Chassis strength

[John L]

I was rather alarmed the other day when a friend perched on the rear wing, to notice that the top of door gap has got bigger. It goes back again once the weight is off.

I have had a thorough look underneath and can see nothing untoward, have I missed something? but having never tried this on any other car, so I have nothing to go on. It seemed that the whole of the rear tub is able to move, I have looked at the tea shirt part, but of course I cannot see on the top of it, to see if any of the welds have come adrift. All the body mounts appear to be tight.

Can anybody tell me if I do have a problem, or was this how flexible the chassis always was?

Regards John

[jerrytr5]

No problem, they're all like that. Haven't you noticed how difficult it is to open or close the doors when jacked up?

Jerry

[stuart]

No problem, they're all like that. Haven't you noticed how difficult it is to open or close the doors when jacked up?

Jerry

Yours might be but if the structural integrity is correct it shouldnt move around that much. My 4a can be jacked anywhere and at any angle and you can still open and shut the doors without any notable difference.

Stuart

[rpurchon]

my 6 is the same, & when jacked up doors difficult to shut.

try or dont try this when driving down the road put your finger in the rear gap of the passeger door.

it will open and close slightly when going over bumps,i have a ex usa rust free chasis.

richard

[67_gt6]

Yours might be but if the structural integrity is correct it shouldnt move around that much. My 4a can be jacked anywhere and at any angle and you can still open and shut the doors without any notable difference.

Stuart

 

Likewise, although the door gaps change by 3mm or so at the top

 

Andy

[JOHN'S TR6]

THANKS GUYS. REVELATION NO 7, CHAPTERS 2 VERSES 4-6

I FEEL NOW THAT MY TR6 CHASSIS IS NO LONGER FALLING TO BITS.

IT LOOKS SOLID UNDERNEATH, BUT FOR MONTHS I WAS IN A DEPRESSION THAT THE CHASSIS HAD HAD ITS DAY.

LAST TIME I JACKED IT UP, I COULD NOT CLOSE THE OFF SIDE DOOR AT ALL UNTIL LOWERED. IT MUST BE SAID THAT THE SHAPE OF THE OFF SIDE DOOR IS A BIT DODGY THOUGH.

WHEN I TOLD FRIENDS THEY ALL SAID THINGS "OH MY GOD, THAT DOESN'T SOUND GOOD"

AFTER READING THE LAST FEW COMMENTS TONIGHT, I FEEL A WHOLE LOT MORE POSITIVE.

 

THANKS EVERYONE

[harrytr5]

It should not deflect that much when sat on.It is different when jacked up at the rear and then should only deflect by a small amount.I can still open and shut my doors when jacked up but only just.Mind you I built my TR5 myself completly.If the chassis is on its way out at the rear,the door gap will increase at the top.You need someone in the club near you to have a look at it.

Regards Harry.

[boxer]

Hi john i dont knowwhere you are but if you are anywhere near Thame in oxford your welcome to run your tr over my pit to have a good look around. if its any consolation mines just the same.

Bob

[JOHN'S TR6]

Hi john i dont knowwhere you are but if you are anywhere near Thame in oxford your welcome to run your tr over my pit to have a good look around. if its any consolation mines just the same.

Bob

 

 

Thanks for the offer Bob. I Will bear that in mind.

I live in South wales. My car actually came from Headington in Oxford a year ago today.

 

John

Edited July 25, 2007 by JOHN'S TR6

[John L]

Thank you for your comments.

From the comments, some of feel it should flex and some say it shouldnt, I must say I would have thought that it should be better than it is in my case. I could accept 2-3 mm, but surely more that this must mean something?

Does the body in any way add to the strength?, as it all seems to bend at the point behind the seats. Does the rear section of the gearbox tunnel add some rigidity to the body at all? I havent dug around this part yet to see if something is moving at this point, or if the welds are broken.

Need to do some some research I think?

 

Regards John

[EricTR6]

I've been told from many restorers that you have to put struts between the door posts if you remove the doors or the tub, to prevent the flex. So I think its very normal for the TR6 to flex in some way, but the doors should still open.

 

When "sitting" on the rear wing, I don't think it normal for the chassis and doors gaps to change that much !

Edited July 27, 2007 by EricTR6

[Richard Crawley]

Sorry guys both Stuart & Alec are correct; it’s definately not normal for the door gaps to change when you sit on the rear wing! I completed a total body/chasssis restoration 3 years ago & my chassis is now as solid as a rock. If you jack these cars on the corners, the chassis will twist & this can cause the doors to stick but they should still open & close. I never jack my car this way & use a modified (lowered) trolley jack to jack in the centre of the front cross member (it’s reinforced) or under the cruciform (tee shirt), then sit it on axle stands at the corners; jacked in this way the doors will open & close without any problems.

 

A chassis that moves has deteriorated to some degree, this in itself may not be serious but it won’t do much for the handling! Unless it really is bad, you probably wont see much by looking underneath either; mine looked fine but was totally shot under the cruciform plates, the trailing arn sections & the rear cross members. The only permanent solution to put strength back into the chassis is to take the body off cut out/off the weak bits & replace with new.

[rpurchon]

regarding the chasis bending when jacking up.how do you jacking up the car.

scissor jack lifting 1 wheel just up enough to get the wheel off.

or big trolly jack lifting it so theres only 1 wheel touching the floor.?

i know a mechanic who worked on them early 70s.when i told him

the doors didnt open/ shut.he grinned "yep they were like that back then"

perhaps the people that make the new chasis [ctm] should answer this one.

richard

[Richard Crawley]

regarding the chasis bending when jacking up.how do you jacking up the car.

scissor jack lifting 1 wheel just up enough to get the wheel off.

Best place for the standard scissor jack is in the tool roll to keep the car original or in the dustbin! I would never use it except if caught out in an emergency.

 

or big trolly jack lifting it so theres only 1 wheel touching the floor.?

 

Only one wheel touching, how on earth do you manage that?

 

i know a mechanic who worked on them early 70s.when i told him

the doors didnt open/ shut.he grinned "yep they were like that back then"

perhaps the people that make the new chasis [ctm] should answer this one.

richard

 

I can only repeat what I said in my post I only ever jack my car at the front or back centre; I would always avoid jacking at one corner. If you do this, you will inevitably get problems with the doors as the chassis twists because your trying to lift all it’s weight from one point;. The doors used to catch on mine prior to restoration but it was never a case of not being able to open/shut them. I can’t remember what it was like in the 70’s just after I bought it but since it’s been restored, it doesn’t bend in the middle; the proof is sitting out in my garage!

[rpurchon]

i wouldnt use a scissor jack either unless a puncture away from home.

i have big trolley jack and yes it will lift 3 wheels off the floor.the last time i did it was to stone chip

the bottom of the new cills.

back to the original post how big was the person sitting on the rear wing 8stone or 20 stone.

[John L]

The weight is about 90kg, But also by leaning on the back wing it would open up a bit, and if jack at the outer corner by the trailing arm it open more, but you can still open the door, its a bit hard to pull, but its not locked completely.

I think I will take to CTM shortly and get them to give me difinative answer.

Regards John