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| Rack teeth count https://www.ausmini.com/forums/viewtopic.php?f=2&t=101884 |
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| Author: | eightfifty [ Sat Jun 10, 2023 6:54 pm ] |
| Post subject: | Rack teeth count |
Readers, I have been asked to recondition a number of steering racks and have come across something a bit puzzling. We've all discussed in previous posts the issue of AYA6001 and AYA6001A which concerns the inclusion of a pinion spacer, different drive gear pinion, and different casting to accommodate these, but I've now noticed that some racks that present themselves have a different number of teeth on the rack. These rack assemblies are all AYA6001A with the pinion spacer, but some have 15 teeth, and some have 20 teeth. The rack lengths are the same in both cases. I've seen this now about 4 or 5 times. A picture is shown below. Naturally when something like this pops up I check a drawing or two to see if I can find a reason, but all drawings for AYA6001 show 15 teeth on the rack. However, what I have noticed is that a Morris 1100 steering rack drawing shows 20 teeth, but it is a longer rack over all. So, it is my conclusion that when the 1100 was being manufactured, Steerings Pty Ltd (no doubt owned by Cam Gears), decided to add extra teeth for all the racks (Mini and 1100) and simply chopped off the felt bush end and threaded it to suit the vehicle application. This probably would have saved them producing two separate parts (for cutting of the rack teeth). If any of our more experienced practitioners have any other idea or suggestion, I'd be interested to hear it. Also pictured below is a tie rod that came off one of the proposed items for rejuvenation. I thought it was either a novel way to adjust the toe in, or at least shows what might happen if you hit the kerb too hard. Regards Tony |
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| Author: | drmini in aust [ Sat Jun 10, 2023 8:59 pm ] |
| Post subject: | Re: Rack teeth count |
I always understood that the 6001 rack was a short version of the M1100 rack. In fact I have assembled many over the years with M1100 tierods to give more rod end engagement for negative camber race etc Minis. I've never counted the teeth though!! 'Diecast' on here used to work at Cam Gears if he spots this thread he might enlighten us. 
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| Author: | Bill B [ Sun Jun 11, 2023 3:17 pm ] |
| Post subject: | Re: Rack teeth count |
For clarification: will the number of teeth on the rack affect locating the centre position of the rack for reassembly with its pinion? I guess that the centre is still midway between the LH and RH end stops - just that some teeth won't reach the pinion at all on the 20 tooth rack? |
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| Author: | eightfifty [ Sun Jun 11, 2023 5:50 pm ] |
| Post subject: | Re: Rack teeth count |
It's something I did wonder at first, but you are correct to say that the extra teeth do nothing at all for the Mini application, and they are all towards the felt bush end. The two racks are the same overall length. So now we have three versions of AYA6001. The first type with no pinion spacer, the second type with a pinion spacer, and a third type with pinion spacer and extra rack teeth - all the same part number (although P&A renamed the last two versions AYA6001A). I've also noticed two other part numbers for these Australian made racks, AYG6008 (longer rack length, otherwise identical to 6001A) and AYK6082 (different ball housings otherwise identical to 6001A). Both these introduced mid way through 1967. All the parts books I have say to use AYA6001A as a replacement rack for the Mini range. However, there is a note in my files that suggests AYG6008 (with about a 0.6" longer rack length and hence greater travel between stops) applies to YDO6 which is of course Cooper S. I am still checking the application of this part number. |
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| Author: | diecast [ Wed Jun 14, 2023 10:00 pm ] |
| Post subject: | Re: Rack teeth count |
Hi All As Doc said, I used to work for CamGears (TRW Products in Marrickville). By the time I got there in the late 1980's, they had stopped making mini/moke steering assemblies years before and any leftover bits had already been sent to the skip bins. No, I can't shed any knowledge on rack teeth counts. Cheers Diecast |
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| Author: | eightfifty [ Wed Jun 21, 2023 7:13 pm ] |
| Post subject: | Re: Rack teeth count |
Thanks Diecast for your message. You might be interested to know that the Cam Gears drawings (at least early ones) are stamped "Steerings Pty Ltd" of Gardeners Rd Mascot. Evidently they must have moved as business picked up in the 60s. I've written up an article on steering rack reconditioning process which is now available on my web page under "Articles" at http://www.leylandaustralia.com.au. I hope interested readers will find this useful, and would be happy to discuss any aspect of it. I've also read the article written by Chris Katiskas which is referred to in another recent post from the reader in Guam who was wondering if he should recondition his own rack. Now, Katsakis is a knowledgable guy, but this article contains several errors which could be potentially dangerous and I feel I should mention them here in case someone follows his advice. In this article, there is an apparent ignorance of the presence of a pin which does through the lock ring and ball housing in to the rack shaft. Just going on what he shows, Katiskas has just sheared off the pin completely while undoing the ball housing apparently believing that the only connection between the lockring and housing are the stakes on the surface between them. But these stakes are to stake the pin so that it doesn't fall out. You can see the sheared off pin in one of his photos, and then a semi-circular hole through the thickess of the ball housing in another photo which goes unremarked. In later reassembly, the need to re-pin the two parts to the rack is not mentioned. As well, the procedure of setting the ball housing preload is totally wrong. Sorry Chris, but you must have been having a bad day on that one. Regards, Tony Cripps |
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| Author: | timmy201 [ Wed Jun 21, 2023 9:01 pm ] |
| Post subject: | Re: Rack teeth count |
Hi Tony, Was there a particular date or external measurement to identify the 6001 rack compared to the 6001A? I have a 6001 rack dated 23/09/75, it has the annular groove for the pinch bolt and 20 tooth rack Edit: I have found the diagram in the link below, the presence of the spacer between the pinion and top bearing would make this a 6001A rack? I have been able to source some spacers HYL3758 which should be correct for the 6001A rack? viewtopic.php?p=1069274#p1069274 |
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| Author: | eightfifty [ Wed Jun 21, 2023 10:12 pm ] |
| Post subject: | Re: Rack teeth count |
Externally, the racks are identified by the amount by which the pinion sticks out the top of the housing, the AYA6001A having a reduced length of pinion showing compared to AYA6001. Internally, the pinion itself can be identified by the presence or absence of an undercut just above the gear teeth. On an AYA6001, there is an obvious undercut. in AYA6001A, there is no undercut, and if you look carefully, you can see that the diameter of the pinion is 10 thou greater than the rest of the pinion shaft for a very small length just above the gear teeth. AYA6001A requires the ring spacer, and also requires external spacers on the rack to keep the rack square with the body when fitted using the U bolts. It is important that the ring spacer, when placed on the pinion, is such that there the chamfer on the inside diameter lower face sits on the pinion teeth. Some spacers have chamfers on both upper and lower surfaces and so either way is OK, some have just one chamfer, and if this is put in up side down, the sharp edge of the spacer will dig into the pinion corner with the teeth and cause a weakness. The presence of the ring in your picture indicates AYA6001A, but I can't see the detail of the pinion at the top of the teeth to know if this is the correct one. The AYA6001A was introduced in early 1967. The annular groove was changed to a tangential groove in late 1973 so it is possible to have AYA6001A with either type of pinion groove. |
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| Author: | timmy201 [ Thu Jun 22, 2023 8:55 am ] |
| Post subject: | Re: Rack teeth count |
Is there a measurement of the pinion “stick out” to compare? Mine is approx 1.06” and the drawing in the other thread suggests the 6001 is approx 1.35-1.40 |
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| Author: | eightfifty [ Thu Jun 22, 2023 9:36 am ] |
| Post subject: | Re: Rack teeth count |
Just looking at your picture, this is an AYA6001A. The measurement should be 28mm for 6001A as compared to about 35 mm for 6001. The picture below shows the different types of pinion. It is important not to mix them up between 6001 and 6001A. The pinions are both the same overall length. it is the height of the housing that causes the amount sticking out to be different. EDit: OK now I see your problem. The picture below shows the absence of the undercut, but the part actually shown is from FAM7306. This pinion is shorter in overall length compared to AYA6001/6001A. You can tell the difference from the AYA6001 pinion not only because of the overall length, but also the thicker part down the other end where it sits in the lower bearing (see left side of upper picture below). However, the pinion you show in your picture has a "thin" bearing area and so is not the same. Perhaps if possible you could measure the overall length of your pinion and also confirm that the AYA6001 is stamped on the pinion housing? Drawings indicate the following: AYA6001 - no spacer, with undercut AYA6001A - spacer, no undercut, circumferential groove AYA6001A - spacer, no undercut, tangential groove All pinions the same overall length. This also agrees with my observations of actual pinions, but I don't have a loose AYA6001A pinion wi th tangential groove to show. The one with the tangential groove I have is 3mm shorter in overall length as mentioned above, and I think it came out of a different rack (not sure what). |
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| Author: | timmy201 [ Thu Jun 22, 2023 9:59 am ] |
| Post subject: | Re: Rack teeth count |
Thanks for that Tony, I’ll have a closer look at it all tonight |
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| Author: | eightfifty [ Thu Jun 22, 2023 10:22 am ] |
| Post subject: | Re: Rack teeth count |
Well i can clear up one question. The picture above which I show as AYA6001A is actually a late UK pinion from FAM7306. However, it is the absence of the undercut that was the most important thing. I'll edit the picture so that it is correct. The pinion for FAM7306 has the thicker bearing surface at the lower end, and is shorter in overall length compared to AYA6001/6001A, but I do not know what measurement it will give if put into an AYA rack. The only mystery to me here is that in your picture above which shows the pinion loose, this does not appear to have the thicker bearing surface and so it looks to me like it is an AYA6001/6001A pinion. This should give a meaurement of 28mm, not 1", when placed into a 6001A housing. |
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| Author: | timmy201 [ Thu Jun 22, 2023 11:09 am ] |
| Post subject: | Re: Rack teeth count |
Mine was loosely assembled and is at 1.06” which is approx 27mm |
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| Author: | diecast [ Thu Jun 22, 2023 2:41 pm ] |
| Post subject: | Re: Rack teeth count |
Replying to eightfifty's post yesterday. I was aware of them being located at Caringbah/Taren Point for a number of years, before relocating to Marrickville. I've no knowledge of them being at Mascot - you learn something every day. |
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| Author: | drmini in aust [ Fri Jun 23, 2023 3:55 pm ] |
| Post subject: | Re: Rack teeth count |
Loosely related... I think a pity of all this is the 9/16 pinion bearings for all Mini racks are unobtainable and have been so for years. This despite the fact that the Chinese made racks still use them. I know this because I destroyed one to salvage its bearings. 
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