Speedo, lets try to stump the experts with this one :huh2:

[Kiwisurfing]

Hello all,
Just a random "problem" that no local mechanic can make sense of here so let see how you lot all go with it,

2 hilux surfs, both 2l-t (both non efi in other words) both have R150f gearbox and yet mine does 2900rpm at 100kmh and my mates one only chugs along at 2400-2500rpm at the same 100kmh speed.
The only difference between the trucks is ones a 1990 and the others a 1989 but I doubt this matters much.

Weird of what? Wheres the logic in this?

PS. they both also actully 100kmh as verified with gps.

Cheers, not really important just bugs me not knowing why my trucks sucking through so much more diesel than mates on long runs because of this.

[Albannach]

Different final drive ratios. Next...

[Kiwisurfing]

But the speedo cable comes off the rear of the gearbox right? both same gearboxs?

Or unless a previous owner has been playing with the diffs, both engine bay tags are the same so would have to have been by asn owner some time in its life, still how would my mechanic not figure this one out?

[Albannach]

Yes, it does.

Maybe your mechanic is stupid?

[Kiwisurfing]

Ok then, if someone has played with one of our trucks diffs, how can I tell what they are without pulling apart and counting teeth, both engine bay tags are same so that wont tell me

[Apache]

If the gearing (inc tyre size - thats effectively part of the gearing) is the same, what the hell else can it be??

Somewhere in your drivetrain, as Albannach says, the gearing is different, and its probably the diffs as they aint all the same.

[Kiwisurfing]

and how do both speedos say 100kmh at the right speed with gps, a diff change should screw this up right?

[Albannach]

Ok then, if someone has played with one of our trucks diffs, how can I tell what they are without pulling apart and counting teeth, both engine bay tags are same so that wont tell me

Turn the propshaft 4 complete turns, count the number of turns your rear wheels do and divide by 4.

EDIT: I was talking to Shirley when I wrote that. It's four wheel turns and count the propshaft turns, then divide by 4!

Sorry!

[Albannach]

a diff change should screw this up right?

Yes, as would a tyre diameter change.

[Kiwisurfing]

cheers everybody, will do that tonight, raining at the moment so more thinkiing about going for a play in the mud than counting wheel turns right at this moment

I would suspect that my diffs are bigger then and speedo may have been somehow corrected, basicly an excuse for me to finally go buy some 33 inch tryes ha ha

[BUSHWHACKER]

Are you much fatter than your mate?

[Albannach]

Gearbox slip? I've been thinking that may be the cause of the overheating issues we have in our trucks...

[yoshie]

Are you much fatter than your mate?

[nos4ra2]

If both speedos are verified by GPS, it can't be diff ratios, because the speedo takeoff is on the gearbox-ie you've got 'over the ground' and gearbox speed correlation.

I'd go for Albannach's explanation of gearbox slip.

[Kiwisurfing]

okies update, looks like my truck has 4.556 diffs vs mates 4.3 but still if the speedos are both 100 and gps 100 its kinda weird, what is this gearbox slip you talk about?