Yeah, this 240 has 155,000 on it, so it's not exactly at the top of its game, either. z
Which Mazda tranny do I use? I'm assuming 1/2 ton with the small block pattern? Did the 4.9/5.0/5.8 all use the same ratios?
90% of my driving is with an empty bed or very light loads. The thing will almost never see any real loads. Hell, I bet the original 3 speed stick would stand up fine for a while!
You're right on there...The Mazda M5R2 was used in the 1/2 ton and light 3/4 ton trucks with a six or small block. They all had the same ratios.
For an old 2wd truck the one to find is the 88 to 91 model because it has the speedo drive stuff.
370 gears will probably be too low depending on tire size. With 31"s I'd say 3.25's or so and smaller tires 300 gears. It's best to gear for 1700 RPM at cruising speed with the 4BT.
I got another complete 4BT from the friend that was driving my '71 when it died a couple days ago. I detailed it up nice today and painted it up black (not a fan of cummins beige). I also bought the "366" 3200 RPM governor spring to install. I've worked on a good number of diesels, but never actually gotten to the innards of an injector pump before. I was a little hesitant at first and looked through all kinds of instructions for the 366 spring install on the web, even printed off a 13 page step by step procedure.
Well, once I took the first 4 screws out I started to realize how darn simple these IP's are inside and threw the instructions in the trash.
The whole spring swap detailed in 13 pages of BS takes 12mm, 17mm wrenches, a 5MM allen wrench, a thin steel rule and 5 minutes for a braindead monkey with one arm tied behind his back to complete.
A VE pump makes a quadrajet look like cutting edge rocket science.
Dustin
Out of curiosity how different is a S547 from a S542 tranny, their supposed to look identical but what about a spline count mating to a 205 and gear ratios? The page said they were for 95 and newer trucks with small blocks so wondering if this could be an option or not.
Also would there be any benifit to running a Zf 6 speed if I found one 4 a deal, what would I need to make it work an adapter plate?
I'm pretty sure the only difference between the 42 and 47 is the input shaft. The 47 started with the new body style and used a 1 3/8" input shaft like the 6 speed. The 47 is not very common and only found in the modular and diesel bellhousing pattern.
If you find a deal on the 6 speed it's a great tranny, I haven't figured out how to mate it with the 205 yet, working on it. Keep in mind if you find a non-small block bellhousing tranny you'll need to buy an $800 adapter to make it work.
The benefit to the 6 speed is a granny gear and it's a bunch stronger. The ZF 6 speed and ZF diesel 5 speed have almost the same ratios, the 6 speed just has a granny and different shift pattern.
Ok I'm all mixed up now I wanted to make sure what spline count the 205 case has for sure. So I went down to my storage unit and brought one of them back home, pulled the adapter housing off and it it 31 spline counting the bumps or the dips doesn't matter I counted about 10x each. Does this mean we can use the earlier Zf 5 speed 4x4 app?
