Builds Diesel Conversion to Isuzu 4BD1T

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Hello Sir, I have read your thread three times and love it. I see that you are using a H55F trans.. In your parts list you said that you got a rebuild kit for this also. Can I ask where you got this kit? Also do you think $1000 for a H55 is a good price? I just purchased a 4BD1t that was running when I helped take it out of the truck it was in. Trying to find a Downey Bell Housing to mate what ever transmission I decide to go with. Any ideas where to find one of these. Where is a good place to source a master gasket kit? Thanks again sir and what a great build you have done.
 
Hi Bluehawk,

Thanks for the compliments! I have since swapped out the H55 for a land cruiser auto (A440F) and haven't looked back. If you look in the diesel section under 4BD1T you will find my thread about how I did the conversion. I personally wouldn't use the H55 because of the cost and the low overdrive ratio. I would go with an NV4500 tranny if I were to go with another manual trans. The ratio is much better with overdrive and it is a stronger transmission. I had problems with my swap eating pilot bearings and after the 3rd one I got mad and decided to swap to an auto. I lost a couple of mpg's but gained a higher overdrive ratio and love this auto tranny. Used H55's are hard to come by cheap because the demand is so high and new ones are over $2k now.

Hope this helps.

Thanks,

Don
 
The NV4500 HD is beefier than an H55, but the standard NV4500 (gas versions) is probably right on par with the H55.

With the NV4500 you will likely need an adapter to the transfer case and the engine. Need custom crossmember and clutch hose, possibly special clutch pieces depending on which engine/adapter setup you are using.

The H55 fits right in place of your 4 speed or A440. Only one adapter necessary to connect it to the engine (Isuzu or Cummins). Overdrive is not spectacular, but 3.73 gears are very available for 60 series and work excellent with 33" tires and a Cummins or Isuzu. 4.10's and 35's work well with the H55 too.
 
I had lots of problems with my H55 when I first did this conversion. None of these problems were due to the H55 tranny though. I attributed my problems with too many adapters in between the Isuzu engine and the Toyota tranny. I burned up 3 pilot bearings in about 9 months and even though I used a dial indicator to dial everything in before installing it, having two flywheels and and a big spacer and custom special clutch plate and Downey chevy to toyota bell housing, it was just too much tolerance stacking and I gave up and made my own adapter for the A440 auto.

If 69Ramblers adapters were being made back then, I would have jumped all over them and been way ahead of the game. Using one flywheel and a thinner engine mounted adapter housing, his setup is perfect for swaps due to the reduced length and simplicity of its design.

Don
 
I have to agree with Don on the adapters. I also went through a pilot bearing and next time I have an excuse to remove my engine, I'm going to talk to 69rambler about one of his old kits with the steel adapter and ball bearing pilot bearing.

My h55 is working well and I have 3:70's and 33's, so no complaints.

Doug
 
I am looking at doing this down the road. I have a fj62 auto and 4:56 gears with 33 inch tires. this works perfectly with the gas engine (though the engine is getting old and a little weak). would this ratio be a problem with the bd41t? it's right on the mark gear wise with the speedo but I'd be worried I'd be possibly over revving a diesel. any thoughts?
 
Hi Franklin,

I would consider 3.70 gears with 33's to be a minimum with this engine. I don't like to cruise over 2200 RPM if I can help it, and if I can stay at 2000 or below I get much better mileage with this engine. I am currently running 3.70 gears with 35's and it works great with plenty of power for the hills. If you want a great gear ratio calculator, go to http://www.grimmjeeper.com/gears.html

You wouldn't have any trouble selling your diffs because someone is always looking for lower gears for bigger tires. Someone would probably swap you straight across for some 3.70 diffs.

69Rambler is making adapters now to bolt up this engine to your A440 transmission which is what I am running now in my truck behind this engine.

Don
 
Hello again sir, would you be interested in selling your H55? Think I want to go this route due to the fact that I could use my stock trans and keep everything as close to stock. Will be using Dustin's adapters that he is making, so only the one adapter in the whole system I hope. THANKS AGAIN SIR
 
Franklin,

I modified a Stewart Warner speedo ratio gear changer to work with my speedo cable. It is a 33% faster ratio and it reads correct with an FJ62 transfer case. I just used my GPS to get the proper speed and then took the percentage and got a ratio changer off Ebay to correct it.

Bluehawk,

My H55 was sold about a year ago when I did the conversion to auto.

Thanks,

Don
 
Hello again sir, would you be interested in selling your H55? Think I want to go this route due to the fact that I could use my stock trans and keep everything as close to stock. Will be using Dustin's adapters that he is making, so only the one adapter in the whole system I hope. THANKS AGAIN SIR

PM incoming.
 
GLTHFJ60 got your PM and sent a return, Thanks.

Don, really like your engine run stand. Could you give me dimensions on the bottom frame? Is it made from 2" tubing? Hard to tell from the pictures. Thanks for all of the help. I'm sure I will be asking alot of questions in the near future as my build progresses.
 
In the H55 Cruiser, at one time I was running 4:11 gears with 37" tires and felt it would be nicer with higher gears.
I put 3:70's in and now it's better for extended 70 to 75HPH highway cruising. It didn't damper acceleration in city driving either.


With an H55, even running 3:70's I wouldn't go below a 35" tire if you do much highway driving.
 
Don,
Was checking on the H55 and some one sent me a PM about them. They said that they had a few but it depended on my set up as to which one I would need. I have a 1990 4BD1t motor and will be using the 1984 FJ60 t-case. He said that the BJ had a fine spline and that the HJ and FJ had course spline. I guess since I will be using my 60 t-case that I will need a course spline H55. Kinda new to all this and learning alot as I go. Any advice and input would be great.:confused:
THANKS

Ryan (Bluehawk)
 
Hi Ryan,

You want an H55 with the coarse spline from an FJ/HJ setup. The BJ trannys have a longer input shaft and fine spline and won't work. They also have a smaller nose cone, 35mm instead of 38mm as in the FJ/HJ so they need a smaller throwout bearing setup.

The runstand that I use is my buddies and it is a comercial made one that is adjustable to fit just about any engine. The base dimensions are 32" x 46" and it is made from 2" tubing.

FL Cruiser is dead on with the gear ratio info. When I was running my H55 with 3.70 gears and 35's it was just a little under geared at highway speeds. 70 was doable but it was a little wound up at that speed and doing approx. 2250 RPM. I like being closer to 2000 when cruising down the highway if possible with this engine. I found myself only driving at 67 to 68 a lot of the time because of not wanting to wind the engine up too much and to get better mileage. Now that I am running 27% overdrive with my auto, I cruise right at 2000 RPM and 75 mph and my engine loves it.

H55 is a great tranny and I love them, but just know that you will limited by your overdrive ratio. I consider 35" tires to be a minimum with this combo unless you don't mind driving 60 to 65 on the highway.

Hope this helps,

Don
 
Don,

Yes very much sir. I was looking at the link you posted on the gear ratio calculator. Do you happen to know the ratio on the gears of a H55 and ratio of stock fj60 tcase? I plan on running 35" tires when it is all said and done. Thanks for the measurements and I will send pics of the test stand when I get it built.

Ryan
 
Don,

Yes very much sir. I was looking at the link you posted on the gear ratio calculator. Do you happen to know the ratio on the gears of a H55 and ratio of stock fj60 tcase? I plan on running 35" tires when it is all said and done. Thanks for the measurements and I will send pics of the test stand when I get it built.

Ryan

The H55 has a 4.9:1 first gear ratio and a .85:1 5th gear ratio. The stock 60 split case is 1:1 high range and 2.27:1 low range IIRC.
 
Has anyone ever put in/replaced/etc a "better" overdrive ratio/gear into the H55?
 
I was thinking the perfect setup would be an H55 or 4 speed with an add on overdrive like the Roamerdrive on a splitcase.

Wonder why the Roamerdrive guys don't do it? Maybe they've missed all the people putting diesels in Landcruisers lately?
 

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