I have an '88 f350 2wd truck. I know where I can get a cheap 94 f250 4wd. I'm thinking of trying to transform my 88 to 4wd. Anyone ever done this? I think I have the twin i beam in the 350. Please, somebody tell me it'd doable.

 

Have I ever done it, No. Could it be done, Yes, if you know a good welder and mabey access to a machine shop. The addition of a transfer case to your transmission (assuming you can bolt one up) means shortening up the drive train. Then you have to cut a hole in the floor board for the 4x4 shift lever. You also have to make sure the gears in the front and rear differentials match. That would probably mean using both axels from the 94. Add on a dozen or so other unexpected problems and you are done. Probably better leaving it alone.

 

If you want an off-roader that you can scratch an not worry, take the cheap F250 and do a little to it, assuming it could be drivable and hit the woods, mud, sand, rocks, etc. A key consideration is the type F350 you have, Budd wheels (dually) or SRW? Lotta work, mixed components (350's had solid axles), fabrication issues, and $$$$'s.

 

The thing is, my 88 is a 12' rack body with dump. Can't easily convert a 250 to that. Just trying to gauge the feasibility of doing a swap. From one standpoint, you could figure Ford would keep as much stuff aspossible interchangeable. keeps costs down. But you know Ford, always making things difficult

 

Be careful here...if ya havn't read up on this conversion it may surprise you...

Ford pickups are extremely interchangeable...many parts will convert and bolt right in.

The 80-85ish F-350s were TTB D50 models. A TTB 4wd will bolt up under that F-350. There is a 4wd conversion tech article on our website (link above) for an F-150, but the swap is similar.

In 86 or so Ford went to a solid D60 up front on the F-350. That is a lot better for strength, but more difficult to swap in.

You don't even have to cut a hole in the floor, all 2wd models have a panel siliconed in to cover the 4wd hole. Ford built the cabs all for 4wds, then patched the hole for a 2wd. Look underneath, you'll see the hole. You can even get the 4wd indicator lights to work as the wiring should be there.

You'll need to change the tailshaft on your current transmission to make it able to adapt a Borg Warner 13-56 transfer case, or get a 4wd transmission if that isn't possible. A driveshaft from a 4wd F-350 with the same wheel base will fit, but a custom length driveshaft can also be done for around $100-$200 (modify your old one).

Do a search cuz theres a TON of people who have talked about doing it. On a Ford it's pretty easy. A good weekend wrencher can do it no problem.

 

wow... justin, you make it sound so easy... I'd be tempted to do it if I didn't know I don't have the resources available to me.

Ryan

 

Did you read the tech article? It's really not bad at all. I mean, you need to know how to take it apart and put it together, but that's not very difficult. It's almost the same job as removing the stock parts and putting them back in. It may make a first timer get confused at some points but you can figure it out.

The 4wd ttb will bolt in place of the 2wd twin i-beam...the brackets in the middle are the same and the arms are the same length. The front suspensions are direct replacements, I believe you'd need to change the transmission crossmember to a 4wd one, get any front driveshaft from a vehicle with the same trans, probably doesn't even need to be an F-350 could be in a F-150 too I believe.

I've never done the swap myself but I was going to. I read all about it and even had my own threads on it here in the past. I know how to do it but I didn't end up doing it because my truck got totalled lol. Bought a 4wd and theres my F-150 in the gallery after 2 years.

 

Ok gt221, You are elected to come to my house and show me. You're in MA and I'm down in CT
'Splain the difference between a ttb and a twin I beam.

 

TTB is the first version of a 4wd indepedent suspension, started in 80' and ended in 96. It's basically a differential on the drivers side, with axle shafts going through to transmit power to the wheels. It's a dana 44, just like the solid axle version, but made so that either wheel can move independently.

The Twin I-beam is the same basic design, but without a differential and without axle shafts and hubs. It's just two beams. Take a look around under there...

 

not to sound like a dink but wouldnt a solid axle swap be alot easier?????

 

To me it's considered more difficult. The trucks are just not setup to be that way. You'd need to fab up a bracket for the track bar. You'd also need to find a way to hold the axle in place, either by special hard to find/expensive to buy radius arms, a 4 link (diffilcult), going to leafs (fab brackets for shackles), etc etc...it's beyond easy in my opinion. The TTB swap isn't as strong as the solid D60, but it's a bolt in job...

 

i did one before on a 87 f-150 2wd . made it into a 4wd. i was fortunate enough to find a truck that was already a 4wd and swap all the parts into my 2wd . but i did make one big mistake and did not check the gear ratio in my rear and ended up with 2 different gear ratios. and had already junked the truck. so i had to mess with different size tires on the front and back to get the wheels to turn at the same rpm so i didnt end up destroying the truck . that was a pretty good lesson learned.

 

Ya, the gearing needs to be within 1% of eachother, and don't put it in 4wd if the tires or gears aren't the same size.

I ran my truck w/ different gear ratios for alil while, just didn't put it in 4wd.