Badfrog Posted January 27, 2011 Report Share Posted January 27, 2011 (edited) Hi guys, Some blokes at the TCF can't figure out the geometry of their rear suspension on a live axle TR3 or TR4. Would you believe that the french automobile technical review (RTA, local bible for professionnal mechanics) show the leaf with extra thickness (two short bits of leaf spring) on the passenger side? Obviously a nonsense, IMO. I think it's either due to the very incomplete changes done for LHD factory production (no changes in bonnet bulge or handbrake sides) or to a misconception in the RTA manual. What do you think? I told the guy with the reinforced passenger side I would inquire with the TRR. In the mean I advised him to date hugely overweight Oktober Fest Queens in full security. Cheers, Badfrog Edited January 27, 2011 by Badfrog Quote Link to post Share on other sites
stuart Posted January 27, 2011 Report Share Posted January 27, 2011 AFIK US market TR3/3a/4`s had the left side spring with the extra leaf/distance piece added. To cope with the slightly larger framed drivers . Stuart Quote Link to post Share on other sites
Smokey Posted January 27, 2011 Report Share Posted January 27, 2011 The distance piece is correct on the passenger side. The axle runs OVER the spring, so the distance piece LOWERS the car on that side, meaning that the drivers' side is now higher at rest since the two springs are the same rating. When I was redoing my rear suspension, it took me a while to figure this out. Quote Link to post Share on other sites
roy53 Posted January 27, 2011 Report Share Posted January 27, 2011 Stuart do you meen that fatism was around in the fifties? Quote Link to post Share on other sites
RandallD Posted January 27, 2011 Report Share Posted January 27, 2011 Yes, passenger side is correct - though even if we were all a little weight-challenged in the US I'm surprised the weight of the driver really caused the car to tilt all that much! Quote Link to post Share on other sites
Smokey Posted January 27, 2011 Report Share Posted January 27, 2011 I believe that the rationale for the spacer was two-fold: the driver would be on his own most of the time (this was the 1960s, so it was likely a he) and when there were two aboard, the driver likely weighed more than the passenger. And maybe any spirited driving, when a level car was deemed more important, occurred mostly solo. TR4s did not have an anti-sway bar as standard, so "level" was relative anyway. So a LHD TR4 tilted about 1/2" to the right when it rolled off the assembly line. Quote Link to post Share on other sites
Alec Pringle Posted January 27, 2011 Report Share Posted January 27, 2011 The unequal springs were a bit of an oddity, paradox even - they only appeared from TS26904, rear springs had been identical previously. Then disappearing from rhd cars at CT2828 in favour of equal springs once again, but continuing on lhd cars until CT23382 before reverting to matched springs. There must have been a logic, but what ? Cheers, Alec Quote Link to post Share on other sites
LGFromage Posted January 27, 2011 Report Share Posted January 27, 2011 I reckon that a harder rear spring on the drivers side (RHD) was specified to reduce the effect of torque reaction on a solid rear axle. That is the tendency for the driver's side rear wheel to lift on acceleration. In the UK a fat driver would futher help to reduce this effect though in the US the opposite would be true. It is just a thought but it seems reasonable. Tim Quote Link to post Share on other sites
MadMarx Posted January 28, 2011 Report Share Posted January 28, 2011 My TR4 has equal springs and two shims as a spacer on the right side (LHD car). Quote Link to post Share on other sites
Steve Priest Posted January 28, 2011 Report Share Posted January 28, 2011 Reading this post, I wonder if this could be the problem on my car. It's a US import TR4 that's been converted to RHD. The rear passenger side does sit about an inch or so higher than the driver's side. I did hear about this a while back but after a cursory check couldn't see any obvious difference in the springs. What exactly do I need to look for to tell if the springs are different? Is it just a case of extra leaves or spacers, or do I need to get my tape measure out? Steve Quote Link to post Share on other sites
vivdownunder Posted January 28, 2011 Report Share Posted January 28, 2011 Steve, look above the top leaf of the spring, where it clamps between the axle housing and the shocker arm plate. There were two short sections of spring (as said, only on the pass side) that acted as a lowering block. They were held in place on top of the spring by the centre bolt. It has been speculated this caused each spring to have a different rate, but not so. The lowering block was contained within the clamp, so it had no effect on the spring. Manuals all say the TR2-4 spring rate was 128 in lbs for both leaf springs. Probably a gimmick about it levelling out the car when travelling one up, as driver weights vastly differ. Or maybe to level up the headlights ?. Regards, Viv. Quote Link to post Share on other sites
Badfrog Posted January 28, 2011 Author Report Share Posted January 28, 2011 Smokey, I believe you are right. will test, will tell. Cheers, JFS Quote Link to post Share on other sites
Steve Priest Posted January 28, 2011 Report Share Posted January 28, 2011 Steve, look above the top leaf of the spring, where it clamps between the axle housing and the shocker arm plate. There were two short sections of spring (as said, only on the pass side) that acted as a lowering block. They were held in place on top of the spring by the centre bolt. It has been speculated this caused each spring to have a different rate, but not so. The lowering block was contained within the clamp, so it had no effect on the spring. Manuals all say the TR2-4 spring rate was 128 in lbs for both leaf springs. Probably a gimmick about it levelling out the car when travelling one up, as driver weights vastly differ. Or maybe to level up the headlights ?. Regards, Viv. Thanks Viv - will take a look. If it does turn out to be the case on my car and I want to try and level it out, could I remove the extra bits or would I need to replace the springs? Thanks for your help. Cheers, Steve Quote Link to post Share on other sites
vivdownunder Posted January 28, 2011 Report Share Posted January 28, 2011 Steve, for safety sake I'd take a leaf spring to a spring works to remove the lowering block sections. It would need a shorter centre bolt. No problem re-using the spring, but you may need shorter U bolts on that side. Regards, Viv. Quote Link to post Share on other sites
Smokey Posted January 28, 2011 Report Share Posted January 28, 2011 Hi Steve, I believe you can just move the shims over to the other side. As Viv indicated, the shims have a hole in the middle that fits on the centre bolt of the spring. When I was rebuilding my rear suspension, I thought the shims were on the wrong side until I realized that the spring is BELOW the axle. The springs rates are the same on each side, and as Viv and MadMarx said, the shims do not affect spring rate, only the height of the body relative to the axle. The driver's side should sit higher when the car is empty. Quote Link to post Share on other sites
MadMarx Posted January 28, 2011 Report Share Posted January 28, 2011 as far I remember these shims are fixed to the spring. Maybe bolted? Quote Link to post Share on other sites
Badfrog Posted January 29, 2011 Author Report Share Posted January 29, 2011 (edited) Yes, they easy way is to swap leafs. Thanks to everybody for their help. Quoting Alec: "The unequal springs only appeared from TS26904, rear springs had been identical previously. Then disappearing from RHD cars at CT2828 in favour of equal springs once again, but continuing on LHD cars until CT23382 before reverting to matched springs. " Here is my conclusion: Moss sells a unique ref. for TR2, TR3 and TR4 (to CT 23382. This pair contains spacers for the PASSENGER side. Moss reasons are probably stock simplification. Moss: http://www.moss-europe.co.uk/Shop/ViewP ... dexID=2357 1) So, basic setup : 2 leaves ref. 208636 2) To rebuild the old system (TR2, TR3 et TR upto CT2828) with different leaves but no spacers: one driverside leaf ref. 208636 for the passenger side and one harder driverside leaf ref. 301017 for the driver side. Badfrog, you live, you learn. Edited January 29, 2011 by Badfrog Quote Link to post Share on other sites
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