6.9 t-19 to zf 5 speed question again!!!!!!!

[crm391]

I have a 1987 6.9 f350 4 wheel drive and will be installing a zf 5 speed out a 7.3 of 1991 vintage, my question? Can I use the 11 inch flywheel and pressure plate assembly from a 6.9 with a sprung 1.25+10 clutch disc that fits the zf along with the zf throwout bearing and clutch fork? Does anyone manufacture this disc, I have read on several threads from other sights that it does exist but no one gives specific part numbers, any way what is the best way to go on this swap?Thanks

 

[Goose_ss4]

the only way you can swap in the zf is only if your 6.9 had a zf in it before. the zf was installed with a dual mass flywheel from the factory, and you cannot use it with the clutch for that flywheel. the pressure plat, flywheels, and through out bearring all need to come from the same truck. if you dont you will never be able to push the clutch in far enough for you to shift or put it in gear. that dual mass takes up some room and is thick than a single mass from the factory. south carolina clutch sells kits. i had just replaced mine since i was making to much power.

 

[gonecrazyi]

Not completly true, the 86 6.9 that I swapped into my 89 has the 5 speed and luk clutch kit that were on my 89 7.3 motor, bolted right to the back of it. Works great and bolted right in.


As for using a 4 sp flywheel, I think that I have heard of it being done but I cant seem to remember who did it.

 

[Diesel JD]

Billy you're right, Cheaper Jeeper used a 6.9 solid flywheel and bought about $100 worth of parts from Autozone to make it happen. I can't remember what all he did to it to make it work but you should be able to find the thread with a little digging. Otherwise you need to get the DMF and goodies from the 91 donor truck or buy the SMF conversion kit, and they ain't cheap. I think the TOB is ZF specific and the pilot bearing works for either transmission(not 100% sure of this though) if it were me I'd buy a kevlar pilot bushing from South Bend Clutch instead of a standard pilot bearing. I have a custom built mechanical clutch and even with that squirelly setup the clutch effort isn't too bad with the kevlar bushing.

 

[Silver Burner]

The only negative I've read about using the SM flywheel is all the excess noise when in neutral with your foot off the clutch. I'm maybe a month away from doing this myself. Have the part # for the LUK clutch kit and I'll probably have my SM 6.9 flywheel resurfaced and just reuse it.

 

[plywood]

This is just a "I thought I remember reading", but I thought I remember reading the DMF is balanced with the engine it is installed on and it cannot be transferred to another engine with out the risk of out of balance problems.

 

[smokin69]

Not true.

 

[hce]

I am about two steps ahead of you in the swap. I came up with 3 options. I will go from cheapest to most expensive.

1. Use the 6.9 flywheel 6.9 pressure plate 11" sprung disk as cheaper jeaper did. The clutch disk is for a 92 f-450 with a 7.3. The problem with this is autozone no longer sells the pieces. Centerforce sells the disks and pressure plates separately disk #381040 and pressure plate CF360033. I would order from summit racing. Use a throwout bearing out of a 7.3 zf application. Fort wayne clutch said that they could piece a clutch kit together if needed.

2. Single mass flywheel conversion for a 7.3. I am looking at one from phoenix friction and I will have the flywheel rebalanced(its good to have a friend with a machine shop). toss up in price between 1 and 2.

3. Southbend takes a 6.9 flywheel and drills it for a 13 inch clutch $650.

I am unsure if a 6.9 flywheel could be redrilled to fit a single mass conversion pressure plate and disk as they have a extra set of springs on the clutch disk and the relief hole on the 6.9 is smaller then the 7.3 smf

 

[franklin2]

Why do they make DMF to SMF conversion flywheels for a zf setup, if the factory 6.9 SMF will work? I don't think 6.9 SMF will bolt right in a zf setup, and that's the reason why they include a flywheel in the zf smf conversion kits.

 

[BigRigTech]

I can say from experience that a 6.9 T19 SMF will work with a ZF....I just did this swap when I put the 6.9 in my F350, I re-used the T19 11" pressure plate with a new Fenco 11" clutch disc, 1.25" input, 10 spline with springs....looking at it the 11" SMF from the 6.9 4 speed it looks identical to the 12" SMF I have in my 91 with the ZF....Runs, drives, works fine....Cost me $100 for the new disc, part number CP31103A. The TOB is the same from a T19 to a ZF.

My thread.

http://www.oilburners.net/forums/showthread.php?t=37745

 

[franklin2]

I can say from experience that a 6.9 T19 SMF will work with a ZF....I just did this swap when I put the 6.9 in my F350, I re-used the T19 11" pressure plate with a new Fenco 11" clutch disc, 1.25" input, 10 spline with springs....looking at it the 11" SMF from the 6.9 4 speed it looks identical to the 12" SMF I have in my 91 with the ZF....Runs, drives, works fine....Cost me $100 for the new disc, part number CP31103A. The TOB is the same from a T19 to a ZF.

My thread.

http://www.oilburners.net/forums/showthread.php?t=37745

One last question; Are all zf's created equal? You used a 460 zf. Is it possible the diesel zf may have a different depth to the bell area, thus causing the 6.9 SMF to be too thin to work with a diesel zf?

I just want to make positive in my mind that this will work. I thought I read somewhere it would not, and the different tranny may be the difference.

 

[BigRigTech]

I can't answer that 100% but from what I've seen everything looks to be the same depth.....I can't see Ford asking ZF to make 2 different BH depths because of a flywheel. I can measure the depth of a ZF diesel trans tommorow if someone here can measure a 460 ZF and a IDI T-19 to see if there is any difference...I have a spare diesel ZF for my 91 on my garage floor....I have a T19 for a diesel too but it's stored in my cube van at the junkyard up the road. Something tells me the diesel ZF's have the boss's for 460 starter bolts in the case but I can't remember if they are drilled/tapped or not.

 

[franklin2]

I can't answer that 100% but from what I've seen everything looks to be the same depth.....I can't see Ford asking ZF to make 2 different BH depths because of a flywheel.

Well they asked them to make a whole different casting for a oddball diesel pattern that they dreamed up from somewhere with an adapter. Why they didn't make the adapter to match a 460 is beyond me.

In all these threads I have forgotten if the 460 zf input shaft has the same spline count as the diesel zf, but if they do, if someone had access to the zf part numbers, they could look up and see if the input shafts for the 460 and the diesel are the same. If they have different part numbers but the same spline count, I am assuming they are different lengths.

 

[BigRigTech]

They are the same in my trucks, 10 spline - 1.25"....Now I have heard that the 460 ZF can come with a 1-1/16" input too, but I can't confirm that...I can tell you this -the input shaft from a T5, M5OD and ZF are all basically the same length - I can use a M5OD shaft to install a ZF clutch - it's only 1-1/16" but it works fine to install the clutch and PP.