Comment

Comment by Norman Silverman on April 12, 2019 at 2:58pm

Thanks, Jason. I'm tempted but it will now have to wait till my mechanic has another slow day. These guys are Bulgarians (which means they did not grow up with these cars) that I use to service my MBZ Diesel (which they DID grow up with). My other car is a 66 Imperial which has a very similar set-up and is EXQUISITELY sensitive to vibration caused by balance-even though it is constructed and attaches in almost exactly the same way. My issue is very slight (I am EXTREMELY PARTICULAR) so I fear that if I do the swap and my mechanic is correct, I may make things worse. I DO have the matching front half that goes with the good rear, but I am missing some small parts to connect them. Someone removed the carrier and did not hold on to the slinger and other parts.  I also have a brand new carrier and bearing. If I find the small parts that would enable me to re-assemble the two halves correctly (they are marked) I may just put the whole thing together and swap it out entirely. We'll see......

Comment by Jason Edge on April 12, 2019 at 2:35pm

Norm, I've never had or heard of a good rear throwing the driveline out of balance.  That does not mean there is no merit in having the entire front, center member bearing and bracket, and rear section balances as an assembly, however,  my thinking is since the center member bearing and bracket is bolted to the frame this creates a stationary point where further vibration should not be propagated. In that thinking I believe it would be more advantageous to balance the front section and rear section separately. I have never done any deep dive study into this but have also never had much of any negative feedback from customers that swapped in a rear section. The bottom line is there are just 4 5/8" bolts at rear and one large retaining nut holding it together and you are looking at 30 minutes to 1 hr install time at best. I would pop it in and give it a spin.  This is one subject I have to keep an open mind. Be sure to tell us how it goes and if there was any balancing done. I would be very curious how the entire assembly would be balances as a unit. I would assume the center member bearing is fixed in some vice like contraption, since it is the one non-flexing and stationary component of the drivetrain. Almost everything else has some back and forth and up and down flexing. 

Comment by Norman Silverman on April 12, 2019 at 2:12pm

I managed to secure a rear half of a drive shaft that passes the "Jason Test"; it puts up rigid resistance to being moved. When I went to my mechanic today to swap out the sections he said he'd be glad to do it, but that doing so would through the drive shaft out of balance, unless after we re-assembled the two halves i took the driveshaft to a driveline place and had them balanced as a unit. I don't remember seeing anyone refer to this process (balancing after assembly) so is it advisable/necessary? Thanks. 

Comment by Norman Silverman on December 4, 2018 at 3:06pm

Vibration on my 64 is felt more strongly when I actually accelerate than when I am just running along (although it is present then, too). If I shift in to neutral, it pretty much goes away. Does this sound more like CENTER BEARING/CARRIER or weak CV joints. I'd like to be prepared before I take things apart because I will be using a lift provided for 4 hours on a Saturday morning by my regular (diesel) mechanic. All opinions welcome-especially good ones. 

Norm

Comment by Norman Silverman on June 28, 2018 at 9:05pm

Fantastic and highly informative!!!!

Comment by Jason Edge on July 8, 2017 at 1:53pm

Main thing is to have the driveshaft locked down in a vice, and angle it so you get max wrench jaw on the square of the nut.

Comment by Jason Edge on July 8, 2017 at 1:37pm

I use a very large adjustable wrench to remove the center member bearing bracket nut. I hold it in place on a bench vice with the nut pointed up, and wedge the jaws of the adjustable wrench in just right to make sure it has a good grip on the nut. The nut backs off counterclockwise.

Comment by David Thomas on October 15, 2016 at 11:37am

When I first started to do the rebuilds, I wish I had been more observant and knowledgeable about the CV joints. It was after I had disassembled and reassembled them several times before I began to visualize what might be the problem. By then, I had no idea what the driveline shops had done. I don't know what they did or if they tried to get things centered up during assembly. I surmise they don't attempt or take the time to get the CV joints centered. Even if you have the shaft balanced, and they didn't try to get the CV joints centered, you'd have everything running in different circles. When they balance a shaft it is put on a lathe type machine with the joints straight in line with the shaft. They spin the shaft with a dial indicator riding on the tube adjacent to the joint. The dial indicator shows the deflection of the tube, they add weights on the tube to make it run more true. This only corrects one component if the CV joints are not centered also. Like I said previously, if the connecting yoke ears are deflected a few thousands and the u-joint is off a few thousands, things can get out of sorts real quick. I think the run of the mill driveline shop won't take the time to get the CV joints centered. 

Comment by Jason Edge on October 14, 2016 at 4:04pm

David, thanks for the detailed reply. With your comment "Over the last 25 years I have had 3 different drive shafts repaired professionally numerous times by local shops with mixed results. None of them really satisfactory." you have reiterated the same response I have received from many others. My question is do you have any idea why these "professional" shops have such a high fail-rate in this endeavor? I would say a good 1/3 of the VG used drive shafts I have sold have went to customers that spent a small fortune having them rebuilt with bad results.

Comment by David Thomas on October 14, 2016 at 3:41pm

I suspect that your abilities and the interest to pay attention to detail would most likely result in a superior outcome. If the drive shaft you have is close to right, you could check to see if the bearing cup retainers are snug against the yoke on all 4 sides. Use a feeler gauge set to see if there is more space between the retainer and the yoke on one side than the other. I try to remove any space when I assemble the joint.

Another source of driveline vibration is the transmission tail shaft housing yoke bushing. There should be very little movement of the yoke in the transmission bushing. Barely perceptible movement.  

• ‹ Previous
• 1
• 2
• Next ›
• Page