1989 F250 Light Duty???
 

Hello everyone. I just joined the forum and just purchased my first Ford truck! To make a long story short; I was in the market for a 3/4 or 1 ton truck and I found a great deal that I couldn't pass up. I got a heck of a deal on an '89 F250 4x4 302FI 5spd. Come to find out, it's some kind of Light Duty F250? According to the VIN it only has a GVWR of 6,001 - 7,000 lbs??? Does anyone have any additional info on this situation?

Thanks.

Well, that truck is going to have a lighter duty strenth suspention, and maybe frame as well, but i am not sure about that at all right now. The fact is you can easily build up the leaf springs in any way you want. If hauling large farm loads, and trailers my favorite is leaf springs with seperate over load springs. This way the overoad helper springs are only used when loaded down heavy. This will give you great handling yet a great way to haul a lot. If the frame is built not as strong as you need it to be you can always add to it and double C- channel it, anything like that. But, just as well thats a lot harder to do and more time taking. You could easily beef up the clutch and brakes. Anything to help you haul more without over doing it. Hope this helps. At least with my f-150 that had a lower gvwr, when compaired to my friends, his had a stronger frame, better leaf spring suspention, better front suspention, and etc. I believe this is the case in yours. As long as you have the ZF 5 speed transmission, a 302 v8, and a pretty low geared rear end there should be a lot you can haul!

I'm pretty sure the frames are all the same between the LD/HD 250 and 350's. The springs are lighter, less leaves on the LD and the the rear axles are semi floating axle vs the full floating axle on the HD. The front may be a dana 44 vs a dana 50 on the HD.

Thanks guys. That truck does have 8-Lug axles and overload springs. But it is geared high. I definately need to get some lower gears. Hopefully it has the ZF 5spd and not the 1/2 ton Mazda R2. Do you all know if the gears from a regular F250 fit? Or do I need to look for some from a 1/2 ton?

I'm no expert, but I believe what you have is essentially an F150 with a higher GVWR. Do you know if you have the mazda 5 speed or ZF-5? What rear? My F150 GVWR is 6250 which I'm pretty sure is the heaviest you could get an F150 at the time

I was thinking the same thing about it being an F150. I even told my buddy after i drove it that it was geared really high - like maybe it had a 1/2 ton drivetrain in it. But sure enough, it's all original, matching running gear. It has 8 Lug axles and looked like a 3/4 ton when I looked at the undercarrage. It has leaf springs on the front. Tonight i'll see what 5 spd it has. I can get "regular" F250 gears very easily, but will they fit in this "mini" F250? I'd like to add 4.10s or lower.

if you changed that out to 3.55 gears you could get decent fuel economy and good towing. Not sure if you are worried about high way speed but, with 4.10 gears you could really tow some stuff very well! Now, if you are not worried about highway speed and its a pure farm truck you could put 4.56 rear end gears in it! Massive torque, but your top speed may be 55 or 60 mph if not 50mph. Low gearing is torque multiplycation:) Served me super well in the past. If it is the light duty rear axle in the back, you could change out the whole axle assembly to a heavy duty 250 or 350 one. Lots of great options. 302 is a great engine i know i enjoyed mine, but my drive train was geared to high in my truck as well. The mazda's M5OD (transmission) bearings are not able to handle large loads such as towing. You should be able to look under it and tell pretty easy. Thats great news. But, as far as affordable swaps, you could go with a four speed low gear (again if you are not worried about highway speeds) new process np435 has the lowest gear ratio's and are strongest built, but the borg warners T-18 and T-19's are great too! None of these have a overdrive. But serious towing power is very posible, let us know what you find out. A ZF transmission will cost more but you do get overdrive which is nice

buddy of mine had a 90 light duty F250. It had the HD Dana 44 TTB front axle and a semi floater 10.25 in the rear. His had the 302 and a zf...

I would say leave the front alone and switch the rear to a full floater. If you want to change gears, It is my understanding that you could put a dana 50 3rd member in your HD 44 housing. So I would say that you should find a truck with a full float rear and a 50 front and take the rear axle and the front 3rd member from another truck. I would say 4.10 gears would be a good combo for your uses. You cant swap in a dana 50 because the arms are different lengths IIRC.

or if you want to do it right, and if funds allow, find a solid dana 60 for the front.

But if you want to keep it simple, just swap in a full floater from a truck with the same gearing as your front and be done with it. No matter what you decide. Get rid of that semi floater.

Thanks for all of the input! Drew - this is great info! I have my fingers crossed that it is the ZF. If not, then it looks like the trans is going to be the first thing that will die on this truck. I don't really want to spend much money on this thing, but i think the gears are something i will have to do. I have found an entire rear end with 4.10 gears for $175. I think it's a F.F. I could pick up a third member pretty easliy too, but i don't know if i want to spend the money. Do you think just the ring and pinion from the D50 will work in my D44? Blue - if I can find some 4.56's for cheaper than the 4.10's, I will be ok with sacrificing the top speed. Thanks again for all the help.

Drew - How did your buddy's Light F250 hold up? Any major issues/weaknesses I need to anticipate? Was it able to do what a real 3/4 ton could do?

Thanks.

My F-150 has a GWVR of 6250.....

My 89 F250 is a HD truck, full floater Sterling axel with 3.55 gears. With the 302/aod it sux pulling anything! MPG is around 14. Best to go with 4.10 gears with the 302 engine so it can rev up in to its power band.

According to Wikipedia, my truck should have a GVWR of 8800. See if i listen to that stupid site anymore! It never said anything about a Light Duty. :-huh

I hear ya eddie. When I test drove this truck, my first thought was "this truck is geared too high"! I actually stopped and made sure I had it in first gear! I think 4.10's will be the best bet. Now i just have to figure out which ones will swap into my "whimpy" F250. :-huh

You would probably be fine with the axles and tranny that are in the truck unless you are going for big big loads. My friend and neighbor has an 89 250 LD 4x4 with the 300/5spd in it. He has used the truck since it was new for hauling firewood every summer and fall. Also had a 10ft camper and a 18ft boat behind it when he went camping. Only mod he ever did was air bags in the rear. He's never had an issue with it, still going strong. Don't know for sure what he has for gearing.