[DeTomaso] Metal particles in Transaxle

[Pantdino]

Wayne,

Here's my recollection of when I looked into this extensively:

Does the bottle of Castrol say GL-5, for hypoid differentials?

If so, you are damaging your ZF in using it. Hypoid gears require a different chemical makeup because of the great deal of sliding the gears do over each other. (Look up hypoid gears online.) There are no hypoid gears in a ZF transaxle.

The chemicals that make the hypoid gear oil able to sustain that sliding friction without breaking down are sulfur-based (hence the smell). These sulfur chemicals bind so strongly to the metal that softer metals (like brass) that when they come off, they take some of the metal with them.  Hence the synchro rings are damaged.

The correct thing is to get a GL-4 oil like Red Line MT-85.  If you find the limited slip clutches are binding too tightly and you get noise from the inside tire when you are starting out when turning, like at a stoplight, you can add a little bit of limited slip additive to make the oil a little more slippery.   But if you add too much you'll make your synchro rings ineffective, so you have to add a little bit at a time until the grabbing problem is solved to your liking.

The upshot is that yes, you can use GL-5 oil in a ZF, but you'll be damaging your synchro rings and gears.   Synchros require some friction between the rings to work. If the oil is too slippery, the spinning ring does not make the next one spin like it is supposed to, so the next gear is not brought up to speed.  And ZF work is not cheap.

Sorry if something here is not right, but I'm pretty sure the conclusion is correct.  Ferrari transaxles are basically the same in terms of design, and those guys are totally anal about this stuff.




Jim.




-----Original Message-----
From: Wayne Boian <wayneboian at windstream.net>
To: detomaso <detomaso at server.detomasolist.com>
Sent: Mon, Jun 24, 2019 8:32 am
Subject: [DeTomaso] Metal particles in Transaxle

  I change the oil in the Transaxle  last night and found metal particles
  on the magnetic drain plug.  See attached photo.
  The car has maybe 3,500 to 4,000 miles since the fluid was last
  changed. There was no other foreign material in the container used to
  drain the fluid.
  How  mush sleep should I be loosing over the amount of metal particles
  in the photo.

  FWIW, I am using Castrol Limited Slip 80W-90 in the transaxle.

  Thanks
  Wayne
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-------------- next part --------------
     Wayne,

     Here's my recollection of when I looked into this extensively:

     Does the bottle of Castrol say GL-5, for hypoid differentials?

     If so, you are damaging your ZF in using it. Hypoid gears require a
     different chemical makeup because of the great deal of sliding the
     gears do over each other. (Look up hypoid gears online.) There are
     no hypoid gears in a ZF transaxle.

     The chemicals that make the hypoid gear oil able to sustain that
     sliding friction without breaking down are sulfur-based (hence the
     smell). These sulfur chemicals bind so strongly to the metal that
     softer metals (like brass) that when they come off, they take some
     of the metal with them.  Hence the synchro rings are damaged.

     The correct thing is to get a GL-4 oil like Red Line MT-85.  If you
     find the limited slip clutches are binding too tightly and you get
     noise from the inside tire when you are starting out when turning,
     like at a stoplight, you can add a little bit of limited slip
     additive to make the oil a little more slippery.   But if you add
     too much you'll make your synchro rings ineffective, so you have to
     add a little bit at a time until the grabbing problem is solved to
     your liking.

     The upshot is that yes, you can use GL-5 oil in a ZF, but you'll be
     damaging your synchro rings and gears.   Synchros require some
     friction between the rings to work. If the oil is too slippery, the
     spinning ring does not make the next one spin like it is supposed
     to, so the next gear is not brought up to speed.  And ZF work is not
     cheap.

     Sorry if something here is not right, but I'm pretty sure the
     conclusion is correct.  Ferrari transaxles are basically the same in
     terms of design, and those guys are totally anal about this stuff.

     Jim.

   -----Original Message-----
   From: Wayne Boian <wayneboian at windstream.net>
   To: detomaso <detomaso at server.detomasolist.com>
   Sent: Mon, Jun 24, 2019 8:32 am
   Subject: [DeTomaso] Metal particles in Transaxle
     I change the oil in the Transaxle  last night and found metal
   particles
     on the magnetic drain plug.  See attached photo.
     The car has maybe 3,500 to 4,000 miles since the fluid was last
     changed. There was no other foreign material in the container used to
     drain the fluid.
     How  mush sleep should I be loosing over the amount of metal
   particles
     in the photo.
     FWIW, I am using Castrol Limited Slip 80W-90 in the transaxle.
     Thanks
     Wayne
   _______________________________________________
   Detomaso Email List is not managed by POCA
   Posted emails must not exceed 1.5 Megabytes
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   use the links above.
   Members who post to this list grant license to the list to forward any
   message posted here to all past, current, or future members of the
   list. They also grant the list owner permission to maintain an archive
   or approve the archiving of list messages.