Thursday, April 19, 2018

Fast pinions for Austin 1800 steering racks

Fred Podner (Bolwell Club - Vic.) writes :-

Austin 1800 Racks and Fast pinions

As you may be aware many of our cars have Austin 1800 steering racks.  In the Nagari when combined with the XW stub axles and long steering arms the result is aa 4 turns lock to lock steering.  Many people have installed “fast pinions” which use the standard rack but the pinions have another tooth.  This increases the speed of the steering to about 3.5 turns lock to lock which makes to possible to catch the rear end ( similar ratio to GTHO’s and Bathurst chargers).  The Austin 1800 rack was also used in Mk7’s but with  many cars with Torana front ends it is hard to know how many cars have the Austin 1800 racks and if the steering needs the increase in speed.  At this stage there has been renewed but only limited interest in the fast pinions but the items have a very high set  up cost so we need to get a reasonable quantity produced and for that we need member interest and we need to understand how big the market is for future stock.  There has been at least 2 production runs that I am aware of in the past so quite a few Nagari’s and only one mark 7 that I am aware of has had the upgrade.  I can only assume that about half the Nagari’s with original racks have had the upgrade ( those with torana front ends run the torana rack  which is not suitable for the is upgrade).  If you have a Nagari and you are not sure if a fast pinion is installed then check the lock to lock  ( 4 turns is standard and 3.5 turns will already have a fast pinion installed- I am not sure about Mk7 standard turns lock to lock).   Installation of the fast pinion usually involves no modifications but the shims may need to be adjusted ( no one has had to do this in my experience).    In the case you have an Austin 1800 rack I would appreciate knowing A/ if you have a fast rack or not  and B/ if you are interested in a fast rack pinion. The first time they were made I think they were $300  the last time I did it they were $150 ( ten years ago ) and this a function of volume  the more interest the lower the cost.  I think if we can get interest this will be the last time around as I doubt I there will be sufficient volume for another production run in the future.  PS if people are aware of good gear cutting companies that may be competitive for small run production please let me know that also.  PS if you move the rack even small changes in position can upset the bump steer assuming you have set it at some point ( correcting bump steer – one of the best things to improve your car if it has not been correctly set up.) Regards Fred Podner

Ken Williams writes :-

G'day Fred,
As you may recall, I fitted one of your fast pinions to my Nagari soon after I bought it and it was the best thing I could have done.  It made little difference to the steering effort required, but in my case, reduced the turns lock to lock from 3.8 to 3.3, which at least gives a fighting chance of catching the rear if (when) it steps out.  Fitting the pinion was easy and required no changes.  I liked it so much I bought another for the rack to be fitted in my Mk.7.  While I probably won't need another, I would recommend the fast pinion to anyone who does not have one. 
Cheers,  Ken.

If anyone is interested in one of these pinions, they are welcome to email me on and I can pass your interest on to Fred.

Rob Wragg writes :-

Hi john
Just in the process of rebuilding the rack in b847 have managed to get a Austin Kimberly rack of ebay don’t know what condition it will be in the current one is held together with steel brackets as the diecast ends are loose on the metal middle pipe section. I think the kimbnerly ones are 4 turns not 3.3 would I need one of these pinions you are talking about. I am not sure what b8 47 is. Reguards rob wragg snr. Ps might just swap the parts over into a shortened Kimberly rack if they are the same. 

Fred responds :-

Right now I am not 100% familiar with Leyland products that’s not to say that you might well be.  So first things first.  The original racks are Austin 1800.  I don’t know the difference to the Kimberly which the body I think was larger, whether the underpinnings are the same as the Austin 1800 or not I don’t know. ( I grabbed an Austin 1100 rack once and got it home to find the outside was different to the Austin 1800, I never checked the internals and that’s on the to do list one day).  I know that some parts are interchangeable between leyland cars but I have never got any conclusive proof of what is interchangeable ( I suspect the Austin 1800 locking rings are the same on some MGB models, have to find an MGB expert to show my locking ring and part numbers to).

Lock to lock is a function of the rack pitch, the length of the threaded position of the rack the rack stops  the pinion the steering arm and any suspension stops. I don’t know what the original Australian Austin 1800 was but think it was quite high ( some very early English  Austin 1800 racks had even higher ratios but they cured this at an early stage and I don’t think any of those racks were fitted to Australian cars).
I recently installed a new rack housing on a Nagari where the housing had come apart.  You need to retain the original rack ( toothed shaft) as it would have been shortened in addition to the housing) unless you plan on machining down the rack internal shaft as well as the housing.  I can send you photos and advice ( a photo of yours would help. Otherwise I am assuming you have the outer sleeve welded onto the original ( as per the repair pictures attached) – I have only ever seen one Bolwell without the outer sleeve ). If you have done set  steer before ensure you can put the rack back in the exact position ( or you will need to redo the bump steer - even a mm change can have a significant effect- I have a trick for this).

If your rack housing ends have worked loose it would have done so for a reason .. please check the rack supports for cracking or flex.  The original “bent” rods aren’t strong enough  This was the problem on the Nagari rack I fixed.  Also check the supports for square and parallel so that bolt up doesn’t stress the housing ends against the housing tube.  Consider triangulating the bracing ( or cross bracing) what engine / sump style do you have?

Doing the front bump steer best thing for under $100 you can do to your car if it hasn’t been setup for minimum bump steer ( assuming you can do toe in and have access to simple measuring equipment ( if you can stretch to borrowing or buying a digital level you can do the castor too ( Best $60 I have spent I use it on everyone’s cars).  I can give you some advice if I know what you can tackle or what tools you have or need.  Happy to chat about what you have done on the car/ plans for the future.  Unless you are confident and experienced I would advise caution when doing work on the rack ends.  Housing repair / replacement will require the rack end/s to be removed, involving resetting the locking rings.  Failure to get the correct engagement will run the risk of the rack ends loosening and coming off resulting in instant loss of steering.  Note replacement of the pinion does not require the tie rods to be disconnected from the rack

I will add you name to the interested list.  At this stage you are the first but I had 2 requests a while ago ( maybe one was yours).  Due to the high set up cost we ae still a long way off getting a viable number produced but I am encouraged as we now have a start.

Cheers Fred

PS I haven’t swamped you with info as I may be preaching to the converted but happy to provide more detail just need to know what will be of help.

No comments: