HELP! POSS NEW 5 SPEED FOR 100 BUCKS!!! HELP!!

[rjjp]

nobody mentioned if i could mix and match the gears? or the gear ratios for the ZF6?

Out of the ZF5, yes.
I don't think the ZF6 parts will fit in a ZF5 case.

 

[blown84]

im gonna guess that mine has the wide ratio gear set, cause it barely moves in first, and shifts are pretty big jumps. you gotta getter wound up pretty good to get any good pullin outta the shifts.

and id be usin ZF5 parts in the ZF6, but only if they have a more idea gear ratio. for instance, i want granny gear to be able to pull a house down, and only have to pull 2000 rpms to run 80. OOO!!! if i could run 80 at 2k, at 3k id be doin 120!

 

[bignastystacks]

That looks like a diesel ZF, I thought the gasser ones had rounder bellhousings?

And you had to cut the 4x4 shifter....wow limited tools for sure! If you have a auto now, the shifter will be different at the base.

I have a zf in my truck now Only reason im swapping is because I dont have 3rd gear... wont be an issue. Worst case I would make a new one.

 

[hesutton]

and id be usin ZF5 parts in the ZF6, but only if they have a more idea gear ratio. for instance, i want granny gear to be able to pull a house down, and only have to pull 2000 rpms to run 80. OOO!!! if i could run 80 at 2k, at 3k id be doin 120!

A ZF6 will not bolt to your IDI without major mods, more than required to get a 460 ZF5 on an IDI. You will also need a custom flywheel and clutch. JayBee did it once and that's the only time I've seen it done. It was a major project and there is no advantage of a ZF6 over a ZF5. Both are overdrive 5 speeds, but the ZF6 has a "low" gear under 1st. That's a ton of trouble for a granny gear only.

Heath

 

[blown84]

A ZF6 will not bolt to your IDI without major mods, more than required to get a 460 ZF5 on an IDI. You will also need a custom flywheel and clutch. JayBee did it once and that's the only time I've seen it done. It was a major project and there is no advantage of a ZF6 over a ZF5. Both are overdrive 5 speeds, but the ZF6 has a "low" gear under 1st. That's a ton of trouble for a granny gear only.

Heath

damnitall heath. way to kill my day!



lol. really, thanks for the info. guess ill just go with a ZF5 then.

 

[hesutton]

damnitall heath. way to kill my day!



lol. really, thanks for the info. guess ill just go with a ZF5 then.

Sorry. But, that's probably going to give you the best bang for your buck and effort.

Heath

 

[blown84]

i think you are right. for some reason, i seem to remember that the ZF6 was a double OD though... i wonder how hard that would be to do?? but i digress...

heres a curiosity though: if a PSD ZF5 will bolt up, no problem, why wont a PSD ZF6?

 

[hesutton]

i think you are right. for some reason, i seem to remember that the ZF6 was a double OD though... i wonder how hard that would be to do?? but i digress...

heres a curiosity though: if a PSD ZF5 will bolt up, no problem, why wont a PSD ZF6?

The ZF6 made it's first appearence on the second generation 7.3 PSD in '99 (1st "SuperDuty"). Different bellhousing pattern with the new gen trucks.

Heath

 

[blown84]

doah! those goofy ********...

 

[hesutton]

Here is what Jason (JayBee) did to make it work. He's a fabricator and has his own business so it was a bit "easier" for him, but not easy.

Ok, I am still getting occasional requests for info on how to do this swap, so I'll make a post with all the info I can remember on how to do it. It's been almost 2 years since I did it, so please excuse anything I forget to mention.

I now have about 20,000 miles on the truck with the conversion, and could not be happier. My only complaint in that time was with the ceramic puck style clutch disk I used. I have since replaced it with a conventional LUK disk and love it! There will be more on this to follow.

First of all, you have to remove the approximately 1" thick adapter plate the IDI's use in order to get the clutch and flywheel spacing correct. In other words, the bellhousing on the ZF6 is deeper and the input shaft is shorter, so the spacer has to go. The 7.3 powerstrokes have a different bellhousing bolt pattern cast into the block compared to the IDI. The good news is the 2 dowel pins, and 4 lower bolts do match up. The upper 2 bolts are the only difference. I made a stepped adapter to go from the upper 2 bolts on the IDI block to the upper 2 bolts on the ZF6. It was 2 pieces of 1/2" x 2" flat steel bar overlapped and welded together, making sure both bars were parallel after welding. The lower bar bolts to the upper holes in the block, and the upper bar sits behind it and has the upper 2 holes tapped for the tranny bolts. That makes the front face of the upper part of the adapter flush with the rest of the bellhousing in the block. I bought the stock tranny dust plate for a '99 and had to cut a little clearance into it for the adapter.

The next big hurdle is the clutch. The ZF6 has a 1.375" input shaft, and the smallest disk you can find with that spline is going to be 13" diameter. A 13" disk will not fit under any pressure plate that fits an IDI flywheel. My first way around this was to use a custom made 12.25" disk with the 1.375" spline and 4 ceramic pucks per side. This disk turned out to be miserable! The more you tried to slip it, the harder it grabbed sending the truck into convulsions. Backing up to a trailer was virtually impossible. So, I recently went a different route.

I had already used a LUK solid flywheel, so I pulled it back out and redrilled it for a LUK 13" PSD pressure plate. I now have the LUK pressure plate and disk for a '99 PSD and it works great. It reduced the pedal effort, virtually eliminated the gear rollover noise, and is very smooth. This is definitely the way to go. Oh, and you can't use a LUK flywheel for a PSD because they have a different bolt pattern on the crankshaft.

The clutch hydraulics weren't too bad, but not a simple bolt together deal, either. I used the correct master cylinder for my year truck. I used a slave cylinder for a '99 ZF6. The fork, pivot, and throwout bearing were all for a ZF6. The only real problem was trying to come up with a clutch hose that would work. I ended up making adapters that fit into the clutch and slave with a -3 AN on the other end. I then made a stainless steel braided hose to connect them. Bleeding was the typical pain, but it has worked great ever since.

The shifter ended up in exactly the same spot as a ZF5, so the tranny tunnel cover for a manual and boot all bolted up fine. I made my own cross member for the back of the tranny by heavily modifying the one that was in my truck with the E4OD. You might be able to bolt in a cross member from a '99 ZF6 - I'm not sure - was too cheap to buy one.

Of course you'll have to visit a driveshaft shop and get yours modified or a new one made. I also went to a '99 E350 disc brake rear axle at the same time, and had an all new driveshaft built to fit.

The ZF6 does not have a speedo drive gear. This is where a '92 up truck has the advantage. I used a speedo from the '92 up truck and made it fit inside my cluster with some slight customization. The '92 up speedo is all electronic, and I was able to drive it from the sensor on the rear axle.

The 7.3 IDI starter bolts directly into the bellhousing of the ZF6 and works fine. The bellhousing lower cover for the '99 bolted right up.

Oh, I did have to bend the floor of the truck up just a little bit for clearance, but it's under the seat and totally unnoticable.

I think that about covers it... If I remember anything else I'll reply to this post. If anyone wants a flywheel redrilled I could probably take care of that part of the conversion for them.

Jason

He sold the truck a while ago:

CLICK HERE

Heath

 

[blown84]

wow. too much work... i want somethin i can basically bolt in and go. speakin of which, will the shifter for the ZF come through the floorboard in the same place as the T19? and is the speedo sensor on the t-case or the tranny? cause obviously, if its on the t-case, that makes that part a wee bit easier.