"rediculously high" ( gearing in modern vehicles )

skin1235, Jan 8, 10:16am
Just an update

this was posted back in sept, since then it has been running with no front driveshaft and no caps on the hubs, ie diff not turning, because when the caps were removed back in sept ( on the way home from welly ) the diff would not turn at all ergo the driveshaft removal

I have finally got around to doing something about it
I figured the diff would need to come out and be either replaced or overhauled
so I run it up on the ramps and remove the pan etc, dig the diff out of the accumulated dirt etc so I can find the bolts to remove it
and find the diff now turns, has one lumpy spot but other than that it turns quite smoothly
grab the waterblaster and give the surrounds a good clean etc then go for a drive to dry most of the water off, climb back under and pop the diff cover, the oil was like black glue, and stunk, I mean stunk, eye watering stunk
quite good visuals of the internals so a spray pack of degreasol later was able to find a small lump of sealant stuck in the bottom of one crown wheel tooth, baked hard by boiling oil, chipped that out with a screwdriver and the pinion lost its lump, another bottle of supercheap degreasol and it was spinning well, no bearing noise, still had preload etc
so refitted all, put caps and shaft back in, and filled it with EP90 ( cos I had a bottle here)

its not a LSD as I thought, and its a 3.73:1 ratio

and it drives well with no noise at all, even spinning all 4 it makes no noises

I may have got away with boiling it until it seized although the noises it was making and the grabbing it was doing at the time certainly indicated something terminal

bwg11, Jan 9, 3:56am
Yes, interesting, how things have changed. Remember how my first 850 Mini was 4000 rpm at 60 mph (100 km). In those days a sustained 4500 rpm was considered high enough for a cruising speed which was about 68 mph or 110 kph.

Different today, my SUV is 1700 rpm at 100 kph, wife's Swift Sport about 1800. My classic mini has a 3.1:1 diff which 3000 rpm at 100 kph and keeps up with open road traffic without the need for excessive revs.

tweake, Jan 9, 4:09am
hilux/surf varies quite a bit. they had different models with different gearing and also different tire sizes. eg some are 4.3 diff with 29" tires and others are 4.5 diff with 31" tires. same engine and gearbox.

lookoutas, Jan 9, 4:40am
What you guys are missing here is who controls the bucks.

I was told this one day by a mate who seemed to know what he was talking about (for once) that some time back, Ford produced a model of Falcon that was extremely economic, coz they stuffed up the erg-controls big time. The very next model reverted to how someone on a much higher plane preferred it to be.

race_hemi, Jan 9, 4:41am
Yep, my LN106 powered by the all powerful 2.8 3L grunter sits on 3000RPM at 100km/h whilst fitted with 32" tall tires. It tops out at 110km/h. At 120 going down the Mangaweka you are near staring god in the face.

tintop, Sep 21, 2:53am
T = Turbo ?

Longer legs?

skin1235, Sep 21, 3:26am
yeah dave, last time I checked toyo had about 12 different diff ratios for the 86 to 94 range, petrol of diesel, NA or turbo, even lift kits had their own ratios, made it hard when needing a replacement front diff in the ln65

tintop, Sep 21, 3:54am
Pretty sure my original was 4.3, and it growled - found a replacement, hoping for a 3.909, but it was another 4.3.

lookoutas, Aug 8, 2:08am
That's right rob - it's hitting that sweet spot. Nothing worse than a car that needs notching down a few cogs to get it humming for overtaking.

Mind you - it's good fun!

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