Datsun 620 3 inch block lower question please help!

[sick620]

k so awhile back i droped my truck. flipped the leafs removed 1 or 2 and put 3 inch blocks. i did it all my self. my blocks are flat blocks with no angle to them. shortly after installing the blocks my carrier bearing went bad. i installed a used carrier bearing from the junkyard it looked to be in very good shape. now it to is going bad. i can here the problem again now when driving. and the carrier bearing appears to be tearing apart again. does my problem have anything to do with my driveline having a slight angle to it? if so what can i do to fix it? please help:mellow:

[datzenmike]

The angle from the tranny to the d/s should equal the d/s angle to the rear end. Even in two piece d/s the input angle should equal the output angle as below:

 

http://i138.photobucket.com/albums/q251/datzenmike/Tranny/transdriveline.png[/img]"]

 

Because of the nature of leaf springs a 3" drop shouldn't affect this very much. The carrier bearing seldom goes bad as it transmits no power but just supports the d/s in a rubber do-nut. If the do-nut rubber is rotten it will allow the d/s to flop around. New u-joints are imperative on a d/s to prevent vibration also.

Edited September 8, 2009 by datzenmike

[motavated]

You know I have a 79 diff on my 74 truck and dropped it 2 inches with flat blocks. I need to make or buy a straight drive shaft...

[sick620]

ur pretty much saying that it is fine how it is? what else could make it go bad.... i have brand new u joints in it.

[slam_dat_sun]

I to put a brand new carrier bearing in my 1974 620 , I did not flip my leafs or remove any leafs . I put 4" blocks in with an angle and I asked around on ratsun and learned when doing what I did it is best to put a 1"-1 1/2" square tubing under the carrier bearing . That is suppose to put it back in the same angle , I hope I helped

[slam_dat_sun]

The angle from the tranny to the d/s should equal the d/s angle to the rear end. Even in two piece d/s the input angle should equal the output angle as below:

 

http://i138.photobucket.com/albums/q251/datzenmike/Tranny/transdriveline.png[/img]"]

 

Because of the nature of leaf springs a 3" drop shouldn't affect this very much. The carrier bearing seldom goes bad as it transmits no power but just supports the d/s in a rubber do-nut. If the do-nut rubber is rotten it will allow the d/s to flop around. New u-joints are imperative on a d/s to prevent vibration also.

 

And I am not 2nd guessing what is being said here by datzenmike I am just saying what I did

[yello620]

You need to put a spacer between the carrier bearing and the crossmember. Right now your drive shaft is running with a "V" shape to it, low at the carrier bearing. Raise the low point of the "V"(carrier bearing) at least an inch, maybe more.

[sick620]

ya thats kinda what i thought yello620. thats what people have been telling me to do. i just wanted to make sure. i know thats what u do to a 520 so i figured it had to b the same.:D

[datzenmike]

You need to put a spacer between the carrier bearing and the crossmember. Right now your drive shaft is running with a "V" shape to it, low at the carrier bearing. Raise the low point of the "V"(carrier bearing) at least an inch, maybe more.

 

Yes. In my head I was seeing the diff going lower on the truck but the opposite was true. Either way, the drive line angles must be preserved as in the photo for the least vibration and wear. A two piece is slightly more complicated.

 

Thanks to BEEBANI for the tutorial on this.