Lancia Motor Club

Model Technical and Interest => Aprilia, Ardennes and Ardea => Topic started by: davidwheeler on 03 November, 2016, 06:26:24 PM



Title: Rear spring
Post by: davidwheeler on 03 November, 2016, 06:26:24 PM
I am currently engaged on dismantling the rear end (have not got round to mantling yet - it is all being very difficult!)    I need to change the spring and found that 36.362 was immovably attatched to the bolt 38.74127 - so had to cut it out.   Examination of 36.362 showed it to contain a roller bearing with traces of felt oil seal grooves either side, rather than the expected silentloc, but this seems integral to the body of the piece.   I cannot press out a bearing with 10 tonnes anyway!     Does anyone know any better than this or must I get the innards ground out so that I can fit a conventional roller bearing?


Title: Re: Rear spring
Post by: davidwheeler on 03 November, 2016, 06:33:31 PM
picture


Title: Re: Rear spring
Post by: simonandjuliet on 03 November, 2016, 07:59:20 PM
From memory, it is not a bearing assembly as such , but a machined housing with needle rollers, inner sleeve and cover, so it won't press out.

I will look out the bits and photograph them - although I see Noel is online and may have already done it ....

ps I think it seizes because the bolt bends between spring and bearing - it is drilled for greasing and is not solid


Title: Re: Rear spring
Post by: BlueSky on 03 November, 2016, 09:18:22 PM
Umm, well yes I have had look! Simon is correct in that it is manufactured as a unit and is not designed to be disassembled. There are two possible options, on my car someone has ground them out and replaced the rollers with a PB bush, or Cavalitto have new replacements. The same applies for the top 38-360 part where the cable loops over.

Noel


Title: Re: Rear spring
Post by: simonandjuliet on 04 November, 2016, 09:26:37 AM
The bearing in bits ......



Title: Re: Rear spring
Post by: davidwheeler on 04 November, 2016, 02:06:45 PM
New is the way to go, thank you Simon.  Next problem is how to get this lot apart so as to renew the bearings.     I cannot press the torsion bar out of the tube using 38-74028 to press against.   I fear it will be very difficult to undo this item as well, probably much heat will be needed even though there does not look to be much thread, after which I can get at 38-74031 and remove the bearing.
All ideas welcome!
Unfortunately I also cracked one of the aluminium clams for 38-74020 which can be welded but if anyone has a spare please?
Thank goodness the wheel bearings seem OK.


Title: Re: Rear spring
Post by: davidwheeler on 04 November, 2016, 04:39:56 PM
Making progress, 74208 has yielded to modest heat but 74031 remains intransigent even when red hot!   I fear I may have to drill it and weld it up again afterwards.


Title: Re: Rear spring
Post by: BlueSky on 05 November, 2016, 01:59:36 AM
Simon how did you get the bearing bits out?

David you know the torsion bar bearing is an odd size, 45mm bore, 78m OD and 18mm width & difficult to find? The wheel bearings are a standard size and are probably worth replacing anyway as they are not expensive.

Sorry don't have a spare alloy clamp piece. You should also think about replacing the rubber doughnuts they hold in place, available in Italy at the same place you can find the odd bearings!

Noel


Title: Re: Rear spring
Post by: simonandjuliet on 05 November, 2016, 09:21:03 AM
Noel, the bits shown are "new" repair parts, I presume supplied by Lancia originally. The bearing housing has a flange that is turned over once it has been assembled

I have found a clamp shell for David



Title: Re: Rear spring
Post by: ColinMarr on 05 November, 2016, 10:04:07 PM
I am full of admiration for what you guys are doing! Seeing the photographs of the cable-fitting reminded me of how grateful I once was to have had a spare. Beware, they may look OK, but the inner stands of cable can corrode without much to show on the outside. See my post under “What is the ideal emergency kit?”

Colin


Title: Re: Rear spring
Post by: davidwheeler on 06 November, 2016, 12:18:00 PM
Simon how did you get the bearing bits out?

David you know the torsion bar bearing is an odd size, 45mm bore, 78m OD and 18mm width & difficult to find? The wheel bearings are a standard size and are probably worth replacing anyway as they are not expensive.

Sorry don't have a spare alloy clamp piece. You should also think about replacing the rubber doughnuts they hold in place, available in Italy at the same place you can find the odd bearings!

Noel
I've found the bearings at Ferri Adelio but whence the rubbers please?


Title: Re: Rear spring
Post by: simonandjuliet on 06 November, 2016, 01:18:35 PM
I have some NOS rubbers we could use as a pattern if you can't find them at a sensible price

In the same box I found these other rubbers, but not sure what they are for - do you recognise any of them ?

The one with the rear groove has part number 37.000.514 and I have a load of them .......


Title: Re: Rear spring
Post by: davidwheeler on 06 November, 2016, 02:02:33 PM
38-74215 are the ones I think.  Mine are not too bad I suppose but remanufactured could easily be fitted at a later date.    I'll try Omicron tomorrow to see if they have anything.


Title: Re: Rear spring
Post by: davidwheeler on 07 November, 2016, 02:00:40 PM
Omicron use 6009s which are 45x75x16 and make a carrier for them.  I shall wait on Ferri Adelio for a few days anyway.    I have managed to get the old bearings out, I made up a tool, shown below.  What is not seen is the 3 foot tube applied to the bar!   The bolts are to keep the tool in engagement.  I put the bearings in the press to start with and applied 3 tonnes to the bearing to press against the housing end thinking that may loosen things slightly.  One side then came fairly easily but the other fought to the last thread!


Title: Re: Rear spring
Post by: simonandjuliet on 07 November, 2016, 02:23:40 PM
Looks like fun !

I like the pipe chain vice - plus can you show some more photos of the tool, did you make it ?

ps Parts on their way


Title: Re: Rear spring
Post by: Jaydub on 07 November, 2016, 09:36:02 PM
Simon
Are the rubbers with the rear groove, caliper seals? That`s what they remind me of.

John


Title: Re: Rear spring
Post by: davidwheeler on 09 November, 2016, 09:27:23 AM
Ferri Adelio have  come up with the goods - at a cost of E202.52 inc VAT and delivery.   I suppose that may be about the same as the Omicron solution.  Pity I did not know of the need a few months ago, could have saved quite a lot of money!


Title: Re: Rear spring
Post by: davidwheeler on 09 November, 2016, 05:47:36 PM
Here is the tool.  A bit crude but made this way for speed and simplicity.  One could think of refinements like a central bolt and swivel arrangement but quite how to manage the bar (which needed a LOT of torque applied to it) I have not yet sussed out.


Title: Re: Rear spring
Post by: frankxhv773t on 09 November, 2016, 07:26:30 PM
I think it produces torque. You apply a force. :D


Title: Re: Rear spring
Post by: davidwheeler on 10 November, 2016, 08:06:04 PM
"Torque, moment, or moment of force is the tendency of a force to rotate an object around an axis, fulcrum, or pivot. ... Loosely speaking, torque is a measure of the turning force on an object such as a bolt or a flywheel."   I applied a force to the 3 foot steel tube and produced a torque in the tool.  See, I am even more pedantic than you!
I have spent most of today rebuilding the high ratio final drive with new bearings.  I found it necessary to squeeze gently in the press to make sure they were properly seated (even after baking in the oven!).  Now it has all gone together withthe original shims, the tiniest amount of backlash and a nice even strip of engineers' blue on the teeth.  I hope it will be quiet on the road!


Title: Re: Rear spring
Post by: frankxhv773t on 10 November, 2016, 10:37:55 PM
Thank you David. We pedants must unite against loss of accuracy in the use of language.


Title: Re: Rear spring
Post by: davidwheeler on 11 November, 2016, 09:06:09 AM
Or even loss of precision.
Next question - How do I set the torsion bars when re-assembling the rear suspension?  There is, presumably, a set angle to the horizontal of the trailing arms before they are attatched to the spring.


Title: Re: Rear spring
Post by: ColinMarr on 11 November, 2016, 12:41:07 PM
The car needs to be levelled up and the torsion bars inserted (vernier adjustment) so that they are unstressed and 'neutral'. Not that I have ever seen one, but originally there would have been marker plates inside each rear wing cavity to help with this, as in the attached photo. In practice, I think the best thing is to set it up so the transverse spring looks flat and then insert the bars. What fun!

Colin


Title: Re: Rear spring
Post by: davidwheeler on 11 November, 2016, 07:37:37 PM
Thank you for reminding me!    In the "Lancia Ardennes..." story there is a photo


Title: Re: Rear spring
Post by: simonandjuliet on 11 November, 2016, 09:53:08 PM
On my car it is in a slightly different position - 2nd vs 1st ??


Title: Re: Rear spring
Post by: davidwheeler on 12 November, 2016, 09:29:05 AM
It is not clear in the copy but the original picture one can read "Monter la BARRE apres ??? (?ceci)
                                                                                  porte le bras porte roue a 1?0 m?
                                                                                 entre cette (----------)ligne et
                                                                                    la partie                     superieure
                                                                                      du joint                   de cardan" 
(sorry, no accents on my English keyboard)

which is to say "Mount the bar after this ??? (after this way?)  put the wheel carrying arm at 1?0 mm(?) between this line and and the upper part of the universal joint."
Question is how many mm?   Could you give us a close - up of your plate please Simon?  And in any case, what does it actually mean - it does not appear to make a huge amount of sense!

Unfortunately the Restauration describes refitting the torsion bars off the car "in the same orientation as we found on dismantling" and one cannot see at what angle this is.  I notice they use "sangles robustes" which sounds so much more poetic than "ratchet straps" to re-attatch the spring to the subframe before mounting the whole thing on the car - a bit like I did when I replaced the cable straps but I had the advantage of the weight of the car!    I prefer my spring compressor.


Title: Re: Rear spring
Post by: simonandjuliet on 12 November, 2016, 09:42:34 AM
Here's mine in Italian - the plates on either side give the same distance of 155mm


Title: Re: Rear spring
Post by: BlueSky on 12 November, 2016, 10:38:47 AM
The following information is from the factory A.S.T. Sketch 60 I-PM provided by Paul Mayo.
Torsion bar setting on Saloon:
Italian coupling non-greaser = 159 mm
Italian coupling greaser = 155 mm
English/Hardy Spicer coupling = 164 mm
Datum is horizontal line joining shock absorber fixing bolts.
Torsion bar bearing: Lancia 2048307 or 2048056, RIV Tipo 137827 or 5741 – 45 x 78 x 18 mm

My car doesn't have the plate with the settings, in the past I've just marked the torsion bars before removing them, put them back in approximately the same position and then adjusted the height once it's all back on the car. I'd measured the height to the bottom of the rear guards as a guide as well and then basically set them to what looked right!
Noel


Title: Re: Rear spring
Post by: davidwheeler on 12 November, 2016, 04:02:27 PM
Is this with or without the spring?   With I presume?   If so what is the approximate position of the unloaded trailing arm?


Title: Re: Rear spring
Post by: BlueSky on 13 November, 2016, 05:01:14 AM
I would assume it's with the spring. I used the "suck it and see" method! If it's all gone back together with lots of grease then you can adjust the height by jacking up a trailing arm until you see the torsion bar splines are free, use a puller to withdraw it before moving it a notch or two, lower the car on it's wheels, give the rear end a good push up and down, if you have friction shockers loosen them off first, a bit of trial and error should get right.
Noel


Title: Re: Rear spring
Post by: davidwheeler on 13 November, 2016, 02:10:11 PM
Unfortunately one of my torsion bars is immovably fixed in the swinging arm - even 10 tonnes failed to shift it!      I will start from about 30 degrees and see how it goes from there!


Title: Re: Rear spring
Post by: ben on 14 November, 2016, 11:11:38 PM
Hi David
             I think 30 degrees will give a very high ride height.
             On my car the trailing arms are about 10 degrees below the horizontal when the car is static with no weight in it.

             With one torsion bar stuck as you describe (probably a whack with a big hammer is more likely to shift it than a steady load in a press---or both!--but you will have tried this I expect) you do not have the luxury of the vernier type of adjustment on that side. This normally allows setting to within 1 degree because the inner spline has 42 teeth and the outer one has 48 teeth.

             1 degree of rotation of the trailing arm alters the setting height by about 4mm.

             Your best bet will be to fit the stuck bar first which presumably will go back the way it was before you took it to bits so should be ok even though moving only the inner spline changes the angle by about 8.5 degrees for one tooth. You can then measure the height on that side and set the other side to the same dimension.
             It will be easiest to do this height setting process without the transverse leaf being installed.Whether this is possible depends on the design of your spring compressor. If you have to do it with the spring in situ it requires manipulation of jacks under the body and under the wheel hubs to achieve the correct height setting and probably some extra weight in the boot will be needed.Either way the objective is to manipulate the radius arm angle to achieve the 155mm setting dimension (or whatever figure you are stuck with from side one) and then rotate the torsion bar until you find the position where it slides in with minimum alteration of the swing arm angle being required.  I think this "zero stress" position for the torsion bar should correspond to a typically loaded car.
           As Noel has pointed out working with the transverse spring in place you can judge if the ride height looks ok directly without worrying too much about the 155mm setting dimension.

Ben   


Title: Re: Rear spring
Post by: BlueSky on 15 November, 2016, 03:17:55 AM
I'm glad Ben has come up with proper technical explanation. I would have thought you could get the siezed torsion bar to move with a generous soak in penetrating oil and gentle heat repeated over a few days before the big hammer treatment!
Noel


Title: Re: Rear spring
Post by: davidwheeler on 15 November, 2016, 09:45:23 AM
Ben has just clarified on the phone that the trailing arm height is set without the spring attatched.   Posted in technical information thread.
The torsion bar bearings arrived from Ferriadelio yesterday in disintegrating vintage brown cardboard packets but immaculate inside their anti-rust paper (and very securely packed).


Title: Re: Rear spring
Post by: davidwheeler on 08 December, 2016, 04:34:55 PM
We are making progress at last.   Yes, several days of oil, spread the slot with a cold chisel and a heavy hammer and the splines relented and the torsion bar came out.     After much cleaning and painting and general tarting up I am now re-assembling.    I set the trailing arms to the prescribed height and the torsion bars went straight in on both sides so I am not sure about Ben's vernier effect - perhaps they are set right at the factory and it is just a case of getting things in the right position.    I am not using the original final drive so the inner splines must be set in the right place to start with as standard.      I have assembled one good spring from two and cleaned the rust off the leaves and applied much transmission grease.  When I have fitted it to the car I shall wrap it up with duct tape.   I fitted the new trailing arm bearings and packed them with unfeasably thick grease as the original seals got carbonised in the removing of the old ones and I shall then wrap greasy string round the shafts on both sides.   With any luck, it will not need to be disturbed for another 70 years.   All I have to do now is make new spring end shafts and repair the brackets that take the shock absorbers - the holes have got a bit enlarged over the years.


Title: Re: Rear spring
Post by: simonandjuliet on 08 December, 2016, 04:53:43 PM
Great progress - I have had problems with the torsion bar in the past as well. Any photos ?

May be able to help with the shock absorber mountings if you get stuck


Title: Re: Rear spring
Post by: davidwheeler on 08 December, 2016, 06:28:02 PM
Well, it is pretty well all up together so photos would not be very revealing!    The mountings just need a bit of welding so thanks but no thanks.


Title: Re: Rear spring
Post by: davidwheeler on 09 December, 2016, 06:14:51 PM
Have made two new spindles for the spring ends having realised that I do not need the shock absorber brackets as I have side mounted (adjustable) shock absorbers.    Have applied the spring compressor and tightened it up ready for the morning - I think 5pm is too late to start re-attatching the spring and removing the compressor, it needs a clear morning head.


Title: Re: Rear spring
Post by: JohnMillham on 09 December, 2016, 08:15:54 PM
Have made two new spindles for the spring ends having realised that I do not need the shock absorber brackets as I have side mounted (adjustable) shock absorbers.    Have applied the spring compressor and tightened it up ready for the morning - I think 5pm is too late to start re-attatching the spring and removing the compressor, it needs a clear morning head.
. I wouldn't stand in line with it! There's an enormous amount of energy waiting to get you!



Title: Re: Rear spring
Post by: davidwheeler on 10 December, 2016, 05:38:30 PM
True enough John but it is all up together again...  I did up the compressor even tighter, the channel section bent gently and I still had to use the coil spring compressor to approximate the trailing arm and cable mounting but nothing went spang.     She is now back on her wheels, level and ready to go but test drive will be tomorrow in daylight.


Title: Re: Rear spring
Post by: davidwheeler on 11 December, 2016, 03:52:03 PM
Brief spin round the block.  The "new" cwp is silent and the clonks have gone so I must have done something right.    Seems as swift as ever, too, despite the higher gearing.   The Nardi bits help of course.  Must now try to calibrate the speedo.


Title: Re: Rear spring
Post by: ben on 12 December, 2016, 05:23:40 PM
Well done.

I should probably rebuild my diff as it has too much backlash and has been leaking for the past 40 years or so but the oil is keeping the spring nicely lubricated!

You mentioned that the torsion bars went straight in on both sides.That is exactly what should happen but usually to achieve it requires rotating the bars to find the position where this is possible without moving the trailing arm from its set position.

If the shafts had the same number of splines at both ends it might be necessary to move the trailing arm to get the splines to line up (by up to as much as half a spline in the worst case) but with the vernier system provided by having different numbers of spline teeth at either end the shaft can be rotated to a position where the splines will line up at both ends with negligible re-positioning of the trailing arm.


Title: Re: Rear spring
Post by: davidwheeler on 21 December, 2016, 10:11:08 AM
I hear what you say but the fact remains that I did not have to do any rotation, it would be highly unlikely that I would choose just the right position on both sides by chance?    Too late now to count the number of splines - has anyone got a shaft out to enlighten us?    In the meantime I have been flying around in my refurbished car.  The higher gearing means that I am going even more too fast!    At least the speedo now registers the correct speed.


Title: Re: Rear spring
Post by: ColinMarr on 21 December, 2016, 12:37:36 PM
I can assure you that possibility of vernier adjustment is real - there are unequal number of splines between inner and outer ends. As I posted at almost the start of this thread:

"The car needs to be levelled up and the torsion bars inserted (vernier adjustment) so that they are unstressed and 'neutral'. Not that I have ever seen one, but originally there would have been marker plates inside each rear wing cavity to help with this, as in the attached photo. In practice, I think the best thing is to set it up so the transverse spring looks flat and then insert the bars. What fun!"


Title: Re: Rear spring
Post by: ben on 21 December, 2016, 06:23:20 PM
A shaft I have to hand has 42 splines on the inner end and 48 splines on the outer end.

Because these numbers are both factors of six I think it means that there will be six equi-spaced positions where the shafts should just slide in.

This in turn means when the shafts are offered up they are bound to be within +/- three splines of optimum and only a very small movement of the trailing arm is required to enable them to slide in without any rotation of the shaft.

At the risk of upsetting the purists I think this is another (not uncommon!) example of Lancia over-engineering. Or it may just be a by-product of a design decision to make the inner spline smaller than the outer so that the shaft can be fed through more easily on assembly.


Title: Re: Rear spring
Post by: davidwheeler on 21 December, 2016, 06:51:33 PM
Serendipity!