Completion update - New trunnion lock washer frustration

[Hamish]

I have been in the process of changing my 3a to 4 front suspension. 
 

I bought the parts over a year ago as I gathered what I needed. 
the 3deg trunnions were fine until I tried to wind the lock washers on to the pivot shaft splines they were bloody tight then the thread gave both the nut and pivot shaft thread broke !

i now see doing some searching here and elsewhere that the Rimmer lock washers are too hard to pull on to the spline 

what is the answer please I have a new trunnion on order. 
 

can you press them on ?

heat them up ?

use the old ones ?

 

thanks for any advice

H

Edited May 31, 2020 by Hamish

[Lebro]

I would use the old ones.

Bob.

[BlueTR3A-5EKT]

41 minutes ago, Lebro said:

I would use the old ones.

Bob.

+1

Peter W

[Lebro]

I got the same trunnions, probably from Rimmer Bros. I noticed that the metal used for the shaft was very hard, & the thread had a tendancy to chip off at the end rather than burr over. (this would have been when first using the nut to pull the splined washer on. I think I probably tapped the washer on further before using the nut again. I may have also been using new washers. I would not again. BTW the thread remained OK on the main part of the shaft where the nut ended up.

Bob.

[RogerH]

The shaft and its splines need to be hard in order to broach the splines into the washer.

The washer needs to be softer than the shaft. 

You could open the hole in the washer out very slightly to reduce to broaching effect,  It may be on the small size in the first place.

 

 

Roger

[Hamish]

Thanks for the comments

took these this morning. 
too p#ssed off last night 

the thread has gone in the middle. 
the other side was a different trunnion in that it was cross drilled for the split pin it was tight but useable
this one is for the nyloc so not cross drilled may be different suppliers I can’t remember. 
 

as I say I have been gathering the bits for over a year to spread the cost. 
 

some pics for your engineering perusal 

I was just too ham fisted I think and did what was suppose to happen without the experience of “that’s too bloody tight STOP”

H

ps more pleased with the pictures off the phone. !!!

[Tim T]

When I did my 3a I had similar issues. Some washers were too tight and some were too big. I also noticed that the splines on one new trunnion was not even the same as on the other new trunnion. Again I had bought the parts ages ago and didn't discover the issue until a couple of years later when I finally got around to doing the job. Mine came from Moss and they did sort out the issue without any questions even though I was way past their warranty period.

Cheers,

Tim

[RogerH]

Hi Hamish,

impressive pics.  Nuts and bolts are not precise items.  One or more parts of the thread are touching at any one tine but not all the thread.

With a normal softish nut/bolt the thread gently deforms for all the thread to take the load

With a hardened bolt there is little give so one thread will take the brunt and fails, another takes over and fails etc.

The washer should be quite soft if you are going to use the shaft as a broaching tool.  if you stroke the washer with a file does it give the impression of soft or hard???

 

Roger

[RobH]

4 minutes ago, RogerH said:

One or more parts of the thread are touching at any one tine but not all the thread.

With a normal softish nut/bolt the thread gently deforms for all the thread to take the load

That sounds like as good reason for the thread not to be dead-hard Roger. What prevents similar progressive failure in service?

I wonder whether the OEM part had the threaded bit 'let down' by selective re-heating ?

 

[RogerH]

Hi Rob,

I would assume that the OEM part did not require such a high load to broach the washer. 

The  normal attachment torque isn't that great.

 

oger

[Hamish]

Hi

thought I would update this thread.
 

I bought a new trunnion and this one was cross drilled for split pins but I ordered nyloc nuts as that’s what was recommended for the new trunnions. Seems to be hit and miss on whether they are cross drilled or not. 
 

I don’t have any reamers so I drilled out the lock washers enough that they still press on the splines. Without shock and springs the suspension rises and falls with just my moving it  with some resistance.

both sides of my suspension now has castor and camber TR4 style fittings. Together with Ali  hubs and uprated stub axles. And new gaz adjustable shocks. ( these are adjustable on the car) I felt the konis that we’re on it were on their way out  1/2 a turn all or nothing.

the stub axles have a course thread - I would prefer a fine thread to give more variable when tightening and setting the hub nut/play.

i have nos pads and new discs. Everything is all greased including all the steering links on the box system.

i stuck with the springs  on the car ( uprated a bit I think) in the end as I felt the 420lb were very stiff. These can be changed later if I need more spring weight.

i had a metal plate under the spring pan with spacers to deal with the lip for my uprated anti roll bar mount. But as it was all apart I have now put this plate between the spring pan and the wishbone and it has firmed this up a lot. 
 

I don’t run with the disc back plate, there just isn’t the room with the Revington Ackerman steering arms even with the small ball joint on the steering arm. 
 

hmmm what can I do next ......

[stuart]

Have you shimmed the spring pan all round to compensate for the anti roll bar plate being in between? And you could touch up the black on the chassis

Stuart.

[Hamish]

58 minutes ago, stuart said:

Have you shimmed the spring pan all round to compensate for the anti roll bar plate being in between? And you could touch up the black on the chassis

Stuart.

no and yes

[stuart]

28 minutes ago, Hamish said:

no and yes

Reason I said about shimming the spring plate is the possibility it may now crack as its unevenly held down now.

Stuart.

[Lebro]

As far as I can see you now have the late TR4 setup which gives 3° castor but retains the 2°+ve camber ?

Bob

[Drewmotty]

Take a look here if you want a simple solution to negative camber Hamish. 
I can send you a sketch of the blocks if you are interested. 
 

https://www.tr-register.co.uk/group/devon/social-report/2019/11/1695/In-the-Garage-Winter-19

[Lebro]

+1 for Andrews solution, I fitted adjustable upper fulcrum, & it was a PINA to set up !

Bob.

[Hamish]

7 hours ago, Lebro said:

As far as I can see you now have the late TR4 setup which gives 3° castor but retains the 2°+ve camber ?

Bob

  Went for shortened wish bones as a trial .

Pm sent andrew

but can’t face stripping it all out again. 

[BlueTR3A-5EKT]

54 minutes ago, Hamish said:

  Went for shortened wish bones as a trial .

Pm sent andrew

but can’t face stripping it all out again. 

I was going to suggest Moss TT3003 negative camber vertical posts but I see they are back ordered.   The first pair are still doing grand service on my  TR .   I fitted them in early 1990.

Peter W

[Hamish]

1 hour ago, BlueTR3A-5EKT said:

I was going to suggest Moss TT3003 negative camber vertical posts but I see they are back ordered.   The first pair are still doing grand service on my  TR .   I fitted them in early 1990.

Peter W

Just taken those off peter. 
didn’t want to double up the effect with the top wishbones I had. 

[Ian Vincent]

16 hours ago, Lebro said:

+1 for Andrews solution, I fitted adjustable upper fulcrum, & it was a PINA to set up !

Bob.

I also fitted the adjustable top fulcrum but was able to borrow an old Dunlop suspension setting tool that included camber angle and found it relatively straightforward. The hardest part was welding it in position once I’d got it right. 

Rgds Ian

[Lebro]

Ian.

Measuring the camber angle was not the problem, I used a modified spirit level against the wheel rim. It was the fact that you had to make guess at the right position, re-assemble everything, drop the car down, bounce the suspension, roll it back & forth a few time to get everything settled, then take the measurement.

Unless you are very lucky you won't get it right 1st time (or 2nd), so you raise the car take the wheel off, slacken the bolts (& nuts !!!) holding the fulcrum, move it a bit, do the bolts (& nuts !!) up again, put the wheels back on, drop the car    -------   etc etc    Then once you finally get it right, you do the same for the other side.

It's not something I would contemplate doing again !    The welding was the easy bit.

Bob.

[stuart]

1 hour ago, Lebro said:

Ian.

Measuring the camber angle was not the problem, I used a modified spirit level against the wheel rim. It was the fact that you had to make guess at the right position, re-assemble everything, drop the car down, bounce the suspension, roll it back & forth a few time to get everything settled, then take the measurement.

Unless you are very lucky you won't get it right 1st time (or 2nd), so you raise the car take the wheel off, slacken the bolts (& nuts !!!) holding the fulcrum, move it a bit, do the bolts (& nuts !!) up again, put the wheels back on, drop the car    -------   etc etc    Then once you finally get it right, you do the same for the other side.

It's not something I would contemplate doing again !    The welding was the easy bit.

Bob.

Thats why I dont like fitting that kit either.

Stuart.

[BlueTR3A-5EKT]

2 hours ago, stuart said:

Thats why I dont like fitting that kit either.

Stuart.

It was the level of work required that inspired me to modify the factory vertical post machining drawing  to give a negative camber of 1.5 degrees.  I then just sent the modified drawing to the UK maker of the standard posts and asked for a batch to be machined with the regular angle ones - He was happy as it doubled his order and he only had to change one dimension in the machining programme.  I had toyed with the spacer plate idea that is given in the Devon Group newsletter,  with hindsight it is an elegant and suitable solution.  The Revington kit allows for accident damaged or bent TR chassis suspension turrets to be compensated for.

Up to this point in 1980 the only other options I knew of were - Cutting the top wishbones, constructing adjustable wishbones with rose joints, the Revington moveable top wishbone mount kit or that blacksmith's favourite, bending the vertical post.

My only criticism is that the centre line of the post pivot angle whne projected down to the road (line scribed through centre of top ball joint taper and trunion thread centre) moves slightly toward the inside of the tyre footprint when the stub axle angle is changed. 

Cheers

Peter W

[Hamish]

43 minutes ago, BlueTR3A-5EKT said:

It was the level of work required that inspired me to modify the factory vertical post machining drawing  to give a negative camber of 1.5 degrees.  I then just sent the modified drawing to the UK maker of the standard posts and asked for a batch to be machined with the regular angle ones - He was happy as it doubled his order and he only had to change one dimension in the machining programme.  I had toyed with the spacer plate idea that is given in the Devon Group newsletter,  with hindsight it is an elegant and suitable solution.  The Revington kit allows for accident damaged or bent TR chassis suspension turrets to be compensated for.

Up to this point in 1980 the only other options I knew of were - Cutting the top wishbones, constructing adjustable wishbones with rose joints, the Revington moveable top wishbone mount kit or that blacksmith's favourite, bending the vertical post.

My only criticism is that the centre line of the post pivot angle whne projected down to the road (line scribed through centre of top ball joint taper and trunion thread centre) moves slightly toward the inside of the tyre footprint when the stub axle angle is changed. 

Cheers

Peter W

Peter

you gave a PM