Alfa Romeo Forums banner

1 - 20 of 21 Posts

·
Registered
Joined
·
273 Posts
Discussion Starter #1
My '87 spider has developed a vibration that I think is coming from the driveshaft. The universals seem tight...no play and the support bearing seems sound, but if I wrap my hand around the driveshaft, I can move it around pretty easily. The movement is in the rubber in the support bracket. How stiff should the rubber in the bearing support be?
 

·
Registered
Joined
·
7,278 Posts
my support bearing has a little movement in the rubber, but then again, it is rubber so I presume a little movement is ok!

If you push the prop up and down at the support bearing, is there any clicking? That would be the bearing and that would not be good.

I had a sudden terrible vibration too this summer, and it turned out to be the support bearing bolts had very, very slightly worked their way loose (you couldn't tell visually) I took them out and applied a little loktite and tightened them back, all well since.

Your guibo/flex joint is OK I take it?........that is obviously the first thing to check.
 

·
Premium Member
Joined
·
1,692 Posts
Speaking from recent experience, a worn "onion" on the output shaft of the gearbox can cause a noticeable driveshaft vibration. Here's what mine looked like. My Alfa specialist commented that it was the worst he had seen.



Gearbox rebuild wasn't cheap, but needed to be done to replace that shaft. Hopefully, this isn't your problem, but you can check it by removing the front portion of the drive shaft.
 

·
Registered
Joined
·
273 Posts
Discussion Starter #4
ouch!

Rich, Please forgive my ignorance...I have not actually taken one of these apart yet. what would cause the end of the output shaft to wear so much? I thought that it was isolated from the drive shaft by this rubber donut. This is very scarey!
 

·
Premium Member
Joined
·
21,129 Posts
The support bearing is at the rear of the front shaft. This kind of damage is not normally caused by the support bearing. This is extreme, though I had one that the "olive" pictured here wore completely through one wall of the mating bushing in the front of the driveshaft, ran about 1" off center at all times.

Andrew
 

·
Premium Member
Joined
·
1,692 Posts
Rich, Please forgive my ignorance...I have not actually taken one of these apart yet. what would cause the end of the output shaft to wear so much? I thought that it was isolated from the drive shaft by this rubber donut. This is very scarey!
My car has about 175,000 miles on it. (I've owned it for just over two years). The output shaft goes into a socket (bushing) on the front end of the driveshaft, and should be loaded up with moly grease, which is held in by a rubber piece that fits around the "olive." My mechanic said that the type of wear I have is caused by not having the grease in that socket. Over time, with any slight misalignment, both the inside of the socket and the olive will wear. And once the hardened outer part of the olive is worn, it will wear more quickly.

As I understand it, the rubber donut transfers the rotation from the gearbox to the driveshaft, but the alignment is maintained by the onion and socket.
 

·
Registered
Joined
·
7,278 Posts
the bushing into which the "onion" on the output shaft fits, is usually called the 'top hat' bush, #7 here (which I outlined in blue)
#6 is the rubber seal that keeps the grease in there.
 

Attachments

·
Registered
Joined
·
273 Posts
Discussion Starter #8
Hey guys, thanks for the quick education! Now I'm really worried about what I'm going to find! I can see thst if the olive is worn, I'll be looking at a project!
 

·
Premium Member
Joined
·
1,692 Posts
More common for the bushing (7 in SS4's post) to be worn than the olive. And that's a much easier situation to deal with. Good luck!
 

·
Registered
Joined
·
273 Posts
Discussion Starter #10
Thanks Rich...I've replaced a couple of bronze pilot shaft bushings on my old mgs and they showed a lot of wear while the shafts showed almost none; in fact, the new bushings needed ro be reamed. There was, however, no appreciable side forces like could get genersted in the alfa scenario. It is a pretty severe vibe...I do hope that its not a disaster! I think that I'll get it up on stands next week and get a closer look.
 

·
Registered
Joined
·
2,075 Posts
The bushing in the drive shaft is steel and seem to also be fairly hard based on the small amount of damage shown after chiseling it out of the drive shaft.
 

·
Registered
Joined
·
549 Posts
For the S2 on spiders, whats the procedure for replacing the driveshaft center support and/or bearing? Press the bearing onto the driveshaft first, or into the center support?

Can the support be changed without replacing the bearing? By just sliding it on? Reading up on this, I don't understand if the center support has the bearing pressed into it and then both are pressed onto the driveshaft?
 

·
Registered
Joined
·
143 Posts
Drive shaft bearing

For the S2 on spiders, whats the procedure for replacing the driveshaft center support and/or bearing? Press the bearing onto the driveshaft first, or into the center support?

Can the support be changed without replacing the bearing? By just sliding it on? Reading up on this, I don't understand if the center support has the bearing pressed into it and then both are pressed onto the driveshaft?
I'm about to replace my 87 spider center support as the rubber has deteriorated. The bearing is good - no play. My question is the same as the quote above. Can the support be replaced without removing the bearing?
 

·
Premium Member
Joined
·
1,470 Posts
you will need a bearing splitter and press (or puller)

The central support bearing is "pressed" into the rubber housing in the support frame.

If you want to replace the housing frame and it's integrated/captured rubber bushing, but use the old bearing, you will have to press the old bearing out of the old bushing and then press it into the new frame/bushing unit.

You will also have to remove the tapered flange piece (that connects to the rear shaft) to get at the central support unit.

If you are going to go to all that trouble, you might as well pony up an additional $30 for a new bearing while you are at it.

The first photo below shows the rip in my rubber carrier bushing before I replaced it.
 

Attachments

·
Premium Member
Joined
·
1,470 Posts
installing bearing into carrier

Here are a few photos showing a new bearing being pressed into a new central carrier bushing/frame unit. Note that the bearing has to fit far enough into the metal bush carrier to allow the retaining clip to slip into the groove.
 

Attachments

·
Registered
Joined
·
143 Posts
Thanks for the in-depth reply.
I think the 105 series was a little different because you can buy just the rubber insert. That's what was confusing me.
Agree, might as well do it all while apart.

Thanks.
 

·
Registered
Joined
·
34 Posts
Looking For In Drive Shaft Specialist Raleigh NC

I need to have my u-joints replaced and while the whole thing is out am planning to do the center bearing as well. I am being warned how bad the center bearing clip is and that it needs to be drilled to get it out.

I have the parts to rebuild it and would like to take it to a shop that knows these 115 drive shafts. Does anyone know of a good shop for this in Raleigh North Carolina?
 

·
Registered
Joined
·
34 Posts
Took Advice

Exotic Coach on Barefoot Industrial Dr (Rd)? off Glenwood, near Carmax[/QUOTE

86 Spider, I took your advice and Exotic Coach has drive shaft and parts I ordered from Centerline. They were able to do the center bearing no problem but are struggling with the U-joints. Being told no taper on the u-joints and that they are hard to get in square.

BTW this was an unmolested drive shaft in a very low mile car so they were not damaged by a PO or mechanic in the past. This is the first time they have been touched.

They have had the drive shaft about 4 days. Wondering if there is a better supplier of u-joints that have tapered or chamfered cups. Would love to find some that have grease fittings.
 

·
Premium Member
Joined
·
1,470 Posts
The factory U-joint caps are not tapered, and the correct U-joints are not carried by all suppliers.
The problem replacing the universal joints is that the outer surfaces of the yoke castings they fit into are not flat or perpendicular to the bore so they are a little tricky to setup on a press.
 
1 - 20 of 21 Posts
Top