i havent been on for a while. ive got an 88f450 superduty dump 7.3 with 5 speed and transmission is out.will a 4speed out of a 6.9 f 250 work. thanks denny

 

yes it will , but without overdrive you will only have a top speed of around 45 MPH.

 

ouch.these beasts sport 4.63 (axle code 72) or 5.13 (axle code 73) gearing.without an OD trans,you'd really be limiting her use.she would be begging for another gear at 35-40 mph and probably scream for mercy at 45-50mph in direct drive Denny.
really would be best to find another zf5 unless it's just a yard truck? you'd pay more than the extra cost the zf5 is over an old 4 spd in fuel pretty quick if she's still road worthy.
keep in mind,the trans are 4wd versions for the drive line brake.if she's payed her dues and isn't for the street anymore,then that's not needed anymore i suppose so an old 2wd 4 spd would move her around the back 40......but then the trans are likely different lengths and getting into driveshaft swaps etc.dunno there,someone else will have to help.

 

will that be all holly cow.will i have a lower low gear then too.

 

ok thanks a lot,yes she'S IN PRETTY GOOD SHAPE YET AND STILL ON THE ROAD QUIT A LOT SO I BETTER FIND THE RIGHT ONE FOR HER. is the zf5 about the only one

 

what all truck's had the zf5 transmission that would work in the 450 super duty. would the f150 have the same.

 

you need a 4 wheel drive diesel trans.

 

my 450 dump is only 2wd with the 7.3

 

correct. but the F-superduty uses a 4 wheel drive trans to mount the parking brake on the back of the trans. and diesel transmission will only bolt to a diesel engine. gas engines have a different bolt pattern and will not work.

 

ok, thanks alot tom that really helps me a bunch,is the liter duty trucks heavy enough or are they different,and is there certain years that will fit, mine is an 1988. thanks so mutch denny

 

You just need to find a zf-5, 4x4, diesel transmission. Should have been from 87-94?
They are pretty distinctive as far as the shape of the transmission goes, and you know what the shifter pattern looks like.

Also, you won't find a diesel in a F150/bronco(unless someone put it there after market), and the only OD manual transmission put behind our IDIs is the ZF-5, so it's pretty easy to tell.
You'll be looking at f250/350's, and perhaps larger(?).

 

I read at a couple of places that the early Power Stoke ZFs will work on the IDI as well, but confirm that before buying.

I've also read that the ZF6 can be made to work too, but all you gain out of it is a granny low.

 

The ZF-5 out of a 7.3L Powerstroke will fit and work, in fact the S5-47 in those trucks is a tad stronger than our S5-42 ZF's. That said, two points not yet mentioned are that the F450 diesel ZF's have the wide gear ratio with the "true" granny first and very low reverse gear. The pick-up versions had the close ratio gearing and higher reverse. Check the plate on the side of your ZF and see if it has the wide ratio (5.72-0.76 and 5.24 reverse) or close ratio (4.14-0.77 and 3.79 reverse). If you have the wide ratio type which you probably do, and you want to keep that gear spacing, you will need another F450 diesel ZF, OR... You can buy a 460 gasser ZF which has the wide ratio gears and re-drill the bellhousing holes to fit the IDI (known as the type 4 mod on OBN) (Compatability of ZF Gas 460 trans with IDI). You can also put the diesel main case on the 460 ZF guts but you need to get the pre-load right on the input shaft bearing. Also, since you will be shopping for a ~used 4x4 ZF, don't forget to look for the common problem spot which is a crack in the rear case by the 4x4 shift lever studs. There is a pic of it in this thread (ZF input shaft play: new bearing or full rebuild? - Ford Truck Enthusiasts Forums). And of course you want zero input shaft play... which is what that thread is about. Good luck, hope that helped.

 

thanks again all of you,just got back on and read the post's the zf-6 sounds like what i need with the lower granny gear cause mine isn't low enough sometime's what trucks had them in it.haven't checked to see what the plate say's on the side

 

Denny, sorry but the ZF-6 will not work for your application. The output shaft diameter and spline count is different on the ZF-6 4x4's, and it will NOT mate up with your drive line brake unit. Also, the ZF-6 low gear is 5.79:1 which is basically identical to the wide ratio ZF-5's low gear at 5.72:1 ratio. You will not gain a lower gear with the ZF-6. I am starting to think someone may have put a close ratio ZF-5 in your truck that has the 4.14:1 first gear instead of granny. Check it out, but at any rate, what you need is a wide ratio ZF-5 4x4 transmission, not the ZF-6. Hope that helps.