Title: Toe-in Post by: Raahauge on 29 October, 2022, 07:19:44 PM I hope it is acceptable to put a request on here, - does anyone have a spare track rod I can borrow whilst I compare/check/modify mine, or buy.
I need more toe-in and I have run out of adjustment . The rod was bent when I bought the car, as if it had been towed with it, and I think in straightening it may have lengthened a little. The published figure is 6 to 8mm and I have about 4.5 Thanks and regards Mike Title: Re: Toe-in Post by: Mikenoangelo on 29 October, 2022, 08:35:03 PM I can measure mine which I think is original if that would help.
Mike Title: Re: Toe-in Post by: Raahauge on 30 October, 2022, 11:02:47 AM Thank you Mike, that would be most useful.
Title: Re: Toe-in Post by: Kari on 30 October, 2022, 11:44:00 AM A very interesting subject!
To my surprise, I didn't find any information about toe-in in the original owner's manual issue Aprile 1935 Xll. However, I did find data in the Belna Handbook which states a toe-in of 5 - 6 mm. That would be about 0° 40' to 0° 50' About 10 years ago, I wanted to know the length of the Augusta track rods. During a Sliding Pillar Rally and on other occasions I did measure several track rods. I have found several different lengths but not by much difference. I've found lengths between 1110 mm and 1116 mm from centre of bore to centre of bore. The toe-in can be varied by turning the eccentric bolts 31-4430. I wonder if the adjusted toe-in can be checked on a drive-on test stand. I look forward to the length of track rod Mike has on his car. Early cars had a very thin track rod which was replaced by a more substantial one later on. Diameter of tube approx. 25 mm. regards Karl Title: Re: Toe-in Post by: Raahauge on 30 October, 2022, 06:48:11 PM Good evening and thank you. My dimensions are from La Lancia by Weernink.
I have been playing with tyre pressures but have concluded that I really do need more toe-in. By my rough measurements and calculations the 2mm available adjustment at each side would produce a maximum variation at the wheel rim of 5.3mm My trackrod measures 1113mm between centres and is 24 diameter (flat rad car) I have spherical plastic bearings at each end so there is no give whereas there would be a small amount with standard rubber bushes. I recall some discussion about the originality or not of rubber bushes with eccentric centres, (might have been about Aprilia) I wonder if these were available as a fix for such a situation? Mike Title: Re: Toe-in Post by: Mikenoangelo on 30 October, 2022, 09:52:11 PM On my car the trackrod bolt centres are 1115mm apart. The trackrod itself between the insides of the "u" shaped yokes is 1051mm and the trackrod is 27mm diameter - this being a late car made in 1936. So it seems we have the same length although different diameters.
When I worked on the front axle I reassembled the trackrod with the same adjustment as received, having no means of measuring the toe in and no reason to think it might be wrong. However when my son, who is very well attuned to such things as he works for JLR, said he felt there might be too much toe in I kept an eye on the wear of the front tyres and sure enough are now showing more wear on the outer side of the tread. So I need to check the toe in which my local garage are able to do with some laser kit. Without taking the trackrod ends apart, which I did not have time to do today, I can't say at which extreme they are adjusted but all 6 holes on the top bolt head are symetrically aligned to the rear of the car with the locating pin in the extreme inner hole as in the photo below which perhaps suggests that the toe in is currently set to the maximum? The UK translated version of the instructions advises 6-8 mm or a quarter inch of toe in. This converation is for me very timely! Mike Clark Title: Re: Toe-in Post by: Raahauge on 30 October, 2022, 10:24:17 PM Mike, thank you for the measurement.
I agree you have it set at maximum toe-in. I measured mine by placing straight edges (planks of wood) elevated on tins against the tyres and measuring the distance between them at the front and rear of the tyre. You then have to take into account the distance for and aft between the measurements, in my case 22inches and calculate back. There a number of components involved and therefore lots of scope for variation apart from any bumps it may have had. My front wheels are rebuilt and the tyres run true as otherwise it would not of course work. Title: Re: Toe-in Post by: Running Board on 31 October, 2022, 08:23:02 AM the original silent block bushes are eccentric , many argue otherwise as theirs have been replaced by concentric bushes and the parts book drawing doesn't illustrate them as eccentric , i have a very original belna ,every steering bush is eccentric , this gives more toe in any direction depending on how its fitted into the steering arm .
There have been many debates on this topic with arguments on wrong track rods fitted etc , early cars have a much lighter track rod, there were less made so impossible for every late car to have an early track rod fitted "by chance" we made new eccentric bushes out of polyurethane type bushes off the shelf in demon tweeks , they machined in the lathe have been fitted since 2006 with no issues and correct track Title: Re: Toe-in Post by: Mikenoangelo on 31 October, 2022, 10:08:03 AM James are you saying that the eccentric bushes gives additional adjustment over that given by the through bolt with the locating pin? If so do you have any dimensions for the PU bush that you made?
I'll have to dismantle my trackrod ends to look at the bushes. They are a tight fit in the steering arm ends and are nipped by the bolt so that any turn of the steering winds up the bushes and has a self centering effect. Is that how you PU bushes work or do they rotate on the bolt? Mike Clark Title: Re: Toe-in Post by: Running Board on 31 October, 2022, 10:46:08 AM James are you saying that the eccentric bushes gives additional adjustment over that given by the through bolt with the locating pin? If so do you have any dimensions for the PU bush that you made? I'll have to dismantle my trackrod ends to look at the bushes. They are a tight fit in the steering arm ends and are nipped by the bolt so that any turn of the steering winds up the bushes and has a self centering effect. Is that how you PU bushes work or do they rotate on the bolt? Mike Clark yes as it moves the pivot point of the trackrod end , we had terrible problems getting the toe in correct, with concentric bushes and standard track rod (we measured 3 all the same)it had too much toe in , fitted eccentric bushes and could get correct toe , my dads car had 1 eccentric bush when we restored it , the belna cabriolet had none but my belna saloon had a full set , it has been argued that the rubber " moved " rubber simply cannot shift from one side of the bush too another and remain unform in thickness , i will have a look on my dads pc to see if he has any pics of the bushes he made or drawings ,from memory the sleeve in the pu bush is only pressed in so can rotate in the bush so the bush doesn't twist Title: Re: Toe-in Post by: Running Board on 31 October, 2022, 10:48:48 AM this is a factory bush
Title: Re: Toe-in Post by: Raahauge on 31 October, 2022, 01:12:52 PM All the rubber bushes were unusable when I came to it on my rebuild.
From recollection the typical maximum advised torsional rotation in degrees on these type of bushes which are commercially available is in the low 20's with the highest I found to be about 30. The one on the drop arm has to rotate over 40. The originals must have had a rubber composition that allowed for this high degree of torsional flexing. I couldn't see a way forward with rubber so changed all mine to Igus plastic rod-end bearings which are an exact replacement save for the axial length, - spacers are needed. The one on the drop arm is bigger and needed a sleeve. From all the comments it looks as if the eccentric rubber bushes allowed a general adjustment and the fine tuning could then be done with the eccentric pins at the ends. I will investigate PU rather than alter my track rod. Mike R. Title: Re: Toe-in Post by: Running Board on 31 October, 2022, 02:48:01 PM My dad did a lot of research into eccentric bushes , he learnt a good amount from ruberry owen trailers who used them on steering trailer axles , the main reason was that they can articulate through a steeper angle than a concentric bush , i suppose this would make sense with them being such a small diameter i would imagine there would be a hell of a strain on them if one suspension was fully up and other fully down , from what my dad found out there was less load on the bush in these extreme circumstances DO NOT ASK ME TO EXPLAIN HOW OR WHY!! :D
Title: Re: Toe-in Post by: Raahauge on 31 October, 2022, 08:41:56 PM I was just thinking about Pu bushes and the amount of eccentricity needed when I realised that my statement that the 4mm of adjustment available at the rod ends provides 5.3 at the wheel is correct but misleading, the affect on toe-in is double that.
I think that means that the movement of the pin by one hole on one side changes the toe-in by just under 1mm. There is a surprising amount of adjustment available with the addition of eccentric bushes. Title: Re: Toe-in Post by: Kari on 01 November, 2022, 10:31:53 AM As I have predicted, the subject is gaining momentum!
May I pass my personal opinion. The “eccentric” silent blocs (bushes) With all respects what the late Morris has passed to us Augusta boys by publishing the Augusta Newsletter and collecting valuable information for us to use, there was one little thing Morris and I agreed that we don’t agree: the eccentric bushes in the Augusta steering. I do agree that there are other applications which are using eccentric bushes as Morris has stated. Now, why would Lancia go to the expense and install adjustable eccentric bolts in the steering when the toe-in could be adjusted by eccentric bushes? And how would that be done during assembly of the car in the factory? As experience shows, the range of adjustment by the standard bolts is enough in most of all track rod lengths. If a eccentric bushes are found on a car, they are very old and the car has been standing a long time in a position causing permanent load on the bushes, thereby getting deformed (plastic flow). Another point that might rise an eye brow or two: to clamp or not to clamp the silent blocs. I think the bolt in question is not designed the inner bush of the silent bloc to be clamped to the track rod. The surface area is just to small. If clamping would be needed, there would be a serrated bush like the silent bloc at the front of the rear springs. The nut is very light, the few treads can be stripped easily. I don’t think the rubber in the silent bloc is soft enough to allow a turning of 60° + as it does at the drop arm at full lock. Therefore, I believe that the bolt should be tightened just snug to allow the inner bush of the silent bloc turning around the eccentric bolt. There is only little movement while driving, even on a curved road, there is almost no wear. There is an argument that the twisting of the rubber would aid the self-centering effect of the steering. It might help, but I think the self-centering is done by the built-in castor. On my car, in the last 60 years, I have changed many silent blocs but there are still the original bolts present. Every couple of years, I remove them and put a light coat of grease to the bolt and bush. For about 2 years or about 6’000 miles I use PU silent blocs which Peter Renou has given me to test. No problem. I look forward to the comments. Regards Karl Title: Re: Toe-in Post by: Mikenoangelo on 01 November, 2022, 11:46:56 AM That makes sense to me Karl. However although when driving the main force for self centering no doubt comes from caster angle, with the bolts nipping the inner sleeve of the bushes there is a significant self centering effect even with the car jacked up off the ground.
I'd better devise some means of measuring toe in and investigate my car again and try loosening and greasjng the bolts. . Mike Clark Title: Re: Toe-in Post by: Running Board on 01 November, 2022, 01:37:29 PM As I have predicted, the subject is gaining momentum! May I pass my personal opinion. The “eccentric” silent blocs (bushes) With all respects what the late Morris has passed to us Augusta boys by publishing the Augusta Newsletter and collecting valuable information for us to use, there was one little thing Morris and I agreed that we don’t agree: the eccentric bushes in the Augusta steering. I do agree that there are other applications which are using eccentric bushes as Morris has stated. Now, why would Lancia go to the expense and install adjustable eccentric bolts in the steering when the toe-in could be adjusted by eccentric bushes? And how would that be done during assembly of the car in the factory? As experience shows, the range of adjustment by the standard bolts is enough in most of all track rod lengths. If a eccentric bushes are found on a car, they are very old and the car has been standing a long time in a position causing permanent load on the bushes, thereby getting deformed (plastic flow). Another point that might rise an eye brow or two: to clamp or not to clamp the silent blocs. I think the bolt in question is not designed the inner bush of the silent bloc to be clamped to the track rod. The surface area is just to small. If clamping would be needed, there would be a serrated bush like the silent bloc at the front of the rear springs. The nut is very light, the few treads can be stripped easily. I don’t think the rubber in the silent bloc is soft enough to allow a turning of 60° + as it does at the drop arm at full lock. Therefore, I believe that the bolt should be tightened just snug to allow the inner bush of the silent bloc turning around the eccentric bolt. There is only little movement while driving, even on a curved road, there is almost no wear. There is an argument that the twisting of the rubber would aid the self-centering effect of the steering. It might help, but I think the self-centering is done by the built-in castor. On my car, in the last 60 years, I have changed many silent blocs but there are still the original bolts present. Every couple of years, I remove them and put a light coat of grease to the bolt and bush. For about 2 years or about 6’000 miles I use PU silent blocs which Peter Renou has given me to test. No problem. I look forward to the comments. Regards Karl I think we will have to agree to disagree too , a couple of major points that are being over looked , no one seems to be able to get the correct toe on their vehicles with concentric bushes and a standard track rod , yet my car has had the correct track for 16 years with eccentric bushes and standard track rod no issues . you still require the eccentric pins to fine adjust the vehicles track , it would be crazy to try and adjust the toe accurately by rotation of the eccentric bush on its own . Did Lancia send every Augusta out of the factory with the wrong length trackrod? Why wouldn't Lancia fit eccentric bushes? many other manufacturers do , i cannot answer why they fit them , like i have said previously i cannot answer why they are used in the steering on truck trailers .........but they are. rubber doesn't move uniformly when taking a "set" like you describe , it will bulge rather like a tyre does when it goes flat and generally the center metal sleeve becomes detached from the rubber , yes i have seen silent blocks do this so we can agree on that , However , the block that i've posted a picture of ,the rubber is clearly flat and uniform , nothing has shifted or taken a set . Its a real shame as around 10 years ago we bought some parts from the late Norman Stewarts estate , included 1 brand new eccentric bush which i'm damned if i can find ! Title: Re: Toe-in Post by: Raahauge on 01 November, 2022, 06:23:38 PM I don't imagine that the eccentric rubber bushes would have been any more expensive than the concentric variety and they could easily have been assembled in a more or less neutral position on build. That would have given the factory an easy solution if they were not able to achieve the correct toe-in with the only the eccentric pins.
For general information/interest. I originally installed Igus joints that were 12mm bore and 26mm od ref. KGLM12. (same dimensions as the rubber bush) I have now spotted that there is another in their range with the same bore but with an od of 22mm ref. EGLM12 which is shorter axially and a lower capacity but still robust enough, (3800N compared with 5400N). This would allow me to make eccentric sleeves and thus fix my problem. I agree with Kari that one might have expected a serrated sleeve if the inners were not expected to rotate, expense did not seem to be a constraint. Has anyone seen any discussion from Aprilia or Aurelia owners which have the same arrangement? Mike R Title: Re: Toe-in Post by: Kari on 02 November, 2022, 10:31:44 AM No problems James, the discussion serves to solve technical issues on our Augustas.
I was wondering if the diagonal tyres installed at the factory, required a toe-in of 5 -7 mm, measured at the rim, in order to run straight. That would explain the length of the original track rods. I don't know the length of my original track rod, as it was destroyed in an accident. Then, the (second hand) replacement was deeply corroded on the outside, a fact I didn't like. Then I had a new rod made using the original forks. This rod is 1116 mm. I have measured a toe-in of 2 mm which feels fine with my Michelin X tyres, however the data is only approximate as the rims are not quite true anymore after 87 years. The IGUS joints, which are used by Mike seem to be a good solution. Will they last when subject to water and dirt? Decades ago, I have inherited a tool which serves to measure toe-in. With it, the distance between the inside of the rims can be measured at the 3 and 9 o'clock position. The difference determines the toe-in. If there is interest to build one, I'll be glad to pass on the dimensions. The photo is distorted due to the camera angle, all angles are 90°. Regards Karl Title: Re: Toe-in Post by: Running Board on 02 November, 2022, 11:11:14 AM No problems James, the discussion serves to solve technical issues on our Augustas. Just for future reference , we use a snap on / john bean 3d alignment system in work , very over the top for a pre war car but has one massive advantage , it detects run out on wheels and compensates for this which is really handy with the state of old wheels , some rims we see run out of 3mm+ especially wire wheels , the system can be programmed for any vehicle provided you have your own information to input (toe , camber angles) very clever how it does it , the system is used world wide , hunter use snap on's software on their 3d aligner too so this should be able to be done by any reputable garage with one of these aligners I was wondering if the diagonal tyres installed at the factory, required a toe-in of 5 -7 mm, measured at the rim, in order to run straight. That would explain the length of the original track rods. I don't know the length of my original track rod, as it was destroyed in an accident. Then, the (second hand) replacement was deeply corroded on the outside, a fact I didn't like. Then I had a new rod made using the original forks. This rod is 1116 mm. I have measured a toe-in of 2 mm which feels fine with my Michelin X tyres, however the data is only approximate as the rims are not quite true anymore after 87 years. The IGUS joints, which are used by Mike seem to be a good solution. Will they last when subject to water and dirt? Decades ago, I have inherited a tool which serves to measure toe-in. With it, the distance between the inside of the rims can be measured at the 3 and 9 o'clock position. The difference determines the toe-in. If there is interest to build one, I'll be glad to pass on the dimensions. The photo is distorted due to the camera angle, all angles are 90°. Regards Karl Title: Re: Toe-in Post by: MichaelElsom on 02 March, 2023, 03:18:04 PM At long last it would seem that my car may be back on the road.
In the course of the various jobs I had to change the track rod as the original had got bent - don't be rude enough to ask how.... The axle on the car has eccentric bushes (as does my spare front axle), it is a second series car and as far as I am aware the two track rods started out the same length. My tyres are the Michelin Comfort type. I replaced the pins in the places I had marked before removing them and so hope the track won't have been disturbed. Bearing in mind my general level of incompetence it is quite possible that I haven't achieved that. Having tried to follow the learning on toe-in I feel I ought to get it checked. Please can someone tell me what it ought to be? Title: Re: Toe-in Post by: Mikenoangelo on 03 March, 2023, 01:19:46 PM The very first post on this thread by Mike Rahauge quotes 6-8 mm as per the Uk version of the instruction book, this will be from rim to rim.
Mike Clark |