A while back, I bought an Autometer Diesel Tach with the Alternator Probe. I'm now about to do the 3G swap. My tach is currently calibrated to the old 1G alternator. When I put in the 3G alternator, will I have to recalibrate the tach? Or since the pulley is the same, won't it read the same?

 

I didn't know Autometer had a tach with an alternator probe. Just found the install pdf from Autometer. It mentions that calibration depends on the pulley drive ratio and number of poles on the alternator. If you're using the same pulley, that would be the same. I'm not sure if the poles would be any different though on the 3G.

You might as well try it and see what happens. Seems like it is easy enough to calibrate though if you need to adjust it.

 

But.... I don't have a timing gun with the ferret meter to check the timing anymore. Had to return it to R&D. Maybe I can rig up a fine threaded turnbuckle to lock the throttle at a very specific RPM, so that I can check it once the 3G is back in.

 

I was going to say just pick a speed and note the tach reading, but then noticed you have an automatic so thats not guaranteed like it is with a manual trans...

The turnbuckle idea should work though. Just remember to take a reference reading with the old alternator before taking it out.

 

I'd just put it in first and run it up against the governor, noting rpm reading before and after the swap.

 

I'm with the pick a speed, and note the rpm idea, but do it at different speeds, and note both the high idle and regular idle speeds.

 

I just finished the 3G Swap. I made some "C"-shaped hooks out of some scrap aluminum bendable pipe at different lengths to lock the throttle linkage at different RPMs. I wrote down the RPM readings from the tach with the 1G alternator. Then after the 3G install, I placed the pipes and checked the tach.

Turns out that the RPMs were the same with the 3G as the 1G.

 

Could you throw up a couple pictures of your custom made hooks? Might be useful to someone in the future when they go to time their engine.

Glad to hear you were able to swap the alternators around without having to mess with the tach setting.

 

Just to confirm, I'm currently getting 14.1-14.5V with my new alternator. That seems high.... Is that typical? I have an aftermarket digital voltage gauge in my van, so I can see the voltage in real time. With my 1G, I never exceeded 13.0V. (It sits at 14.1, then climbs to 14.5V over 10 seconds, then falls fast to 14.1, then repeats. Since it's cycling up to 14.5 then falling and repeating, I'm assuming it's wired correctly and not constantly charging non-stop.... )





Here's a pic of one of the pipe hooks (which coincided with an RPM of 1970):



I'm sure most of you could visualize how to insert it into the throttle linkage, but just to clarify, here's a quick sketch:

 

I see 14-14.5v out of my 1G set up while driving. It drops into the 13v range if I have both AC blowers on high (the rear one seems to take a lot). Idling with nothing on the voltage is usually in the 12v range (12-12.9) when I first start the van and then climbs into the mid 13's.

Next time my alternator dies I am looking to swap in a 3G.

 

Do it sooner than later. My 1G wasn't even bad. I had it rebuilt about 2 years ago.

On a recent trip to the junkyard, I stumbled on a newly-dropped off 95 Taurus. I almost didn't check, cuz I've gone up to so many of these 90's cars only to find out it's a 3.0 or the alternator had been extracted already, but this time the gods took pity on me.

Opened the hood, and the unmolested 3.8 sat there. I grabbed a sheet of paper from the glove box, and compared its 8.5" edge to the mounting bolt distance. It looked right about 1/4" shorter than the short edge of the 8.5x11 sheet of paper. Confirmation! An 8 1/4" ear 3G!

Now, I can gab on about how it's better and amps and whatev, but the really nice thing about that alternator is the size. For our vans, every extra inch goes a long way. This 130A 3G is about 1" diameter less than our monstrous 100A 1G, so you can get an arm in above the alternator REALLY easy now. So do the swap sooner than later. The extra space is luxurious.

 

I have been checking out the 3G swap for a while now. I even priced out a new 3G off a 3.8 for the swap. I just keep weighing out the $ I want to spend and and the benefits. Got a little rust to repair, a turbo, a 4wd e4od (8 speeds would be awesome) swap and some passanger mods......house battery, 12v fridge, microwave etc.

If only money didn't matter.

I have started to getting 17-18mpg mixed pretty recently with better fuel. I keep telling myself to prioritize....anyone have a quality 4wd e4od they want to sell?

 

You gunna do the dreaded 4x swap? If you do, photograph everything so I can learn from your hard work.

 

You do know going 4x4 and adding a transfer case only gives you an additional: super slow, real slow, slower, and slow...
It won't help your mileage, and the added weight from the transfer case and heavier front axle with make mileage worse, not better....

I don't want to say going to 4x4 isn't worth it (cuz for other reasons its way more useful than 2wd) but it wont save you mileage, and unless you have some money and the time (or suuuuupppppeeeeerrr cheap parts and lots of time/your time doesn't matter) its not worth your time or money to go 4x4. Been there, done that.

 

4wd would be nice, but no. After the snow we have had the last 2 winters I have looked into it, but its a little more $ and time then I want to invest. I would like to get rid of the open diff I currently have though.

Here is a link to a good resource about converting our IDI vans to 4wd. http://www.glinx.com/~sbest/4vanhow.htm

The DNE2 overdrive I have is a direct bolt on to the 4wd e4od according to a number of members that have them. That means that in theory I could use the 4wd e4od with the DNE2 bolted to it instead of a transfer case. Then all I would need is the correct length drive shaft along with a stand alone controler etc.

I would end up with 8 gears total and a locking torque converter. The double overdrive would mean I could run a higher rear gear (4.10s or 4.56s) and still have lower rpms on the hwy than I do now.