STEERING RACK

The Mangusta rack was sourced from a Renault Dauphine. These racks where also used in the very early Renault 4. The later racks are interchangeable with some work. The internals are not interchangeable.

champ
Do you know anything about the Renault rack that is faster and fits in the same housing?

Dick Ruzzin

The Renault 4 racks had all the same ratio. My best guess is, this is the one you could use:
renault 5 rack

Check with Wilkenson Pantera. He has quicker ratio Mangusta steering racks.

DICK RUZZIN

Thanks, Richard.

Dick,

I have recently done some work on Jonathan Root's car. One of the things I was asked to look at was the steering and alignment.

Jonathans main gripe with the steering was the low gearing and the way it grabs, pulls and tramlines.

After studying the front end for quite a while I realised the Mangusta's biggest problem is excessive positive scrub radius. I measured it at 6" (150mm) this is alarming to say the least!
The only way to reduce the scrub radius is to redesign the upright. This would then require longer A arms or relocated pick up points on the chassis - probably both.

The Renault rack is actually very well made, way better than the Pantera rack. On the turn plates I measured one rotation of the steering wheel achieves 13.5 degrees of rotation at the road wheel. For comparison a Pantera achieves 18 degrees.
On a road car changing the rack on the Goose for one with a quicker ratio would actually exaggerate the scrub radius problem and make the steering wheel grab and pull even more than before due to the fact the driver effectively has less leverage at the steering wheel.

I decided the best course of action was remove all the play from the steering system and align the car. I also modified the steering arms and replaced the outer tie rod ball joints with a Rose joint (Heim if your American) This enabled me to completely remove all the bump steer. I calculated the ball joint (now Rose joint) needed to be raised 8mm on the right side of the car and 5mm on the left. It would be possible to achieve the same thing by raising the rack but I dont like to do it that way.
I bought the extra long M16x1 Rose joints from http://www.mcgillmotorsports.co.uk/ The proprietor says he had them specially made for another car and thinks he is the only source for that particular size world-wide. A normal M16 Rose joint would have a thread pitch of 1.5 not 1mm.

I replaced the two Hook joints in the steering column. This was the source of all the play on this low mileage car. The original joints had bronze bushes. I was able to buy direct replacements with needle roller bearings and grease nipple! They are very expensive at approx £80 each!!!! I got them from Roger Brotton rogerbrotton@btinternet.com

The rag joint between the column and the rack had no play in it at all so I did not touch it.

Alignment:

I found the castor to be 4,3/4 degrees on one side and 6 degrees on the other. I set them both to 6 degrees positive.
The camber was already correct at 1/2 degree negative.
I set the toe in at 1/4"



Regards, Johnny

Johnny,
Thank you very much for that information, much more than I have been able to find through many searches.

I have questions, The Rose joints, do they replace the lower ball joints?

My front end is in excellent shape and I have recently had it very successfully aligned. The car now has a rear thrust angle of .03 degrees.
There is no torque steer either in braking, driving or full acceleration. I am very pleased but am interested in your information about bump steer. My steering joints are worn, I have searched but nor found them so your sources are very interesting to me. They have needle bearings but I have found that the cups have worn on the ends, resulting in play. My plan before hearing from you was to replace them with new Borgeson type joints, as I did on my shift linkage. Do the u-joints you found allow replacement of the trunion without changing the cage that is welded to the steering shafts?

Great hearing from you,
I will find the bridge material and send it.

All the best, DICK RUZZIN

Steering arm before

After

I later added a rubber boot to the Rose joint.

New steering trunions with needle bearings not bronze bushings like original.

Hi Dick,

I did not replace the lower A arm bushings with Rose joints, I replaced the tie rod outer ball joint with a Rose joint so that I could shim it up and down until I found the perfect height that eliminated the bump steer. I mounted it in double shear by modifying the steering arm and drilling out the taper to accept an M16 bolt.

Yes, I was able to change the steering column trunions without changing the cage. It was a time consuming job because they are so small and the cage bends easily.
I did grease the upper ball joint but did not add a grease nipple, I should have done that.

Johnny

'Rose joints' are called 'Heim joints' or rod-ends in the U.S. Speedway Motors in Nebraska sells sealing washers for 'joints' where the original boots are nonexistent or hard to locate- 6 per pkg for around $12. Each joint needs two. Dirt-track racers use them extensively.

...If Your going to Go with Heim Joints...Purchase the Ones with a 'Grease Nipple'/Zerk Fitting!! You can Grease them 'In-Place', Grease In, pushes the Dirt Out! The joints will wear much slower if Not at all; they'll Last much longer!! Yes, the rubber washers work, but Fresh Grease is Great too.

A couple of observations...The neck on that New Heim Joint is very Thin! It will Snap-Off there! I do NOT recommend 'Heims' for a Street/Road Car. They are for the RaceTrack Only(There are NO 'Potholes' on Racetracks). (Although I have Used them On the Street at the Ends of 'Anti-Sway' Bars). The Original Ball Joint 'Looks' Thin, But is actually Much Wider, when Viewed at 90 Degrees.

Last...What is with the Stacks of Washers?? Johnny, Your Better than That!! Get on a Lathe and Machine Some 'Spacers' out of Stainless Steel! OR are they There Temporarily?? Just My Opinion. Your work Looks Great!!...

Thanks Marlin,

It would have been nice to use a Heim with a grease nipple but M16 x 1 is a very unusual size. They are normally M16 x 1.5

I dont think they will break off because they are top quality at £40 - $64 each, made in Germany not China!
Also, at the other end of that tie rod there is another OEM Heim joint that threads into the end of the rack that is only 12mm. I have never heard of that one failing on a Mangusta.
I think most Heim joint failures (excluding the cheap Chinese ones) are due to the application exceeding the allowable misalignment. I spent a long time making sure mine would never exceed their misalignment angle.

As for the washers, I am ashamed to say they stayed. Your right, I am better than that! Maybe I will turn down some nice spacers tomorrow..

Johnny

Heims on military aircraft use grease nipples from the bottom of the threaded shaft via a long drilling up to the ball. Strength is not degraded in this way and in most cases it's as easy to access with a grease gun as on the head. I've done this with Heims used as shift-shaft supports. Use a new sharp drill and plenty of lube, and the steel shanks drill just fine, in case you ewant to 'roll your own'.

J,
That is a great trick, I do not know about the ball joints that you buy today but all of my joints after 60,000 miles are as tight as can be,

When I bought my ball joints for my new shift linkage, they came in loose and I had to return them for new ones. I do hear people complain about wear.

Dick Ruzzin

I am communicating with two companies in France about parts to rebuild the steering system. As I always do, I will include any important information, part #s and sources found to this forum.
All information given to them so far has not led to the proper rack. Usually the end bushings, bearings and rubber boots are needed to restore the steering rack.

Does anyone have their rack out of their car, or the bottom of the front luggage panel out so that a couple of pictures can be taken?

The top of the rack with the removable cover is the most important part to identify the rack.

A couple of good images would really help my sources identify the appropriate parts.

Thanks for the help,
DICK RUZZIN.

Mine is still in the car, I c

If you are able to supply images please send them to the forum but also send copies to me at <dickruzzindesign@aol.com> so that I can pass them on easily.

Thanks.
DICK RUZZIN

Hi Dick,

I will shoot some pics for you. Leave it with me.

Regards, Johnny

Thanks Johnny.

DICK RUZZIN

Back when I was restoring ZONKEY I found that the ball bearings were in pretty bad shape and set out to find a set. This may be of help:
http://home.earthlink.net/~rlbpantera/rack/
Fortunately at the time Larry Stock had some in stock and I bought a set. I don't know if he still does but it's worth a try. None of the other venders did.