Drive shaft Vibration

[1-ton]

I have a 2-piece driveshaft on my lifted 1991 Crew cab. The rear drive shaft is vibrating a little at the carrier bearing because that is the one place on my driveshaft that has too much of an operating angle. The rest of the u-joint operating angles are good.

I want to put a CV-joint (a.k.a Double Cardan) at the rear driveshaft carrier bearing slip yoke. I do not want to spend thousands of dollars on a complete custom driveshaft because I know the only problem with my driveshaft is at the rear driveshaft carrier bearing.

There seems to be not much choice in building a CV-joint for that area of a 2-piece driveshaft. I did find one possible option at Driveshaft Specialist in Texas (pictured below). I have had a couple of drive line shops tell me it cannot be done. When I ask why?...they cannot come up with a straight answer. It seems like more of an opinion than based on technical reasoning. Any thoughts or solutions to this?

 

[Bent77]

I wonder if some of the deflection in the carrier bearing is causing a concern. How are the multiple length driveshafts in big trucks assembled? Slip on the other side of the joint?

 

[obijuank5]

I was going to suggest Craig at driveshaft specialist. I have had hundreds of shafts built by them. Its completely doable but why can't you just shim your carrier bearing down?

 

[Bent77]

I was going to suggest Craig at driveshaft specialist. I have had hundreds of shafts built by them. Its completely doable but why can't you just shim your carrier bearing down?

They move the vibration to the joint at the case. Had that issue on my long bed. Finally went one piece, but that’s not a good option for the Crew!

 

[1-ton]

I was going to suggest Craig at driveshaft specialist. I have had hundreds of shafts built by them. Its completely doable but why can't you just shim your carrier bearing down?

I have already done that. it is shimmed down about 1-1/2". Shimming the carrier bearing down too much causes a clearance problem when off-roading. If it hangs down too low, it could get ripped right off my truck when wheeling. I want the carrier bearing back up where it belongs to protect it during off-roading.

In the 30 or so years of the existence of the Chevy square body crew cab, it seems like I am the first person to ever try doing want I want to do with my driveshaft because nobody I talked to has ever heard of putting a CV-joint right at the rear drive shaft carrier bearing on a crew cab. Even the experts at driveshaft builder shops seem to have never heard of such a thing.

 

[Bent77]

I know @mrk5 has shared your issue, but I think he moved the carrier back

 

[1-ton]

He had a complete driveshaft built for his rig that cost a lot of money. I do not want to spend that kind of money, when I know the problem is in only one area of my driveshaft.

 

[Bent77]

He had a complete driveshaft built for his rig that cost a lot of money. I do not want to spend that kind of money, when I know the problem is in only one area of my driveshaft.

If you follow his thread, also note he had an output bearing issue. Food for thought

 

[dyeager535]

I'm not saying this to inflame anyone, instead of the SYE and CV, it probably makes more sense for *most* people to retain the slip yoke. Adding a CV to the existing shaft would be an easier/cheaper option in general, one would think.

Here's one, right? http://www.dennysdriveshaft.com/p15...with_transfer_case_slip_yoke_for_n.html#photo

 

[1-ton]

I'm not saying this to inflame anyone, instead of the SYE and CV, it probably makes more sense for *most* people to retain the slip yoke. Adding a CV to the existing shaft would be an easier/cheaper option in general, one would think.

Here's one, right? http://www.dennysdriveshaft.com/p15...with_transfer_case_slip_yoke_for_n.html#photo

I called Denny's driveshaft about 7-months ago, and they said that the slip yoke you posted a link to was meant for output shafts and not the slip yoke at the carrier bearing. I asked them if they knew what size the carrier bearing slip yoke size was on an old Chevy like mine hoping that maybe the carrier bearing slip yoke splines were the same size as out-put splines, and they said NO! I would have to figure out that one for myself. At that point they just wanted me to go away. This is the type of answers that lead me to think that no driveline shop has ever dealt much with any old square body Crew Cab driveline issues before. Or that maybe the people I am talking to at driveline shops where just little kids when the old Chevy square bodies came out, which is why they know so little about them.