Steering: 140: Power steering

[friffies]

HI I have been asked if its possible to use 164 power steering system on a 144 has anyone done this

[john.wigley]

Originally Posted by friffies

HI I have been asked if its possible to use 164 power steering system on a 144 has anyone done this

I'm afraid that I can't help you there, 'friffies', but bearing in mind the age / availability of 164 parts, might not a better option be to consider fitting one of the modern electric PS systems? I have seen them advertised recently in CCW for under £1000.

Regards, John.

[friffies]

HI John I have a number of 164 set ups just hoping some one has done this THANKS

[classicswede]

It has been done but not easy. The 164 is longer wheel base so the angle of the steering box is not the same. You would need to add in UJ's to make it work

[142 Guy]

The 140 does have a factory power steering option listed in the parts manual. The attached screen grab shows the picture from page 3-C20 of the parts manual for the 1972 and earlier cars.

As described by classicswede, the parts manual shows the offset connector with U joints and what appears to be a different upper steering column. If your collection of parts includes the steering shaft parts, perhaps it is a drop-in swap from the 164 to a 140.

The acid test would be to find a parts manual for a 164 and compare the important parts numbers to the equivalent page from the 140. I would provide you with the 140 part numbers so that you could check; but, for some reason my scan of the manual is missing pages 3-C16-19 which have the important part numbers. I do have parts numbers for the guts of the PS pump and PS unit; but, it lacks the all important interconnecting stuff.

If the 140 to 164 parts numbers line up (including the steering shaft parts with the shaft with the U joints) then this might be an easy swap from a 164 to the 140. If the 164 'power steering mechanism' is the same; but, the 164 lacks the offset U joint it may require some fiddling; but not a huge amount of work. Steering components such as shafts, U joints and collapsible sections are readily available and may just require a little welding and machine work to adapt fittings to the splines on the shafts.

I fitted an EPS unit from a Nissan Versa to my 142 which involved a lot more work. Creating a new lower steering column which included U joints and a splined collapsible section to fit to the output of the Versa EPS unit just involved measuring, trolling the parts catalogs, cutting and fitting and a couple of trips to a machinist / welder.

Replacing that idiotic flexibly mounted offset piece in the steering column that Volvo uses as a collapse mechanism with a combination of splined collapsing shafts and U joints was the best possible improvement for steering precision.

[arcturus]

For what it's worth,I fitted electric power conversion to my 144 and it has ruined the feel of the steering. Pump up your biceps and put a couple of extra pounds pressure in your front tires

[classicswede]

Originally Posted by arcturus

For what it's worth,I fitted electric power conversion to my 144 and it has ruined the feel of the steering. Pump up your biceps and put a couple of extra pounds pressure in your front tires

I keep saying the same. Electric power steering is not good

[142 Guy]

Originally Posted by arcturus

For what it's worth,I fitted electric power conversion to my 144 and it has ruined the feel of the steering. Pump up your biceps and put a couple of extra pounds pressure in your front tires

Adding a column mount EPS does nothing to alter the steering linkage kinematics of the Volvo's steering mechanism. Most of what passes for feel in the 140's steering system is friction / drag. The equivalent of the friction damper that used to be stuck on some motorcycles 50+ years ago. The amplification effect of a column EPS power steering tends to dilute that friction effect.

If you want to improve the feel of your steering increase the amount of caster. The 140 came with the absolute minimum safe amount of caster (0 to +1.0 deg) to minimize steering effort (more caster = more steering effort). Any less caster and the front wheels would wobble like the front wheels on a shopping cart. With the 140's minimalist caster the mechanical gain inherent in EPS makes the steering overly sensitive to user input at higher speeds. Increasing the caster increases the tendency of the steering to track straight ahead once the car is moving with any significant speed. The self aligning effect of increased caster increases with speed and you will perceive this as resistance / feedback in the steering wheel. Modern cars with power steering tend to run +5 deg or more of caster.

Two other factors to consider. The first factor is that Volvo equipped the 140 with a very large diameter steering wheel to provide mechanical gain in the steering system. With power steering that mechanical gain is unnecessary and contributes to overpowering the 140's minimalist caster. A 13" - 14" steering wheel is a much better choice when retrofitted with power steering. The second factor is that the 140 has a lot of slop in the steering mechanism which translates into a fairly large dead zone (vagueness in the steering) when the steering is on center. A lot of this originates from the flexible break away coupler that Volvo uses in the 140 steering column. The 140 steering box also has a dead on center effect even when its perfect. You can adjust this out; but, at the risk of increased wear to the steering box. The dead zone is equivalent to hysteresis which is not your friend when you increase the forward gain (power steering) in the control system.

With my column mount EPS system I have a 14" steering wheel and Michelin 185 all season tires.. When I installed the EPS I replaced the Volvo break away column section with a collapsible splined column. There is nothing I can do about the slop in the 140 steering box unless I try to replace it with a rack. I am currently running about +1.8 deg of caster. At some point I may consider experimenting with a further increase in caster; but right now I am reasonably satisfied with the level of steering feel associated with increasing the caster to +1.8 deg. If you retain the original 140 hula hoop steering wheel and 165 tires you might want to consider increasing the caster to something more than +1.8 deg because of the inherent mechanical gain associated with the large steering wheel. You could also consider adding a hydraulic steering damper; but, that is more of a bandage rather than trying to address the underlying problem.

[AndrewRowlands]

Originally Posted by friffies

HI John I have a number of 164 set ups just hoping some one has done this THANKS

Hi I have and early 164 without power steering. Would you sell one of power steering set ups to me? Thanks