The 4.88 mega thread!!

anyone have an issue of hitting fuel cutoff during a red line shift?

was merging on to the interstate and needed to get up to speed. was in d, 2nd gear, ended up flooring it and when the truck got to 6k i hit what feels like a fuel cutoff and it fell flat on its face. then upshifted to 3rd and off i went.

stock 04B04 TSB tune and the gears. Never experienced this before so i'm wondering if the gears are confusing the ecu.

 

Negative. I’m not sure where your shift points are but I can’t red line truck unless I put it in S mode.

 

it pulled right to 6k and then fuel cutoff then upshift.

 

I’ve had what felt like fuel cut off as stock, stock with 33s, OVtune with 33s, OVtune with 33s and 4.88s and finally OVtune with 35s and 4.88s. Mine is only first 1st to 2nd though

 

I might have to hope and see if ovtune 1.05 resolves that or see if they can adjust a custom tune for it.

 

I know he is aware of the issue but hasn't figured a fix as the problem only happens on a few trucks and is intermittent on those trucks.

 

At the dealer right now with that same issue. There’s a transmission update due to what they are calling a “stumble” during wide open throttle

 

occurring at redline? or the stumble where under 2k it feels like little bumps or hiccups?

 

Stumble meaning when you give it a fair amount of throttle nothing will happen. Then it’ll downshift and hit the fuel cut out and then find the correct gear.

 

So I have been following many topics on TW and finally decided to sign up and join the conversation.
In regards to the 4.88 thread I saved up the $$$ and pulled the trigger on putting new gears in.
My 2017 4wd off-road package Tacoma has 22000 miles on it. I will be having my 3rd set of 4.88’s put in the rear diff to try and resolve a whine between 55mph and 70mph ( more pronounced on deceleration ). Of course the manufacturers says it the installer and the installer says it the manufacturer). No need to throw anyone under the bus so I don’t want to name names. HAS ANYONE ELSE HAD THIS PROBLEM?
I have followed break in procedure 100% maybe even more than required.

 

the only issue is a whine? honestly that's just the nature of the beast. 4.88's are aggressive and are cut for strength, not quietness. I have the ever so light whine at 65 cruising. Doesn't bother me one bit. Plus, the tacoma isn't exactly a heavily sound deadened vehicle. I'd say leave them alone and enjoy the truck.

 

So you think it’s common. Have you heard of others with similar whine. The first set of 4.88’s whined but not as bad as the second set. If I would have know the second set was going to be worse I would have kept the first set in. However I have put 4.10’s and 4.56’s in other trucks (T100 and F250) and had no whine at all.

So has anyone else had a whine with 4.88’s. Is it just what they do or should I find a new installer. I will try had take a video for you to hear.

 

well i can't say what you're hearing or if it's normal or not. i do know that the bigger the ring and depending on how they are cut, whine just comes with the territory. my s550 GT mustang had gear whine just from swapping in a few poly bushings with factory 3.55's.

bummer the second set is louder. did they notice any strange wear patterns on the gears? all new bushings and races?

as an fyi, my manual 18 pro had worse whine then my 4.88's in this truck. (no i don't have the pro anymore - traded it in for the 17 OR and much happier).

i'd say let the shop try again and take their time but most manufacturers don't have a guarantee on whine, just failure.

oh and make sure they're putting in enough gear oil. i noticed mine was a little low after the break in. i filled it up with over 4qts (when it started coming out the fill hole) with Mobil 1 synthetic 75w90 and the whine was lessened.

 

I’ve been trying to upload a video, but can’t figure it out.

Just surprised no one else has commented if they have had similar whine after regear. It may be next week before I get new gears,but I will update my findings.

 

It’s time to go to another shop. There shouldn’t be a whine!

 

Upload it to youtube and then link here. Ive found this is the easiest way.

 

They are a reputable shop and all they do is diffs (recommended by gear manufacturer). I figure if they are willing to put one more set in (on their dime and time), what do I have to loose. I may not have been clear, but the next set will be the third. Most likely next week so I will keep you updated.

Also want to be clear 4.88’s are much better than stock. I will be going to 285/70/17’s once I have the $$.

 

good article

https://www.onallcylinders.com/2014...k-guide-diagnosing-common-ring-pinion-issues/

notice they bring up the various gear sets and how they're cut and that higher numerical gears tend to make more noise.

 

Have you had the diff whine TSB performed yet? It's just cab dampeners for the most part but it was specofspecif for the whine on decel.

 

I had my gears sent out to be REM polished prior to install and no whine or any noise.I dont think i heard anyone with a whine if they had REM polishing done first.