Gear selection

[Guest]

Got a problem; Had gearbox rebuilt by very reputable people, all fitted together and slotted into vehicle fine. Tested by driving car (early 911 with 915g'box) and everything perfect. Put away in garage and next day, started her up selected reverse, but then couldn't get out of reverse gear! Even to the extent that if I selected another gear everything just locked up. Only way I could stop it careering down the road backwards was by keepimg foot on clutch.
Weird thing is it had only sat in the garage overnight between being perfectly OK and not....any ideas before I haul it out and get it stripped again?

 

[Nick Moss]

Have you spoken to the rebuilders? Who installed the gearbox? If the guys that rebuilt it did so then call them. Otherwise check that with the engine off the gearlever is selecting gears. If not check the UJ at the back of the gearchange ros, this needs careful setting up. Is the cluth operating correctly?

 

[early 911]

Although highly unlikely, I've heard of people suffering stiff gear changes after simply replacing the oil (normally with Swepco). Does sound ominous mind . . . good luck in sorting it (with the rebuilders).

Phil

 

[912UK]

The same as Nick check the linkage set up and the clutch I had this once on a 912 I was going to break and i thought the box was naff till I saw the linkage was lose and then once set up it was a nice box.

When I replaced the linkage on the 69 car it took a few hrs to get it perfect so they can be a fiddle.. and as for the clutch the correct amount of play on the cable is most important..

That sweptco I heard was the dogs nuts but I have heard some interesting stories on that stuff of late.. might be the cold weather but very odd the oil is that changeable I used EP80 and a gear box treatment A tiny crunch when very cold if moved fast to 2rd from 3rd ( which it didn't do before ??) but once warm 10mins max in very cold it's silk ... in the summer it's silk.
Good luck......

 

[911hillclimber]

Albeit quite a time ago, Bob Watson rebuilt my early 915 4 speeder and my current late 915 5 speeder, but he showed me the selector mechanism under the small (about 80mm x 80mm cast plate) on the side of the box.

I wonder if the rods/selectors have slipped?

If so I know there are special jigging tools to set them correctly (not a suck-it-n-see type of task) and these are even sold in Tweeks catalogue etc.

I think the rods could have slipped and the box is now jambed in reverse.

Graham

 

[Guest]

thanks Guys, Hillclimber's logic makes sense as I couldn't get it to change even with the linkage disconnected and a pair of mole grips on the gearbox shaft! Also used same oil as before (Silkolene Syn5). Oddest thing of all though is how it worked perfectly for a quick drive around the block...but next day was completely kapput. Only makes sense that something got stuck after a couple of miles driving.
Its now removed from the car and returned to the rebuilders...they're just as baffled, so are stripping it again for a look. I'll let you know the outcome.