caution regarding R151 behind a 1HD-T

[John Young]

I've always known that the R 151 is the light duty transmission and there were questions about durability when adding a turbo charger to a 1HZ and I assumed the same regarding using the R series transmission behind a 1HD-T. Nevertheless when we retrofitted a 1HD-T to Mr. Blue my 2003 105 we stuck with the original R151 transmission. It had been fine for a couple of years but I recently went out in the desert and pushed the pedal pretty hard a few times, and after that I found that it would pop out of first sort of randomly and very annoyingly. We pulled the transmission a few days ago and found that the thrust washer for first looked like this:

We will be putting an H151 with revised 2nd and 5th hearing behind the 1HD-T.

So no grand revelations here, but I thought I would at least share a photo here as support for the idea that the R151 is really only suitable for a 1HZ without a turbo.

 

[JuanJ]

Hello,

Yes, R15x transmissions cannot handle the power of, say, a 1HD engine very well.

It might be safe to say that if engine power if 170 HP or more, it is wise to use an H15x transmission.






Juan

 

[AussieHJCruza]

Yep, broke 3 of them with a 160rwkw 1HD-T in a HZJ105, they can't take anything resembling reasonable power

 

[John Young]

Yep, broke 3 of them with a 160rwkw 1HD-T in a HZJ105, they can't take anything resembling reasonable power

What were the failure modes for those three? The thrust washer that failed in my case just seemed like such a strange failure

 

[TheBussman]

What were the failure modes for those three? The thrust washer that failed in my case just seemed like such a strange failure

The thrust washer is the most common failure i know of, marlin crawler makes an upgraded one. After that i don't know what the next thing to break would be.

 

[AussieHJCruza]

What were the failure modes for those three? The thrust washer that failed in my case just seemed like such a strange failure

Generally manifested itself with losing reverse or first but there was general carnage in the box, could well have lost the thrust washer which meant something could walk around a bit and took the teeth off a few gears

 

[John Young]

Thank you.

As long as we're talking about this stuff, I realized I made an error a few years back, but I swapped in a 1HD-FT into a 1HZ 80 series. And I didn't change the flywheel. So now it will start slipping if I give it the beans sort of towards the top end in third and fourth. Is bother some but not so bothersome that I'm going to drop the transmission anytime soon. There's a lot to learn about this stuff, but I really enjoy working with diesels much more than what the gasoline motors.

Fortunately, the 1HZ 80 came with the H-series transmission from the factory so at least I didn't make that mistake.

 

[bottombracket]

I'm running an r151 behind my 74 series 1HDT/G turbo with a 300mm flywheel and Exedy 300mm 21spline clutch. I am careful with it and it's holding up fine.

Exedy clutch is ISD136U.

 

[John Young]

I'm running an r151 behind my 74 series 1HDT/G turbo with a 300mm flywheel and Exedy 300mm 21spline clutch. I am careful with it and it's holding up fine.

Exedy clutch is ISD136U.

View attachment 4112948

Thank you for the specifics on that @bottombracket. I am thinking about trying a Chinesium flywheel after having some good experiences with the quality of the machining but for the clutch itself I don'd think I want to take a chance given the price point I'm being quoted:

 

[mudgudgeon]

I'm running an r151 behind my 74 series 1HDT/G turbo with a 300mm flywheel and Exedy 300mm 21spline clutch. I am careful with it and it's holding up fine.

Exedy clutch is ISD136U.

View attachment 4112948

74 is a lot lighter than a full size wagon