I'm thinking of tinkering with my iron 5-speed. I want to inspect it before it gets installed to verify it's in good order.

the story goes it was rebuilt at least a decade ago by a mercedes shop and then shelved and traded hands once or twice till I go it. The guy I bought it from supposedly worked at the shop it was built in. it supposedly came off a V8 w115 car.

In the least, I'm going to open it up and take a look. It's supposed to be rebuilt internally.

But the gear ratios are odd so knowing nothing about this tranny, I'm wondering if some of the gears may have been swapped inadvertently. I'm also wondering if it would be hard to swap a gear or two to change ratios.

Here's what I measured (not super accurate - hand turned and counted)...

5th - 0.87 < this one seems odd. it should be taller than this.
4th - 1.0
3rd - 1.43
2nd - 2.33
1st - 4.0 < might be nice to lower this a little
Rev - 3.6 < same here

I'd love to get closer to this (711.117)...
5th - 0,806
4th - 1
3rd - 1,436
2nd - 2,401
1st - 4,695
Rev - 4,078

Theoretically, I bet that could probably be done, but you would essentially be completely rebuilding the gearbox. It would take a ton of work, all the syncros would still have to work, so you would have to find gears that fit both the pressed countershaft and the pressed synchro splines as matched sets, or machine them and harden them.

Who knows? maybe a lot of the main shaft stuff is common and you can interchange stuff. You might have to find the tranny in question and pull gears out of it though to really know if it can be done.

I'd certainly like to see pics. Starting this weekend I am going to start moving some of my projects over to the new house so I can tinker on them at night when the kiddies are in bed.

Sounds like it might be a little beyond the time I have for it.
I'll start by popping it open to see what it looks like from the side cover.

btw, are there places that sell gear/syncro sets? (classic center?)

Yes classic center does have SOME of the parts. FI sold me his 5 speed which as a bent 4th arm and he was told by a rebuilder it was NLA. Take pics of the inside please!

265 rebuild (bmw) :
http://www.pbase.com/victorhall/trans_rebuild

Boy that input shaft sure looks familiar.

(04-28-2010 01:25 PM)winmutt Wrote:  265 rebuild (bmw) :
http://www.pbase.com/victorhall/trans_rebuild

Boy that input shaft sure looks familiar.

Has a 265 sitting in storage.... hmmm....

there seem to be a lot of those 265's around too, I found at least 6 cars out of about 25 BMWs in a yard the other day that probably had 265's in them. At least the year range fit

Finally got some time to pop open the gear boxes

Here they are together. The dirtier one w/out bell housing is the G-wagen 4sp transmission originally mated to the M110 engine. The clean one is a 5sp and supposed to be from a w115 (m117?) V8. It might be hard to see but the 460 transmission has larger teeth presumably to handle higher torque at lower RPMs
   

Here are close-ups of the transmissions.
w460:
   

and w115:
   

The casings, shafts and syncros look identical. Gears have finer teeth in the w115 transmission. The ball catch mechanism that bolts to the side cover and makes the gear levers snap to the right positions is slightly different only that the w115 has one ball for the 5/reverse lever while the w460 has two balls for that lever.

Also a nice confirmation of the "oral history" - the 5-speed is clearly rebuilt and never run. no signs of operating temperatures yet and all seals and surfaces look new.

Conclusions: it looks like I could easily swap gears in sets from the w460 to w115 to change gearing if down the line, I decide it's worth the trouble to get that reverse gear lower or to have bigger teeth. But I'd need a new source if I were to get a taller overdrive.

-Christian