HDJ80 Terrain Tamer/NPC Clutch Thickness/Longevity Questions

[CaptBeardilocks]

Hey All,

I have a moderately built 1HDT 5spd, running 19psi Green Wheel. I run pretty heavy weight-wise, as I live in the truck 10mo out of the year. I'm in the process of switching from an H151 on 33s to an H152 on 35s. I have about 40k miles on the Terrain Tamer HD clutch I put in when I built the truck.

While the transmission is getting swapped I'm looking at the clutch and trying to decide if I should run it or replace it. And I can't find jack for info out there,

I know stock clutches on stock trucks can run for 200k miles easy. Running higher boost and much heavier weight than stock I'm sure I need the HD clutch. I have absolutely no complaints about the TT HD clutch, I would just really like to both NOT do this job again any time soon and also not spend where I don't have to. The TT was $1150 shipped when I got it 4yrs ago but is only about $850 shipped today. But still money that I don't want to spend unless I have to.

Replacement spec on the clutch is 0.3mm to the rivets. Mine are showing ~1.3mm average to the rivets. But I have no idea what a new TT clutch plate thickness is, so I have no idea if I'm halfway through it's life or what. I have some anecdotal reports of Nissans only getting about 60-100k miles out of Safari Tuff clutches (which I believe is what TT uses). But no info on the TT in 80's.

Does anyone know the life expectancy of a Terrain Tamer HD or NPC clutch? (I believe both use modified Exedy plates).

Or does anyone know the thickness new (either at the rivets or total thickness) of the TT clutch plate?

 

[Workhorse]

I installed an NPC 1300Nm clutch when I did my HDFTE and H152 conversion in my 100. I’ve heard horror stories about terrain tamer requiring a ton of leg pressure to depress the pedal. (I don’t know this firsthand.)

I went with the NPC because I wanted to maintain factory soft pressure pedal with super clamping power. It did just that. I love it and I wouldn’t trade it for anything. By the way, I have about 70,000 miles on it since completing my swap in roughly June 2022.

Go NPC 1300nm system. In my opinion you won’t regret it.

 

[CaptBeardilocks]

I have had absolutely no issues with the TT and found it very user friendly (admittedly having not driven a stock HDJ80 manual more than about 30 miles).

Thanks for the mileage update. As far as I know both NPC & TT use Exedy clutch plates but could use different springs.

I hate the idea of throwing out a perfectly good clutch with miles left on it but the trans is a PITA to get out of the 80.

Are there any US based distributors of NPC clutches?

 

[CaptBeardilocks]

Here’s what my current clutch plate looks like.