mark_smugglers Posted May 29, 2017 Report Share Posted May 29, 2017 Hi What is the correct length of standard shocks when fully extended? I know that Richard young had issues with some recently that extended too far, jamming the steering when fully extended. I've just bought some new ones from and wanted to check. . ( my original ones are both seized so there's no way of comparing them). Thanks Mark Quote Link to post Share on other sites
barkerwilliams Posted May 29, 2017 Report Share Posted May 29, 2017 (edited) Mark, It depends on the length of spring you have fitted. After reverting my springs to original lengths I had to have new rear shocks made 1" longer than standard as they "topped" out. A "catalogue" length is a good starting point but may be incorrect for your setup. I do not know of a correct means to determine the right length, but the shock absorber should have more compression available after the suspension hits the rubber limit stop. It should also have more extension available if the wheel is raised from the ground (wheel dangling not jacked up!!) and the spring extends fully. So measure the dynamic range of the two fixing points of the shock and that must be within the operating range of the shock. Incidentally I found custom length shocks are readily available at no additional cost to stock items. Alan Edited May 29, 2017 by barkerwilliams Quote Link to post Share on other sites
RogerH Posted May 29, 2017 Report Share Posted May 29, 2017 Hi Mark, Richard raised quite a complicated thread that needed some looking into. He found his replacements (apprx 330mm) were 30mm longer than his original 'standard' strut - apprx 300mm Indeed it did cause the steering to become stiff. However if you read all of his thread it may have been the repro top ball joint that was the problem there. I sent this query to Moss and they initially quarantined all the stock (quite a lot of struts) whilst they investigated. They found that somewhere along the way the supplier/manufacturer did start to make them longer oops! After a fair bit of testing they found that if the top ball joint was of decent quality then the extra length made no difference to the suspension assembly. The quarantined stock was put back into service. Any new stock replacement will be to the original length. Regarding the top ball joint - I don;t know any history of these items but they appear to work under normal conditions. I would suggest not to buy repro if you can help it. Have a second thought about cheap items - they are cheap for a reason. Roger Quote Link to post Share on other sites
Z320 Posted May 31, 2017 Report Share Posted May 31, 2017 (edited) Hi, my TR4A IRS came with black "no name" shock absorber, max. 309 mm long, since years I drive used Spax, bought from a friend, max. 310 mm long, I got Monroe Radial Matic R2548 NOS in my workshop, max. 302 mm long, also Armstrong 62-1390 bought from the USA as NOS, max. 305 mm long. All do not limit the deflection of the front spring on my car when I lift it, therefore they should be max. 300 mm long, better 295 mm, as Roger wrote. The deflection is limeted on my car by the upper wishbone on the spring dome. No problem, my old top ball joints and track rod ball joints are able to angle wide enought. My new ones too. Problems began with my new steering rack one year ago! On the old one the track rods have been able to angel 37°, on the new rack only 24°! Before I lift the car I always have to put the track rod ball joints from the tie rod lever to aboid damage. That´s annoying! The shock absorbers should be more 10-15 mm shorter, probably I solve this with 4 DIY shock absorber brackets. Ciao Marco Edited May 31, 2017 by Z320 Quote Link to post Share on other sites
Waldi Posted June 1, 2017 Report Share Posted June 1, 2017 Mark, I had the same issue as Richard, my new shocks came from TR Shop, they were 330 mm long, the old ones 300 mm. With the new shocks, the trunnions contacted the spring pan in the lower position ( wheels hanging in the air). I think this gave a very high lateral force on the trunnions that then caused the high friction on my steering. TR Shop said "they sold hundreds with no issue". The number stamped on these 330 mm long shocks is S-600772. MP11 13 B 10 2. I raised a PQI form to adress this issue and recommend we all do this if we feel we are sold wrong spec parts ( if we cannot resolve it ourselves with the supplier). Roger & fellows handled this very well, end I was impressed with the effort they took. I finally did send the shocks back for a refund and ordered Konis (80-1784) from a supplier in Germany. They measured same length as the old original(?) ones. I do not know if my upper ball joints were replaced in the past, I installed one new and the other was in good order, son't know if this was to original specification. Both sides jammed. Regards, Waldi Quote Link to post Share on other sites
mark_smugglers Posted June 6, 2017 Author Report Share Posted June 6, 2017 Thanks all. Looks like I will be sending hem back then. Quote Link to post Share on other sites
Richard Young Posted June 6, 2017 Report Share Posted June 6, 2017 (edited) Mark, Just to clarify Roger's comment re. top ball joints.Mine were from Rimmers, so I presume they would have been of decent quality and probably same as what Moss stock.Interesting that Moss state that there is no issue if they were of decent quality. At the end of the day, the problem arose simply because the shocks were 330mm and should have been 300mm and the extra drop was causing the top ball joint to bind and cause the stiff steering issue. Yep, send them back.I chose GAZ, more expensive but problem solved. regards Richard. Edited June 6, 2017 by Richard Young Quote Link to post Share on other sites
RogerH Posted June 6, 2017 Report Share Posted June 6, 2017 Hi Folks, to support Richards comments. The strut should be apprx 300mm. Any longer and there is the chance of the top ball joint complaining. When the struts became longer is a mystery. However Moss have instructed their supplier to sort out the length. Roger Quote Link to post Share on other sites
mark_smugglers Posted June 6, 2017 Author Report Share Posted June 6, 2017 Thanks. Mine were from TR shop- am sending them back. Rimmer's told me today theirs are 330mm Moss told me today theirs are 304mm- will query that with them tomorrow given your input. Thanks again all. Quote Link to post Share on other sites
RogerH Posted June 6, 2017 Report Share Posted June 6, 2017 Hi Folks, regarding these longer struts - these are the very basic struts, not Spax or Koni. Do you really want to run with these. Roger Quote Link to post Share on other sites
mark_smugglers Posted June 6, 2017 Author Report Share Posted June 6, 2017 Thanks Roger. To be honest, I will leave the debate on different types of shock absorbers to others and to a separate post. All I was after was a like for like replacement of the originals and I'm just a bit surprised that both Moss and Rimmer's seem longer. I'm in no great rush so if Moss sort out their supplier I may wait for that. Thanks again for all your help. Quote Link to post Share on other sites
Z320 Posted June 6, 2017 Report Share Posted June 6, 2017 Hi, another interesting question, still not asked, is how short they must be full compressed. Years ago, before my Spax, I ordered very cheap black ones from a GB-suplier. - max. 334 mm long - with no limitation of the deflection. - min. 232 mm long - with no limitation of the compression I sent them back and got the usual comment as answer. Ciao Marco Quote Link to post Share on other sites
mark_smugglers Posted June 7, 2017 Author Report Share Posted June 7, 2017 Thanks Marco. How short should they compress to? Mine are seized so I have no way of telling! Quote Link to post Share on other sites
RogerH Posted June 7, 2017 Report Share Posted June 7, 2017 Hi Mark, originally there should be an upper and lower bump stop. The damper, whether a lever or a strut, should have plenty of travel left after the TA has stopped at the bump stops. You need to measure this bump stop gap and see if the strut is acting accordingly. Roger Quote Link to post Share on other sites
stuart Posted June 7, 2017 Report Share Posted June 7, 2017 Hi Mark, originally there should be an upper and lower bump stop. The damper, whether a lever or a strut, should have plenty of travel left after the TA has stopped at the bump stops. You need to measure this bump stop gap and see if the strut is acting accordingly. Roger Thats on the rear Roger, I believe this thread is concerning fronts. Stuart. Quote Link to post Share on other sites
RogerH Posted June 7, 2017 Report Share Posted June 7, 2017 Thats on the rear Roger, I believe this thread is concerning fronts. Stuart. oops!!! This last week-end I was with somebody that had the back end of the trailing arm break off. My mind is on that track. Ignore my post above. Roger Quote Link to post Share on other sites
stuart Posted June 7, 2017 Report Share Posted June 7, 2017 oops!!! This last week-end I was with somebody that had the back end of the trailing arm break off. My mind is on that track. Ignore my post above. Roger Presumably had an incorrect tube shock conversion fitted then? Stuart. Quote Link to post Share on other sites
RogerH Posted June 7, 2017 Report Share Posted June 7, 2017 Hi Stuart, it was a GAZ strut and hadn't been there long. Roger Quote Link to post Share on other sites
Alec Pringle Posted June 7, 2017 Report Share Posted June 7, 2017 " I will leave the debate on different types of shock absorbers to others and to a separate post.All I was after was a like for like replacement of the originals " A reasonable enough logic, but . . . . . . I'd suggest that the likelihood of an unbranded basic budget repro item matching the quality of the original equipment item is not all that great, or rather in my personal experience it is extremely unlikely. Offhand, I can't think of any 'white box' aftermarket part that I've purchased, for a TR or any other car, that matched OE calibre. Cheers, Alec Quote Link to post Share on other sites
Waldi Posted June 7, 2017 Report Share Posted June 7, 2017 Marco, I just measured: The extended length of my old shocks is 300-305 mm, which is correct I believe. The compressed length is 250 mm. These were aftermarket, Munro. The new "standard" ones I ordered were not stiff at all (subjective, I know), but when I compared them with the new konis it was a day&night difference. The konis have a rebound rubber inside the upper tube(sleeve). Ciao, Waldi Quote Link to post Share on other sites
Z320 Posted June 7, 2017 Report Share Posted June 7, 2017 Hi Waldi, I measured the minumum length of the shock I own, all with rebound rubber inside: - the old black ones: only 280 mm ! - Armstrong: 271 mm - Spax: 263 mm - Monroe: 258 mm The "old black one" have been to short, the car alway hopped on the rebound rubber, that made the suspencion very uncomfortable. Armstrong and Monroe I never had on the car, Spax worked very well. Until I put 25 mm shorter coil spings on the car, what look very nice. They are still the original ones pressed shorter by a coil sping producer. With this shorter springs the car hopped very bad and stiff on the rebound rubbers. The rubbers looked like squezzed, see the attached photo, for me it was undrivable. https://goo.gl/photos/g8dmtNHUaKCjyUQq7 I solved this by cutting both rubbers 25 mm shorter. So I guess for original spring lenght the shock absorbers should be compressed 250-260 mm long, with shorter springs they also must be shorter. I will solve this next with DIY lower brackets. Ciao Marco Quote Link to post Share on other sites
mark_smugglers Posted June 7, 2017 Author Report Share Posted June 7, 2017 Loads of information here. Thanks all for all your help. Much appreciated. Mark Quote Link to post Share on other sites
Waldi Posted June 8, 2017 Report Share Posted June 8, 2017 Hi Marco, The variation in maximum en minimum length between the different manufacturers is interesting. Off course we do not know if any of them is exactly as per the OEM items. Both dimensions are important, because the shocks can cause high loads on the suspension components if they hit an end stop frequently (the rubbers inside the shocks are there for a purpose, they shave the peak of the impact loads). Your comment about shorter or longer springs is important: if we modify our springs (coils) to change ride hight we should check that the shocks are of a suitable length. Especially if they have a shorter travel like your old "black ones". There are more knowledgeable people on this forum than me, has this ever been adressed? Cheers, Waldi Quote Link to post Share on other sites
Z320 Posted June 8, 2017 Report Share Posted June 8, 2017 (edited) Hi Waldi, I told several TR-drivers with lower coil springs and "problems" or "progressiv springs" that they hop on the rebound rubber.They all looked at me with big eyes as I am obvious a fairy tale teller. So - I perhaps could be wrong? But I remember a friend´s TR6 restauration book with a notice to the front suspension, something like "shorter coil springs may need some modifikation on the brackets". By the way I looked on the bill and in my scrap box: my springs are made only 20 mm shorter, so I cut 20 mm of from the rebound rubber. Ciao Marco Edited June 8, 2017 by Z320 Quote Link to post Share on other sites
Waldi Posted June 8, 2017 Report Share Posted June 8, 2017 Marco, That makes sense to me. Off course, the travel is also depensing on the spring rate of the coil. If you drive prudent, it would also be less critical. Regards, Waldi Quote Link to post Share on other sites
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