4.8 final drive
 

Autofactory and a few other brands have a 4.875 final drive. I think its a Toyota part and is about 19% reduction over the stock 4.1 ratio.

Has anyone fitted one? How is it?

I'm planning to keep my car NA and I think this will really make the car come alive. I think subjectively it will make the car feel much quicker. Objectively, it may not mean a faster lap time, but I don't really care about that..

I've got 5.1 and love it.

Got any videos for this? The only racing footage I've seen on youtube is from autofactory japan with their 5.1 racer.

Awesome.

Was it the autofactory one? Who fitted it for you? Any noise?

I am very interested too in a review...DD, track, performance, highway, anything :)

Weir Performance has am inexpensive 4.88 too fyi ...they also have a 5.29 for the brave ;)

5.1 wow I have the 4.55 and also love it exept on the highway revs are too high for cruising

whats youre crusing?

4.88 would do amazing things for an automatic.

The supra kit? goes all the way up to 5.71. IDK for daily 4.88 seems like a bit much, but it would keep me from speeding! and be good for AX

Can someone elaborate on this please?

The auto has taller gears in the tranny than the manual while both have a 4.1 final drive. So a more aggressive final drive would bring the auto more in line with the manual.

How costly is something like this start to finish having a shop do everything?

The automatic is pretty fun to begin with, but the internal gearing (in the transmission) puts it at a huge disadvantage to a manual because both have the same 4.10 rear gears from the factory. There's a reason the manual is a full second quicker and it isn't just the weight. A change to a ratio like 4.88 would give it much more favorable overall gearing on line with the manual. Ever notice that automatics in muscle cars have higher (numerically smaller) final drive ratios than manuals? That's because of the torque converter's multiplication effect. You quite literally don't want too much of a good thing. I'm making a quick guesstimate that 4.88 would be enough to wake the automatic up nicely without going overboard. Someone with easy access to gear ratios of the transmissions (they are on the forum somewhere) could be more precise.

Edit: Damnit, while I was typing that mess, the short answer got posted.

Lots of discussion here: http://www.ft86club.com/forums and here: http://www.ft86club.com/forums/showt...ad.php?t=27647

If I recall correctly from the above (and at least one other) thread labor was close to $1k. Obviously cheaper if you can do the installation yourself, but it is something you have to get right the first time and takes a lot of experience.

Parts can be fairly inexpensive if from a donor or pricey if you buy from Cusco, MFactory, etc. The second thread includes part numbers and more detailed pricing for at least a partial DIY project.

Weir has new parts for a much better price than some of the others as well and has a good reputation if you don't want to go used.
Those labor hours (they need to remove the rear end from the car, dismantle it, and put it back in so there are a lot of hours) make the shop's labor rate a big influence on the total cost. You decide how cheap you want to go there.

http://ft86speedfactory.com/mfactory...-gear-556.html

So this is everything? Then just ask the shop "hey, I want a final drive swap whats it gunna cost?"

tune or anything else required?

The actual installation of the gears inside takes a bit of time, yes. But, dropping the pumpkin only takes 30min-1hr tops and is super easy.

Tune not required, but generally speaking, never a bad idea if you don't have one already. I'm trying to talk the wife into a OFT for the upcoming b-day.
Even then, if I thought I could swing it, I'd get the rear end changed out first.

If you can afford it and pull together all the parts, it really does seem like a smart upgrade for the way a lot of people drive their 86.

Agreed. But that link really was everything required for install?

I clicked on that link and all I saw were the two gears, pinion and ring.
You need shims, possibly bearings, I think there is a gasket that needs replacing, there is more, but those two are the big ticket items.
You also want to shop around.
Check this out:
Weir Performance

i have a 4.55 final drive in mine and loving it. i reckon its the best compromise for acceleration and highway cruising. 3000rpm at 100kph in 6th is fine for me.

i also have a spare lsd diff, maybe i should try 4.88 or 5.1 lol

I bought Cusco stuff. They have an LSD option that you can use Toyota 4.9 or 5.1 gears with. All up it was around $2k shipped to Australia. I did the install myself.
Videos aren't that useful for comparison. But here's one anyway.
[ame]http://youtu.be/3eB3qeOLcI8[/ame]

^ Looks pretty ballsy to me. :-)

@86drift how did u find the Install. Do u think this is a DIY project or a leave it up to the professionals kind of thing.

Imo and my experience...I wouldn't DIY this. I have done many simpler/intermediate DIYs (such as all suspension parts, rear diff swaps, transmission swaps and mild dismantles(swapping out the already assembled clusters inside tranny case), swapped heads, helped swap engines, basic engine tuning and operation, etc., etc...basically anything that's relatively easy to bolt on and off or has a higher degree of tolerance checking or calibration...and I have done basic electrical for cars and also music production gear); but, something that looks like it needs specialized tools that I(or most people) don't usually have (like presses, etc.) and also requires critical tolerance measurements (shims, etc), I am honestly just scared to mess things up even in the slightest (or, to seemingly get it right first (for the first few weeks) only to find out it breaks and/or is unreliable after a couple months), and will just leave it to the pros. Also, using wood/rubber blocks, mallets, hammers, clamps, sticks, poles, etc. to get the bearings out just sounds too ghetto for me and risky/prone to damage things.

I've had pretty competent friends in the past, novice'ly rebuild the bottom end. Everything seemed good at first for the first couple months; but the slightest of miss-measurement of tolerances will for sure not work a long time like oem. Gear installations inside trannys and diffs and rebuilding of engine blocks are things I don't trust my skill level with and will leave to the pros. I could be wrong though; and, those FD pinion and gear might really be feasible and not too hard to install for a DIY'er..but I really don't know how critical all those tolerances need to be to be oem/super reliable (so your question is a good one and I'd love to hear others' opinions on it)..but, for now, I just don't want to risk it.


Here's a great DIY on how to do it:
http://www.ft86club.com/forums/showthread.php?t=54054

Just by reading it....I know I will run into problems lol. And all the makeshift tools (like hammers, sticks, etc) seem a bit scary.

Swapping out the final drive is nothing remotely as difficult and precise as rebuilding the bottom end of an import motor. Sounds like your friends are used to dealing with tenths and hundredths on their domestic small blocks, not the thousandths on an import.

At least you're honest with yourself, just don't let your novice hobbyist friends talk you into monkeying with your block. That's like letting the neighborhood witch doctor treat your cancer.

Hahaha. Ya, I'd never have a novice work on my car's parts that required something as precise as the engine internals...it was a while ago anyways in the 90s and I am totally disconnected with them these days. It wasn't domestics, it was hondas back then (swapping to higher comp jdm r pistons, rods, or just plain rebuilding old ones to stock, etc.) Not saying all of them didn't do it right; just a few. The others that did it right actually did a good job at it and had little cr@ppy shops.

I read lots of good review for 4.8 final drive , but not so much regarding the kit from AUTO FACTORY , wonder does any one have negative feedback for this kit. I heard about like kit from Mfactory might cause some strange noise. But not sure about AUTO FACTORY.

The Auto Factory final drive kit uses an OEM Toyota gear, so it shouldn't make any noise.

MFactory kits may have some gear noise because they're semi-helical cut.

For reference:

• OEM gears are helical cut, which are quiet, but less efficient (more drivetrain loss).
• Straight-cut gears are opposite; most efficient, but most noisy (typically used on dedicated race cars).
• MFactory gears were designed to be kind of in-between.