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Sam W.

Power steering

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So I recently purchased a Datsun 620 pickup and have noticed that the steering on it is insufferable at low speeds due to the lack if power steering. Is there any possible way for power steering to be installed in a 1976 Datsun 620?

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Are the kingpins greased and in good shape?

Running wide tires on the front will also make steering hard, and check tire air pressure on the front.

 

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Raise the front wheels off the ground and you should be able to spin the steering wheel from lock to lock with a finger. If not likely the king pins. Try greasing them and all the steering ball joints.

 

After I switched to 10.5 x 31 tires the steering was terrible. I used a '79 280zx power steering box and a D21 steering pump on a home made mount under the distributor. Later I went to 12.5 x 33 tires. No problem.

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If it's a 1976 620, it has the enclosed steering shaft attached to the steering box. Some fabrication will be required to make your column work with the 280zx box.

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On my '78...

 

4 hours ago, datzenmike said:

The 620 and earlier trucks had a one piece box and column so I had to install a u-joint 720 column to make it work. Plus I was adding a 4" body lift and the column was bending too much. I started with a '79 280zx PS box which was inside the frame and later switched to a 720 or D21, I don't remember, but they look very much the same. The pump was from a D21 on a home made mount below the distributor (L series engine) with the reservoir on the fender. It was an extremely tight fit between the pump and the 'inside the frame' box. Years later I switched to the outside the frame box which would have been a better idea to start with maybe but the pitman arm would have been several inches too far to the left. When I switched to the D21 box I also was doing a Toyota SAS swap.

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😂 Oh if only!!!!!! The 720 column and 280zx PS box I joined at the rag joint. Naturally the two pair of bolts were on a different radius so either/neither 280zx or 720 worked. I used a piece of 3/8" conveyor belt and cut out my own. The 720 column was collapsible and had at least one U joint. I doubt if the 620 ignition/horn/turn signals would mount to it, don't know. At around the same time I swapped in a 720 wire harness and dash so the headlights switch on the column worked.

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I have a 720 column in back of the shop. It's gutted of everything, but the tube remains. I do recall it having a rather small OD though.

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This might work!

 

I didn't try to fit the 620 turn signal ring on or the ignition. I wanted the 720 dash with tach and clock as well as the headlamp/turn signal stalk on the left and the 3 speed wiper with variable adjust pulse delay on the right. It was insane changing to 720 dash and heater. The 620 heater was out and the 720 heater blower over on the far right under the old glove box. Had to seal old air inlet and cut new one. The 620 wiper was behind the glove box so that had to go outside in the fresh air plenum. Once committed I had to keep going.

 

2seccAv.jpg

 

Here's the PS pump...

 

3spyHUU.jpg

 

Home made mount using washers for spacers. Have a welder now. That fitting pointing down to the left is actually a metric bolt that I drilled lengthwise and cross drilled for a banjo connections using copper washers. The inner end I drilled a slight V for the spring loaded regulator pin? The bolt replaced the original fitting that was about 1/4" too long and didn't clear the PS box. Once installed I drove it at least 2 years and never once had a problem with it.

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The 720 non-tilt column is smaller than the 521 column which is likely the same size as the 620 column, but unless one is going to modify the steering gear to accept a collapsible steering column............................... 

 

 

Edited by wayno
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Mike was suggesting a 280zx steering box, which has a splined input.

 

Does anyone have a box they could get spline count and diameter from? Either a 720 or 280ZX box? I am sure I could find an aftermarket universal joint to fit the box.

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This is the PS box I used with the forward facing pitman.

s0epWIE.jpg

 

The pitman arm spline on the '79 280zx is the same as the 620. The 720/D21 was different. All I did was separate the 620 pitman and let drop then remove the 620 box/column. The 280zx pitman faces forward because steering is behind the front wheels. The 620 pitman fits onto the 280zx PS box facing to the rear 180. 

 

I think only the '79 280zx has this PS box. Later zx used R&P.

 

The 720 PS box spline was different so I used the 720 pitman and as I was switching to a 'Yoda SAS the rest was custom fitting anyway.

 

The spline at the column end I used for some reason didn't match the 720 rag joint ... it's been 20 years or more. I couldn't fine a match so I made one.

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5 hours ago, Stoffregen Motorsports said:

Mike was suggesting a 280zx steering box, which has a splined input.

 

Does anyone have a box they could get spline count and diameter from? Either a 720 or 280ZX box? I am sure I could find an aftermarket universal joint to fit the box.

 I have both a 1982 manual steering box and a 1985 power steering box for a 720. The input shaft sizes are different. The manual box is .5675 inch (or there about) and 28 splines. The power box is .6750 (or there about) and 35 spline. I used my digital calipers to measure the diameter with. The splines I counted several times (not easy when dirty and greasy) and came up with the same numbers each time. I haven't looked, but Borgeson has a lot of choices for u-joints.

 

Don

PS- something I almost forgot about. The inputs are different also in the way they are configured. The manual box has a flat end on the shaft with a milled area on the side of the shaft for a bolt in the flex joint that pinches the flex joint onto the shaft. The power box has an end just like the 280ZX box that D.M. pictured. But, then it had a groove cut all the way around the shaft about the middle of the length of the spline. This means that a u-joint, or flex joint, could be put on, and bolted, in any location around the shaft.

Edited by 620slodat
added information
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Not shown, but the zx box had the groove and the pinch bolt for the column or rag joint connection. It could only go on one way. The 620 and zx pitman arms had four black sections on the splines. The pitman could go on in only 4 positions, two (90 and 270) were obviously to the sides. 90 and 180 were equally obvious front and back facing

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You're positive about the spline counts? There are no 28 or 35 spline joints in the aftermarket, at least that I could find. Are you sure those spline counts did not include a double or fat spline? There is a 17mm 36 spline joint available, and I use an 11/16 36 spline joint on the Toyota boxes.

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22 hours ago, Stoffregen Motorsports said:

You're positive about the spline counts? There are no 28 or 35 spline joints in the aftermarket, at least that I could find. Are you sure those spline counts did not include a double or fat spline? There is a 17mm 36 spline joint available, and I use an 11/16 36 spline joint on the Toyota boxes.

 

I went out this morning and double checked my counts. On the manual box, 28 splines is correct. On the power box, 36 is the corrected count. I still wasn't confident in my count, so I counted again and came up with 28 and 36 splines. I'm a cabinetmaker (started in 1968), so accuracy is important to me. I don't know where I goofed up on the power box, (OOOPPPS!!!) maybe because the shaft was dirty, and the light at that time in the evening wasn't very good. Anyway, both boxes had the shafts cleaned with lacquer thinner, sandpaper lightly run over the tops of the splines to make them stand out, and a sharpie marker used on the splines to help keep track of where I was in the count. The power box was out of the vehicle so I could get a much more accurate count on the splines.

 

Anyway, sorry for the confusion, and the spline count is corrected. 

 

I haven't looked yet, but what you found out about the u-joint availability will make a big impact on my decision of which box to use (and steering column). The next big hurdle for me is can the power box be used as a manual if the box has power steering (transmission) fluid put in it. The fluid ports will be hooked together so the fluid could possibly travel in a complete circle through the box and the "lines" without restriction. I plan to eventually put electric power steering in the pickup.

 

Don 

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While possible to use a power steering box with the ports connected together, it will have some drag to it. A non-power box would not have this drag. Electronic power steering is becoming very popular these days, with a few aftermarket offerings. Hot rod guys use them, so if you don't want a clunky OEM unit under your hood, try searching the web for aftermarket units.

 

Here's a link to some steering shaft parts that may come in handy.

 

11/16 is roughly 17mm - https://www.summitracing.com/search/product-line/borgeson-universal-steering-u-joints/shaft-end-2/11-16-in-36-spline

 

Use a Borgeson collapsable shaft - https://www.summitracing.com/parts/brg-450024/overview/

 

And then to connect to the column, you could mill the Datsun shaft with two flats to utilize a 3/4" DD joint. I've done this many times. - https://www.summitracing.com/search/part-type/steering-u-joints/shaft-end-1/3-4-in-dd/shaft-end-2/1-in-dd?N=4294924069%2B4294894928%2B4294894936&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=borgeson

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On 6/22/2019 at 5:44 PM, Stoffregen Motorsports said:

Is the 720 column a bolt-in for the 620?

 

On 6/22/2019 at 5:52 PM, datzenmike said:

😂 Oh if only!!!!!! The 720 column and 280zx PS box I joined at the rag joint. Naturally the two pair of bolts were on a different radius so either/neither 280zx or 720 worked. I used a piece of 3/8" conveyor belt and cut out my own. The 720 column was collapsible and had at least one U joint. I doubt if the 620 ignition/horn/turn signals would mount to it, don't know. At around the same time I swapped in a 720 wire harness and dash so the headlights switch on the column worked.

 

On 6/23/2019 at 9:57 AM, Stoffregen Motorsports said:

I have a 720 column in back of the shop. It's gutted of everything, but the tube remains. I do recall it having a rather small OD though.

 

On 6/23/2019 at 1:52 PM, Stoffregen Motorsports said:

Mike was suggesting a 280zx steering box, which has a splined input.

 

Does anyone have a box they could get spline count and diameter from? Either a 720 or 280ZX box? I am sure I could find an aftermarket universal joint to fit the box.

 

 

I sleeved the end of the 620 column over the end of the 720 column and used the 620 surround. Keeps the interior looking stock.  
 

I used a Toyota PS box to do the back and forth.  

 

Toyota and 720 have the same splines, at least the steering shaft and the box are the same splines.  80-83 yota trucks have a good u-joint. 

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7 hours ago, Stoffregen Motorsports said:

While possible to use a power steering box with the ports connected together, it will have some drag to it. A non-power box would not have this drag. Electronic power steering is becoming very popular these days, with a few aftermarket offerings. Hot rod guys use them, so if you don't want a clunky OEM unit under your hood, try searching the web for aftermarket units.

 

Here's a link to some steering shaft parts that may come in handy.

 

11/16 is roughly 17mm - https://www.summitracing.com/search/product-line/borgeson-universal-steering-u-joints/shaft-end-2/11-16-in-36-spline

 

Use a Borgeson collapsable shaft - https://www.summitracing.com/parts/brg-450024/overview/

 

And then to connect to the column, you could mill the Datsun shaft with two flats to utilize a 3/4" DD joint. I've done this many times. - https://www.summitracing.com/search/part-type/steering-u-joints/shaft-end-1/3-4-in-dd/shaft-end-2/1-in-dd?N=4294924069%2B4294894928%2B4294894936&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=borgeson

 

Thank you for this info and the links for Borgeson parts. I have the steering shaft and box from a 1973 620 (spear made to look like a steering shaft)  a 1985 720 shaft and box with power steering, and the manual box for a 1982 720. Don't know yet what I will use, but likely some kind of combo of what I have. Because of this thread I have more ideas, and the more ideas I get the better for the final outcome. 

 

I am seriously considering electric power steering because the area under the hood of a 620 is at a premium. I definitely am going to leave room for an AC unit (to keep the wife interested in the final outcome) and a turbo on the diesel motor, which will take up most of the available space.

 

Don

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If you want to use the 620 column, you will have some machine work to do to get the lower portion of it supported in the tube.

 

A few years ago, I did a write up on a balljoint conversion, and part of that job was making a new column/steering shaft. Check that link for how to make your -

 

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Found my pics. 

 

720 to 620 column conversion. 

Top tube is the 720 housing
The small piece is the 620 rubber boot clamp. 

fabricated a plate to match the 620 boot. 

Bottom is the small section of 620 column need for mounting to the dash and mounting the surround. 

 

IMG_3638.jpg

The columns were welded together and the boot clamp and firewall plate were welded together and I used the clamp once everything was assembled in the truck. 

 

IMG_3639.jpg

 

IMG_3647.jpg

 

 

The u-joint is 2 of the weird toyota ragjoint u-joint things with the rag ends tossed and just the splined joint ends used. 
I essentially built the earlier toyota u-joint lol. 

720 column Toyota V6 box. 

 

IMG_3654.jpg

 

IMG_3657.jpg

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18 hours ago, ]2eDeYe said:

Found my pics. 

 

720 to 620 column conversion. 

Top tube is the 720 housing
The small piece is the 620 rubber boot clamp. 

fabricated a plate to match the 620 boot. 

Bottom is the small section of 620 column need for mounting to the dash and mounting the surround. 

 

IMG_3638.jpg

The columns were welded together and the boot clamp and firewall plate were welded together and I used the clamp once everything was assembled in the truck. 

 

IMG_3639.jpg

 

IMG_3647.jpg

 

 

The u-joint is 2 of the weird toyota ragjoint u-joint things with the rag ends tossed and just the splined joint ends used. 
I essentially built the earlier toyota u-joint lol. 

720 column Toyota V6 box. 

 

IMG_3654.jpg

 

IMG_3657.jpg

 

Thank you for the pics. Some very good info that will help me with decisions when I get to that point.

 

Don

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Why not electric assisted steering.

 

Redeye I need a blue ST steering wheel as nice as yours, please.

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I am always on the lookout for ST wheels, they just don't show up like they used to. 😞 

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Jumping in a little sooner than hoped but I'm planning to develop a complete bolt-in kit for the 620... Along the lines of Charlie's suggestion above. 

 

I'm testing a 510 kit now (S30 also planned) and am hoping to leverage much of this setup into a 620 by the fall.

 

I started a small Datsun parts business this year (www.datsunrestomods.com) and it's been more successful than planned so additional products are coming to market - CV axles was the first offering. Next is electric power steering, currently in R&D.

 

I should have more info later in August.  

 

 

Edited by DADZSUN
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