| Author | Message | ||
| Mike Charness (Mcharness)
Member Username: Mcharness Post Number: 729 Registered: 8-2002 |
If it's brass, that qualifies as a "yellow metal" and would be subject to potential corrosion. Paul's "aluminum bronze" is a yellow metal alloy, same problem. | ||
| Paul Hill (348paul)
Member Username: 348paul Post Number: 309 Registered: 12-2002 |
We make selector forks for a well known racing gearbox manufacturer and they are made from Aluminium Bronze - this looks a little "duller" than brass, and of course is much more wear resistant. If anyone has an old syncro they want to send me I can send it to my local test house and get a chemical analysis on it - that way we will know for sure what it is made from!! Paul | ||
| Mark Foley (Sparky)
Junior Member Username: Sparky Post Number: 62 Registered: 3-2002 |
Analysis of the picture from Peter (below) seems to indicate there is a brass shifter fork. Would this brass be corroded from use of the wrong oil? Mark | ||
| Hans E. Hansen (4re_gt4)
Intermediate Member Username: 4re_gt4 Post Number: 1540 Registered: 4-2002 |
Yeah, as I mentioned, the ones that I had in my hand were grey, and looked like sintered iron, as they had a bit of a pourous appearance. The mechanic thought they were made that way to absorb/retain a bit of oil. Kind of ironic that we all got worked up into a tither about corrosive oil. (ironic = pun?) Have a happy holiday. | ||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 908 Registered: 5-2001 |
TEMPEST IN A TEAPOT: 308 SYNCHROS ARE NOT YELLOW METAL!!! I believe we've now heard from enough knowledgable sources to safely conclude that we don't have a yellow metal problem after all. I received the following from Ric Rainbolt when I asked him about if the synchros the 308 tranny's he'd rebuilt were brass or other yellow metal: ----------------------- From: Ric Rainbolt Subject: Re: 308 Synchros -material question. Date: Tue, 01 Jul 2003 22:48:26 -0500 To: Verell Boaen None of the four 308 trannys I've had apart had bronze or brass type syncros. When new, the syncros are a dull grey color. -------------------------------------- | ||
| david handa (Davehanda)
Intermediate Member Username: Davehanda Post Number: 1128 Registered: 5-2001 |
Hans, I just got my 328 back from Carlo today. I had asked him about swapping out the Mobil 1 for Swepco, and he said there definately were not bronze/brass synchronizers in a 328 transaxle. He told me not to worry about it...of course I forgot to ask him about the 308. :-( | ||
| Newman (Newman)
Intermediate Member Username: Newman Post Number: 1203 Registered: 12-2001 |
Mine werent brass. They also discolor with use from the heat and oil Im assuming. The new ones I installed looked like steel of some sort and were ground on the faces. I replaced 2nd and 3rd syncros. 1st to 3rd are the same part but 4th and 5th are a completely different design. Also steel like and magnetic as well.  | ||
| Mike Procopio (Pupz308)
Member Username: Pupz308 Post Number: 427 Registered: 10-2002 |
I've posted the a response to my mechanic about this (who has a 308 gearbox open right now)... It's over in the Gear oil thread... http://www.ferrarichat.com/discus/messages/112/267343.html?1057080544 Here it is for reference: Here's a response I got back from my mechanic regarding the gearbox and the gear oil that we use. Summary: 1. I currently use Chevron Supreme LS synthetic gear oil, not Mobil 1 as I had previously thought. 2. The syncro rings on at least one 308 gearbox respond to a magnet. It would follow that they're not 100% brass, but could contain brass. Does anybody know anything about Chevron Supreme LS synthetic gear oil? Here's the dialog I had with my mechanic... MESSAGE TO MECHANIC: Sean, There's a question up on FerrariChat regarding 308 gearboxes. Specifically, what material are the syncromeshes made of? Some have said brass, some have said iron. It's very important, since Mobil 1 confirms that their gear oil (the stuff that we use) is corrosive for yellow metals (e.g., Brass). I know that you've got the other 308/288 engine out, and Mike showed me the gearbox. Could you please check on this for me? Thanks, --Mike RESPONSE FROM MECHANIC: Mike, I cannot determine exactly what material(s) the syncros are made of. However, I can move the syncro rings on this 308 gearbox with a magnet, which tells me they are NOT 100% brass. But I have no way to confirm if these syncros have any brass in them at all (I am not a metallurgist, nor is anybody here an expert in alloys.) This is not to say that YOUR 308 does NOT have brass syncros (we all know how the Italians can be in terms of production variances.) One thing is certain: your 308 has Chevron Supreme LS synthetic gear oil, not Mobil 1. Whether or not the Chevron oil is corrosive to brass I have not yet been able to determine. END | ||
| '75 308 GT4 (Peter)
Advanced Member Username: Peter Post Number: 2896 Registered: 12-2000 |
I don't remember seeing any "yellow" metal in my gearbox...  | ||
| david handa (Davehanda)
Intermediate Member Username: Davehanda Post Number: 1121 Registered: 5-2001 |
Where's JRV? :-) We need the straight deal on this... | ||
| Mike Procopio (Pupz308)
Member Username: Pupz308 Post Number: 423 Registered: 10-2002 |
Also. Paul Newman just totally pulled his engine and gearbox and did some work on the gearbox, including replacing his 3rd gear synchromesh as I recall. He'd know  . | ||
| Mike Procopio (Pupz308)
Member Username: Pupz308 Post Number: 422 Registered: 10-2002 |
This is an important point, Hans! I think my mechanic's still got the engine out of a carb 308, including the gearbox... I'll shoot him an email and see what we find. --Mike | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 595 Registered: 5-2002 |
No brass in my 84 QV | ||
| Hans E. Hansen (4re_gt4)
Intermediate Member Username: 4re_gt4 Post Number: 1539 Registered: 4-2002 |
I just saw a torn apart 308 gearbox (don't know what year, other than it wasn't from a carb car), and the syncros didn't look like brass, but like a sintered iron. Comments? If indeed there isn't any brass, then Mobil 1 gear oil would be safe. |