Help needed stripping ZF

Ross Nicol · 07-08-07, 12:57 AM

I have my ZF stripped down to replace 2nd gear synchro. Everything has gone smoothly so far but to get to 2nd gear I have to remove almost every component from the input shaft.I'm down to the 3rd/4th gear synchrobody (that's what ZF call it in the manual) which is splined on the shaft.The manual shows a puller for getting it off which looks like 2 half rings and a full ring that slips over and clamps the 2 halves.Then you are able to use a press to pull the gear off.My problem is I don't have this puller and I can't see how it is supposed to work. The synchrobody doesn't have any edge for the puller to seat under and there is only .7mm clearance at the rear of the gear. If anyone can help It would be appreciated.I would be able to have a puller fabricated. Hopefully I can get it all back together for next weekend's race meeting.

Ross

Jim c · 07-08-07, 03:08 AM

Ross

Im not there to see the problem (picture would be good).
But I do visualize what you are on about.

Can you not remove the outer sleeve off the syncro hub and get puller legs in where the selector pawls live.

The other thing I have used is bearing remover plates ,these generaly have a knife edge but you may have to modify them.
Bearing suppliers generally have a selection of pullers for sale ,check them out.

Jim

Russ Noble · 07-08-07, 03:29 AM

Ross,

Wasn't that a new trans from RBT at the start of the season? What about their customer after sales service?

Failing that do you remember the "ZF failure" thread? Paul Fleming said there that he had rebuilt heaps of those trans. He doesn't seem to have been on here since, but he could be worth both a PM and an email. Someone on here may know his phone # also. Just a thought.
Sorry I have no experience with ZF's. (I'm trying to keep it that way

)

Cheers

Ross Nicol · 07-08-07, 06:05 AM

Hi Jim, after having another look I see a 1.6mm gap behind the synchro, so I presume you pull the synchrobody and synchro off together.This would explain the design of the puller.The gap doesn't sound like much but I suppose spread around the circumference the lip would be able to pull the thing in a press.
I take your point Russ but I don't think I can claim, as I am racing the car and I've had the box for a year and a half.I doubt I would be inside it now if I was just driving round the streets. Thanks for the tip on Paul I'll look him up.
Ross

Russ Noble · 07-08-07, 06:20 AM

I wasn't thinking of a claim Ross. You're on your own once you start racing. I was thinking more for technical info and further details of the puller.

Cheers

Ross Nicol · 07-08-07, 07:46 AM

Sorry Russ I made a wrong assumption, I've had one of those good and bad days with 50% of things going ok and the rest....well mmmm. Pretty sure I'll be on top of it tomorrow. One good thing is the ease in removing the transaxle from a GT40, it's a breeze to work on. You seem to be having some dramas with your o'seas purchases. Are you interested in that Aviad alloy dry sump pan I've got?

Ross

Big-Foot · 07-08-07, 09:51 AM

Ross - While I've not been into a ZF Transaxle - I've been Corvette ZF's. Not a lot of joy in the jobs either as everything seemed to be very close in tolerances and there was a lot of custom tooling that had to be made for the job.

I am attaching a picture that may help in the location of the puller jaws. You will probably need to fabricate a pair of half-moon jaws out of 1/4" steel plate as I have in the past. The Slider hub is an interference fit on the shaft and you can many times get by with using a heat-gun on the hub and then chilling the shaft with "Freeze Spray" from your local electronics house - or - use a pressurized can of air from your local computer vendor. Using the pressurized can of air "Inverted" you will get a stream of -200f air to put directly on the shaft thereby contracting it.
This combination of tools (home made jaws, heat, chill) have worked for me in the past.

I hope this is of some & help...