Driveshaft...should be easy right?

[PhillyPhiat]

Hello,
I am new on here, but I have been reading all of your helpful threads for a long time now.
Now I need help!!
I had to replace a throwout bearing on my 79 fiat spider. i pulled the trans in order to get at it, and pulled the drive shaft too. i couldnt get the rubber donut-thingie "flexible coupling" off so i just pulled the gear shaft (not sure if thats the correct term) out of the back of the trans/donut shaped thing. slid right out no problem. now i have a problem. trans went back in, easy, even the dreaded starter wasnt too bad. but i can not get the front driveshaft gear back into the female part of the trans. i have spent every minute after work until i go to bed for the past 4 days with no luck. i went to multiple mechanics who told me to stay away from fiats "for this reason" i have the mechanics manual which says it should just slide right in. is there something dumb i am missing?
please help! i am missing prime convertible weather here in philly, we dont get much of it...

ps. the car had a plastic throwout bearing on it, and it shattered. I cant even find all the pieces. put a metal one on now.

[azruss]

one of the things i like about this car is the coarse splines. if you think this is bad, try a TR-3. Look at the end of the splines to make use you dont have a burr that is getting in your way. may want to stick your finger in the splines in the tranny and feel them to make sure you dont have a burr there as well. grease it up good before you start. Do you have the tranny bracket bolted up to the body. It helps to remove that so the tranny can tip down.

[PhillyPhiat]

thanks for the reply. i cant see any burrs and the mechanics i showed didnt see anything either. i tried to clean out the inside piece as much as i could. greased the hell out of it, still nothin. i tried inserting it both with the trans bolted up so i know it's aligned, and then i unbolted the brace and dropped it so i could see better. still nothing. is there a trick or should this thing slide right in?
trying to figure out how to post photos

[narfire]

Don't ask why but there are, how to explain this, two female splines in that housing. They both rotate. SO they both have to line up for the male to go in all the way. You might feel the shaft go in about an inch or more then stop. The next rotating section has to turn just a tad for the splines to line up then the shaft will go in all the way. The collar will turn the second or closer to the front splines.
I went crazy as well and got fed up so I undid one side of the donut (3 bolts) and took it off and then installed the thing on the drive shaft while on the bench. It was simple then.
I feel for you man, these cars never cease to amaze me...

[rlux4]

Did you try to disconnect the driveline at the rear and work it in that way? Leave the center support off also and you get all the angles you need to get it to go in.
Ron

[htchevyii]

I just put new u joints in mine and it went back in without a problem. I couldn't find a breakdown, but there's a funny metal bushing on the back of the trans that fits into the middle of the driveshaft yoke, I guess everything is OK there? if the slip yolk is fully compressed, maybe it could be in the way of the bushing on the trans? You could try pulling he slip yoke apart? You have slid the shaft above the e-brake cable, right? I have pics I can send from a trans and driveline in my garage if you need them to compare to yours. If you need them email me and I'll email them to you, (I tried to post some, but my iPad doesn't like photobucket). Hope you figure it out, things like that an drive you nuts.

[PhillyPhiat]

thank you for all the fast replies!! i noticed the 2 female splines but it didnt even cross my mind that they might rotate independently because that defies logic...but what else is new...
I'm gonna unbolt the rubber donut thing tomorrow. which 3 bolts do i pull? the ones with the heads toward the front? or the back of the car?
also, i dont have a compressor tool? can i just use a large hose clamp?
i'm replacing the front u-joint as well so i have been playing with this thing with just the front drive shaft, so i have the entire drive shaft out in pieces. the rear and the axles are still in place but from the trans to the pumpkin is on my floor...
i did have it up under the e-brake mechanism to start then i lowered the trans so i could see in the female part better and tried working from there. hopefully when its on my bench it will be easier!

[htchevyii]

Hopefully it's not too late, but make sure you mark the driveshaft before disassembly. I didn't and ended up with new u joints and center support bearing in a unbalanced shaft. It turns out that it is balanced as an assembly and none of my local driveline shops had the correct adapters, so I had to buy a used shaft and start over.

[narfire]

Did this a month or two ago so somewhat fresh (after 6 months.... ) I undid the three bolts that allowed the rubber donut to come free of the tranny. It was easier to stick the shaft together on the bench then. I'm sure when all the stars are aligned and tide is high and Elvis was seen in Vegas again, one might be able to slide the drive shaft back in without issues..
When putting it, the donut, back on (it is in good shape/new right) dont worry to much there. I had a small pry bar that I used to help line up the donut with the steel bracket/ring. Light taps with a small hammer helps slide the bolt home/ through so you can get a nut on it.

The u-joints are straight forward BUT do make sure they are seated properly and the retaining clips are in the recesses properly.
Case history here... I put a spare shaft on and it vibrated like mad. I jacked the car up put the axle on stands and then ran it and looked at what was going on. I could see the shaft bouncing around so I checked the u-joints and found one not seated properly. Smacked it and put the clips back in and it was WAY smoother.
Have fun, you'll be on the road this weekend
Chris

[PhillyPhiat]

so...
thank you all for your advice. everything seems to have worked so far. the driveshaft gear definitely went in to the female spline in about 45 seconds or so, once i took it off the trans.
i replaced the clutch fork, throwout bearing, and clutch cable just in case, so i dont have to try to do this twice.

my question now is, say i forgot to mark the drive shaft position before i took off the u-joint... what should i beware of? are most drive shaft weights mounted on the same side or are they counterbalanced? will i damage the car if i try it to see if it wobbles?

[KalamazooJohnny]

I just put a used flexible coupling on my drive shaft, and had trouble getting it started, but noticed the first set of splines inside is plastic, and slightly warped. So I just got it to where it felt like the teeth were kinda lined up and tapped it with a rubber mallet lightly until it slid in.