Mudder Posted January 26 Share Posted January 26 Hello all, I've been lurking on the Seven forum for a while (see intro, General Sevens Disc.) and finally pulled the trigger on a 1999 Caterham S3. The car has been sitting for a while and I decided to give it a good overhaul. The suspension was first on my list and I wasn't surprised to find some of the bushings in questionable shape. The A-Frame/differential housing bush was in bad shape and some of the other ones (front) were ever so slightly deformed. The press fit ones show slight signs of dry rot. Well, I decided to replace them all. And here comes my first question: Tony Weale, in his Lotus Seven book (p.87) talks about replacing the front suspension Y9s with Y16s. Since they are shorter he mentions a spacer which needs to be fitted between the bushing halves. I contacted Caterham Parts but never got a reply in regard to a part number. Do any of you know which exact part number this is, or does anybody know what the correct dimensions are. Thank You! Link to comment Share on other sites More sharing options...
MV8 Posted January 26 Share Posted January 26 (edited) Don't know. I expect it would be the small od of the Y16 bush, id of the inner sleeve, with length determined by taking the control arm tube length minus the depth measured with one bush held in place lightly, multiply that by two, minus 1/8-1/4 for some preload when installed. Edited January 26 by MV8 Link to comment Share on other sites More sharing options...
IamScotticus Posted January 27 Share Posted January 27 (edited) Three more details about your 7 that need to be known. Metric or Imperial? Live axle or DeDion? Because of the changes to chassis, these details must always be divulged. I never found the exact OEM applications for the various bushes, but I have come close enough to know they are mostly Triumph/Morris/ Leyland parts for the Imperial Live Axles. Also, I believe some of those bushes need to be cut short to fit. You will need a hydraulic press Here are my notes on bushes: BUSHES GENERAL ********************** Y16 (tapered)Front Suspension Link Bush AUSTIN FROGEYE SPRITE MG MIDGET & 3000 equiv: MRM220 03471R MGB AH SPRITE MK3 AH 3000 MK3 AH SPRITE MK4 CROSS REF: 2A4027 2A4163 330-520 Y16 88G274 Rover 88G274 Length: 17mm Wide end diameter: 29mm Narrow end diameter: 23mm Centre hole diameter: 12mm Fitment to wishbones and anti roll bar (8 per car) MOSS pn 330-520 *********************** Y9 (Tapered)Control/Trailing Arm Bush EAN# 5016593126077 Cross Ref: Rover 8G621 281-405 Y9 MG Midget 1/64-12/79 MG MGC/GT 1/67-9/69 MGB all TAXI FX4 1/59-12/89 TAXI FX4R 1/82-12/85 ROVER A60 CAMBRIDGE 1/62-10/69 AUSTIN HEALEY BN 1&2 53-56 BN 4&6 SPRITE MK3 3/64-10/66 SPRITE MK4 3/66-10/71 3000 MK3 3/64-10/71 Length: 23mm Wide end diameter: 29mm Narrow end diameter: 23mm Centre hole diameter: 12mm Fitment to wishbones and anti roll bar (8 per car) MOSS pn 282-305 ************************* 636 (B636/2) Length : 3.5mm (1 3/8") Total diameter : 2.7mm (1 1/16") Opening diameter : 1.3mm (1/2") ************************** B636/2 Short (S636/2A) Internal diameter: 13mm External diameter: 27mm Length: 26mm ********************* B6362 Short (B*636/2A) Internal diameter: 13mm External diameter: 27mm Length: 26mm *same as S636/2A with a "B". Typo?) ************************** RB636/2 Wishbone, A frame, Radius arm Internal diameter: 12mm External diameter: 27mm Length: 34mm **************************** BP636/2 Top Link Peened Length : 3.5mm (1 3/8") Total diameter : 2.9mm (1 1/8") Opening diameter : 1.3mm (1/2") ***************************** E2030 Radius Arm Small Length: 31mm Centre hole diameter: 9mm Outer diameter: 19mm ******************************* E2030 Short (S2030A) Length: 26mm Centre hole diameter: 10mm Outer diameter: 19mm ******************************* Bush Eyelet Front (E4-B46-608C) 35MM ******************************* Steering Column Bush (B8466) ****************************** Suspension Bush Kit Live Axle (BU03K) **************************** FRONT Tiumph track ends GSJ158 Lock nut 128022 QR1572A TRACK ENDS ADJUSTABLE ADJ TRE (SKU)CMB1500 TRACK ENDS NON ADJUSTABLE MOSS # 668-040 $16.89/PR Rimmer Bros # GSJ158Q mevspares.co.uk gt6mk2.con JWM Rose joints (don't use) **Triumph trunnion lube EP90 hypoid oil ** Trunnion assembly, washer with larger holes is set on inside ** zerk size 1/4-28 UNF Edited January 27 by IamScotticus 1 1 Link to comment Share on other sites More sharing options...
Mudder Posted January 27 Author Share Posted January 27 MV8, IamScotticus Thanks for your replies! The car has a Live Axle and it was imported as a full knockdown kit to the U.S. back in 1999. I remember checking the frame stamping next to the roll bar mount and it identified as an Arch chassis. Because of that I was under the impression it was an imperial frame...... but I just found out that there is a cross member somewhere in the wheel arch area which makes the identification more definitive. Any other clues?? I am traveling until Tuesday of next week and won't have access to the car. I'll report back ASAP. Cheers Link to comment Share on other sites More sharing options...
MV8 Posted January 28 Share Posted January 28 (edited) I expect you have bonded bushes in the front trunnions, located with set screws instead of the traditional triumph hardware. An indicator is a cross brace on the lower front control arm legs. The distance between the trunnion flanges on the arms is narrower. If water is not kept well displaced from the trunnion, the upright can rust to make a abrasive paste that can sand/wear down the trunnion threads a little with each turn of the steering wheel. Y16s on the live axle A frame have are supposed to have a 1/2x3/4 (x1/16?) washer between them. There should be a steel washer between the bushes and flanges if they are slotted to prevent the bushes from extruding and being cut by the flange slot. Edited January 28 by MV8 Link to comment Share on other sites More sharing options...
Mudder Posted January 28 Author Share Posted January 28 I found setscrews on the trunnions, however the bushes were not bonded. I took the uprights apart just to clean out the old grease (duh) and replace it with SAE90. I am quite sure everything was stock Triumph. The only thing which surprised me was the setscrews. As soon as I am back at my workshop, Ill check the trunnion flange distance in comparison to the trunnion repair set (no setscrew), I have lying around. Yes, I found the small washer when I pulled the bushes on the A frame/differential. What surprised me somewhat is that none of the press-fit bushings (Front and Rear suspension) appear to be centered in there respective location. They are flush on one side and slightly protruding (1/16") on the other. Link to comment Share on other sites More sharing options...
MV8 Posted January 28 Share Posted January 28 It sounds like someone swapped out the hardware (maybe to fit the older control arms?). Do you have the tube added across the legs of the control arms? Here is the correct trunnion with bonded bush from cat: https://caterhamparts.co.uk/other/3992-trunnion-rh-live-axle-1998-onwards.html Link to comment Share on other sites More sharing options...
Mudder Posted January 28 Author Share Posted January 28 Thanks for the link!! The inserts of my trunnions are completely removable, but have a setscrew which arrests the inner metal sleeve. I have the L/H front suspension apart and will attach pictures as soon as I am back at my shop. The picture out of Tony Weale's Seven book perfectly resembles my front suspension Link to comment Share on other sites More sharing options...
MV8 Posted January 28 Share Posted January 28 (edited) It looks like your control arms are correct for the traditional hardware shown. The bonded bush arm would add a longitudinal tube from chassis pivot to chassis pivot. To prevent dynamic caster changes from lateral anti-roll bar movement in bump and roll, some have added clamp collars around the anti-roll bar inboard of the chassis mounts and plastic thrust washers. Edited January 28 by MV8 Link to comment Share on other sites More sharing options...
Mudder Posted January 28 Author Share Posted January 28 Thank you very much for all this information!! I am learning! 1 Link to comment Share on other sites More sharing options...
jbcollier Posted January 29 Share Posted January 29 Some GL5 rated gear oils are corrosive to brass. Make sure you use GL4 rated gear oil in your trunnions. 1 Link to comment Share on other sites More sharing options...
Mudder Posted January 29 Author Share Posted January 29 Thanks for the heads up! Link to comment Share on other sites More sharing options...
Mudder Posted January 30 Author Share Posted January 30 GL 4 it is. Just checked! 1 Link to comment Share on other sites More sharing options...
Mudder Posted February 2 Author Share Posted February 2 It's an Imperial frame (AM99), at least from what I could research. Arch Manufacturing >>> AM 99; cant really decipher the chassis number underneath. There are long diagonal support tubes in the engine bay and I couldn't find a single tube in the back which transitions from a square profile to a round one. Link to comment Share on other sites More sharing options...
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