Inner lower wishbone bushes on TR3a

[Ian Vincent]

I currently have my front suspension stripped down in an attempt to identify and fix a clonk which developed during the recent Pyrenees Rally - some of the roads were a bit rough, to say the least.

I am using the black nylatron bushes and find that they are a very snug fit into inner end of the wishbone arm to the extent that the steel bush is then a tight press fit into the nylatron bush.  There's nothing in the instructions about having to ream them to size but I am assuming that for the nylatron to work, the movement has to take place between the nylatron bush and the steel one. At the moment they are so tight that the only rotation that can take place is between the steel bush and the suspension inner fulcrum pin which can't be right.

Before I get the reamer out, has anyone else had this problem?

[BlueTR3A-5EKT]

Yes have come across this issue. To the point where I have a stock of NOS Triumph white nylons that I use for selective assembly when doing wishbones, and will only use black nylatron after a lot of fettling and assembly.   

Polish the outside of the nylon a touch if it is a tight fit in the wishbone.  Reaming out the inner is fraught with pot holes.

As you correctly state - Wishbone rotational movement is between the nylon and the clamped steel bush.

Does the steel fit the nylon before the nylon is in the wishbone?  If the nylon is snug before going in the wishbone then you will need to relieve it a touch.  The steels are hardened and ground, so not easy to fix without a cylinder grinder or attachment on a lathe.

Are the steels new?  If so what is the outer dimension compared to the old ones?  Could you reuse the old steels?

Are the holes in the wishbones perfectly clean?   That dimension is imperial not metric.  Polish out to clean metal with emery on a split stick held in a drill or find the correct dimension and ream.  Usual issue is the hole going egg shaped after the steel has worn through the nylon into the wishbone.

Once all working smoothly, fit both the lower wishbones and spring pan to each side and check the whole lot goes up and down OK -before- tightening the inner wishbone fulcrum nuts on the chassis.  That's coz the inner diameter of the steels is a sloppy fit on the chassis fulcrum pin.

Did you find the reason for the clonk?  Have you got nylon/bronze steering lever relay bushes? could be the cross bar going up and down and making a clonk on lock.

Lastly - Where did the bushes come from? 

Peter W

 

Edited February 4, 2022 by BlueTR3A-5EKT

[Ian Vincent]

Very many thanks for the prompt reply Peter.

The bushes came from a friend who used to work for a company that manufactured them for one of the TR suppliers - I don’t know which one I never asked.  I wanted to use them because nylatron is (a) much stronger than nylon on its own and (b) is impregnated with Molybdenum which acts as a lubricant.

The holes in the wishbones are the correct size and round.

I also have a spare set of white nylon bushes - supplied by Moss I think, and I tried them but they were very slightly loose on the steel bush.  So in the end I went against your advice and reamed out the nylatron bushes after pressing them into the wishbones so that they are a snug fit - no play, just a nice sliding fit.

I think the clonk was in the ARB but there were a number of other minor issues that I have corrected along the way.

Rgds Ian

[BlueTR3A-5EKT]

1 hour ago, Ian Vincent said:

Very many thanks for the prompt reply Peter.

The bushes came from a friend who used to work for a company that manufactured them for one of the TR suppliers - I don’t know which one I never asked.  I wanted to use them because nylatron is (a) much stronger than nylon on its own and (b) is impregnated with Molybdenum which acts as a lubricant.

The holes in the wishbones are the correct size and round.

I also have a spare set of white nylon bushes - supplied by Moss I think, and I tried them but they were very slightly loose on the steel bush.  So in the end I went against your advice and reamed out the nylatron bushes after pressing them into the wishbones so that they are a snug fit - no play, just a nice sliding fit.

I think the clonk was in the ARB but there were a number of other minor issues that I have corrected along the way.

Rgds Ian

Good outcome with the reaming.
  I never had what I would describe as an easy time doing it, nor did I ever get a good finished surface.   Is your reamer a fixed size or an adjustable?    Mine is adjustable and seamed to cut thru’p’ny bit shaped holes in nylon.   Did you do it powered or by hand?

Peter W

 

PS.  The front suspension inner wishbones, top and bottom, were all nylatron on my car but I found it terribly harsh.  So run nylatron lower and poly upper.   You can go the whole hog if you want and fit Torrington roller bearings in those positions.  The bearings are easily available as they are Mini, which as we all know uses the rubber sealing rings , same as TR.   I gave up on that mod as I felt the suspension improvement and my driving requirements were not compatible.

 I have nylatron bushes in the rear spring back shackle though.   It locates the spring better than the rubber.   They were made for MG, which fits TR.   Plus of course the front eye locator arrangement which I made from phosphor bronze washers, again from a MG.   That stops the rear springs and axle tending to slide sideways on hard cornering.

Edited February 4, 2022 by BlueTR3A-5EKT

[Ian Vincent]

Hi Peter,

My reamer is a hand operated adjustable which I have had for years.  I agree you have to be very careful with how you use it to avoid getting raggedty holes but with care it works.  I have had the same problem in the past reaming out rocker bushes  - i.e. getting a smooth cut.

Anyway sorted now.  The top bushes are poly (superpro) and I am not changing them as they are fine, it was the lower ones that were a bit sloppy.

I'm leaving the rear supension alone as that is all superpro bushes / Revington gear, (springs, rose jointed shock absorber links and lateral stabilisers) and works fine.

Rgds Ian