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1HZ out for 1HDT conversion

Posted: Sun Apr 03, 2011 8:41 am
by fumduk3
hi all need a couple quick q's answered before i get ready to pull the 1hz...... i have a standard 80 series dx part time and want to use the 1hdt engine, g/box but not the full time t/fer case, can my part time 1 bolt up to the t/d box? if not the 1hz box bolts up to the 1hdt just use my smaller clutch flywheel etc? not sure on this stuff would be good to hear from someone whos done a few cheers

Re: 1HZ out for 1HDT conversion

Posted: Sun Apr 03, 2011 7:32 pm
by ferrit
While the 1HD-T is out, Flip her over and change out the Big End Bearings. Bolts and bearings are about $170. Cheap insurance if you dont want to pull the head to replace a conrod when a BEB spins.

Re: 1HZ out for 1HDT conversion

Posted: Sun Apr 03, 2011 10:55 pm
by Northside 4x4
Yeah the big ends in the 1hdt's did have a bad batch until toyota sourced a new bearing supplier. most of them were replaced under warranty/recall but it is still a good idea to replace them if you're unsure of the motors history.

Re: 1HZ out for 1HDT conversion

Posted: Mon Apr 04, 2011 9:53 pm
by fumduk3
yeah BEB's definately for sure, any 1 used a 1hz box behind a 1hdt?

Re: 1HZ out for 1HDT conversion

Posted: Mon Apr 04, 2011 10:10 pm
by 80's_delirious
the gearboxes are the same apart from gear ratios, and different input shafts. You will be able to swap the transfers no worries.

The gearbox frm the 1HD-T will have a higher first and second gear ratio, so not as good for rock crawling type stuff.

Re: 1HZ out for 1HDT conversion

Posted: Tue Apr 05, 2011 6:27 pm
by TheDato
You can use the 1HZ gearbox behind the 1HDT, you will need a 1HDT bearing and clutch cover and an NPR Isuzu driven plate with the correct outside diameter and the right spline to suit the gearbox.

If you look on the Clutch Industries website you will find the ID and spline count for the 1HZ driven plate, then hunt through the NPR Isuzu list for the correct spline and OD.

I used one of their RPM clutch covers with the NPR driven plate. Works a treat.

Cheers
Muz