Engine is out. Transmission rebuild now?

[rjd2]

Hey all,  I've got a quick question for you. So I've got a '73 here that I got for parts, and have decided to try to bring back to life itself. When I got the car, the engine was disassembled; I've never seen it run. I'm not into the car for a huge sum, so while I don't want to end up underwater on it, I can afford to spend some coin smartly. My question is this: what should I do about the transmission, now that the engine is out? It feels like it shifts smoothly, I have no reason to think it has any issues, but I'm wondering if it would be wise to pull it now, and either A) do a rebuild, or B  consider the 5 speed upgrade? It's pretty oily/grimey; I'm fairly sure it hasn't seen any service in a long time, if at all. Reliability is of a higher premium for me than a 5 speed, but I wouldnt mind the upgrade. I've got time, as I'll need to blast the car, do metalwork, so on and so forth. Thanks for the suggestions.

[BarneyT]

Don't worry about the transmission at this time...body work / engine work...the transmission is not that hard to address one way or the other after the engine is back in car and running...

[kbmb02]

Another opinion: If I read your post correctly, engine is disassembled and out of the car, but transmission is still in the car? If that's the case, I'd suggest pulling the transmission out of the car as well. Clean it, check fluid level (would not hurt to replace the fluid and inspect the drain plug), inspect shift tower bushings, shift rod seal, giubo (flex disc), etc.

 

With the shift tower and shift lever installed, you can use a 1/2" electric drill and spin the input shaft; go through all gears and listen for noises. Do this now, and you get an early check-mark. Add that many find installing the gearbox after the engine is installed to be easier (or, installing the whole assembly from the bottom ... search this forum). -KB

[rjd2]

gotcha-thanks. yes, engine is out, trans is in. I think I'll drop the trans out, and do a mild going over of it now. Spending 200-500 bucks on the trans now is not prohibitive; if we were talking 2-3k, I'd feel differently. thanks!

[thehackmechanic]

I'm not aware, nor I believe is anyone here aware, of anyone who cheaply rebuilds the 4-speeds or the 5-speeds. So a "while it's out" rebuild will not be cost-effective. You can try checking for play at the input shaft, and as kbmb02 said, you can try spinning the input shaft, but really you're going to need to put it in a car to see what it does.

 

5-speed conversions are great if you drive a ton of highway miles, but they're quite expensive, as the junkyard source of cheap 320i 5-speeds is long gone. If you drive the car mainly around town, the four speed is fine. It's fine on the highway too; it's your ears that mind the high RPMs more than the car.

 

--Rob

[rjd2]

good to know. thanks.

 

i see the 5 speed conversion/rebuild kit; is this a thing i could tackle on my own, you think? over the course of the few months it'll take to get the body dealt with and engine block machined? or is it a nightmare? i've rebuilt carburetors and such, but never something as big as a trans. i follow instructions well and am patient, though! if it's a black art like engine block work, then i won't open that can of worms...

[TobyB]

I agree with Ken-

pull it and clean it, maybe a new shift seal, CERTAINLY new shifter bushings, then run it.

 

And yes, a swap is a good DIY- if you can install the engine,

you can swap a trans. 

 

But as everyone says, get it back together and running first.

 

t