HDJ-81 Auto to Manual conversion? (2 Viewers)

[Mighty690]

In my heart of hearts I'd like a manual in my RHD JDM 81. Which transmission did Toyota put in the manual HDJ-81s? Would a conversion to manual be much work? (I know sourcing parts would be a bit more challenging here in CA.) Finally, I think I read somewhere that the manual trans rigs have a lower final gear ratio. What kind of RPMs are you turning at highway speeds? (I realize that's tire-dependent to some degree.)
Thank you.
Scot

 

[tweeek]

H151 is the manual trans for the 80 series. Conversion is not difficult. The hardest part is securing the crossmember a couple inches forward. The holes are already in the frame, but have no nutcerts.

You'll need to source the trans, clutch, flywheel, master cylinder, lines, spring assist pedal, interior trim pieces and leather boot. All are available through various retailers, some still available from Toyota.

Lastly, you'll need to resize your driveshafts.

Yes, gearing is much lower. If your using it offroad, your crawl ratio is much better. If using it on the highway alot, it's much worse. Even with 35s your engine will be revving really high.

IMO, the best of all worlds would be the H151 with 3.12 low range and 10% overdrive tcase gears. Leave your 4.10 diffs alone.

All it really all it takes is $$$$

 

[MonsterCruiser]

There's lots of good info in this thread where Nick did a swap:

80 Series H151F 5 Speed Manual Transmission Swap - Includes RHD HDJ81 & LHD FZJ80

 

[CycloSteve]

Personally I am 100% happy with my choice to go with the H151F instead of the ATM.

Gearing wise I an running on 315's,have 4.10's, and the Terrain Tamer OD in the transfer case. This combo puts the RPM at 2400 in 5th doing 70mph...the truck can do that all day long and return 20-22mpg. Not bad for a fully built rig weighing north of 7,000 pounds.

You may want to get in touch with @Jan-78FJ40 as he is in your area and had extensive work done at West Coast Cruisers on his HDJ and H151F.

I say go for it if you enjoy rowing the gears...I know I definitely do...which reminds me, it is time to air down and drive back onto the beach at Turf N Surf.

 

[Mighty690]

Thank you, guys, for your replies. just what I needed.

 

[mudgudgeon]

My HDJ81 had H151, 4.11 gears and 35s for play time.
I found 1st gear occasionally too high on road (if towing, on hills I occasionally would take off in LO 2nd, then shift to HI 1st on the fly). On flat ground, take off in 2nd gear (Hi) worked just fine.
In steep rocky off-road stuff, it really needed reduction gears in the transfer.

I thought of swapping for H150 (with H151 input shaft to keep 300 mm clutch), it has a lower 1st and 2nd, but I think it also has a slightly lower 5th

I'd budget for t-case gears if you spend time off-road

 

[gnarlynick2072]

Conversion really just takes $ and lots of research with parts.

There's a 5th gear reduction kit but I think it's for H150 only, not H151...

5th Gear Ratio Change suitable for Landcruiser HDJ VDJ 76 78 79

 

[slosh]

My base model 80 (98 model) came with the H150 if I recall correctly. It also has part time tcase standard. I run 315 tyres and it cruises on the highway nice, however I don't know the rpm because Toyota felt that a tacho should not be standard.

 

[gnarlynick2072]

My base model 80 (98 model) came with the H150 if I recall correctly. It also has part time tcase standard. I run 315 tyres and it cruises on the highway nice, however I don't know the rpm because Toyota felt that a tacho should not be standard.

The H150 only has different 1st and 2nd gear ratios with single synchro on 1st. So your highway RPMs would be the same as the H151.

The reason I think that conversion kit wouldn't work for h151 is because the 70 series really only came with h150 so the custom counter shaft wouldn't mate to an h151.

 

[77cruiser77]

I thought the 1HZ powered 80 series got the H150 manual transmission and the 1HDT manual received the H151.

When my H55F blew up behind my 1HZ I looked into the H151 for a number of reasons but it was going to cost an awful lot of money. I'd need different bell housings and flywheels and a clutch so I put in a new H55F again. Last I checked my local dealer had access to 7 for 1HZ out of the USA.

An H55F could be a slightly cheaper way to get a manual transmission in there but if you run giant tires and crawl over rocks I've been told the H151 is a tougher case, not to call the H55F a weakling that is.

 

[landcrusher80]

Official 80 Series Manual Transmission Club Thread

 

[mudgudgeon]

I thought the 1HZ powered 80 series got the H150 manual transmission and the 1HDT manual received the H151.

Correct.

The reason I think that conversion kit wouldn't work for h151 is because the 70 series really only came with h150 so the custom counter shaft wouldn't mate to an h151.

It's the gear ratios that makes a H151 and H150 different. Swapping 1st and 2nd gears along with the new cluster could be done to build a H151

 

[gnarlynick2072]

Correct.




It's the gear ratios that makes a H151 and H150 different. Swapping 1st and 2nd gears along with the new cluster could be done to build a H151

Wouldn't it be more involved than simply swapping gears? Would you need to replace the shifter sleeves, synchros, forks? Basically not worth it...

 

[mudgudgeon]

It's the gear ratios that makes a H151 and H150 different. Swapping 1st and 2nd gears along with the new cluster could be done to build a H151

Errrrrrm . . . facepalm moment there!

Contradictory statement above.
The modified cluster for H150 CANNOT be used to build up a modified H151.

The 1&2 gear on the cluster wouldn't match 1st and 2nd gears from a H151.

 

[CycloSteve]

The ultimate setup is the H152F...trouble is finding one in the US.

 

[gnarlynick2072]

The ultimate setup is the H152F...trouble is finding one in the US.

Is there anyone that can get the part number for an H152??

Also would require changing the input shaft to a 1HD/1FZ compatible shaft...

 

[Tapage]

I also find H150 ( on my 80 ) it's often too fast ( stock R&P and 315 ) for off road purposes ..

 

[gnarlynick2072]

Finally found it - 33030-60C50 for H152F gearbox.

Looks like this gearbox has the same 1st gear as the H150. 2nd gear is from the H151, so there will be a big RPM change from 1st to 2nd. And 5th is obviously brand new.

 

[Tapage]

and in the H150 it's already big step between 1st and 2nd ..

 

[Workhorse]

David, there is a place in Australia that rebuilds our H15* transmissions with a taller 5th gear. The company is called 360. This webpage lists 80 series overdrive gearboxes but no info. Click on the HDJ100 overdrive link and see. It says a reduction of 500RPM from 4-5th gear. I wonder if that means a 500RPM reduction in 5th. Kind of neat either way.

Mods | 360 Gearboxes & Diffs