So as the title indicates, I am doing a write up for a transmission swap in my F150 for anyone who might be interested. As far as I can tell it should be a pretty easy swap but I'll document it as best as I can regardless.

So my truck that's getting the ZF5 is a bone stock 1984 2WD F150 with the 300 i6, single crab with the stepside bed, originally equipped with the RTS TS-OD Top Shift 4 speed overdrive trans, mine took a dump on me so it's time for a new one.

Donor truck is a 91 2WD F250 with the 351 Windsor and 170k on the clock. It's ZF5 (which is the S5-42) looks like its in pretty good shape from the outside, stick feels smooth and tight shifting through the gears, input shaft turns easily by hand in any gear including overdrive. I have yet to pop open the PTO covers or remove the case to take a peak inside, would also like to have it dyno tested to verify its condition.

I'll begin removing my junk trans today, I'll be sure to take photos and update as I progress, I'm sure I'll have questions as I go along as well.

Anywho thanks in advance for any info you guys might help me out with along the way! Love this forum and it's helped me out a ton in the past already.

 

Ok already have a question about ordering parts for this thing if anybody is out there: I'm ordering a 11" clutch kit for the ZF5 (I believe its required anyway), do I order the kit for my truck's motor or year or the donor truck's motor or year? I would imagine the same 11" clutch works either way (I know the flywheel has bolt patterns for both 10” and 11” clutches) however looking on broncograveyard.com the part numbers are different between the two truck's motors and years even though they look the same. Do I order pretty much everything for my truck's year and motor? What differences, if any, are there? Is there anything that needs to be ordered for the 351W that the trans came off or at least from the same year as the donor? I know I'll have to at least get the slave cylinder for the '91 ZF5 and then I'll have to figure out an adapter or something to tie it to my '84 master cylinder.

For example, these three clutches are all for the 300 i6, just the specific years are different:
-this one is for a 1984-86 300 i6: https://shop.broncograveyard.com/198...uctinfo/31225/
-this one is for a 1988-93 4-Speed 300 i6: https://shop.broncograveyard.com/198...uctinfo/31231/
-and this one is for a 1988-92 5-Speed: https://shop.broncograveyard.com/198...uctinfo/31234/

the available specs for each appears to be the same, same price, are they the same clutch kit? Or is there minor differences in clearances or anything else? If they are actually different, which one's the one to get?

Thanks again!

 

Don't get a 4 speed clutch kit. I don't know about the 300 sixes and the 351w's, but do know with the diesels the zf bellhousing is deeper than the 4 speed bellhousing. It takes a different flywheel, and I believe the throwout bearing is different.

And in your previous post you mentioned You must have meant the flywheel is drilled for a 10 inch clutch or a 11 inch clutch. No way will a 300 flywheel work with a 351w. The 300 flywheel is balanced while the 351w has a 50oz weight on it.

If I were you, I would order a clutch kit for a 1992 f250 with a 300 six cylinder and a zf 5 speed. If they did not have the 300 six in 1992, keep dropping down a year till you run into them. And I would not use a 4 speed flywheel unless you can prove from several different parts houses they are the same part number as a 5 speed flywheel.

 

Right sorry I was thinking of the flywheel being drilled for 10" and 11" clutches. Thanks for the tip! Ill order the clutch and new flywheel for the 300 i6

 

My 5spd also came out of a two wheel drive 1991 F250, but it was the lighter duty F250, so it had a 302 and the M5OD-R2 5spd trans. Basically half ton stuff in an F250. No adapters required for the master cylinder, they connect the same. So you'll need a slave cylinder and a hydraulic line for the 1991, but order the master for the 1984 (They're cheap, might as well replace it). The 1991 master cylinder will work fine hydraulically, but it won't fit the firewall unless you drill new holes. Just stick with the '84 master, it's simpler.

Good time to install a firewall brace of you don't already have one.

I can't speak specifically about the ZF5, but I used my original 3 speed flywheel with my M5OD 5spd. Works perfect. My truck originally had a 10" clutch, but it was drilled for the 11". I just ordered an 11" clutch for a 1991 F150. Done like dinner.

I think a 5spd swap is one of the best mods for the Bullnose trucks.

 

Dave why the flywheel change?
If I under stand this right the ZF is from a 351 truck (small block bell pattern) going into a truck with a 300 six that has a flywheel already and it is drilled both a 10" & 11" clutch setup.
The only thing I see is getting a 11" clutch disc with the right spline count and dia size and that it is not to long.
I did a trany swap and the clutch disc hub had to be 1-1/16" If you got the easy to find one on everything 1-1/8" the hub would bottom out on the input shaft splines and not dis-engauge.
Dave ----

 

I swapped from a mechanical clutch SROD to a hydraulic clutch NP-435, and then later on from the NP-435 to the ZF5 behind my 300 and there were no differences. It just bolts up. The clutch, flywheel, pressure plate, etc. are pretty much all the same. The only difference is in the slave cylinder in the transmission.
I noticed that places list different part numbers for different years, but I think that has more to do with transmission specific parts that come with it, like the throwout bearing. But, the clutches are all 11" x 1-1/16" x 10 tooth

IF your SROD came with a 10" clutch, then you'd want to order an 11" clutch kit. Most 300 flywheels are drilled for both 10" and 11" clutches.

The reason BroncoGraveyard lists 88 - 92 for the 5 speed clutch setup is because of misinformation. The 300 was discontinued in the Bronco in 1992, but was kept in the F-series trucks until the body year change in 97.
So, just get a clutch kit for a 300 5 speed from 88 - 96 and you should be fine.

 

The reason I mentioned it was when dealing with a diesel you can't do it. I would look it up so see if they have the same part number for the flywheel, we already have the previous poster saying they are the same, so now I am thinking the 4 speed flywheel may work in this application but check to make double sure.

 

I had seen posts about the ZF making noise and the diesel flywheels being different than any others, duel mass or something like that.
Has to do with the power each cly puts out and the low RPM IIRC.
Dave ----

 

Alright I yarded out my old crapped out transmission the other day and got a bunch of pictures if anybody is interested:

First is a picture of my cert label in the doorjam with all the pickup's info on it:


-So again, my pickup a 1984 F-150 2WD stepside short bed single crab, with the 300 i6 originally mated to the now blown up RTS TS-OD Top Shift 4 Speed Overdrive (Trans code: B) with a 2.47 ratio rear end (Axel code: 17)

 

Here's the crap box in all its mechanical glory

 

So I'm by no means a mechanic, and this transmission swap will be one of the more involved things I've done. So I am trying to gear this write up for the lesser experienced peeps out there like me. For example, I assumed I had to unbolt or remove a retaining pin or something to remove the shift stick. Turns out all you need to do is unthread the black collar that screws onto the top of the shift tower, I used a big pair of channel locks but a strap wrench or something would work as well.

 

I'm no expert but I would guess my clutch is due for a service haha

 

It appears that my original clutch was an 11", I swapped the new and old discs between the new and old pressure plates and they appear to be the same diameter.

However I noticed that the width of my old clutch friction material is a bit thicker than the new clutch's friction material, is this any cause for concern?

 

New and old pressure plates