time unless you put your foot in it. Running RPM is around 1200 -1800 in any gear. This is well below the power curve that provides max torque at 4600 RPM.

With the gear change here are some examples: at 40MPH old -1660rpm, new -2072rpm That 412 rpm makes a big difference even if the gears are the same.

Now the Diff gear change gives an additional 20%.

I think this formula is correct:
Our truck has 265ft lbs at 4600 rpm so with the stock gear 3.909 that provides 1036 ft lbs of torque applied to the wheel in 4th gear which is 1:1 ratio. With a 4.88 gear it goes up to 1293 ft lbs. Multiply this by 3.6 (1st gear) and you get 4654 ft lbs applied to the wheels to push the 5,000 vehicle.

With a new shift map I now get to use the available HP. Now shifting takes place between 3000 and 4000 rpm. The difference now is before when you step on the gas to accelerate say in 4th gear, you downshift to 3rd. Now I don't downshift rather I have the power and additional torque to accelerate staying in 4th and as speed goes up shift to 5th.

 

I am planning on buying gears soon and tried to contact couple of vendors here but havent heard anything back from them. Where did you guys purchase your gears from and for how much? Thanks!

 

I got mine from http://www.rogue-offroad.com/product-p/gptaco2016-4.88-8.75.htm
$1325
Spoke to the owner, they do installation too. Very helpfull.

 

Thanks! I will do that. I am planning on taking everything apart myself and then taking the pumpkins to Rearend Specialties in San Jose and get the gears installed

 

Can't go wrong with RES.....

 

Word of caution, check your orders when it comes in. I received my box and scheduled my appointment. This morning when I was about to take my truck to the shop, I noticed that the front gears were missing. Stupid me thought both front and rear gears were in the same Nitro box. Sure enough, it was split into two deliveries: one through Fedex and the other through USPS. Well, I found the USPS box but unfortunately it didn’t have the front set, just another install set without the gears. I’ve contacted the Owner and he’s looking into the snafu. Sucks since the gear shop blocked the next two days for my install....

 

well that sucks! been reading and following - seems like one or more purchasing options have been less than reliable with orders, parts and shipping. Worries me about who I place order with. Care to share initials or more on who did not get it right the first time?

 

I can tell you that without question, SDHQ is a solid vendor when it comes to shipping. They take a lot of pride in their shipping department and one tour of the shop makes that very clear. Nevertheless, I do know that you likely wouldn't have issues with them.

 

probably a good idea to call any vendor being considered to review parts needed, shipping and who to call if something does not arrive as ordered. I'd like to think every vendor on TW list is 100% committed to customer service and competitive pricing.

 

Agreed. I hate the idea of doing everything over email and will always call any customer service line for any given vendor. If they are difficult to get ahold of, or not helpful, usually a deal killer for me.

 

Well, not the vendors fault on this one. Apparently Nitro had a back order on the front gears and didn’t notify him. Luckily he had a set in the store and is sending it out today. FYI, he mentioned that the front gears are in very limited supply so if you haven’t ordered yet, hurry up!

 

I'm heavily thinking about having some 4.88 gears installed in my truck. As my truck is my daily and only means of transportation. How long does it usually take for a GOOD shop to install gears in the 3rd gen Tacoma's? Is it a task that I can drop my truck off in the morning and drive back home the same night for example?