Thread: 4BD1/T and a slushbox?

Ive seen one mounted up against an alison.

light agricultural use so performance wasnt really a requirement it just had to work. Im pretty sure its still lumping along.

youd probabley get away with putting in one of the smaller truck autos though.

An Allison would handle it well but may not be all that efficient. As Dave said agricultural.
JC tried a ZF 4HP22 but didn't last I'm working on a ZF 4HP24 ES with compushift for my next Rangie. Have no proof it will stand up to the torque pulses either. I feel the lock up converter will be the death with the HP 24

so dont use the lockup feature?

Yes, Sprint it would be a fantastic conversion if you found a box that lasted. I enjoyed it immensely until after 3 rebuilds I gave it away for a LT95.

As Tony says a 4HP24EH with compushift should take it fine, IF I wanted to revisit the auto again (I still have all the adapters etc) thats the way I would go.

JC

A heavier flywheel would be the first mod if you wanted a lighter box to last.

Agreed about the flywheel, but the other issue I had was the immense torquue ripping the clutch material off the lockup clutch. That is where the much bigger 4HP24EH torque converter would be a bonus.

I got 10000km out of 1 box, the lock up clutch material ended up all through it and I lost gears eventually due to contaminated valve body etc.

JC

The Isuzu trucks are reasonably common in the USA (re-badged as GM's) and nearly all have auto's.

The Jatco auto's used with the 4BD1T's have a poor name.

Aisin auto's, similar to what is used in some Landcruisers, were used with later Isuzu engines and it appears some people have mistaken these for Allison's.

Over there (USA), several GM autos have been used successfully with 4BD1T/2T conversions into lighter vehicles like ours. They have retained the Isuzu flywheel, which together with the mass of the torque converter, reduces the torsional vibrations.

Originally Posted by Bush65

Aisin auto's, similar to what is used in some Landcruisers, were used with later Isuzu engines and it appears some people have mistaken these for Allison's.

Over there (USA), several GM autos have been used successfully with 4BD1T/2T conversions into lighter vehicles like ours. They have retained the Isuzu flywheel, which together with the mass of the torque converter, reduces the torsional vibrations.

I think the confusion has arisen because all the 6xxx Isuzus run Allison Autos. E.g. the GMC W5 / W5500 (Isuzu NRR FRR) runs the Alison AT542. The GMC4000 was the model which had the 4BD(1/2(T)) and Aisin Auto AFAIK.

Adaptors for GM auto boxes:
Overview

Some drawings and specs of the Aisin box here:
http://www.shinseiauto.com/japanese/.../ata440f04.pdf


EDIT:
Also found this:

N-Series models, offered in wheelbase options of 109, 132.5, 150, and 176 in., feature front disc and self-adjusting rear-drum brakes as standard.

The Class 3 NPR Diesel, available in 12,000 lb. GVWR, and the Class 4 NPR Diesel HD, rated at 14,500 lb. GVWR, are powered by a 142-hp. Isuzu turbocharged 4.8-liter 4HE1-TC diesel. Also new is the MXA5C fully synchronized, 5-speed manual transmission; an Aisin 450-43LE 4-speed automatic transmission is optional.

Assembled in the U.S., the Class 3 NPR-GAS, rated at 11,050 lb. GVW, and the Class 4 NPR-GAS HD (14,050 lb. GVW) are powered by a GMPT-V8 gas engine.

Newly added to Isuzu's lineup, the Class 5 NQR, rated at 16,500 lb., is available in four wheelbase choices. It is powered by the Isuzu 4.8 liter, 4HE1-TC, engine that develops 175 hp. at 2,700 rpm. The Class 5 FRR Diesel, with a GVWR of 18,000-19,500 lb., features a 7.1 6-cyl. Isuzu 6HK1-TC engine that delivers 200 hp. at 2,500 rpm.

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