First time poster For some background, we just bought an '84 Spider and have been going through some of the systems, doing general maintenance, and figuring out what to replace in the off-season. Our Spider has the (apparently classic) gentle thud-thud-thud on hard take-offs from a stop, emanating from somewhere just behind the seats under the car. I can't say that I've isolated the problem, but the center bearing bushing is definitely sloppy and likely contributing to the issue.
To cut a long story short, while the drive shaft is out to replace the center bearing and bushing, I am planning on having the shop replace the giubo and U joints. After doing some reading, it looks like the top hat bushing, top hat internal rubber buffer, and "prop shaft front rubber bush" might as well get replaced at the same time. See diagram on the Classic Alfa site for nomenclature: *classicalfa.com/propshaft-parts-diagram/*
I've read about the "olive" piece and am trying to figure out if the "prop shaft front rubber bush" above is the same part? Any clarifications would be much appreciated. Thanks!
I've searched the Classic Alfa gearbox section (and other sites) for this olive piece, but there doesn't appear to be anything remotely similar. Where can I find one? Or is it somehow integrated into the output shaft?
It is the end of the shaft. It is not a separate component. Most replace the shaft if the olive is worn. I've been working on a "better" method for some years. I might have the fix now. This is not on my list-of-things-to-re-engineer today, but I'll know by this winter. For now, if it's shot, replace the shaft.
The olive is the round end of the output shaft. That is, it is part of the machined shaft, not a separate part. You'll see it when you remove the front section of the drive shaft and notice that it fits in the "top hat" bushing. If lubrication is lacking and/or misalignment occurs, this round end of the output shaft can wear and cause vibration (reportedly). The original gearbox in the '88 Spider had about 160k miles on it when rebuilt. There was some wear on the "olive" but it did not cause any problems. Hopefully, yours is fine.
It isn't necessary to replace or weld the mainshaft. The end of the shaft can be ground down and the "ball" from a spherical bearing fitted. The replacement bearing from an Alfetta driveshaft is the correct size. If the sleeve in your driveshaft is worn, a sleeve with a larger I.D. can be made that fits the outer race of the Alfetta bearing.
If you replace the tranny mount then measure the OD of the new one very carefully and compare it with the one that came out. Many of the aftermarket ones are oversize and will crack the housing. I would not replace one that looks OK.
IF you check, all will be fine with the mount. If you do NOT check, it will be too big and crack the casting. It's really that simple.
From my experiences over time.
While I have never had an issue with the size, what I have seen is people trying to beat out an old one or force in a new one incorrectly and crack the housing.
I have heard that people have been known to freeze the new one if it is too big and after it is installed and warms up, it cracks the housing. So, do not do that.
I have done many successful ones but the last one was oversize. Search on it, it is common. Maybe there is more than one manufacturer and at least one is bad and at least one is good or there maybe just one with lousy quality control.
what I have seen is people trying to beat out an old one or force in a new one incorrectly and crack the housing.
Back in the day, before the ABB, I described a method for replacing the bushing in the Alfa Digest. I did the job with the gearbox in the car which was on jack stands. I used a big gear puller to push the new bushing in and the old one out at the same time. This last time it would not work and I heated the housing and froze the bushing and then pushed it in. The housing cracked after the bushing went in and the temperatures normalized. The mount was a "heavy duty" type from Centerline.
My new transmission mount for the Duetto came from Classic Alfa. It fit well but it is not an easy job to replace. Fortunately the housing did not crack!
I read in 'Alfa Romeo ~Montreal the Essential Companion' that sometimes a new Guibo can cause the driveshaft to thump. Also, friends here on the ABB have stated that it is important when replacing the Guibo not to tighten the nuts all the way to specification until the car is on the ground and you can roll it back and fourth a few times. I tried that on the Montreal and the driveshaft still thumps, so maybe it came with a new Guibo -six years ago...
Jim (a long time Alfa mechanic and friend) says to "replace the U-joint" if the driveshaft thumps; maybe I need to try that on the Montreal. The joint seems tight with no play. It only thumps when taking off, usually in 1st gear or going up my steep driveway.
You have the concept correct, but I can't confirm the dimensions of the replacement parts. The original Alfetta bushings are the correct size and had a split outer race that made it easy to remove. I used this method to save several close ratio racing transmissions.
If you're replacing the olive using a spherical bearing,you do need a lathe to cut off the worn transmission output shaft olive,and turn that area down to a press fit with the spherical bearing ID. I'd check all of the above suggestions before replacing the olive.Unless yours is visually worn,I wouldn't mess with it.To be sure,it wouldn't hurt to measure the driveshaft end bushing ID(tophat),and your olive OD.I believe the tolerance is .002"-.007"max. The Aurora GE12E bearing is very inexpensive,maybe $4.00 ea.,worked for me,but is also made by other manufacturers such as SKF.I believe the center "spherical bearing is available separately too,but I don't have that part number. There's a thread that covers this somewhere in the gearbox forum.The GE12E bearing measures 12mm ID,sphere OD18mm,sphere width 10mm
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Alfa Romeo Forums
2.1M posts
88.6K members
Since 2002
A forum community dedicated to Alfa Romeo owners and enthusiasts. Come join the discussion about performance, parts, modifications, troubleshooting, maintenance, and more!