DaveN Posted April 19, 2017 Report Share Posted April 19, 2017 Gents Late Uk spec. TR6 riding on 195/65 15 tyres What should the clearance be between the chassis front crossmember and planet earth? I even struggle to get my 'racing' jack under there. Dave Quote Link to post Share on other sites
Peter Cobbold Posted April 19, 2017 Report Share Posted April 19, 2017 Dave, I dont use that as as a jacking point, I think its thinner steel than the main rails. I jack each side in turn at the junction between the inner and outer main rails, to the rear of the front wheels. Peter Quote Link to post Share on other sites
Steves_TR6 Posted April 19, 2017 Report Share Posted April 19, 2017 Mine is the same Dave, alloy 'racing' jack fouls on the forward crossmember before the lifting head reaches the main crossmember. Quote Link to post Share on other sites
Nigel A Posted April 19, 2017 Report Share Posted April 19, 2017 Same problem, have to use a scissor jack first. A real pain in the butt! Cheers Nigel Quote Link to post Share on other sites
Ben Freer Posted April 19, 2017 Report Share Posted April 19, 2017 Rings a bell in the little grey cells! If I recall it was only an irritatingly small lack of clearance for my trolley jack (which lived in the boot) with a short length of plank which was used to drive the wheel on to to gain that extra 1.5". Didn't solve the problem if you wanted to lift the whole front up - the plank wasn't that long! Quote Link to post Share on other sites
DaveN Posted April 19, 2017 Author Report Share Posted April 19, 2017 Aha not just me then! I use the scissor jack with a bit of wood on top under the forward side rail, then use the racing jack.... again with wood on the top under the front crossmember! Interesting comment there Peter, however the PO's had obviously been lifting it there in the past. I was being lazy because I took the front wheels off to balance them. Quote Link to post Share on other sites
david c Posted April 19, 2017 Report Share Posted April 19, 2017 Isn't It a small world, I had the same problem this afternoon, carved a small nick in the "lane" outside my house, hoofing great tractors are squishing the the single track and leaving a bit of a hump in the road.I found the hump this afternoon to the detriment of one of the little square thingies that hang from the front chasiss legs. have pumped up the front tyres to 28psi to get just a little more air draft. never really thought too much about ground clearance before, I would love to know what clearance other TR4a's have. Though having read others posts re jacking I can only think that my car is "normal". +1 for driving up on to short planks to get the jack under David Quote Link to post Share on other sites
tthomson Posted April 19, 2017 Report Share Posted April 19, 2017 Same problem with clearance on my 4A Quote Link to post Share on other sites
Guest ntc Posted April 19, 2017 Report Share Posted April 19, 2017 Then they all sit to low. Quote Link to post Share on other sites
foster461 Posted April 19, 2017 Report Share Posted April 19, 2017 My racing jack just clears but I have relatively new standard length but uprated springs. Stan Quote Link to post Share on other sites
Nigel C Posted April 19, 2017 Report Share Posted April 19, 2017 Believe me, you've got nothing to worry about...... Quote Link to post Share on other sites
BrianC Posted April 19, 2017 Report Share Posted April 19, 2017 Dave, I dont use that as as a jacking point, I think its thinner steel than the main rails. I jack each side in turn at the junction between the inner and outer main rails, to the rear of the front wheels. Peter The TR4/4A WSM recommends using the front cross-member. Is the TR6 chassis material thinner than TR4A? I've always used the cross-member on TR3A and TR4A and never had a problem, although I do use a short piece of wood between jack and chassi to spread the load. Quote Link to post Share on other sites
Peter Cobbold Posted April 19, 2017 Report Share Posted April 19, 2017 The TR4/4A WSM recommends using the front cross-member. Is the TR6 chassis material thinner than TR4A? I've always used the cross-member on TR3A and TR4A and never had a problem, although I do use a short piece of wood between jack and chassi to spread the load. Brian, Dont know thickness for sure, but it was already distorted when I bought it in '78....so I avoid making it worse. Jack wont fit anyway - 41/4 inch clearance...so I run front wheels onto short lengths of timber. Peter Quote Link to post Share on other sites
DaveN Posted April 19, 2017 Author Report Share Posted April 19, 2017 Come on then Neil please. What should the clearance be? Certainly from my point, it only got me thinking about it as I ragged the car round the slip road off junction 6 of the m4, right on the 'edge' so to speak!......oh what fun!! The only thing I can think off besides settled springs is the tyre profile, but there's only about 0.5 ins difference between the profile diameters of all the tyres recommended. Dave Quote Link to post Share on other sites
Peter Cobbold Posted April 19, 2017 Report Share Posted April 19, 2017 Come on then Neil please. What should the clearance be? Certainly from my point, it only got me thinking about it as I ragged the car round the slip road off junction 6 of the m4, right on the 'edge' so to speak!......oh what fun!! The only thing I can think off besides settled springs is the tyre profile, but there's only about 0.5 ins difference between the profile diameters of all the tyres recommended. Dave Dave, As the springs/ride height are an unknown quantity you might find the rear suspension bottoming in fast and tight cornering. When that happens all the cornering force goes through that one tyre....and the spin is sudden and uncatchable. Peter Quote Link to post Share on other sites
DaveN Posted April 19, 2017 Author Report Share Posted April 19, 2017 Peter I have rebuilt the rear end completely, the springs are slightly uprated and the leverarms I flushed out and filled with Penrite no. 2 oil. I also tweaked the return valve a bit too. (And amazingly for 40+ year old shockers they don't leak at all. Mr Armstrong got that right!). Quote Link to post Share on other sites
mike3md Posted April 20, 2017 Report Share Posted April 20, 2017 Clearance is a problem for most trolley jacks. A word of warning - if using the front cross member to jack up the car, make sure that the 'head' of the jack cannot slip, especially if the cross member has become oily in this area. Ask me how I know......... I made up a H shaped steel bracket that fits the cross member and the head of the jack, and to obtain clearance have 4 lengths of scaffold board on the garage floor which I drive onto when putting the car away. Mike Quote Link to post Share on other sites
stuart Posted April 20, 2017 Report Share Posted April 20, 2017 To gain a little clearance prior to jacking, reverse quick and stand on the brakes, the weight transference will pull the front suspension up a bit which is usually enough to make the difference. Stuart. Quote Link to post Share on other sites
Peter Cobbold Posted April 20, 2017 Report Share Posted April 20, 2017 Peter I have rebuilt the rear end completely, the springs are slightly uprated and the leverarms I flushed out and filled with Penrite no. 2 oil. I also tweaked the return valve a bit too. (And amazingly for 40+ year old shockers they don't leak at all. Mr Armstrong got that right!). That should be OK. Its lowered but not very stiff rear springs that can cause a spin. I made that mistake that and had a 70mph 360 on a track day. Ground clearance was 4 1/4 inches.... Peter Quote Link to post Share on other sites
Alec Pringle Posted April 20, 2017 Report Share Posted April 20, 2017 OE spec chassis dimension ground clearance was 6 inches . . . . . Cheers Alec Quote Link to post Share on other sites
DaveN Posted April 20, 2017 Author Report Share Posted April 20, 2017 Thanks Alec. It's a new (ish) chassis so possibly the springs gave settled. Either way I'm happy with the handling. Dave Quote Link to post Share on other sites
mike3md Posted April 20, 2017 Report Share Posted April 20, 2017 If I followed Stuart's tip for lifting the front, I would be through my garage doors............................... Quote Link to post Share on other sites
stuart Posted April 20, 2017 Report Share Posted April 20, 2017 If I followed Stuart's tip for lifting the front, I would be through my garage doors............................... It was meant as an "On the road" assistance! Stuart. Quote Link to post Share on other sites
parry Posted February 13, 2018 Report Share Posted February 13, 2018 Seems like ground clearance is a general issue from this. My suspension had been lowered when I bought my car, and apart from the jack not getting under, the exhaust manifold has been squashed, I'm guessing due to grounding out at speed, and the sump has numerous dents. While the handling was great on a smooth road, we don't have many of those, and it was also not great on speed bumps. As I'm now rebuilding the car I'm considering changing the springs, and possibly even going for the Moss "uprated road/rally 390lb springs" (https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/steering-suspension). Has anyone used these? It says they have a "slight raise in ride height", but not sure how this will translate in terms of how the car will look and handle, so any insights would be much appreciated before I make a decision. Thanks! Parry Quote Link to post Share on other sites
oldtuckunder Posted February 13, 2018 Report Share Posted February 13, 2018 OE spec chassis dimension ground clearance was 6 inches . . . . . That's going to be interesting in this years SHCC championship, as for Roadgoing class there is a requirement for original ground clearance (less allowance for tyre size. I wonder who's going to be bringing along a few blocks of carefully sized wood? Alan Quote Link to post Share on other sites
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