T-18 Transmission 4WD - Zf-5s42 swap
 

Hey guys,

I have a 86 f150 with 460 motor and t18 tranny 4wd. I was driving on 4th gear and suddenly didn't feel the gears engaging. Pulled over and learned that the truck wouldn't move in any gear. I read through a post from 2011 in this forum and realize that I might have a bad clutch disc or shaft. If it is the shaft, then might swap to the zf.

Has anybody done this before? If yes, can I use the transfer case from t-18 for the zf? what modifications am I looking at other than drive shaft, cross member and some drilling on the cabin floor to bring the 4wd drive lever?

Cheers,
PK

Cant answer question but are you sure it is not the transfer case being the cause?
It is also something the power has to go thru before it goes to the diffs.
Dave ----

Yes, it has been done. Several times. I did it w/a 351M, but the 460 makes it much easier. You will need a clutch set for the ZF as the input shaft is bigger. You will need the taller transmission cover that bolts to the floor from a later truck. Your transfer case will bolt up fine, but the mount it sets on will be about 3/4" further rearward and you will have to redrill the frame unless you use the crossmember from the truck the ZF was in. Also, you will need the pigtail that connects to the reverse switch from the truck the ZF comes from.

Hey Dave, I don't know frankly. When this happened last night, called my mechanic, he was like my shaft is gone. When I read through the post from 2011, one owner had the same problem. It turned out he had a bad clutch disc. I might have the same issue because I couldn't find a good clutch + pressure plate to match 460 and t18 tranny. Somehow got it going. Is there a way diagnose if it is my transfer case?
Cheers, PK

Thanks Gary, thats great. Do I need a new fly wheel as well, considering I put a new one to go with my t18? I remember having issues with the first set I bought and then changed it for a smaller clutch set. Basically had to change the fly wheel with a different bolt pattern. I am not getting it out of a truck, so may not have that option. Yeah I would like to use the existing cross member if that is an option. I am guessing that I have to drill holes in the frame regardless of what cross member I use. Correct? I didn't quite the follow the pigtail part. I do have side tank, you think I will have enough room (again guessing zfs are longer transmission).

One more thing - I don't need a bell housing, correct?
Cheers, PK

I think in any case you would need to drop the trany & transfer case (tfc) to check the clutch, input shaft of trany and with the trany & tfc apart you would be able to turn the input shaft of the tfc and see if the output shaft turns. Only way I know of checking the tfc.


I was thinking if the tfc has a lot of miles and had a chain the chain might of broke and why I asked about the tfc.


It may be the input shaft or clutch as others have had them go bad but did not want you to over look the tfc.
Sorry cant be of more help.
Dave ----

You shouldn't need a new flywheel, although the bit about a smaller clutch confuses me. However, I did some research on clutches when I put the ZF in Dad's truck and did find a smaller clutch that fit the ZF. So, if you get to that point I can dig that info up.

If you use the existing crossmember you will have to drill new holes. But, with the crossmember for the ZF you won't. And drilling the holes is a pain as you really need to have the upper braces and they bolt to the top of the frame. However, you are only ~1" from the bottom of the cab, so can't come in from above to drill, and there's not enough space before you hit the bottom of the frame rail to get a normal drill in there. But, a right-angle drill and a really short bit will work. And, I pulled the mount bolts on the cab and jacked it up to get more access.

Pigtail is the wire that goes from a connector on the left-side frame to the tranny to connect to the neutral switch. If you don't have that it won't start, and if you bypass the switch it'll start in gear.

The ZF comes with an integral bell housing, but is only ~3/4" longer. However, it is taller and you must have the taller transmission cover. On the other hand, there is plenty of room side-to-side.

...Gary beat me to it and did a better job!

No problem Dave, thank you for responding so quickly.

Gary, you rock. Thanks again.

I am not sure what clutch kit the clutch shop sold but this is what it looked like (attaching a pic) and did not work with the t18. The pressure plate did not let me attach the bell housing. So had to change the whole kit. The first fly wheel had 8 holes and the later one had 6 that fit the smaller pressure plate. Yes we can pick it up later if I go that route.

You are so right about that. I had lot of trouble removing the old cross member because of the elbow that fits to the upper side of the frame. When I put the T18 back, I actually did not put the elbow back and bolted the transmission to the single plate. ((Now that I write this, wonder if the vibration caused this issue. :( )) Is it easy to find a zf cross member and transmission plate? Do you have know of any sources other than ebay or craigslist. I live in Atlanta.

Oh ok, I have the wire connected to the transmission but my truck starts regardless. It used to work when I bought the truck but at some point it stopped working. This is an easy one then.

Cheers,
PK

Gary already told you that the ZF5 has the bell integral with the trans. But since you already have a T-18 on the 460 you must have a bellhousing for a 460, and those aren't real common. So don't just junk it if you switch to the ZF5, somebody will want it.

Although one other thought. You said the flywheel and bellhousing didn't fit together when you first put the T-18 on. Is it possible you have a 351M bellhousing? I believe they have the same bolt pattern as a 460, but not the same depth (don't know which is deeper).

The 460's bell housing is about 1/2" deeper than the one for an M/400

Hey Bob, I did buy the bell housing and paid a handsome price for it. So definitely not giving it away. It came out of a 460. I couldn't figure out why the one shown in the picture did not work with the bell housing.

Hey Gary, is there anyway you know of a lead where I might find zf 4wd transmission. I am looking on ebay and it almost working out to be $1500 without a core.

Cheers, PK

So is it possible he has an M/400 bellhousing instead of a 460 bellhousing?