Would you like me to locate a PS Box for you John?
I think the cost by the time it got here vince would be a bit expensive! if the box I have upgraded leaks that will be an alternative to rebuilding another box although I have some new ideas on that front!
Having just shelled out for a refurb of my Rover steering box I hope I won't be needing to do this conversion but just in case can you clarify something? Pic 4 seems to show 3 threaded 'bungs' while pic 7 states there are 2 threaded 'bungs'...
Now that I'm what you could describe as an older person I've stopped eating health foods. I need all the preservatives I can get.
In old posts i read that the U joint came from a Triumph. The ZF box has a steering shaft with 54 splines which is quit unusual. Doing some research on the internet, i learned that BMW's also have those 54 splines. A visit to the scrapyard got me a BMW steering shaft.
This shaft has an U joint with a flange for the flexible coupling. This avoids welding or brazing which is something i don't feel comfortable with. The company where i buy my steel plate had a piece of 15mm thick steel which was cut out of a large plate by a construction company and brought to them a scrap metal and costed a few euro's.
Studied the 2 options in threads on the adapter plate. The option from i believe Vincentacres is the easiest to make&fit
The Volvo box uses 2 original holes in the subframe but because of that, it is mounted a little higher which lead to a higher positioned steering shaft and pitman arm. In the old threads i didn't find any information about outlining the steering shafts which can be rather critical. For solving the outlining, 2 U-joints are needed. If there is only 1 U-joint, the center of the U-joint should be the point where the steering shaft center line from the box meets the cars steering shaft center line.
The one from Vince and Warwick seem to have some problems with an LHD box as the bolt for the hole on the RH upper corner seems to hit the Volvo steering box housing.
So i believe it is time for some shed engineering finding out which adapter plate to use. The hydraulic connections on an LHD Volvo box are in the same position as the Rover one so no worry's there. A visit to a hydraulic shop got me the right adapter to arrange the oil feed connection to the box
I wish you all a Merry Chrismas and all the best for 2017.
Hi Peter, the steel plate above with top written on it in yellow works for RHD versions. I imagine a LHD car would be mirror reversed. Don't pay too much attention to the 'green' wooden template, as most of the measurements for that was based upon extrapolation. (Vince)
Peter please double check the dimensions before you spend the time and energy making it! There are several ways of making the adaptor and with your engineering skills I'm certain you'll find the most appropriate method.
Thanks for the remark. I planned to copy your drawing on a jig and do some checks but its very valuable information to start with. Due to the thickness of the adapter plate and due to the fact that one has to make the holes in exactly the right spot as there is not much room for jiggling, it takes a fair bit of time to make it. There are also a lot of production tolerances involved so the perfect solution may be different for different cars. With the piece of 15mm plate, I bought a few pieces of 8mm thick steel and think about making a jig consisting of 2 8mm plates. One with the hole pattern (all with threads) of the steering box and one with the hole pattern(also with threads) of the subframe and connect these with each other by 2 bolts and nuts with oversized holes so these can be adjusted to each other on the car to find the best steering box position. Then copy the hole pattern on the permanent adapter plate. It takes a bit more time but otherwise you may end up with making 2 or more adapter plates to find the best solution.
In the end i believe it will work (see Warwick's car and others). The steering column has also some possibility's for adjustment.
An update. Found out that the distance between the underside of the pitman arm and the center of the lower steering box holes were almost identical on the Volvo and P5B steering box (only 2mm difference). The rest of the dimension were identical to Vince's drawing. I also found out that the dimension from underside pitman arm to the center of the steering shaft is approx 18mm more on the ZF box then on the P5B box. So it is not possible to achieve exactly the same set up with the ZF box.
Gave the Volvo box a clean, a coat of primer and black paint and made the short adapter plate.
Comparing it to the picture of the plate and my adapter plate, shows a difference between the position of the hole in the middle which i cannot explain. Bought a 10.9 M10 thread which is considerable stronger then the 8.8 one and cut 2 pieces and connected the BMW U joint to the Rover coupling. Also cut a bit more thread on one of the original steeringbox mounting bolts and cut it to the right length.
Checked the holes on the project Coupe subframe
Then removed the Rover steering box from the car and fitted the ZF box and found out i didn't like the positon of the ZF box option. The center line of the pitman shaft has a different angle/position, compared to the Rover set up which causes the pitman arm end sits higher and the balljoints on the pitman arm get for me to close to the subframe and other parts. Also there is not sufficent room between the ZF box and the Rover steering shaft to fit the U joint.
Then removed the upper thread end which runs threw subframe and steering box and the bolt which runs threw the subframe and is fitted to the adapter plate. So i could rotate ZF box and adapter plate and try to find a better position for the steering box. As on my ZF and P5B box the distance between underside pitman arm and lower mounting hole on the box, are identical i need to use the lower hole in subframe and steering box. I found a suitable position which gives the ZF box almost an identical position of the pitman arm and leaves enough room for fitting the U joint on the steering shaft.
There is just enough room to fit the BMW U-joint with the Rover coupling
I can feel that the Rover coupling gets a bit more stress but its not a high speed shaft and i believe it is acceptable.
I will now make a new adapter plate which shape wise looks like the one on Vince's drawing. The steering box job is not a very nice job to do as its cold in the garage and as i don't have a lift. It means laying on kind of short isolation sheet on the rather cold floor. That's the price for using the P5B as a daily driver so cannot wait for better temperatures.
Great information, preparation and work Peter. As always with your work, a thoroughly professional approach to the task. Looking forward to your "on the road" feed back regarding this conversion. Happy new year.
PS. Did you have to slightly relieve the splines in the Rover pitman arm or on the shaft for it to fit Peter?
I didn't modify the splines. It seemed to fit well and gets deeper over the splines then in your situation.
A new adapter plate was made. With this plate there is 1 bolt which runs threw the subframe and volvo steering box. Underneath a picture of the work in process. The holes are checked with the jig. The final adapter plate differs a little bit from the jig. I left more "meat" at the underside of the left upper hole.
The picture of the finished adapter plate went wrong.
Then modified the hose end connector on the hose from pump to steering box. The thread in the box is M14 x 1,5 and the connection on the hose is 1/2" JIC UNF type. I searched a long time to find a M14 x 1,5 to 1/2 " JIC UNF adapter but couldn't find one so cut the small flange on the pipe end and fitted a cutting ring with nut and an coupling with M14 x 1,5 thread on both sides which is used to connect pipes and hoses. These items were purchased at my local hydraulic shop. As the surface under the hexagon is very small, a copper ring cannot be used so the guys advised me to use hydraulic thread locker. On the picture you find the original setup on top and the modified set up underneath.
I fitted this setup and it seems to work and doesn't leak. As i had my doubt about this setup i found another coupling which has identical threads and can be fitted and there is room for a copper ring and at a price of Euro 0,52,- i ordered 2. This in case, the setup starts to leak.
I could use the original banjo eye on the box return hose as the banjo bolt on the Volvo box has almost an identical diameter as the Rover one although the thread is different.
Fitted the box, adapter plate and hoses to the car and checked everything. It was all oke and made a test drive which went well. No leaks anymore and the steering is noticeable less vague although my Rover box wasn't too bad and i got used to it. Have made more trips and did some checks but it is all fine. Still have to check if the rods have to be adjusted and have to get a new MOT on the car.
Hi Peter, could you provide more feedback with regard to the Volvo power steering box performance in general use when you get the opportununity? For instance, turning circle, straight ahead stability at speed, steering wheel return to centre after a turn (self centering) and any inherent vagueness.
A few things i already found out. The turning cycle is less but i can't tell you how much. I have driven the car up to approx 110km/hr and the car feels better at straight ahead stability although with the Rover box it wasn't to bad (although not comparable with a modern car). My son just recently passed his driving test and the first time he drove the Rover (with the Rover box still fitted), i noticed he had to get used to the Rover box and was continuously correcting too much. Rather quickly he got used to it and wasn't overcorrecting anymore. The self centering issue,i can't tell at the moment. I will check it and let you know. For sure the Volvo box is less vaque but i didn't mind the Rover box being a little vaque and a lot can be done with adjusting the thread end on the top correctly. It belongs to the character and the charm of the car. My primary goal was to get rid of the leakages and it looks like that was successful. I bought the box from a guy who deals with old Volvo's a lot and he said, the Volvo boxes never leak. Normally i like to change seals before i fit items like this to a car but couldn't find a seal set being offered from major classic Volvo suppliers all over Europe. So i fitted the box without changing the seals.
What i forgot to mention on the installation is that i had to move a plate on the firewall where the steering shaft runs threw a little upwards as the steering shaft was touching this plate.
Did some higher speed runs this week up to 150 km/hr and the cars feels much less vague on these higher speeds, A lot less corrections needed and the car is definitely more comfortable to drive. I noticed that in general i now drive the Rover faster compared with the time it had the Rover steering box. It definitely is a worthwhile mod for an LHD car as Volvo boxes are rather easy to find. An it didn't drip a drop of steering fluid since the installation of the Volvo box....
After a month of work taking apart all the left front suspension and removing the Rover power steering box I have located a Volvo 164 steering box to begin work on putting it in the Rover. So while this "may not be the beginning of the end, I think it is at least the end of the beginning". The after and before pictures below.
My garage is unheated, so progress in Michigan has been slow. But I have managed to cut out a rough wood template for the Volvo 164 box with the holes lined up and it seems that it will fit. There is an extra hole where the 3rd bolt will be to mount the plate to the subframe. I have used the lower rear bolt hole on the Volvo box to also mount the plate to the frame with one long bolt that will go through frame, plate, and box all together there.
Looks like you're progressing well with this conversion Ken. Please do add to this post as yours is a left hand conversion. Can you also post any specific findings, data, or tech details that adds to the knowledge base as it will assist others of like mind. (Vince...aka enigmas)
Thanks for reposting the great pictures Warwick! I see that you used the square plate and left out the hole behind the shock absorber as an extra mount. I assume you've had no problems with the stability of the mounting? Also, what did you use for the coupling to the volvo input steering shaft from the Rover shaft in the car? The Volvo rag connector disc is not as large in diameter as the Rover one, and I see mention of using a Triumph coupling, but Peter V. used a BMW one with modification. Peter's mounting plate looks a bit more complicated, and the square mount still has 3 mounting bolts for the plate to the subframe, so should be as strong and easier to make? I used your reversed picture to post here and believe it should work. I'll post more as I go on, but need to wait now for some warmer weather.
Without the time to review all 6 pages of this thread I will just mention the following:
The Triumph coupling works and works well assuming you have the correct connector on the ZF box. These boxes had 2 different types so you need to make sure you have the compatible one.
I also seem to recall needing to very slightly over drill the holes in the Triumph block - maybe only 2 of them - it was a while ago...
Lastly you will find the hydraulic hose and screw connection a tight fit (too tight) against the inner wall of the wheel guard. For this reason you will likely need to cut a small portion of the metal away to provide the necessary clearance and allow the box to install straight without interference.
Thank you Owen. Fortunately my Volvo box has the hydraulic fittings on the top and not the side, so hopefully I won't have to cut the fender well for more side clearance. Do you know which Triumph model/year the coupling came from? It apparently needs to be a 3/4" shaft with 54 splines.