Builds Isuzu 4HE1TC into FJ62 (1 Viewer)

[astr]

How does the Isuzu normally send tach signal? Is there an issue with the type of signal that it sends so it wouldn't work with the std wiring and tach?

-Phil

Normally, the Isuzu does not have a tach so no tach signal for that purpose exists. There is an rpm sensor in the IP that goes to the TCM for transmission control. I don't know what this signal looks like. For the FJ62 tach, you need 3 pulses per engine revolution. Normally, this signal comes from the ignition coil primary. If you look at this signal on an oscilloscope, you can see that is very "noisy" so the tach input circuitry has to do a bunch of filtering of this input signal. This filtering circuitry allows you to drive the tach with some pretty bizzare signal, i.e. the signal from an ABS wheel sensor.

Below is what the standard tach signal looks like on a stock FJ62, very typical of a Kettering ignition system. When I get a chance, I'll post a photo of what the signal from the ABS sensor looks like.

 

[rchalmers3]

astr,

It's been awhile since I looked at primary ignition patterns, but I would have to disagree: that pattern does not look at all "noisey".

I'm guessing, but maybe instead of filtering, the tach circuitry reads the voltage differences (hi-low) and counts or averages them to create output pulses for the tach meter.

It would be interesting to see the input and output signals in comparison....

I expect the ABS sensor signal to be a sawtooth or square wave, which will be much prettier than a coil saturation/dissipation pattern.

Rick

 

[astr]

astr,

It's been awhile since I looked at primary ignition patterns, but I would have to disagree: that pattern does not look at all "noisey".

I'm guessing, but maybe instead of filtering, the tach circuitry reads the voltage differences (hi-low) and counts or averages them to create output pulses for the tach meter.

It would be interesting to see the input and output signals in comparison....

I expect the ABS sensor signal to be a sawtooth or square wave, which will be much prettier than a coil saturation/dissipation pattern.

Rick

It does looks like your typical automotive ignition waveform, however, it is "noisy" as compared to what you would see from a magnetic transducer or a hall effect switch. My guess is that the tach uses some sort of R/C network to smooth the waveform and get rid of some of the ringing followed by a clamping circuit to get something resembling a square wave, maybe followed by a one-shot to get a fixed length square wave followed by an integrator to generate an analog voltage to drive the meter movement. Remember, this 1980's technology. But then I'm only guessing.

It would be interesting to look into it further but I'm content to leave it a mystery as long as it serves my purpose - display the RPM of the 4HE1 with the minimum amount of modification.

I would expect you are right regarding the ABS sensor output. I still intend to put a scope on it once I have the sensor mounted on the engine to see what the output looks like. I'll post the results here once I've done it although it is not high on my list of priorities.

 

[RAYJON]

I may have missed this but did anyone look to see if the output shaft on the a442 and a440 are the same or is the a442 more like the a540?? just a thought..

i like the idea of possiblely using the a442 in my 93.. with the a540 belhousing and converter, and a toyota diesel trans controler....

 

[astr]

I may have missed this but did anyone look to see if the output shaft on the a442 and a440 are the same or is the a442 more like the a540?? just a thought..

i like the idea of possiblely using the a442 in my 93.. with the a540 belhousing and converter, and a toyota diesel trans controler....

Post #96 has photos of the A440F and AW450 output shafts. If anyone has or can take a photo of the A442 output shaft, please post up. I suspect that the electronic A442 is probably cvloser to the AW450 than the A440F.

 

[boots4]

Glad I found this thread! I've just finished reading it and it's great to see new things tried and I'm excited to see you succeed. Thanks for your level of detail and I hope for the best. 175hp and 347ftlbs is going to make it very easy to drive your rig everywhere.

 

[ozwallaby]

C'mon Astr.... break radio silence.... you must have made SOME progress......

 

[astr]

C'mon Astr.... break radio silence.... you must have made SOME progress......

I've spent a good amount of time getting my mill working correctly so that I can mill the spacer. Still not done but getting close. I did order and receive a McNamarra gear and have a T-case rebuild kit on order. I also discovered that the sensor hole above the flywheel that was plugged on my engine was used by the 4HK1 series for a crank position sensor so I have one of those on order. I hope to use this sensor to provide a signal to drive the stock FJ62 tach.

A general question for those who have been following this thread: Once the spacer is finished, the next step will be to assemble the AW450 transmission using the A440F output shaft. Would people like to see this process documented? Basically, I will be following the FSM. It will be the same process that one would go through to do an overhaul. If I do document the process, it will slow things down even more. What say you?

 

[ThePookieBear]

I for one would like to see it documented. I know its alot of extra work load on you, but if you're willing to do it I would be down with that since this is probably the route I would go in the future.

 

[ozwallaby]

Post it all up and the people who don't want to read can NOT read it...

 

[euclid]

I've spent a good amount of time getting my mill working correctly so that I can mill the spacer. Still not done but getting close. I did order and receive a McNamarra gear and have a T-case rebuild kit on order. I also discovered that the sensor hole above the flywheel that was plugged on my engine was used by the 4HK1 series for a crank position sensor so I have one of those on order. I hope to use this sensor to provide a signal to drive the stock FJ62 tach.

A general question for those who have been following this thread: Once the spacer is finished, the next step will be to assemble the AW450 transmission using the A440F output shaft. Would people like to see this process documented? Basically, I will be following the FSM. It will be the same process that one would go through to do an overhaul. If I do document the process, it will slow things down even more. What say you?

I would like to see how the A440F shaft goes into the AW450, other than that I'd say skip it. Here's a thread that pretty fully documents the rebuild process.
Here's part 2.
Just posting those to ilustrate that it's been covered, which may free you to skip it.

 

[astr]

I would like to see how the A440F shaft goes into the AW450, other than that I'd say skip it. Here's a thread that pretty fully documents the rebuild process.
Here's part 2.
Just posting those to ilustrate that it's been covered, which may free you to skip it.

Thanks euclid. It would be a repeat of the two threads so I'll just focus on the specifics as related to merging the two transmissions together.

 

[jb BJ73]

just curious, do the aw450 internals appear to be stronger than the a440f(clutches, ect). and if they are will they fit in the a440f housing?

 

[astr]

just curious, do the aw450 internals appear to be stronger than the a440f(clutches, ect). and if they are will they fit in the a440f housing?

I haven't broken down the subasemblies yet to compare. IIRC, the AW450 may have more plates in some of the clutches/brakes. I want to eventually do a side-by-side comparison of the components.

As far as direct interchangeabilty of the complete subassemblies between the two transmissions - no, there are enough minor changes that can't be swapped.

 

[AppleTech]

Just checking in - hope all is well with you! How goes the project?

-Phil

 

[astr]

Just checking in - hope all is well with you! How goes the project?

-Phil

I apologize for no updates but I've made no progress specific to the conversion. I finally got all the parts together for my mill and hope to have it running by this weekend. Then I can finish machining the spacer that I need for the transmission. Its been very frustrating as everything always takes much longer than you think.

 

[astr]

The Quest for the Perfect Spacer

Well, I finally made some progress this past weekend:

THE GOOD NEWS: The mill is back up working and we are becoming friends!

THE BAD NEWS: I did get the piece of aluminum that I had loped off the front of the AW450’s extension housing milled down to the right thickness; however, I had failed to take into account the interior shape of the casting as well as the position of some tapped holes. The end result was that these “flaws” impinge on the machined gasket surface that would mate up to the T-case adapter. The first photo shows the machined side of the spacer with the outline of the gasket traced on it. The red arrows point to the problems areas.

Next step is to try and make the spacer out of a piece of ½” aluminum plate. As z-power suggested earlier in this thread, create a dxf file of the spacer shape and hole locations and convert that to G-code which will allow the mill to cut the spacer. I’m very much a noob regarding CNC and G-code writing so this will be a slow learning process. I think some optimist named it G-code. I believe it stands for “Gee – it actually worked” . Unfortunately, the stuff I produce should more appropriately be called S-code!

The 2nd and 3rd photos are of the “flawed” spacer installed between the T-case adapter and the AW450 transmission. It fits perfectly! The idler gear now aligns properly with the output gear and the park pawl, which is located in the T-case adapter, aligns with the park gear that is located by the A440F output shaft.

 

[AppleTech]

Great work! I am wondering why a gasket is necessary though... Isn't the adaptor a sealed unit or does it share fluid with the tranny?

Nevermind... Just realized that the adaptor replaces the extension housing, which holds trans fluid.

 

[Dougal]

Next step is to try and make the spacer out of a piece of ½” aluminum plate. As z-power suggested earlier in this thread, create a dxf file of the spacer shape and hole locations and convert that to G-code which will allow the mill to cut the spacer. I’m very much a noob regarding CNC and G-code writing so this will be a slow learning process. I think some optimist named it G-code. I believe it stands for “Gee – it actually worked” . Unfortunately, the stuff I produce should more appropriately be called S-code!

S-code, I like it.

If you like I can try to crank some G code from a DXF for you. I finally got my mill back up and running after the spindle speed controller took a dump.

Have you considered getting it water jet cut? That'd only leave the holes to be done by your mill.

 

[astr]

...If you like I can try to crank some G code from a DXF for you. ... .

I might take you up on the offer. I would like to have the capability myself so I'm pursueing the CamBam package as you suggested.

.. Have you considered getting it water jet cut? That'd only leave the holes to be done by your mill.

No I haven't. I would have to farm it out to have it water jet cut and, if I get desperate, I can cut it on the band saw. The interior and exterior outlines are not dimensionally critical.

My current thinking is to do it all on the mill. If I can create a good drawing file (dxf) defining the hole positions and interior and exterior outlines, I may be able to make the whole thing without removing and re-registering the piece on the mill table. I would only have to change tools. As I have a quick change spindle and multiple collet chucks, I can preset all the tooling. Then it would be alsmost as easy to make multiple spacers as it would be to make one. Not that I'm interested in manufacturing these things, but it would give me some spares.

By the way, I was impressed with how much metal that mill was able chew off and how quickly! It took me about an hour to run the whole job and have spent at least three hours cleaning aluminum chip out of everywhere and everything. Its a good thing that I buttoned up the "electronic" cabinet before I started.