unclepete Posted September 21, 2005 Report Share Posted September 21, 2005 That will teach me to run in convoy 280 from Robin Hoods Bay Yorkshire to Wakering in Essex with 2 TRV8s and a Toyota MR2. Brilliant run through a 'scenic route' which took in some of the Lincolnshire Wold drain roads which are straight but not always flat and in a 3a with a steering box not for the faint hearted. Took a Rail Crossing a bit enthusiastically and on landing the windscreen cracked The National Windscreen man turned up next day and then took 2 hours (with my help) to fit a new one. I couldn't find an article or instructions anywhere to go about fitting one easily!!! any ideas? The next thing is, are there any add on cross members or strengthening for sidescreen cars, without carving or cutting lumps out her, so that she stays in roughly the same shape after brief flights. Unc ??? Quote Link to post Share on other sites
marvmul Posted September 21, 2005 Report Share Posted September 21, 2005 I wonder if chassis strenghtening would have prevented the windscreen from cracking. Some use the stanchion of the windscreen to get out of the car : then the stanchion bends after some time, putting strain on the windscreen. Het is also possible that one of the small screws was making contact with the windscreen. In both cases, the jump over the rail crossing can be enough to crack the windscreen? Quote Link to post Share on other sites
Don Elliott Posted September 21, 2005 Report Share Posted September 21, 2005 If the top of the chrome frame got to become a bit flatter (less curve), possibly by people pushing back on it, or by a DPO having the engine compartment cover flip back onto the frame, this will straighten or flatten the top of the frame. This will pre-stress the glass and a good bump as you experienced is enough to crack the glass. Make sure, before inserting the new glass into the top part of the frame that the curve in the frame is correct. Don Elliott Quote Link to post Share on other sites
BrianC Posted September 21, 2005 Report Share Posted September 21, 2005 I have seen an article recently about stiffening the sidescreen bodies by building a front cage inside the footwell area. I can't remember if it was in a recent TRaction, Roger Williams' "How to improve TR2-4A" or on a website via a link from this forum. I'm sure someone else will remember. It looked a lot of effort, so I reckon aeroscreens would be am easier option. Nice to know replacement screens are still available though (but at what cost?). Quote Link to post Share on other sites
Don Elliott Posted September 21, 2005 Report Share Posted September 21, 2005 If your sidescreen TR is solid, if the frame is straight and if it's all bolted securely together, there should not be any need for any further structural additions to prevent the windscreen from cracking. Don Elliott Quote Link to post Share on other sites
unclepete Posted September 21, 2005 Author Report Share Posted September 21, 2005 Nice to know replacement screens are still available though (but at what cost?). Thanks for the help guys. National Windscreens had 4 screens in stock! All laminated and made by Pilkington Glass. Cost the insurance excess of £50 The crack appeared along the bottom middle of the window frame where there are no screws. I did notice however that the hood screws along the top of the frame go right through to the glass groove but as the glass dosn't go this high when installed is it a problem? Unc Quote Link to post Share on other sites
unclepete Posted September 21, 2005 Author Report Share Posted September 21, 2005 If your sidescreen TR is solid, if the frame is straight and if it's all bolted securely together, there should not be any need for any further structural additions to prevent the windscreen from cracking. Don Why do all the track boys fit stiffeners? The sidescreens are renowned for flexing under normal driving let alone a bit of enthusiastic criusing. Speaking to Bill Piggott at Duxford last year about panel fit and alignment he remarked 'that no ammount of fiddling about, getting all the panels exactly millimetre perfect, would matter a jot after driving a couple of hundred miles as they would move about anyway'. Unc Quote Link to post Share on other sites
Don Elliott Posted September 21, 2005 Report Share Posted September 21, 2005 Pete - If by "track boys" you mean TR3 racers, then over here they all have aeroscreens or low level cut down perspex windscreens. They don't need stiffeners for the windscreens they use. Don Elliott Quote Link to post Share on other sites
unclepete Posted September 22, 2005 Author Report Share Posted September 22, 2005 If by "track boys" you mean TR3 racers, then over here they all have aeroscreens or low level cut down perspex windscreens. Don 'Nuff' said, Didn't think of that! Better get some Aero screens. Unc Quote Link to post Share on other sites
rudi Posted September 22, 2005 Report Share Posted September 22, 2005 Unc, So far I had no problem with the windscreen myself. The posts from Marvmul and Don are certainly correct, I guess this is the main reason and not the chassis flex. I do not know if severe scuttle shake can cause the windscreen to crack, or simply add to the risk. However I do consider a strengthening of the scuttle to get rid of the shake. In rallying and enthusiastic driving w/o the hard top fitted, shake of the scuttle can be enoying. You will find posts on how to reinforce the scuttle by using the search tab in the forum. I ev. might take the route of adding a low front cage with door bars to my rear roll bar and bolt the front hoop to the battery box or the "simpler way" as decribed in one of the posts. Regards, Rudi Quote Link to post Share on other sites
Dave Herrod Posted September 22, 2005 Report Share Posted September 22, 2005 There was a recent forum link to (I think) the australian Tr register on the subject of installing a goal-post bracing to prevent scuttle shake. As Peter says, I am always amazed at quite how much my TR seems to flex when It gets bounced around over rough roads. Could it be that the transverse flexing just twisted the screen frame a bit too much? Dave Quote Link to post Share on other sites
Dave Herrod Posted September 22, 2005 Report Share Posted September 22, 2005 Sorry to have repeated Rudi's post: it wasn't there when I started typing, honest! Dave Quote Link to post Share on other sites
marvmul Posted September 22, 2005 Report Share Posted September 22, 2005 Peter, I think you misunderstood Don Elliot : he just said that chassis stiffening is not necessary to prevent the windscreen from cracking if the windscreen frame is correctly mounted. He didn't say the sidescreen chassis doesn't flex. Quote Link to post Share on other sites
Guest GDalzell Posted September 23, 2005 Report Share Posted September 23, 2005 Did the crack originate at one of the studs on the top of the frame where you attach the hood? If they are slightly too long. they press through the rubber surround. I've had a newscreen crack from this point event thoughh it wasn't even installed. Regards Graham Quote Link to post Share on other sites
unclepete Posted September 23, 2005 Author Report Share Posted September 23, 2005 Peter, I think you misunderstood Don Elliot : he just said that chassis stiffening is not necessary to prevent the windscreen from cracking if the windscreen frame is correctly mounted. He didn't say the sidescreen chassis doesn't flex. Marvul I quite agree with Don, the racing boys fit aero screens for obvious reasons. However, even a correctly mounted windscreen is in effect, a braced frame, from one side of the car to the other. Having now taken one to bits, it can be seen that, other than the glass, the windscreen frame is pretty flimsy. Ergo; if the rest of the car flexes enough, somethings gotta give! - and did! Graham The crack appeared accross the bottom of the screen where no screws are fitted (I know what you mean about the hood studs though, see my previous posts) Unc Quote Link to post Share on other sites
BrianC Posted September 25, 2005 Report Share Posted September 25, 2005 Cracking due to contact with the hood screws is a well-known problem, but I also seem to recollect there were some replacement screens around in the 70s which were not to the original spec. I can't remember whether the screens are supposed to be slightly curved or completely flat. My TR3A is away at the moment, but if I can remember where I buried my spare ones I will check - at least one is an original from a 1958 TR3A. Quote Link to post Share on other sites
BrianC Posted September 25, 2005 Report Share Posted September 25, 2005 I checked both my spares and they do indeed appear to have some curvature - approx 0.5" from centre to end horizontally. Possibly some vertically but probably too small to measure reliably. Although both screens are in frames, I am pretty sure the curvature is built-in rather than due to the frame shape but it is a long time since I saw one naked! At least Alec's post confirms my recollection of past problems. All of my screens have manufacturer's markings but I didn't make a note of which. It also reminds me there was some debate as to whether the problem only affected laminated or toughened screens or both. Quote Link to post Share on other sites
BrianC Posted September 25, 2005 Report Share Posted September 25, 2005 I have just consulted Roger Williams' "How to Restore TR2, TR3 and TR3A" and this also states that the windscreen is curved. He also suggests avoiding use of the windscreen stanchions for support when entering and exiting the car. I guess 40-50 years of this by previous owners could contribute to stress in the glass (not to mention distortion of the body at the foot of the stanchions, as I discovered in my TR3A prior to a respray many years ago). Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.