Intro and Advice

[trok]

Hey guys new to the forum. 

Long time auto guy that recently acquired a 521. 

Needless to say it's an amazing little truck that puts a smile on my face when I drive it. 

Pics of the truck soon to come. 

 

After introducing myself I'm naturally going to ask for something, ha. 

I'm in search for an upper and lower center bearing bracket. 

For some reason the PO only has the upper installed but split it in the center in order to bolt the center bearing down to the cross member.

I welded the bracket back together but the mounting holes didn't line up after so i had to recut and bolt down again.

Not sure if the center bearing is original hence the split bracket but needless to say the shaft wobbles under load.  

 

I know I could go solid driveshaft but was hoping the bottom bracket would be the key to my problem. 

 

Any insight guys or possible brackets laying around in someones garage?

 

Love the forum, thanks in advance.  

 

 

 

 

[mrbigtanker]

So if your talking about the carrier bearing then get rid of it and get a 1 part shaft,i think the 520 ones fit,if not i might be able to help you out.But not until we get pictures.

[Cleopatra Jones]

POST PICTURES!! We're picture whores here....and welcome!

[flatcat19]

Advice...pics get attention. 

 

 

 

Lots of people have reported the difficulty location a proper drive shaft support bearing. 

Ask a driveline shop the cost of going 1 pc. 

[wayno]

This seems kinda strange that the lower bracket is not wide enough, how far apart are the mounting holes from center to center?

[trok]

Hey Guys, thanks for the advice so far. 

I'd like to try and keep the twin shaft if possible just in case I want to lift it later. 

Would a single shaft hit the crossmember if brought back to factory height?

Pics are below of the truck and center bearing bracket.

I'll take better pics later as these don't do it justice.

 

Looking forward to the datsun wisdom on this bracket situation.

 

[wayno]

When it was out of the bracket, is the rubber piece round or slightly flatter on one side?

You could add/weld another piece of metal between the two sides also, I do realize that is not a proper fix, but it will likely get you back on the road without having to worry about it.

Where are you located in Oregon, Portland?

Is that the Loyd center parking area?

[trok]

Thanks Wayno, 

As far as I can remember the rubber piece is rounder more donut like, then there's a flat metal ring around that. 

I thought about welding an extension piece but I'm still missing the bottom bracket so the bearing is butted up against the subframe.

Might do that as a last resort, does the bearing/ donut appear factory though?

Not sure if this makes a difference but the tranny is from a 280z.  

 

I am in the Portland area by the way.

Truck is drivable, just clunks when I'm under load. Mainly on takeoffs. 

[Tucson620]

Hey trok - cool truck!  Is it green?

 

I might be able to help you out with the carrier bearing parts - let me check when I get home.  I put in a 5 speed and converted to a 620 carrier bearing back half.

[wayno]

Thanks Wayno, 

As far as I can remember the rubber piece is rounder more donut like, then there's a flat metal ring around that. 

I thought about welding an extension piece but I'm still missing the bottom bracket so the bearing is butted up against the subframe.

Might do that as a last resort, does the bearing/ donut appear factory though?

Not sure if this makes a difference but the tranny is from a 280z.  

 

I am in the Portland area by the way.

Truck is drivable, just clunks when I'm under load. Mainly on takeoffs. 

 

All you really need to do is hold it still, pin it down, maybe the clunking is something else, seems like if it was moving around, the bracket would be bent open at the top, but maybe it is, you just don't have a photo of that.

I just looked around, and I cannot find any 520/521 brackets around here at the moment.

[trok]

Thanks tucson,

the truck is a faded mint green mixed with rust, ha. 

 

It's hard to see in the pictures but the bracket is split on top but not necessarily bent. 

My theory is that the torque from the power train gets expelled through the drive shaft and finds the paths of lease resistance i.e. rear axle carrier and improperly mounted center bearing. 

Maybe it's easier to just pony up and get a single shaft.

Does a single shaft have enough clearance at stock height?

 

If anybody has the brackets though let me know. 

Thanks again.

[datson4life]

I got the carrier bearing brackets if thats your issue

[wayno]

No, a single driveline will not clear at stock height, you have to cut out the carrier cross member, and you lose your e-brake when you do that also, no one ever talks about that, they just talk about having a single driveline.

Stay with the carrier bearing driveline, for now till you get the parts you need, just weld a piece of metal in that gap, and it's better to be slightly to tight, than to lose.

 

EDIT

OK, it has brought to my attention that maybe a single driveline will fit at stock height, it will definitely fit on a lowered vehicle, but before I used such a setup, i would lift the whole back of the truck off the ground by the frame, if that driveline even touched that cross member even just a little, I would not use it, not even a chance of me using it.

[Tucson620]

Trok - I think the rubber isolator piece around your bearing looks non-stock.  As Wayno mentioned, should not be round (like it looks), instead flattened on one side.  Took a pic of mine here.  Will PM you about brackets, if you need those.

 

Wayno - never heard single drive line requires cutting and whatnot - for installation?  Seems like a lot of people have them, including stock 520s.

 

[datzenmike]

The J13 520s were single piece drive shafts on the L520 and L521s through June '69.

[wayno]

OK, I suspect that you have a 720 rubber piece in your truck, it might be a late 620 also, but I have never looked at a 620 driveline to know, my 720 carriers have a perfectly round ring around the rubber piece, and they are bigger round also, so it would make sense that you would not be able to make it fit in a 521 carrier frame piece/cage, and any uncut 521 piece is going to need to be cut also.

Like I said, you should just weld a piece of metal across the gap, make sure it will be tight, and go with that for now, and if you come across a 521 in the wrecking yard, or someone parting one out, you could grab the whole driveline complete as long as it is good.

I cannot recall if you have the stock 521 transmission, if you do, you will be fine.

Maybe someone put the wrong rubber piece on your 521 driveline, and the 720 metal cage has a wider mount, so it won't work on a 521 cross member without modification of the cross member mounting holes, and I suspect it's not as easy drilling a couple holes either, but I could be wrong there also.

[datson4life]

Mine one piece fit cause im lowered about 4 inches, yes stock height might be an issue for a one piece

[uberkevin]

Hows the ride when 4 inches low?

[trok]

Thanks for all the help guys, after looking at tucson's carrier bearing it seems like mine is not original.

Not sure what mine's from, but now it makes sense why they would cut the bracket to make it fit.

 

Next question would be if there's a factory bushing still available or replacement.

Other than that, think I might just have to go to a single drive line.

[trok]

Just read your post wayno and think your right.

Going to research what the carrier is from, just assumed it was factory initially.

Checked some of the wrecking yards but none of them seem to have 521's out here.

[wayno]

Just read your post wayno and think your right.

Going to research what the carrier is from, just assumed it was factory initially.

Checked some of the wrecking yards but none of them seem to have 521's out here.

 

521s are few and far between these days in the wrecking yards.

[datson4life]

Hows the ride when 4 inches low?

Horrible, but i really only drive it to meets/shows, i highly dont recommend 4 inch drop for daily drivers unless u wanna slowly murder ur 521

[uberkevin]

Ha, well I guess I will not lower it another inch.

 

Oh how long is your one piece drive line? Theres two in the yard around me but I wanted to know how long the 520 drive line should be before I grab one or both. Their sitting in the back of a 69 521.

[trok]

So just a quick update.

Tucson620 was patient enough to help me figure it out.

The five speed conversion on my truck is using a 620 front shaft.

The center bearing is from a 620 making the 521 bracket to small thus why it was cut to make it fit.

Hessianben's post clarified the solution so now I'm in search of 620 center bearing brackets.

If anybody has those available I'd definitely be interested. 

[wayno]

So just a quick update.

Tucson620 was patient enough to help me figure it out.

The five speed conversion on my truck is using a 620 front shaft.

The center bearing is from a 620 making the 521 bracket to small thus why it was cut to make it fit.

Hessianben's post clarified the solution so now I'm in search of 620 center bearing brackets.

If anybody has those available I'd definitely be interested. 

The center cage will not likely fit in the 521, the mount holes are farther apart, at least I believe they are.

620s are easier to find, just go to the pick and pull site, check the inventories of all the yards close to you, and go grab what you need, as it is likely that it will be there, but I still don't think it will work, but maybe you can drill new holes if they are not to close to the 521 mount holes.

This is what happens when people start moving parts around, I do believe that jon521 did this, but he made a adapter bracket that moved the holes for the cage mount about an inch farther back, so the adapter was drilled for the 620 carrier cage.