ZF crack question

I had a ZF with a similar crack. When pulled apart it had a few sheared off ring gear bolt heads that had wedged between the bottom cover and ring gear causing the crack.(that's why they recommend safety wiring them) I was able to weld up the cover although it would slightly seep oil through the aluminum in the area that was welded and repaired after. would have to wipe it off once in a while.

I saw some billet replacement covers offered by a vendor I will look and see if I can find the vendor.

You have to remove the transaxle to remove the two long bolts that go across the cover to the side plates then there is about twelve or so bolts that hold the cover on.

Here it is.
http://www.ipsco.org/Pantera%2...%20Cover%20Plate.htm

quote:

I saw some billet replacement covers offered by a vendor I will look and see if I can find the vendor.

I thought it was IPSCO that made those...

Rocky

thanks for the reply, but its actually not that cover plate. Its the part of the trans that the plate bolt up to.

My concern would be why it cracked. If it was me I don't think I would even move the car if I thought the ring gear bolts could of caused this to happen. Regardless the whole transaxle most likely will have to be removed to weld it up.

Separating the rear section of the ZF that contains the gears and shafts requires a significant disassembly of the ZF. Not for the faint of heart. I think that you will need to live with it unless:

1) You wish to pay for a re-builder to disassemble the unit

2) Take on the project yourself

3) Live near Houston and I'll help you rebuild it.

JT

Sadly, I dont live near Houston, but thanks for the offer!

This seems to be a lot bigger job then I thought. Any other ideas? JB Weld?

Give JB Weld a try. Has bailed me out many times. Can't hurt.

JB weld would probably seal it up if you get the area clean and apply it. Is the crack new or just a imperfection in the casting that has started leaking over time?

The ZF has three main castings, plus the bellhousing. The aluminum ones are structural members so magic glues will not remedy the flexing that works the crack and will only grow worse. The first casting is directly bolted to the bellhousing and holds the differential. There is a rectangular access cover bolted to the bottom of this casting. The second part, only about 8" long, holds the transmission gears and the rearmost part is a shaft cover of cast iron.

If I interpret your description correctly, the leak is in the transmission casting. Cracking can happen there if someone unknowingly unbolts the speedometer angle-drive on the right side, behind the halfshafts. Done wrong, this frees up a 4" extension shaft to FALL INSIDE! There's not much extra room in there so driving the car with the shaft loose inside can and has driven that shaft into the case, cracking it & wrecking the little $250 shaft. I've welded up a couple of cases from this. I've also seen other loose metal parts drift around inside and get caught in the gear mesh, with similar results. The scary part is, you don't know if the chunk is still in there.... Spraying degreaser on the case, wipe clean and watch for appearance of a drop of lube should tell you whats happened. Maybe you'll be lucky and only have a loose or stripped metric allen bolt holding the trans-case to the diff-case.

If it IS cracked and I were you & didn't know ZFs intimately, I would bite the bullet and ship the whole ZF to RBT Transmissions in Los Angeles for tear-down and repair. Figure $1500 minimum charge if nothing else is wrong inside. FWIW, that is an $8000+ transaxle (once fixed) you have there! Aluminum cases are easy to weld (with heli-arc) but the innards must be out and the aluminum degreased to get weld to stick.

The ZF and bellhousing unbolts & slides back 6" to clear the clutch, then hoists out without otherwise disturbing the engine. It weighs 160 lbs in this condition- get a friend or two to help, and a hoist. And be careful not to hurt anyone, or bash the car. Good luck.

I agree with Jack's advice. There is likely something in there that has caused the crack. Better to have it repaired at this time before something potentially catastrophic

Thanks all. I'll most likly throw some JB Weld on for quick fix. Bosswrench, I'll most likly end up going your route in the long run. I'll just take the whole thing off and send it to someone.

thanks again.

quote:

Originally posted by Bosswrench:
If I interpret your description correctly, the leak is in the transmission casting. Cracking can happen there if someone unknowingly unbolts the speedometer angle-drive on the right side, behind the halfshafts. Done wrong, this frees up a 4" extension shaft to FALL INSIDE! There's not much extra room in there so driving the car with the shaft loose inside can and has driven that shaft into the case, cracking it & wrecking the little $250 shaft. I've welded up a couple of cases from this. I've also seen other loose metal parts drift around inside and get caught in the gear mesh, with similar results.

Contrary to what Jack says removing the angle drive has no effect on the ZF, just do not take out the 10mm bolt below the speedoemter drive without having something clamped to hold the speedometer drive as that holds the driveshaft in place.

IMO you are throwing the dice if you continue to drive teh car or JB weld the crack. There's potentially a problem and it can only get more expensive the longer you ignore it.

Julian

Getting back to this...I have good news and bad news! The good news is that my quad 48 IDF project is finally compete (need to get a pic stat). The bad news is that my jerry rigged epoxy patch only worked for a month or so haha. After further inspection, it looks a lot like the crack in this post.

http://pantera.infopop.cc/eve/...490078765#4490078765

Lets say I have some bolt heads rattling around in the ZF, would I be able to remove them by taking the sump cover off, or do all the internals need to come out? I'm somewhat handy with the wrench, but the internals are a little intimidating.

If you want to play with the assembly, fine. Not only will you learn about the assembly but if it needs shipping for welding, every part removed lightens the shipping weight. You will need very high quality metric allen wrenches for this work, and a copy of the ZF Overhaul Manual. POCA sells them in their manual collection as well as some vendors. Take lots of photos as the work progresses. Time WILL pass while the work goes on and you WILL forget details during reassembly.

Remove the ZF from the car, then remove the bellhousing and lower cover. Remove the iron side covers. Remove the transmission case allen bolts. There are numerous internal ribs and divider bulkheads inside that prevents full draining, so be prepared for a mess on the floor! These things also catch & hold debris so you may find a surprise or two.

The tranny case likely won't separate from the diff case even with the bolts out, unless you lift the whole assembly and while holding the diff case vertically, bump the protruding clutch-input shaft hard against a thick piece of wood. There is no gasket but there may be some contact cement. The final part to take off is the iron end-plate. In all the removed sections, there are shims that will need to be put back exactly.

You will likely break a few metric allen bolts in stripping the assembly; ZF used very tight reduced-head bolts and the allen hexes often strip out. Seals are generic but some bearings are not. RBT sells all needed parts. Also do not skimp on gaskets- the gasket's thickness controls some gear mesh depths, so use real ZF parts. Gaskets, bearings and seals are the only cheap parts in there! Good luck, and if at any time you feel in-over-your-head, the vendors are there for you.

If you decide to disassemble even the lower side of the box (where the ring gear lives), you will find that there are a number of shims that are on cross bolts. Make sure that you keep track of where each and every bolt / washer / shim came from, and assemble it the same way when you put it back together.

From my experience (in which I was a helper, and not the journeyman), working on the ZF is a job where you need to reassemble it exactly like it came apart.

It's not the kind of thing where you throw all the bolts / nuts / washers into a coffee can and then hope you remember where they went when you are putting it back together.

Rocky

AH HA moment! I think I found what the issue is. As I was examining the zf for removal tomorrow, I noticed the bolt that retains the speedo gear was missing. This most likely explains why the speedo stopped working a while ago I stuck a magnet down the opening and sure enough it's my speedo drive (I assume) that's rattling around in the trans. A couple questions regarding this...

Any possibility I can remove the sleeve and try to fish it out with a magnet, ill just assume no, so I'll go onto my next. Did anyone have any luck pulling this out but just removing the lower access panel on the ZF? Also, when installing a new one, does it simply slide in from the top and held in place with the retaining bolt, or does the gear and sleeve need to be inserted from inside the differential case?

thanks!

From reading previous posts the only way to remove the bottom plate is to remove the 2 transverse bolts, but there isn't enough clearance for them to be removed so you have to jack the ZF up.

The diff case area is separated by a bulkhead from where that little shaft wound up.

I know I just read recently that someone had managed to fish one of those speedo shafts back up into place, must have used a magnetic tool or maybe one of those claw things.

I looked about and couldn't find the post. I hope they'll speak up.

Good luck.

The answer is a definite maybe! Two owners I know of HAVE managed to fish a speedo driveshaft back out the hole with an extension magnet, once the steel sleeve is out of the way. Many more have NOT been so patient or skillful. Both say no damage occurred; one happened to his Pantera while the owner was doing maintenence on his ZF so the gearbox parts were not moving. There's not much extra room inside!

And of course, even if successful, if any internal damage HAS occurred, the ZF will need to come out and be stripped. Driving with a chipped tranny gear almost guarantees your $10,000 ZF will soon become a $1000 collection of parts as something jams a synchro & locks up all shifting.

AS for installing new parts, clamp a Vise-Grip pliers onto the drive tongue of the speedo driveshaft and lower it into position, then tighten the little bolt into the assembly before removing the clamped pliers. The bolt-end goes through a hole in the steel sleeve and rides in a deep groove cut in the driveshaft end, so it acts as a retainer for both. In the original design for GT-40 & Mangusta, the transmission was upside-down, so a freed speedo driveshaft tended to slide OUT, not INTO the gearbox as with Panteras.

Oh yes- the leak: is it in the bottom of the transmission case, maybe a series of small radial cracks in a little bulge? If one drives a Pantera with the speedo driveshaft laying loose in the bottom of the transmission case, chances are extremely likely that a spinning gear will snag the loose shaft and drive it into the aluminum case like a blunt nail, cracking the case from the inside. I've welded up two cases from this happening, once the ZF is out, stripped from the diff and carefully solvent-cleaned. The gears & shafts were not removed from the trans case section for either repair. A VERY thorough inspection of every single tooth in the trans miraculously showed no damage, but the speedo driveshaft gear-end was so badly mauled it was replaced. A few vendors have used spares available; they are very expensive for a 4" shaft but nothing like replacing transmission gears! Good luck.

Success! I was actually able to remove the speedo driveshaft back out the hole it fell into. I actually unbolted a majority of the ZF preparing for the lift, but figured I would give it a try. I threaded a bolt onto the sleeve and used a slide hammer to yank it out, and then was able to fish the speedo drive using a magnet. The extra space created when the sleeve is out did wonders. And wow, that thing was chewed up pretty good; guess I know what caused the crack. I haven't "properly" fixed it yet, just re-patched it for now. I'm just glad that drive is out of there.

Thanks again for all the help, I don't think my Saturday would have been as successful without it.