Isuzu 4BD1T swap part II : now w/ A440F auto

[longbow]

Hi Don,

Glad to see another 4BD conversion going in!

I use Roadrunner Torque Converters in Phoenix to do my work. They are a good company to work with. I looked around for a while to make sure that I got a diesel Toyota torque converter to do this conversion. That turns out to have been a waste of time. I have learned a lot over the last few months about torque converter design and rebuilding. The only difference between your 3FE torque converter and a diesel Toyota one, is the stall speed. I have since learned from the boys at Roadrunner that I can take my gas torque converter and lower the stall speed during rebuild (by replacing the stator assembly) and turn it into a diesel converter. I wouldn't waist my time looking for a diesel torque converter and this is how I am doing my second conversion. They quoted me $225 for the rebuilding and lowering the stall speed. They can turn stuff around in just a couple of days too.

As far as the bolt holes for the BJ converter, I used the toyota flexplate layed over the Isuzu torque converter plate and made sure it was centered by measuring with a dial caliper many times all the way around to be sure and centered on the pilot, and then clamped it down with 4 clamps. I then used the holes in the flexplate as a drill guide and drilled all the holes with my drill press.

Let me know if you need any other help with this.

Don

 

[dontoy]

Don,

Thanks for your quick response and great information. I have wasted so much time & energy trying to determine which direction to go and you have now made it a no brainer. I will be sending my gas A440F converter off to the guys at Roadrunner Torque Converters to rebuild and lowering the stall speed.

Concerning the bolt holes for the BJ converter. I assume you laid the toyota flexplate on the back side of the Isuzu plate to use as a drill guide since you mentioned centering it on the pilot. Did you then use a transfer punch to locate/then drill holes in the plate large enough to clear the Toy converter bolt heads? Would this then be followed by drilling smaller holes (bolt shaft dia) through the clutch face surface? Sorry for not getting what your saying.

Yet another question- Is it correct to assume an A440F would have to be overhauled in order to replace the gas governor with that of a diesel? If this is the case then I plan to lower the stall in the torque converter but just use my gas A440F as is.

thanks again

Don Ferguson

 

[longbow]

Hi Don,

You just need to drill the holes from the back side of the isuzu plate like you said. No need to recess the holes because there is already a recess on the plate right in that area on the isuzu plate. I went to the bolt and nut shop here in town and purchased some button head machine screws and they fit perfectly for the recess that is there on the back of the Isuzu plate.

As far as the governor is concerned, I was worried that mine was a gas governor in my tranny but my shift points are not too bad right now. My goal is to get a diesel governor, but for now it is working just fine as it is. My 1-2 and 3-4 shifts are just about perfect. The shift for 2-3 is slightly higher at about 2500 but it isn't that noticeable during normal driving around town. If you can find a diesel governor then put one in, if not, I wouldn't worry too much about it. By the way, I believe you can change the governor out without a complete dissassembly of the tranny. You would just need to remove the transfer case and then the transfer adapter housing from the rear of the tranny and then you can access the governor from there and remove it out the back.

Hope this helps,

Don

 

[dontoy]

Thanks Don.

As soon as I get the seals changed out on the 4bd2, oil pan modified, and turbocharger rebuilt I'll be pulling the 3FE, A440F, and tranfer case out of the Crusier.

Buy the way do you remember the OD of the 5/8" 6061 AL plate that I'll need to buy?

Thanks again for ithe nformation and advice.

Don Ferguson

 

[longbow]

Don,

The plate I used was 13.5 inches in diameter.

 

[ZDOG]

According to this the governor for the AW450 is listed as an A440 part.

https://www.wittrans.com/showfilter.aspx?Category=1287&Section=119

I know my A440 sure feels like it shifts way too early for the torque curve of the 3FE.

 

[astr]

According to this the governor for the AW450 is listed as an A440 part.

https://www.wittrans.com/showfilter.aspx?Category=1287&Section=119

I know my A440 sure feels like it shifts way too early for the torque curve of the 3FE.

There is no governor on the AW450 as that function is performed by the TCM.

I suspect that the only difference between the diesel and gas governors on the A440F would be the internal springs or weights if even that. If you have access to a Toyota parts catalog, you might be able to pinpoint the difference. There really isn't much to the actual governor.

As Longbow stated, you can access the governor without a complete teardown of the transmission. You will have to remove the T-case and T-case adapter.

 

[dontoy]

Thanks guys for all the feedback.

Don- 13.5" plate dia sounds great. I measured 13" across the luggs of the Isuzu bell housing that will face the A440F. Thanks for the info reguarding the governor.
Were you able to use any of the bottom bolt holes on the Isuzu side of the adapter plate? In the photo bolts are only in the upper 5 holes.

Zdog- I'm counting on the fact that the A440F seems to want to shirft early.

Astr- Good to hear that the governor can be removed through the back of the A440F. I kind of want to open the T-case to see what shape the splines on the output shaft etc are in so maybe that may be the time to go on in and replace the governor. I'm also considering doing the T-case gear ratio change. It would be the one that gives 10% overdrive and a 4.0 low range.
Maybe best just to do the initial 4bd2t conversion and see were everthing stands first though.

Don Ferguson

 

[longbow]

Don,

I used 7 of the 8 bolts. The one that you can't use is the one at lower left at 7 o'clock. It is almost directly over the toyota bolt. Also if you look close, the lower right one I had to trim a little bit of the head of the flush machine screw so it would clear the isuzu bell bolt. I don't know why, but that is the only front photo I took and all the bolts weren't in yet.

I was thinking of changing out my governor too, but it drives so nice right now that I really don't have the need to.


Don

 

[dontoy]

Don,
Thanks so much. Will be replacing seals today and maybe adjusting the valves. With luck the harmonic balancer will arrive as original is shot.
Don F

 

[UZJ40]

Excellent thread, very informative! Thank you!

 

[mr jits]

Keep me posted. I am going to start looking for an engine to start tearing into. It will definately be a slow build process over the next year or so.

clint

Clint, if you find another Isuzu while you're looking let me know. I'd love to do this swap as well. It'll be a slow one for me too, but I'm set on doing it.

 

[Dirtgypsy]

Clint, if you find another Isuzu while you're looking let me know. I'd love to do this swap as well. It'll be a slow one for me too, but I'm set on doing it.

Thread hijack for MrJits. I have located a full drivable 88 NPR flatbed in Seattle. Have not pulled the trigger as Christmas wiped my funds. I have the guys contact info if you want me to forward it to you.

Clint

 

[Burning Oil]

Very good thread. I liked the first one also. Im getting real close to finishing mine.
What did your MPGs come out to?

 

[longbow]

My speedo cable broke right after I put this in so it took me longer to calculate the mpgs than I expected.

I am right at 23 to 24 MPGs on the highway and about 21 to 22 around town.

Don

 

[busmup808]

Longbow

I have a 4bd1t in my garage with a intercooler. I have a 91 LC with the 3fe/a440f. Did you leave your gears to 4.10s? I was going to regear mines to 4.88/5.29s to compensate the lack of power and put ARBs. I don't want to regear again if i do the swap. By the way, I really appriciate the info you and the other guys wrote/pictures for the swap. Nice work!

 

[longbow]

Busmup,

The FJ60's have 3.70 gears and to be honest I wouldn't re-gear at all. With my 35's I feel that my gearing is close to perfect with the diesel engine. Diesels make their torque much lower in rpms but they top out much sooner as well. I really don't take mine over 2500 to 2600RPM very often. When I am out wheeling I just idle through most terrain and it very rarely bogs down when in 4L. Unless you are going to use this as a trail rig only, I wouldn't re-gear that thing.

Before I do my 80 swap, I am probably going to re-gear to 3.70 because I want my RPM's to be as low as possible at 75mph. My 60 is my daily driver and with the A440 tranny and 3.70 gears it sits right at 2000 RPM when I am cruising at 75 on the highway with 35" tires. I honestly wish that they made 3.50 gears for cruiser diffs because I think that would be ideal for a cruiser with a diesel.

Just my 2 cents.

Don

 

[longbow]

Whoops! I just realized that I don't think anyone makes 3.70 for the smaller front diff on an 80 series so you may be stuck with 4.10's

 

[FL cruiser]

With the Isuzu, dropping to lower gears you'll hardly notice any power loss driving around town. It's nothing like what happens to a 3B when you add bigger tires or lower the gears.
Even with 37" tires I went from 4.11's to 3.70's.

 

[folsom50]

With the Isuzu, dropping to lower gears you'll hardly notice any power loss driving around town. It's nothing like what happens to a 3B when you add bigger tires or lower the gears.
Even with 37" tires I went from 4.11's to 3.70's.

Really?! That's good to know. I'm in the planning and acquiring stage and have been really torn on what trans. (final OD), gearing, and tire size to run for the perfect rpm.