81 240d Manual Tranny swap question(s)
 

My 81 240d's manual transmission just bit the dust (lost 3rd, 4th gear, not the linkage or shifter assembly, lever at tranny moves freely back forth).

I have found one locally (Austin, TX) from a 78. Will that bolt in? or if not, what adjustments?

or, does anyone here have one that might go right in?

Thanks

I'd expect the manual gearboxes to be the almost the same for those years - you should be able to see either 716.005; 716.210; or 716. 214 stamped on the outside of the casing(s) along with the other numbers that make up the serial numbers

1981 is the changeover year from iron case boxes to aluminum case, and could be either. If yours is an iron case, the '78 box will be a direct replacement. If yours is an aluminum case, the iron case box can be used, but will require the matching selector, shift rods, mount, slave cylinder, and perhaps the forward portion of the driveshaft.

jr:

Have a close look at the connection of the 3-4 lever to the shaft that enters the trans case.
There is a bolt that retains the lever to the shaft. If it has backed out the lever will swing freely on the shaft, per your description.

Frank is correct. To visually compare, the aluminum case is one piece (no separate bellhousing) and the iron case is a two piece affair (separate bellhousing).

Gotta love the tech advice known and shared by the Old Timers here......

(I'd forgotten that the aluminium casings have different shifter rods and mechanisms)

I've heard of people losing their "shift-ability" because the bolt holding the lever to the shifter fork on the inside of the gearbox has come loose - access to these hex Allen bolts is tight when fitted in the car but might be worth checking...

Stretch, see post #4.

Aggggh!

This has happened to me on my 190D and 240D. If it's loose, put some locktite 290 (wicking kind) on the thread and tighten it up. If it's backed out completely you have to put some weight behind it and twist to get the cap screw started in the fork because it shifts when the capscrew backs out. If lowering the transmission from the back doesn't give you the room you need and you don't want to remove the transmission, you can drill through the transmission tunnel and push on the hex bit and capscrew from the inside.