The 4.88 mega thread!!

Do not enter anything in the gear selection window in hypertech. Leave it blank. @JerryTaco figured that out IIRC

 

So for the Hypertech, JUST do the tire size, not the gear ratio. There is a box that shows final drive ratio and you want that to be at or near 1.0xxx. Again, do NOT enter the old or new gear ration, just tire sizes in inches only.. That will yield the best results. I compared my speedo with 3 different GPS speedometers and it is dead on.


As for the lights and 4wd issues.... The installer could have either a) screwed up the front diff 4x4 actuator - which can happen . or b) maybe did not reconnect said actuator. Really only two reasons why you'd have those lights on and the 4x4 issues.

 

Ok, got it. Can you let me know why to NOT enter in gearing? 3.91 / 4.88? And thanks for the insight on the lights and 4WD issues. Do you know, by chance, if the transfer case uses a chain when engaging 4WD, or is it a gear mesh?

 

I believe the transfer case itself is chain driven but the acuation/diff engagement happens at the diff if I recall correctly.

As for the ratio vs. tire size, I wish I had an answer for you. Ultimately, however you do it, you want that final drive ratio to be what I stated in my previous reply. Tire size was how I landed there so that's what I stuck with. It was a process of trial and error for me, so it took a few tries to get it right

 

It’s because our speedo uses the ABS system at the wheels to calculate speed. It only uses tire size as a variable.

So if you had just gotten a regear, you wouldn’t have needed to recalibrate your speedometer.

 

Ah ha! Got it. Which incidentally helps me to troubleshoot the ABS/DSC issue. More and more it seems like I have a busted/inoperable ABS sensor(s) after the shop did some work. Wouldn't that explain both the ABS/DSC and the Hypertech non-functioning problem? The Hypertech unit could be working properly, but if the ABS system is bad, then the Calibration is probably not receiving the correct information?

 

who did your work for the regear? hopefully they fix what they broke. I'd think the broken abs connection would be the cause of your other problems - still only mod the tire diameter input and not the gear ratio.

 

This is the one and only negative review so far i can find on 4.88 upgrade. Mine are sitting in garage waiting to send off to rem

 

Sending mine out soon they have been sitting on my work bench for a month and its killing me!

 

Who are you having do your install? I not sure yet but looking at Unitrax or Mobile gear.

 

Getting mine installed this week.

 

Im from socal i only found two shops. Im thinking about tri county gear but they want 1300$ plus labor to drop diff he couldnt give me an exact tome but said 2 hour min so 1600$ or so and 4 full days he said

 

4 days seems a long time. Seems a little high on install from what i have heard. I am going to research a couple place's before deciding , i want it done right one time from someone that has done Tacoma gears. Seems like 2 days is the going time to get them done.

 

Yep - but I think his issues are installer related and not poor performance from Nitro or the decision to go 4.88's. Hopefully the installer will fix their error(s) and all will be good.

On a side note - installers shops I have talked with here will not use any owner provided parts, including gears or master kits, for installs - they require all parts to be provided by them = $$$. Something for those thinking of regearing to consider before they buy gears for install.

 

Yup. My shop is doing it in 1 day. $1200 OTD i supply the parts

 

I bought the 4.88 Nitro Diffs and supplied to my installer - SWAT Customs in Fremont, CA. They specialize in Toys and Jeeps. 2 Days, $1,100 price matched a different shop in San Mateo.

From what I've learned in the forums, it seems most likely that a something broke in the ABS system, which is contributing to both the ABS/DSC lights and also the non-operable Hypertech.

I have a new issue that's related to 4WD error too. Here's the story ... background is that this is my 1st 4WD, so I have to ask lots of questions and rely on what I can learn from others. 1) There was a big deal made about the break in process for the new Nitro Diffs. Something that could be avoided with REM polishing, but for me, the break in seemed fine. 100 miles, stop and start traffic is good, take a break every 20-30 mins to let it all cool down. After that, drive normal until 500 miles with NO towing. After 500, change the fluid and you're all set. Bets to avoid towing until after 1,000 miles. 2) To me, that all assumed RWD only but I'm thinking, what about the Front Diff too? Doesn't that need a break in? So I call the shop and ask, Hey - Ok to run around town in 4WD so that I'm also breaking in the Front Diff? He Says Sure, but don't take tight corners and not on the freeway. Cool. So that's what I do. 3) Now I'm getting an error saying "2WD - 4WD Mode Change Failure". Damn! 4) No I researched a few hours and learned all about transfer cases, AWD vs. Part time 4WD, no 3rd differential in PT 4WD that allows for front/rear slip, etc. Bottom line is that you AVOID driving 4WD on pavement. Ugh - I didn't know which is why I asked. SOme lessons I learn the hard way, but again - I asked and was told incorrectly. Now he's starting to say No, I never said that. Fck.
I'm guessing I messed something up in the transfer case, broke the connector chain or something, I really have no idea. Other than 4WD no longer work son my brand new TRD OR and that sucks.

Question now will be if the shop that gave me the bad advice decides to fix or hangs me out to dry. If I go back to the dealership, I have no idea if they're going to say 'No Warranty Coverage' due to the 4.88 Diffs, suspension changes, cut cross members, etc. If it turns out to be a couple hundred bucks to fix, no big deal - I'll chock it up to me being an idiot and the cost of learning. If we're getting into $1k+, then I'm not playing nice anymore.

Thoughts, comments, suggestions, guidance, welcome. As long as it's productive - please no "dude you should have known better". Lol. Yeah Yeah, I know this - now. We all do stupid Sh*t and learn. Here's my sign. Ha.

Cheers - Happy new year. Hopefully 2018 will the year of bad ass off roading and gettin' stuck and unstuck, IN 4WD!!

 

@CooleyOne

FWIW, I doubt you broke your Tcase. It is not the weakest link in your drivetrain. Take a look at some rockcrawling videos and compare that to whatever driveline bind you caused driving on dry pavement. What you did was not good, but unlikely to be causing a catastrophic failure. You would mostly have caused some minor tire scrub, not a broken Tcase. I'd look into 4WD actuator and ABS modules. If you have an auto, I would not be surprised if a lack of ABS would prevent 4WD from engaging. Time to get the truck on a lift with a good mechanic to look things over.

 

Is it the best time to change out needle bearing with ECGS when doing gear change or does that come into play when changing gears? I am not having any issue's with it yet but i hate to have to do it later when this might be the best time.

 

I am doing it for a precautionary measure. Plus they are right up in there when doing the front gears. My shop is including it for free in the gear swap so I said why not.

 

You get your gears polished yet?