The C6 in my 4WD 89 is on it's way out and for a while I've been passively gathering parts for a ZF5 swap so time to get off my **** and get it done.

I got a ZF5 that the PO(a member here) said the reverse shift fork fell off, not sure how he knew this. This sound reasonable, anyone had this issue before, how hard to fix, etc?

I got an 88 F250LD I'm parting out that had a 4 speed to pull the clutch pedal parts out of. Bolt right into my 89? Do I need any different parts then those for the clutch slave?

I got a clutch kit I traded with Racin for, admittedly I don't remember right now it's details, what do I need to check, are they all the same size etc?

I'm replacing a C6, pretty sure I've read that the length is close enough that my drivelines will work?

Three things I don't have yet, a flywheel, and rebuild kits for the ZF5 and the 13-56 I'm going to do at the same time, shopping tips?

 

The shift fork can't fall off, more then likely its broken or worn extemely badly, 5th and reverse use the same fork, does 5th engage and the input to output shaft are locked solidly?

If 5th works but reverse doesn't your looking at either a stipped reverse gear or reverse idler gear.

The nice part of these tranny's is you can take the top off (the main part of the case as everything is bolted in the tail housing) and look at everything/ hand operate them before doing any major surgery, if it's a fork it's not hard to do, if it's gears, total strip and rebuild as reverse is in the middle of everything.

The pedals are a bolt in deal, make sure to get and install the firewall reinforcement plate while your in there, clutch master will work but being a LD250, I'm guessing its a gasser and the line may work but the slave is different, if it's a deisel you should be good to go.

If its a smf clutch and he didn't use a psd clutch and drill the flywheel for the 13" clutch, it should be a 12.5" clutch disc, smf ones have the springs in the disc, dmf have them in the flywheel.

The c6 is about an inch longer the the zf5, the slip yoke on your tc will compensate just fine for this.

Take apart the trans and tcase first, most of the time they don't need bearings, just get new seals after inspecting things and slap it together.

I bought a complete rebuild kit for my zf just to find out everything was in perfect condition, not worth the 350 bones to replace good with good but new parts.

DO NOT buy brass blocker rings for your zf if you end up tearing it down, they wear really fast, get the oem ones.

Look up oil pump mod and shift lever mod for the bw1356, do those two things and it will be bullet proof.

 

Just curious, if your C6 wasn't mated to a 1356, what tcase did you have? On my swap i had a 1356 on my C6 and It swapped right over to the ZF.

 

Thanks for the great info, I'll fiddle with the transmission and check the other things when I have some time.

I'll admit I haven't searched much yet and will more, but any links you have on the ZF work and TC mods you mentioned would be much appreciated.

It was/is I broke the one I had(stuck in low, oil pump issue) and swapped in another from a later truck. But that later one has no speedo output and a different size front drive yoke. I have a third later one, so I'm planning to rebuild my old one with parts from the extra later model one and whatever I need to buy.

 

Does this kit contain the gears or just the syncros...?? If the gears - what is your first gear ratio??

 

Heres the manual for the zf http://www.zf.com/media/media/docume...ce_manual_.pdf
and the tech articles have a good write up for refurbing it also

Here has Rebuild your own transfer case. BW1356 - FSB Forums
a good tear down and rebuild of the 1356, do the second post oil mod as it is stronger, as for the shift fork mod, I'm not finding the site I had once before, but I will be doing this all to a bw1356 in a week or two and will post pics of how I do it.

Also from the sounds of it, the tcase you have with the different front yoke could be the yoke for the double cardan drive shaft for the f350, that thing is VERY hard to find so don't throw it away.

I got my kit off e-bay a few years back, came with koyo bearings and all the syncro's that were the steal ones, seal kit and detent plugs.

These kits just come with bearings and seals (and optional for blocker rings aka syncos) so there not truely rebuild kits, more so refurb kits as they do not come with any hard parts, thats why its worth looking at it first and doing the measurments on the blocker rings to see if you even need to go any further.

 

Thanks again
My stock setup is double cardan, the yoke on a newer TC I tossed in to get by is larger then the joint on my double cardan driveline.

 

That clutch was just a stocker DMF disc and plate.

Disc should work for a 6.9 11" SMF clutch setup with the ZF trans. Im not sure about the pressure plate... I think its 8 bolt no? (6.9 6 bolt)

 

What tolerances do you check to determine how far to go with the rebuild? I was told in some earlier threads that if there was ~any input shaft play at all, to just teat it down and put in a whole kit. Thanks for the advice on the brass synchros btw, really good information there.

 

I have mentioned this before as this is very important, if there's play in the input shaft there will be play in the output shaft also, I would not trust the 3 bearing that run on that shaft, at this point in time the likeliness of the input shaft oil baffle being in one piece is slim to none and you have to setup the bearings so may as well replace them and do the syncro rings at the same time if they getting close to min spec. The hardest part is getting the bearings off but if you cut the cage off the bearing and remove all the rollers you can use standard gear pullers on them, make life a breeze.

As for checking the wear on the syncro rings, you just push them evenly up to the gear and measure the space between them (see pic)

the first one show a good gap between the ring and the body of the syncro (body is part of the gear)

the second pic (I don't have a worn one so I just tilted this one as demostration) shows no gap and this would be completle worn out.

The specs are 1st-5th 0.024" or higher and reverse 0.016" or higher and just use a standered feeler gauge.

For reference, this is the 4 gear syncro ring and body, also shows the input bearing + seal surface, but do note the gear its self is not 4th as 4th is a direct coupling of the input shaft to the output shaft, this gear only drives the counter shaft.

 

Thank you for the excellent advice, explanation and pictures. That really helps. Thanks!

 

Where are you - ifrythings?? Do you want to rebuild mine??

 

Im way up in BC canada.... not sure where your located but its at least 9 hours to the border for me, these tranny's really aren't as scary as they seem, you can actually take the top off of them and check everything out without even needing special tools, and unless the input shaft is loose or dirt ran threw it, the bearings are usually good, tools needed are snap ring pliers and bearing pullers and being a bit creative when pulling the syncro hubs off.

 

I've never been into a transmission before, and at 48, I'm too old to learn!!
Actually I have 14,763 projects on my list and don't need to add another one