Manual gearbox 1UZ drivers - in 'ere

[-Nemesis-]

Been doing some thinking lately and i'm sure my gearing is too short, I thought i'd start a thread so people can discuss their gearboxes and what they like or hate about their gearing?

I'll double check these figures but i'm sure my 1st gear is all over by about 45km/h, 2nd gear runs out at about 95km/h if that (both = redline.) All in all in 5th gear on the freeway at 110km/h mine sits a tad over 3000rpm (but still get's above average 4WD economy.)

That's with an R150f 5 speed and 4.88:1 final gears, with big 33" tyres.

What speeds does your ride pull in the first two gears especially? Are you happy with it?

I'm thinking if I boost this UZ then the gearing is going to be rediculous, with bosst 1st gear will be a waste of time surely, it already seems to run out so quick. Yet at the same time this gearbox seems to have a bit of a hole going from 2nd -> 3rd....

 

[cribbj]

Same with the Supra's V160 6spd box. The car is a heavy pig (3500lbs with driver, or nearly 1600kg) to get launched, so Toyota gave it a granny of a 1st gear, and 2nd isn't much better. Make a long story short, you're cruising around in 4th gear at 45-50 mph (70-80kph) to keep the rev's at or below 3000.

With the xtra torque of the V8, the gearing will be way too short, and I'll probably just launch in 2nd, and 1st won't get used much.

These Toyota diffs could really use some aftermarket ring & pinion sets, but theres just nothing out there for them. You guys in Oz should try to put some pressure on Albins, maybe they'll listen to local boys if enough of you approach them.

 

[greybeard]

..., but theres just nothing out there for them...

I didn't have any problem with ratio choice for my hilux, at least 6 ratios offered to me from 3.5x to 4.8x

 

[cribbj]

Interesting, maybe some size diffs are more popular than others. Where are these ratios available? Albins?

 

[greybeard]

Interesting, maybe some size diffs are more popular than others. Where are these ratios available? Albins?

My diff was done a by a diff specialist is Brisbane. I don't know his original source of parts. IIRC the ratio choice I was offered was: 3.5x, 3.72, 3.9x, 4.3, 4.5x, 4.8x & there might have been a 4.1x offered also. the complete rear diff/axle assembly was sent to him, came back fully reco'd with torsen centre and my chosen ratio (3.72).




HtH

 

[Tacoma_Kyle]

Yeah man. 4.10 is probably the single most common diff ration in Toyota pickups/Tacoma's in the US. Some Tacoma's apparently have 4.11 and then the aftermarket goes to pretty much any numeric ratio possible. Not quite...

 

[gloverman]

There are heaps of different ratios avaliable factory for hilux G series diffs. One very good thing with them. Gets tricky as different models get gearboxes with the same code but with different internal ratios.
I was running a 1kz-te gearbox in my hiace - using a 3.72 diff and 100km/h cruise was 3650rpm. 50km/h in first, 105km/h in second on the limiter and 140km/h in third on the limiter. Not bad ratios but only 400rpm drop between 4th and 5th. 1st and reverse needed to be shorter as it was a van afterall and top needed to be longer. Still drove most places in top gear when towing big trailers with vehicles on them. Cheers

 

[ed_ma61]

well, mine does over 160kmh in 2nd gear, and i need to ditch my diff for at least a 25% shorter ratio....

that sucks

 

[-Nemesis-]

Heheh nice ed, my last 4Runner had 4.3's and with 33" tyres I think I could do about 120km/h in 2nd. I guess 4.56:1 would be a good compromise.

 

[cribbj]

Evidently the availability of different ratios for the Hilux is a different story, and that's really encouraging.

Those of us with the big Supra diff's (220mm ring gears) would really like to find a source of new CWP's with lower ratios.

The USDM version of these big diff's have a 15 tooth pinion and 47 tooth crown wheel for a final ratio of 3.133.

The JDM version keeps the 15 tooth pinion and goes to a 49 tooth crown for a 3.27 ratio.

IMO, a 17 tooth pinion and 49 tooth crown for a final ratio of 2.88 would be right in the ballpark for us.

We had some discussions earlier this year in this thread: http://www.lextreme.com/forums/showthread.php?t=9767

 

[gloverman]

I recently purchased a hilux surf 4 runner manual with the facelift front(JDM import so its a bit mixed up). Staying v6 at the moment. It has a 4.55 diff. 31/10.5-15 tyres. Pulls 2750rpm at 100km/h, 3000rpm is 110km/h. Never seen what it does in 1st and 2nd but will have a try next time I am out of town. Missing my v8 power. This V6 makes 68kw peak at the wheels and uses more fuel than my 1uz van. Cheers

 

[MWP]

Evidently the availability of different ratios for the Hilux is a different story, and that's really encouraging.
Those of us with the big Supra diff's (220mm ring gears) would really like to find a source of new CWP's with lower ratios.

Sounds like you need to start categorising them by Toyota diff series letter, ie:
T series - 7 inch (i think)
F series - 7.5 inch
G series - 8 inch
A series - 8 inch

The G series centers are used in most Hilux diffs (some are F series), all Supras (i think) and probably all 1UZ powered Toyota/Lexus's.
All G series diff centers, pinion and ring gears are pretty much interchangable... though sometimes it does require some persuasion.
You can find out which series (and ratio) it is by the axle code on the engine bay plate.

For example, im using an early 70's Hilux carrier, JZA70 Supra torsen LSD and some 90's Hilux's 4.1 ratio CW&P in my project car ('77 Celica).
As its all G series, with a little bit of machining, it all fit together perfectly.

 

[Tacoma_Kyle]

The early Celica's got T-series diffs right? If so I am pretty certain they are 6.7". I heard apparent RG engines 71-75's got a 7.5" but I dont know for certain.

 

[MWP]

The early Celica's got T-series diffs right? If so I am pretty certain they are 6.7". I heard apparent RG engines 71-75's got a 7.5" but I dont know for certain.

Ah, ok, so T series are 6.7" then... no wonder they are so weak.

Real JDM 70's GT Celicas with 18RG's got F series.
Im not sure about the USA delivered 70's Celicas.
All 70's Celicas delivered to Aus had T series

 

[ed_ma61]

The G series centers are used in most Hilux diffs (some are F series), all Supras (i think) and probably all 1UZ powered Toyota/Lexus's.

the concept of the G series is only valid up to the early 90s. after that the A and B series codes were introduced (some of which are compatible with the old G series) but definitely not consistent across the whole build plate series

late supras/soarers have their own unique A series 200mm (8") diff which is not compatible with any g series gears etc etc

 

[MWP]

I knew they changed to A series at some point, but didnt know when aranoid:

 

[ed_ma61]

sad thing is though, "A series" means nothing.

you cannot predict crown wheel size, nor part interchangability, based on the "A series" code being stamped onthe build plate (unlike the F, G, T series of old) at least 3 fundamentally different "A series" diffs exist

 

[-Nemesis-]

I wonder how hard it is to retrofit a bigger diff in the 4Runner housing, I think I may have heard of it before somewhere (will do some research.)

The V6 4Runners still share the 8" size diff as the Hilux, but overall it is a bigger 3rd member. Has a bigger pinion shaft, bigger bearings and thicker crown wheel. It's much stronger, but it's still only 8"

 

[91_4x4runner]

If I was you Nemesis, I'd look up the e-locker modifications for the second generation yota trucks. They basically do a bit of work to make the 3rd generation 3rd members fit into the housing.

http://home.off-road.com/~kemanuel/elocker/elocker.html

 

[-Nemesis-]

What's the advantage? Is it a bigger diff? I already have an air locked V6 member in mine.