My R151F needs replacing... H55 or H152? (HZJ78)

[Aidan Klimenko]

Just my 2 cents after driving 70 series for 3 decades and being around many of them . I personally prefer the R151 over the H55 because I feel it shifts smoother and the gearing is spread better . I never had a R151 go out not even on the 1HDT powered rock crawler I build on 40" tires , however I have known several R151's go boom usually being in heavily overloaded cruisers doing a lot of driving on bad roads , I feel that H55's would go out just as fast for these driving conditions and had a lot of H55's already in the past that needed rebuilding .

I have 2 R151's here at the shop and one of those is going to a good friend in California for his troopy but the other is available if you want to go the used route ? It came from a 30k mile sideswiped 2016 HZJ76 that I parted out many years ago and then I put it in my crawler and added approx another 2-3 k miles on it . I can sell this one or use it in my next build .

Thanks @joekatana. If I end up going this route I'll let you know. Also, the AC kit you sold me is great! The wife is very happy.

 

[GreaseMonkeyJP]

I hear ya. I'm just having a tough time wrapping my head around replacing a gearbox that's failed twice with the same gearbox. But money talks, and the swap to the H15x definitely would be spendy.

Does anyone know of where to get these "reinforcement kits" for the R151 here stateside? If I did stick with a R, I'd love to do what I can to prolong doing this job again for as long as possible!

Marlin Crawler does have some upgrade parts for the R-series transmission. I have them in my modified R151(different 5th gear) running behind a 1HD-FT for over 120k so far with no issues. My rig doesn't weigh so much though.

 

[Aidan Klimenko]

Hey all—I’ve decided to stick with the R series and have purchased a brand new, post 2021 model from Toyota.

A few members here have mentioned that Toyota recently updated the R trans, making it hopefully stronger.

Does anyone have any insight on what was changed/improved?

The reason I ask is, I’m trying to determine if I’d benefit from installing an “upgrade kit” from Marlin Crawler or similar. Not sure if this would be redundant after Toyotas updates to the box or if the kit would provide further reliability.

Thanks!

 

[jayp2]

H55 requires a diff bell housing than the original 151 I believe.....thats another 5-600.....possibly diff clutch bits too...something to look at confirm/deny

 

[OGBeno]

H55 requires a diff bell housing than the original 151 I believe.....thats another 5-600.....possibly diff clutch bits too...something to look at confirm/deny

Requires different everything.

 

[joekatana]

Hey all—I’ve decided to stick with the R series and have purchased a brand new, post 2021 model from Toyota.

A few members here have mentioned that Toyota recently updated the R trans, making it hopefully stronger.

Does anyone have any insight on what was changed/improved?

The reason I ask is, I’m trying to determine if I’d benefit from installing an “upgrade kit” from Marlin Crawler or similar. Not sure if this would be redundant after Toyotas updates to the box or if the kit would provide further reliability.

Thanks!

I would leave it as is , I have never known anyone to put these better together then the good people at Mr T .

 

[Aidan Klimenko]

H55 requires a diff bell housing than the original 151 I believe.....thats another 5-600.....possibly diff clutch bits too...something to look at confirm/

I would leave it as is , I have never known anyone to put these better together then the good people at Mr T .

That’s what I was hoping to hear. Thanks Joe.

 

[bottombracket]

Take the new transmission, put it in the truck and run it forever. The end.

 

[Economist LC76]

Very interesting thread!
I’ve tried to check what was changed in R151F from 2007 for the LHD HZJ71.
The catalog shows that it was several R151F versions during this period. 33030-6A412 (2007-2013), 6A413 (2010-2013) and finally 33030-6A414 (2013+).
I’ve checked a difference between 2007 (6A412) and latest 2013+ (6A414). Major parts were updated (green color). I don’t know how big was a real upgrade vs just the number change, but I assume that the gearbox was heavily upgraded.
I am thinking to save some money and buy the latest R151F for my 1HZ.

 

[Aidan Klimenko]

Very interesting thread!
I’ve tried to check what was changed in R151F from 2007 for the LHD HZJ71.
The catalog shows that it was several R151F versions during this period. 33030-6A412 (2007-2013), 6A413 (2010-2013) and finally 33030-6A414 (2013+).
I’ve checked a difference between 2007 (6A412) and latest 2013+ (6A414). Major parts were updated (green color). I don’t know how big was a real upgrade vs just the number change, but I assume that the gearbox was heavily upgraded.
I am thinking to save some money and buy the latest R151F for my 1HZ.
View attachment 3781941

Wow yeah this is great. Thanks for sending!

 

[NoGo2R]

Very interesting thread!
I’ve tried to check what was changed in R151F from 2007 for the LHD HZJ71.
The catalog shows that it was several R151F versions during this period. 33030-6A412 (2007-2013), 6A413 (2010-2013) and finally 33030-6A414 (2013+).
I’ve checked a difference between 2007 (6A412) and latest 2013+ (6A414). Major parts were updated (green color). I don’t know how big was a real upgrade vs just the number change, but I assume that the gearbox was heavily upgraded.
I am thinking to save some money and buy the latest R151F for my 1HZ.
View attachment 3781941

Glad it worked out for you Aidan,

When my HZJ76 ZX trim 2000MY eventually gets to me from Yokohama, this will be one of the first big things on my list...


Would appreciate advice/guidance from any MUD members on the newest R151F (A414)

Since I'll be doing a lot of highway miles, it seems this will have to be my plan for preventative maintenance - since highway miles seems to be the Achilles heel.


To clarify - is the 33030-6A414 replacement "plug and play" or does other items need to be replaced to make it work correctly?

Read something about input shaft to transfer case on the 2013+ R151F being longer than the original 99-01 R151F batch...

Thank you in advance

 

[AussieHJCruza]

if it's a N/A 1HZ, you'd be better with a H150 - got the shorter first of the 152 and the 1HZ doesn't have the power to pull the taller 5th IMHO

 

[SNLC]

I drove a 1HZ power R151 trans 105 7,000kms in May.

It only has 165,000 miles on it and the R151 pops out of 5th regularly.

I have driven a bunch of Cruisers with the R151, it does shift nice but is not suited for a heavy or powerful one.

Cheers

 

[scrad]

I Like this discussion. Reasonable advice. Glad it got bumped up. Any solid info on a late model R151? Do the updates include full spline gears vs the three pronged style?
I have a 2026 new take out from a 79 series i want to put behind a turbo H series. I know everyone says it’s a bomb waiting to Happen. Supra guys run Massive HP through the R series with good success. Is it the 4wd abvuse that does them in? The H series is not getting anywhere near the HP and torque of a 1JZ but i do agree weight and traction is different.

 

[AussieHJCruza]

I Like this discussion. Reasonable advice. Glad it got bumped up. Any solid info on a late model R151? Do the updates include full spline gears vs the three pronged style?
I have a 2026 new take out from a 79 series i want to put behind a turbo H series. I know everyone says it’s a bomb waiting to Happen. Supra guys run Massive HP through the R series with good success. Is it the 4wd abvuse that does them in? The H series is not getting anywhere near the HP and torque of a 1JZ but i do agree weight and traction is different.

the only thing I can put it down to is weight - a JZA80 supra weighs about 1500 kg. A bare bones HZJ76 has got to weigh 2100kg.

The other aspect is max torque in a worked 2JZ wouldn't be until 4k rpm+, very different stresses than a diesel that's making max torque at 1800-2k rpm.

 

[NoGo2R]

I Like this discussion. Reasonable advice. Glad it got bumped up. Any solid info on a late model R151? Do the updates include full spline gears vs the three pronged style?
I have a 2026 new take out from a 79 series i want to put behind a turbo H series. I know everyone says it’s a bomb waiting to Happen. Supra guys run Massive HP through the R series with good success. Is it the 4wd abvuse that does them in? The H series is not getting anywhere near the HP and torque of a 1JZ but i do agree weight and traction is different.

My question from yesterday, which bumped the discussion (I'm not the OP) -

Is the new R151F (2013+) a "Plug and Play" replacement?

Vehicle is a HZJ76 ZX trim 2000MY - R151F (1999 - 2001)

If not a direct remove and replace, what other parts are required to be replaced...?

 

[scrad]

My question from yesterday, which bumped the discussion (I'm not the OP) -

Is the new R151F (2013+) a "Plug and Play" replacement?

Vehicle is a HZJ76 ZX trim 2000MY - R151F (1999 - 2001)

If not a direct remove and replace, what other parts are required to be replaced...?

I have a 2018 r151 on the floor of the shop and can take pictures if that helps?

 

[NoGo2R]

I have a 2018 r151 on the floor of the shop and can take pictures if that helps?

Thank you - but I'm not knowledgeable enough about it tell the difference just by looking.

Near the beginning of the thread, it was suggested to just replace the R151F with another one.
... near the end, it was explained that the 2013+ newest version (A414 p/n) had corrected most of the issues from the earlier designs.

Also, it was the most cost and time effective option.

Installing another transmission (H models, though stronger), would involve replacing multiple other parts - driveshaft, transfer case, bell housing, etc.

My question was when replacing a R151F with the 2013+ version R151F, are there any other parts required to be replaced?

 

[Economist LC76]

Thank you - but I'm not knowledgeable enough about it tell the difference just by looking.

Near the beginning of the thread, it was suggested to just replace the R151F with another one.
... near the end, it was explained that the 2013+ newest version (A414 p/n) had corrected most of the issues from the earlier designs.

Also, it was the most cost and time effective option.

Installing another transmission (H models, though stronger), would involve replacing multiple other parts - driveshaft, transfer case, bell housing, etc.

My question was when replacing a R151F with the 2013+ version R151F, are there any other parts required to be replaced?

I’ve replaced my old r151f (1999) on a new version 33030-6A414. No extra parts are needed, plug&play

 

[NoGo2R]

I’ve replaced my old r151f (1999) on a new version 33030-6A414. No extra parts are needed, plug&play
View attachment 4180101
View attachment 4180102

Thank you