Thread: Which gearbox, & how to fix?

Originally Posted by Dougal

Another interesting thing John. Cheif managed to pull out the fuel pump calibration for the pump on my JDM 1986 4BD1T and it has a max injection volume about 10% higher than the one you have previously posted.

This gives some backing to the niggling memory I have of a claimed 330Nm/100kw rating for my engine. If we take that 6x6 4BD1T curve and crank it upwards about 10%, extend the power line out to 3,200rpm and the numbers seem to fit.
Injection quantities for calibration of 69-73 cc/1000 shots for the 88 onwards and 78-80cc/1000 shots for my pump.

Sorry for going off topic.
The calibration I have is for 86 on, this is what I would have posted, but I have since learn't that Isuzu changed the 4BD1 and 4BD1T late in 88. The 69.6 to 72.8 cc/1000 st at 900 rpm of pump (1800 engine) or 70.2 to 72.2 with boost pressure over 110 mm Hg, calibration would be for 86 to 88, not late 88 on - I don't know what calibration was used from late 88.

The Id number for the 4BD1T IP with boost compensator stated in my 86 on manual is 101401-0660. The Id number on my 89 4BD1T pump without boost compensator is 101401-0890.

This is all academic once we twist the governor screws.

Originally Posted by Vern

Yeah but what are the msa ratio's compared to the lt85?

dougal answered this already but if you have an lt85 you will most likely find 1st gear annoying as i find it way to tall for my liking so thats the main reason why i went with the mxa

So your keeping the 1.2:1 Transfer? if so I'll give this other case to the dude who PM'd me

Originally Posted by rovercare

So your keeping the 1.2:1 Transfer? if so I'll give this other case to the dude who PM'd me

Honestly, I'm not sure - I was waiting to see where the thread went with this, regarding which was more suited to what I was running. I was also hoping to get a bit more info as to whether the LT230R would be okay to run behind an Isuzu engine, what the differences would be between it and the roller bearing variety, etc.

Isn't it the gearbox that takes the real hammering, not the transfer?

Originally Posted by isuzutoo-eh

Isn't it the gearbox that takes the real hammering, not the transfer?

The gearbox takes the hammering (the input bearing torque impulse stuff), but the transfer has to deal with the torque. Hence the preference for TRB vs standard needle rollers + bronze thrust washers in the LT95.
Not familiar with the LT230R but if it has needle rollers it sounds similar to LT95.

Steve

My LT230R is working fine behind my 4BD1T. Only run it 30,000km or so though.

Originally Posted by Dougal

My LT230R is working fine behind my 4BD1T. Only run it 30,000km or so though.

29" tyres and it sits in the shed undriven, hardly relevant

Mike, I've never run a needle roller 230, so don't know, if you found the rangie fine to drive as is, run what it's got