Synchro Replacement

quote:

Originally posted by Dr.Oldsmobile:
- I would like to replace my 2nd gear synchro - If it is beyond my range, is this something that the average transmission shop can do (with parts from RBT) -

Replacing the synchro ring requires tearing the gearbox apart. The ring gear bolts must be replaced too, and the seals. Have you at least spoken to Lloyd on the phone?

Average Transmission Shop Commercial

If you are detail oriented and able to follow the ZF manual, it can be done. However, to get to second requires knowing a few tricks to disassemble the gears from the input shaft. It took me a little thinking and a trick or two shared by Lloyd to help me get it apart my first time around w/o the official tool kit. I'll be happy to share my learnings with you should you elect to take on the challenge. If you are not mechanically inclined or methodical, don't go there.

JT

I went down this road less than twelve months ago and if you are not mechanically inclined it is a huge undertaking. You will need to make a holder thingy for the input and pinion shaft as outlined in other threads. Two big bloody sockets for the pinion and input shaft nuts which were surprisingly expensive and Fing Tight! And the manual http://www.thecarnut.com/Manuals/Bora_Transaxle.pdf .

Also be aware after replacing my second and third gear synchro it did not fix my problem as it was the cone on the gear that was worn, not the synchro.

Wannabe is correct. The ZF (and many Porsche) transaxles use STEEL balk-rings running on steel gear-cones. The arrangement lasts a long time, but both parts in contact wear evenly. So when grinding starts as wear builds up, very often its BOTH the gear-with-integal-cone and the balk (synchro) ring which need to be replaced as a pair- at high cost. And there is exactly 1.0 source for new gears and balk-rings: in Southern CA at RBT Transmissions. The gear steels in ZFs have proven to not be weldable by any known means either- and some very talented people have tried it, all unsuccessfully.

There are others that can overhaul your box- Kirk Evans in Perrysville, Ohio is about the closest one. For some, judicious recycling of less-worn gears and balk rings into your ZF by a skilled tech may fix things for awhile. This is 'overhaul-by-cannibalization'. If you don't want to ship it, load the 155 lb ZF in the trunk of another car, drive across the border to northern Ohio and let Kirk strip it down & fix it. Personally, I'd drive the Pantera down to his shop. He's done this dozens of times- search the archives here for a nearly destroyed ZF he fixed recently for an owner.

Here is just a suggestion, before you tear the ZF apart and spend thousands, try this stuff FIRST. The worst that will happen is that it does not work for you and you will still need to tear down.

Redline MTL "all synthetic", Manual Transmission/Manual transaxle lubricant.

It worked for me and others. If you don't want to go for the fifty bucks to try it, so be it.

I was skeptical too when Gary Hall recommended I try it before I tore the ZF apart.

It is compatible with the gear lube that will be stuck in the ZF and you can't drain out.

It swells the zf gaskets and does not shrink them like the Mobil1 synthetic gear lube does, SO IT DOES NOT CAUSE LEAKS.

You will need to run it in a little. Some feel changes sooner than others. A few hundred miles should do it.

I'm not saying you don't need parts. Just saying that SOMETIMES people over react due to experiences of others and think they have that virus too?

Hopefully this stuff will save you a lot of heartaches and grief. The money you save could put one of your kids through college?

I too had an issue with the cone portion of my 2nd gear being worn out. CRM machine in Gainesvill, GA was able to machine the cone down and fabricate a replacement sleeve out of 01 tool steel and hardened to Rockwell 50. The new gear/synchro clearance is now back to 50 thou clearance and works beautifully. Although the job was not cheap by any means, it was substantially less than the cost of a new gear set and synchro. Chris Mullins (proprietor of CRM Machine) is an incredible machinist and a brilliant guy. The phone # to his shop is (770) 983-7151.