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Center Take-Off Rack & Pinion


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#41 wayno

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Posted 26 December 2017 - 05:57 PM

Is this about power steering or something else?

What year is your 620?

 

I keep coming back to this question, is this about power steering or something else, and what year is your 620?

Are you looking to get rid of the 620 column?


 

 


#42 Moist Lightning

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Posted 26 December 2017 - 06:43 PM

I keep coming back to this question, is this about power steering or something else, and what year is your 620?

Are you looking to get rid of the 620 column?

 

its a 72.5, its sloppy and there aren't many donors near me. I have a ka24de and would like power steering only because i want a tighter steering ration than a manual rack can provide. lastly my uncle was impaled by a 1pc steering column; so safety too.



#43 wayno

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Posted 26 December 2017 - 09:24 PM

OK, so the idler arm you have is likely the same as the 521 and is reversible as I have done it, so if you put an idler arm in the place of the steering box/gear, you will have a complete steering system with no way to steer it.

What I did was put the idler arm where the 521 steering gear went like mentioned above, then I used a 720 power steering gear, I put it on the outside of the frame, the rear hole is shared with the idler arm, the front hole is drilled thru the frame and a sleeve needs to be installed(welded in), then a brace needs to be welded on the top of the frame for the upper steering gear mount hole.

The Pittman arm needs to have the tie rod hole tapered from the bottom up half way so the tie rod can be inserted from the bottom.

The expensive part here is the custom center-link that needs to be made, you see you need a center link with a tie-rod connection on the passenger side, once installed the stock center-link is used to go from the 720 Pittman arm to the center-link tie-rod connection, the custom center-link needs to be strong, mine was made from a single piece of round steel bar turned down to my requirements.

Here is my setup, here is the center-link installed with the stock center-link installed between the custom center-link and the Pittman arm.

100_0154.jpg

Here is the view of the 720 power steering gear installed on the outside of the frame, you can see the stock center-link going from the Pittman arm to the custom center-link, notice how close that arm is to the idler arm on the driver side, it rubs on it.

100_0155.jpg

Here is the idler arm mounted where the steering gear is supposed to be, the frame was rebuilt once in this photo, you can also see here how close the Pittman arm steering rod is to the idler arm, it basically rubs.

DSCN0628.jpg

Here is the custom center-link connection.

DSCN0629.jpg

Now one has to keep in mind that I had already converted over to a ball-joint frontend in these photos and I have 1990 Nissan hardbody V6 disc brakes(dual piston/vented rotor), I use a 720 tilt column, but if you were to use a non-tilt column I believe it will bolt right into you existing column mount and I believe that all your column accessories will bolt right onto that column with very little effort, there is a little more involved here like the column firewall connection that I will not get into here, but if one takes their time and thinks about it, this can be put together in such a way that it will almost look stock.

I have had to rebuild that idler arm/720 steering gear area of the frame a few times now, but this was my first try and I think it has worked out pretty good fir 12 years now.

Just to cover all the bases, here is the area that I had to rebuild for the 2nd time in this photo, our early Datsun trucks were not designed for power steering put on this way, but if it is done right the first time it likely will last a long time, by the way I beat the crap out of this truck, I haul massive amounts of weight on this truck, that also likely plays a part in this part of the frame falling apart.

DSCN1216.jpg

Here is one of the loads below, on another occasion I rolled onto the scales at 7200lbs, the truck weighs 3400lbs.

DSCN0393.jpg


 

 


#44 distributorguy

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Posted 27 December 2017 - 06:57 AM

SO here's the skinny:

The MG Midget R&P has a roughly 19" center to center distance measured from the inner tie rod pivot, so its nearly identical to stock Datsun 620 steering.  Its shorter in overall width, so you could make a custom adjuster to mount any outer tie rod to the rack and correct the track width.  The way the rack mounts is via clamp, and its adjustable so mounting it to the truck couldn't be easier, and you will not need an idler arm, which is a ridiculous idea with a R&P IMHO.  Lock-to-lock is 2 1/2 turns, so very quick ratio.  And they're dirt cheap.  There are several on Ebay for under $50.  



#45 distributorguy

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Posted 27 December 2017 - 08:44 AM

...and the MGB R&P is roughly 45 1/2" wide end to end.  Usable with no modifications if I measured properly.  



#46 Stoffregen Motorsports

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Posted 27 December 2017 - 10:05 AM

its a 72.5, its sloppy and there aren't many donors near me. I have a ka24de and would like power steering only because i want a tighter steering ration than a manual rack can provide. lastly my uncle was impaled by a 1pc steering column; so safety too.

I like the idea of a power rack, but I bet you don't really need power assist in such a light vehicle. Adding a MGB rack would probably lighten the feel enough to satisfy that requirement. I would love to see you use a power rack though, for my own curiosity.

 

I did a write-up a couple years ago on a 320 balljoint conversion. In the thread, I showed how to modify the column to terminate it at the firewall. I like that mod, not only for the reason you mentioned, but also because it allows you more room in the engine bay and more options for re-routing the steering shaft.  Here's the link - http://community.rat...int-conversion/



#47 Moist Lightning

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Posted 27 December 2017 - 12:10 PM

SO here's the skinny:

The MG Midget R&P has a roughly 19" center to center distance measured from the inner tie rod pivot, so its nearly identical to stock Datsun 620 steering.  Its shorter in overall width, so you could make a custom adjuster to mount any outer tie rod to the rack and correct the track width.  The way the rack mounts is via clamp, and its adjustable so mounting it to the truck couldn't be easier, and you will not need an idler arm, which is a ridiculous idea with a R&P IMHO.  Lock-to-lock is 2 1/2 turns, so very quick ratio.  And they're dirt cheap.  There are several on Ebay for under $50.  

 

Thanks for measuring. Not sure it will be short enough though. distance between LCA's is 16".

It would depend how high you need to mount it to compensate, and if the oil pan will allow it.

 

Good info here: http://community.rat...-with-ac/page-2

 

Not sure why you don't like the 2 idler arms. it would keep geometry stock so there is no worrying about bumpsteer and what not. Is there something i'm not seeing that makes it a bad idea?

 

You have convince me to try looking for an end take off solution again. Trying to remain open minded.

 

Edit: another benefit of a center take off is the pinion can be further out making it easier to attach a new column.

 

OK, so the idler arm you have is likely the same as the 521 and is reversible as I have done it, so if you put an idler arm in the place of the steering box/gear, you will have a complete steering system with no way to steer it.

What I did was put the idler arm where the 521 steering gear went like mentioned above, then I used a 720 power steering gear, I put it on the outside of the frame, the rear hole is shared with the idler arm, the front hole is drilled thru the frame and a sleeve needs to be installed(welded in), then a brace needs to be welded on the top of the frame for the upper steering gear mount hole.....

 

 

It's funny you posted, i was just looking through your post on a diff thread.

I would do some things differently but it proves the concept. I do have a question though. you said the frame needed reinforcement due to the pressure added by the power steering. However, properly mounted the idler arm should just swing, it shouldn't be transferring much pressure to the frame. I don't understand what caused your frame to fail. maybe i just interpreted the info wrong?

 

I see you attributed it to the weight somewhat. maybe its just too much load and a rusty frame to start with?

 

Edit: i'm a little slow sometimes. the pressure is only applied when there is a force applied to the tyres that would otherwise shift the steering. With power steering you holding everything in place and forcing it to absorb the energy instead. However, i do think the fact that you load so much weight into the vehicle attributes to this and under normal loads and regular driving should be fine. For off roading or heavy loads like yours reinforcement would be a good idea.

 

I like the idea of a power rack, but I bet you don't really need power assist in such a light vehicle. Adding a MGB rack would probably lighten the feel enough to satisfy that requirement. I would love to see you use a power rack though, for my own curiosity.

 

I did a write-up a couple years ago on a 320 balljoint conversion. In the thread, I showed how to modify the column to terminate it at the firewall. I like that mod, not only for the reason you mentioned, but also because it allows you more room in the engine bay and more options for re-routing the steering shaft.  Here's the link - http://community.rat...int-conversion/

 

Thanks i'm trying to get through it but i'm a visual person and all the pic are broken. Ill figure it out just might take me a bit longer.



#48 Str8jacket

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Posted 27 December 2017 - 01:14 PM

If someone has the time to map out all the suspension points accurately in x y z coordinates i can run it through my suspension program. Like has been mentioned bumpsteer is minimised by locating the pivot points on the intersection plane between the top and bottom control arm points, you can also fine tune it more by moving the rack forward and backward as well. Im happy to play around with different length rack dimension to find the best position.

#49 wayno

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Posted 27 December 2017 - 02:53 PM

Until my last rebuild of the frame 3/4 months ago the bolt that is shared by both the idler arm and 720 steering gear was smaller than the other bolts, it would stretch under the stresses and eventually break, once it loosened a little before it broke when I turned the wheel the actual steering gear would move a little sideways both directions depending on which way it was turned, this movement was hard on the frame, it has a larger bolt/sleeve now.

Also the shared bolt sleeve stuck out of the side of the frame a little, this left air between the frame and and the 720 steering gear, also I didn't sleeve the front steering gear bolt and it is not sleeved to this day, I used a plate on the inside of the frame that allowed me to tighten that bolt very tight without crushing the frame, all this stuff adds up in the end, if I ever did this to a 521 frame I would do some things differently, that was my first time at power steering on a 521 and it was done before this forum even existed, the year before I converted over to a ball joint front end also, I had issues with that also, but it has all been worked out.

The loads I carry may be a part of my frame issue, but these other things likely played a much larger part in the issue, yes I would do things differently now, everything would be rock solid if I did it now, ever since I put that larger bolt in the shared hole my steering has not changed since(it normally gets loose after a month or so), normally I have to tighten that shared bolt every couple months until it finally breaks, I tried tightening that bolt which is larger now and could not move it, my steering has not changed either.

That sleeve I am talking about with the smaller bolt has to be reamed out to except a larger bolt.

Also you have to keep in mind that the 720 steering gear is way taller top to bottom than the 521 steering gear, being the Pittman arm tie rod connection for the steering is much lower that puts more sideways/twisting stress on the frame than the stock steering gear ever put on the frame, another thing to keep in mind is with the stock steering gear it is hard to turn the wheel when not moving, so one doesn't do that often, with power steering it is always easy to turn the wheel putting a lot more stress on the frame more often, I tried to not turn the wheel when I was not moving to much at first, but after years of use one forgets about that stuff and just drives the truck.


 

 


#50 Stoffregen Motorsports

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Posted 28 December 2017 - 10:05 AM


 

Thanks i'm trying to get through it but i'm a visual person and all the pic are broken. Ill figure it out just might take me a bit longer.

I pay for a 3rd party hosting account, so the links should be good. I can see them on my end.

 

Can you do me a favor and check the pics in this thread for me? I had another guy comment that he couldn't see the pics here - http://forum.expedit...gen-Motorsports



#51 wayno

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Posted 28 December 2017 - 10:22 AM

I can see the photos, but I use Google Chrome and have the embed fix extension installed.

That said there are others that I cannot see, so I am assuming you are paying them, but I heard even the paying folks are going to be out in the cold when it's all done and over with.


 

 


#52 Stoffregen Motorsports

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Posted 28 December 2017 - 10:29 AM

I upped the ante this year and bought a good subscription with Photobucket. It gives me another year to figure out another solution.

 

BTW- I just got an email reply from Photobucket support and they suggested clearing out your cache if you're having problems viewing the pics.



#53 Crashtd420

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Posted 28 December 2017 - 10:34 AM

I can see them.... no Google chrome fix , not paying , and using my phone to view ......

#54 wayno

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Posted 28 December 2017 - 10:59 AM

I upped the ante this year and bought a good subscription with Photobucket. It gives me another year to figure out another solution.

 

BTW- I just got an email reply from Photobucket support and they suggested clearing out your cache if you're having problems viewing the pics.

 

Yea it's never going to be their fault if people cannot see the photos.


 

 


#55 Moist Lightning

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Posted 28 December 2017 - 11:50 AM

I pay for a 3rd party hosting account, so the links should be good. I can see them on my end.

 

Can you do me a favor and check the pics in this thread for me? I had another guy comment that he couldn't see the pics here - http://forum.expedit...gen-Motorsports

 

Thanks for fixing. Both threads are all good now. I highly recommended imgur if you are looking for a new solution.



#56 Stoffregen Motorsports

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Posted 28 December 2017 - 11:51 AM

It's true though. If you have an old cookie from when I was having trouble with Photobucket, it may not show the pics.



#57 Moist Lightning

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Posted 28 December 2017 - 11:51 AM

Until my last rebuild of the frame 3/4 months ago the bolt that is shared by both the idler arm and 720 steering gear was smaller than the other bolts, it would stretch under the stresses and eventually break, once it loosened a little before it broke when I turned the wheel the actual steering gear would move a little sideways both directions depending on which way it was turned, this movement was hard on the frame, it has a larger bolt/sleeve now.

Also the shared bolt sleeve stuck out of the side of the frame a little, this left air between the frame and and the 720 steering gear, also I didn't sleeve the front steering gear bolt and it is not sleeved to this day, I used a plate on the inside of the frame that allowed me to tighten that bolt very tight without crushing the frame, all this stuff adds up in the end, if I ever did this to a 521 frame I would do some things differently, that was my first time at power steering on a 521 and it was done before this forum even existed, the year before I converted over to a ball joint front end also, I had issues with that also, but it has all been worked out.

The loads I carry may be a part of my frame issue, but these other things likely played a much larger part in the issue, yes I would do things differently now, everything would be rock solid if I did it now, ever since I put that larger bolt in the shared hole my steering has not changed since(it normally gets loose after a month or so), normally I have to tighten that shared bolt every couple months until it finally breaks, I tried tightening that bolt which is larger now and could not move it, my steering has not changed either.

That sleeve I am talking about with the smaller bolt has to be reamed out to except a larger bolt.

Also you have to keep in mind that the 720 steering gear is way taller top to bottom than the 521 steering gear, being the Pittman arm tie rod connection for the steering is much lower that puts more sideways/twisting stress on the frame than the stock steering gear ever put on the frame, another thing to keep in mind is with the stock steering gear it is hard to turn the wheel when not moving, so one doesn't do that often, with power steering it is always easy to turn the wheel putting a lot more stress on the frame more often, I tried to not turn the wheel when I was not moving to much at first, but after years of use one forgets about that stuff and just drives the truck.

 

Thanks for the detailed rundown. I appreciate the time put into a helpful reply.



#58 Stoffregen Motorsports

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Posted 28 December 2017 - 11:53 AM

Thanks for fixing. Both threads are all good now. I highly recommended imgur if you are looking for a new solution.

I have my own website that I can use to host 3rd party pics, but I ned to get off my ass and do it. And then I need to go and convert all the links from Photobucket to my website, for all the threads that I care about.



#59 G-Duax

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Posted 28 December 2017 - 11:57 AM

Yesterday PhotoBucket was having issues, but today they are up & running again.

All my forum posts have the pictures back up.


"All of a sudden it started making noise, then started losing power. I limped the car home and tried to get it up the driveway, the engine just died."

 

Why do people do this?

A $100 tow bill is never as much as the extra damage you cause by trying to "limp the car home".

 

Don't be that person !


#60 wayno

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Posted 28 December 2017 - 05:14 PM

One would think being they for the most part are only posting a lame warning where photos used to be that they could keep their lame site up and running, but I guess not. :lol: