I have a ZF5 from a 1990 F350 7.3L with 225xxx miles. I am looking to sell it, Im not sure what a decent asking price is? Any suggestions?

 

Answers to a couple of key questions will help a lot on suggesting a price

1) is it a 2WD or 4WD tranny?
2) is it a S-42 or a S-47

 

Now you got me curious, whats the difference? Gear ratios?

 

Yeah, mainly the first 3 ratios, plus the S-47 is a little stronger.

Per Dave Sponaugle.....

The ZF 5 S42 was available with two ratios:
1 -- 4.65 -- 5.72
2 -- 2.60 -- 2.94
3 -- 1.53 -- 1.61
4 -- 1.00 -- 1.00
5 -- .077 -- .076
R -- 4.35 -- 5.24

The ZF 5 S 47 was available with three ratios,
1 -- 5.72 -- 5.08 -- 4.14
2 -- 2.94 -- 2.61 -- 2.37
3 -- 1.61 -- 1.53 -- 1.42
4 -- 1.00 -- 1.00 -- 1.00
5 -- 0.76 -- 0.77 -- 0.77
R -- 5.24 -- 4.66 -- 3.79

The ZF I just put in my truck is the S-47 with the 5.08 1st gear. IMHO probably the best of the bunch being the stronger of the two, and having an almost perfect gear spread for all around use. The S-42 with the 4.65 ist gear as the 2nd best (as far as gear spread anyway), but not quite as strong.

After driving mine a little, with my 4.10 axle gears, I wouldn't want 1st to be any lower, or for 2nd to be significantly higher. For normal driving 2nd is about perfect for taking off from a dead stop, but I still have that 5.08:1 1st gear for when I'm pulling a load and trying to get the extra weight rolling.

If you look at the ratios of the S-47 I have you'll notice that each jump up in ratios is almost exactly half as big as the previous jump
5.08 - 2.67 = 2.41
2.67 - 1.53 = 1.24
1.53 - 1.00 = .53
1.00 - .77 = .23

That's almost a perfect spread to ensure that the RPM drop isn't too drastic when you make an upshift, but still make sure you have plenty of revs left as you're grabbing the next higher gear. Makes it easier to keep the engine right in the "fat" part of the powerband....

Like I said, the S-42 with the 4.65 1st is almost as good a spread - just a little narrower with a 1st gear that isn't quite as deep
4.65 - 2.60 = 2.05
2.60 - 1.53 = 1.07
1.53 - 1.00 = .53
1.00 - .77 = .23

Anyways, that's my 2 cents....

 

It is an S42, 4wd.

 

Well, FWIW, I paid $650 for my S-47 WITH a 1356 t-case attached.....