Dunloprabbit Posted April 4 Report Share Posted April 4 Hi, I have a Herald 1200 Coupe 1961 on a Mk 1 chassis and the Steering Rack needs replacing. I have purchased a new Rack from Rimmers which fits all models except the 948cc (which is now only available as an exchange unit and I don’t really want to go there) When comparing the original rack to the new one there is a difference in length (as per picture). I can correct the length of the rack by not screwing the ball joints on the ends of the track rods as far, and I believe there is enough length to do this. The fixing holes in the chassis would need to be adjusted by about 5mm either side to accommodate the new rack which could be secured by solid mounts or rubber bush mounts. My main concern is that by lengthening the track rods to fit this will alter the geometry and could cause issues (bump steer) Has anyone tried this conversion before? If so, did you experience any unwanted handling issues. Any advice would be greatly appreciated. Hugh Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 4 Report Share Posted April 4 providing you keep each track rod the same length and set the Toe to the book and that spec would be static laden with 150lbs on each seat you will have the designed handling. and whilst its laden check the rear toe easy to set the toe Link to comment Share on other sites More sharing options...
Dunloprabbit Posted April 4 Author Report Share Posted April 4 Thanks very much Pete for the information. I may well give this new rack a try and see how it goes. Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 5 Report Share Posted April 5 there is some weird ideas that one size fits all dont know why a 948 is differing but certainly 4cyl and 6 cyl racks have different ratios the 6 cyl input shaft has a groove machined in the spline to identify the slower rack some may like a 4cy ratio on a 6pot but you will need 6 shreaded wheat to park the engine ground anchor Pete Link to comment Share on other sites More sharing options...
johny Posted April 5 Report Share Posted April 5 Didnt the 948 come with front drum brakes so the suspension might have been different and use a rack to match? Link to comment Share on other sites More sharing options...
Dunloprabbit Posted April 5 Author Report Share Posted April 5 I think that whether fitted with drum or disc brakes doesn’t affect the steering rack length as any difference between the two is on the outside of the vertical link. It would appear the difference in the rack length originates from the 948/1200 Coupe’s having a track of 4ft 1” as opposed to the rest of Herald range having a track of 4ft. Link to comment Share on other sites More sharing options...
johny Posted April 5 Report Share Posted April 5 Possibly but it looks like there are different vertical links and steering arms for front disc and drum versions of the Herald... Link to comment Share on other sites More sharing options...
Casper Posted April 6 Report Share Posted April 6 Although I.m not sue whether it is relevant to this specific issue, I believe the Mk 1 chassis racks/cars had a dofferent lock to lock ratio. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 6 Report Share Posted April 6 21 hours ago, johny said: Possibly but it looks like there are different vertical links and steering arms for front disc and drum versions of the Herald... Different vertical links for early and late models, but the early ones used the same upright for drum or disc brakes. I think the actual steering arm is the same size in both. I can't find any difference in steering racks, the track certainly differed between 48 and 49 inches but none of the manuals I have make any reference to different sizes, procedures or fitting - I'm wondering is this new rack has been built up using the spec from another model, and no-one has informed the vendor / manufacturer? It wouldn't be the first component manufactured incorrectly but no-one ever told the maker, and oftimes they're glad to be told so they can correct their assembly. Link to comment Share on other sites More sharing options...
Dunloprabbit Posted April 6 Author Report Share Posted April 6 Many thanks for you input. Just to add a bit more information. This new rack I’ve purchased is listed as part No. 305932 (All Other models – Standard) on Rimmers web site. The other rack they list is No. 305458R and is for model Herald 948. The measurements of this new rack, overall length and the distance between the flanges, are the same as a NOS part No. 305932. So although it is a pattern part I believe it’s been made correctly and it would be fine if you needed that number. The part number which could be relevant to my vehicle is 305050, which is longer available. This is from the spare parts catalogue Herald 1200 Saloon & Coupe (1st Edition). Hugh Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 6 Report Share Posted April 6 Excellent - thanks for the update!! I (think) I have an early rack from a MK1 chassis in the garage loft, must just compare it with the later versions for curiosity's sake. Hopefully I haven't already used it on a later chassis and not realised... I think the early racks are 3.6 turns lock to lock as opposed to the later 3.7. Link to comment Share on other sites More sharing options...
Dunloprabbit Posted April 8 Author Report Share Posted April 8 Many thanks everyone for your input. I’ve decided to go ahead and fit the new rack. I will let you know how it goes in due course. Hugh Link to comment Share on other sites More sharing options...
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