Drive shaft related

[topbuddy]

My 81 Fiat Spider has a noise coming from underneath and I suspect something in the drive shaft. I couldn't see a forum to post this to so used the general related one. It started with a ticking sound similar to a noisy tappet so I thought it was in the engine, until a short ride yesterday. The ticking grew louder until it was a rat tat sound. The sound is not there when coasting, only when I apply power. I jacked the rear wheels up and put the car in 1st, and you can see vibration where the support bearing holds up the drive shaft, other than that everything seems normal. the faster you accelerate the louder the noise, just like something hitting metal somewhere, but you cannot see where.
Can anyone help me with a suggestion or did anyone experience a similar problem? I don't want to drive it and compound the problem but don't quite know where to start replacing parts.

[RRoller123]

Sounds like the main drive shaft support bearing could be kaput. Auto Ricambi US has a replacement kit.

[topbuddy]

Thanks to RRoller123 for the quick response. I have already ordered that bearing along with a couple of u joints. Do I need to replace them as well and is it difficult to remove the old main bearing, as I did not order the bearing support as it looks ok. Comments please.

[azruss]

usually the bearing isnt the issue, its usually the rubber support in the pillow block. It is very difficult to see problems with the rubber without removing it from the car.

[81SPIDERMATT]

Thanks to RRoller123 for the quick response. I have already ordered that bearing along with a couple of u joints. Do I need to replace them as well and is it difficult to remove the old main bearing, as I did not order the bearing support as it looks ok. Comments please.

I am with azruss and think that the support is more likely to be bad than the actual bearing and the bearing is bounding around within the support .... I did not know you could order just the bearing and yes go ahead and do the u-joints .... mark everything well the way it all lines up before removing stuff ... and the guibo would not be a bad idea right now also

[vandor]

While under there be sure to check out the rubber flex disc just behind the transmission. If it fails the flopping driveshaft can cause a lot of damage!

[johnsje6]

I bought the driveline kit from AR, replaced the u-joints, carrier bearing and guibo on my '79. May as well do it all while you have it apart, and the peace of mind will be a bonus after The Great Thaw happens and we can drive again. Agree that you need to mark all the parts to make sure they go back together with the same alignment they came out with so you don't have balance issues. It is not a terribly bad job, but takes some time, and you will need a vice or big c-clamp for the u-joints.

[Odoyle]

Just rebuild the driveshaft on my 83 and got it rebalanced by Wenco in socal. Said that the middle portion right behind the center support bearing was way out of balance. They did a great job, took a little extra time because he had to machine a part to adapt my driveshaft to his machine. Bolted it back in on yesterday and jacked up the rear end so I could see it spin and it looked straight as an arrow.Not sure if its new fluids or the driveshaft but it feels like I'm putting down power better.

P.S. When your re-installing the driveshaft, make sure to attach the guibo to the transmission-end yoke. Also if your installing a new guibo make sure all 6 bolts can freely go through all the holes.

[bradartigue]

I've never seen or heard of one needing to be balanced - interesting pictures. Curious to know if you can feel a difference, with the two-section design (two rather short sections at that) I've always wondered if balancing was even necessary.

Per the posts above, if you go through the work of removing the driveshaft then it always makes sense to replace the wearable parts (guibo, u-joints, pillow block). The pillow block might take $50 at a machine shop to press it off but its worth it. These things, if still stock, are ancient, even on the newest (1985) Spider.

[topbuddy]

Thanks to all for the answers. I now have all the parts but after reading the shop manual etc am confused. The flexible coupling is held in place by 6 bolts and self locking nuts and the new one has a compressor clamp around the outside which we are not to remove until installed.

My problem is that I can't remove the old nuts and bolts, it is as if they are frozen, is this normal? Also, the manual says to place a compressor tool (70025) around the old flexible coupling prior to removing the bolts. Just what does the compressor clamp do and if it is not on, can I still remove the nuts and bolts? They could not have put them in a more difficult place to remove as the support bars and the back of the transmission hinder getting any tool in place. So just what do I have to do to remove them. I notice that the bolts holding the back flange to the rear end are also a problem, is all of this due to the age of them, probably never changed since new, or what else do I need as tools or to do.
Thanks

[topbuddy]

Further to my previous post, I forgot to mention that the initial problem is definitely the center pillow block, in that the rubber around the bearing has separated from the block itself and therefore is allowing a lot of movement, everything else appears reasonable. What is the opinion of driving the car slowly to a garage if I can't get the shaft off myself verses getting a tow?

[aj81spider]

I took mine off without needing a clamp. Once the nut is off you can tap the bolt through the guibo if it doesn't slide easily.

I'm not implying that anyone is as unobservant as me. However I struggled with mine for a long time before I realized that putting the rear wheels on jack stands let me rotate the drive shaft so that each bolt was easy to access. After swearing at myself for my stupidity the bolts all came off with normal wrenches and not excessive force.

[topbuddy]

Thanks AJ: I had my 81 up on jack stands and could rotate the shaft as you mentioned, however the problem is that I can't get either the nut or the bolt to undo. Do you know if the self locking nuts will come off by trying to loosen the bolt?
All 6 of mine seem as if they don't want to move even under force. In one case I had a buddy try and push with his foot on the wrench for force while I held it in place. No luck.

[azruss]

sounds like someone installed with an impact wrench. These are high grade bolts so you wont break them easily. get some penetrating oil on those nuts for a while and get a longer breaker bar. I think the drive shaft can be removed without removing the guibo. Spline should just slide out.

[Odoyle]

A technique I found useful when removing the driveshaft from the guibo was to wedge a 19mm wrench through the transmission mount and hold one end of the nut, then with a ½ breaker bar break the torqued bolt. To remove the driveshaft in the easiest way just remove the first 3 bolts that connects the yoke (on the driveshaft end) to the guibo and then unbolt the rear axle. Also make sure you have someone help you with re-installation, its rather dangerous and awkward putting the driveshaft back in alone.