The Lotus Grand Tourers

3 occasions of weird external noise. All due to passenger door on catch and not closed. Left side deafness means all noise comes from the right side rear

Hi Tony, suspension, brakes etc all looking very nice. Also noticed exhaust looks new/refurbished. If it’s not aligned just right passing between the frame and wishbone it can knock/vibrate against these parts especially going over bumps etc. it can sound awful, like metal parts clattering around. Might be worth checking the exhaust for a witness marks.

All due to passenger door on catch and not closed.

After the first short drive when this noise became apparent, I noticed exactly that. Passenger door was on first latch. relieved and very optimistic, I went down the street again, but the noise was still there.
Full investigations not yet started - It's wet out there today

Exhaust route should be fine. It's at least 20 mm clear of everything at nominal ride height, but I will be taking a closer look for evidence of contact.
Tony

Cars back in the air and exhaust is again off - After a good look around for signs of contacts.
This could be my noise problem ( fingers crossed). less than 3 or 4 mm clearance between the washer for the front lower link bolt and the Y piece ( nut just right of centre above the silver coloured section).
.
Fiddling could get it further away, but instead I'll use the longer Y piece i got from LB. - will move the Y flare back a good 2".



Next to investigate the ride height differences discussed on the zoom meeting earlier this week, then it can go back together and maybe get as far as the MOT station this time .

Tony

Nice collection of tape measures

Measured in feet too

I must admit, getting the exhaust in the right place is a right pain, I never realised what difference there were in the bits, great info.
When mines been off I usually use exhaust paste and leave all the nuts loose until everything is in place then I tighten them all a bit at a time cos they can move around so much when tightening them up. Perhaps I needed some different bits afterall.

Bash

The clearances where just right on mine until the rubber hangers sagged a few years later.

It now clonks on the drive shaft only after a long run when the rubbers have warmed up and sagged further.

I also find that a lot of aftermarket exhaust rubbers perish and fail really quickly. Are the poly ones any better?

Pete

Pete Boole wrote: ↑

Fri Apr 14, 2023 13:29

I also find that a lot of aftermarket exhaust rubbers perish and fail really quickly. Are the poly ones any better?

Pete

Good thinking. I'll try some polys before next MOT coming up soon.

Pete Boole wrote: ↑

Fri Apr 14, 2023 13:29

I also find that a lot of aftermarket exhaust rubbers perish and fail really quickly. Are the poly ones any better?

Pete

Good thinking. I'll try some polys before next MOT coming up soon.

Update on the ride height. Turns out my drive is not as level left to right as I thought.
In short, with the car sitting on ramps, the rear N/S is about 40 mm lower than it would be if on level ground. I put spacers under the ramp to hold at the right height, now both springs are essentially the same length when compressed and it's all tightened up good. Found this out when I jacked up on the N/S getting the spring to the same compressed length as I'd measured on the Off side, then when I jacked up the off side to the compressed condition, the near side extended ! By jacking the left a further 40 mm, both springs hot the same length.

The lesson here is that if you are doing this work on anything less than a perfectly flat car lift / ramp, check the compressed spring lengths are equal before tightening everything up.

Now - about that bag of spanners in the boot sound. In final stages of refitting the exhaust, i happened to press upwards on the boot floor ( from underneath) and heard a Knock - mainly on the near side, but partly on the Off side as well. It took very little effort, even just one finger pressing up was enough. Was relieved when I realised I got the same noise / movement when I pressed up on the chassis via the Y yoke at the Toe in adjuster cam. - at least this wasn't a movement between body and chassis.

After much head scratching, eventually found this :
https://youtu.be/GsHaaRubRRU
More prominent on the Near side, but evident on both sides. There is a 0.75 mm gap under the 3rd washer in the stack.


Out of time today to see whats wrong, but should be an easy fix once I investigate tomorrow.

Tony

Route cause of the above was exactly as expected. The register on the mid washers was 2.5 mm high. I can only assume that he material thickness at the top of the turret is around 4 mm, as filing 1 mm off the stand height solved the issue.


MOT sorted with no further dramas and tax re-instated ( getting pricey - roll on the 40th anniversary, but a while to wait yet being one of the last cars).

And the results of 6 months work and the jury ? - Wonderful
Clutch : Now has a slight over centre feel and engages where it should - Lovely
Gear selection : Last year I'd fitted the MG rubber gaiter, but 1st and 5th sometimes wanted to jump out. I moved the fastener ring forward about 1/2" whilst the dash was out, and now stays in selection as it should.
Wheel balancing ( or not as it turned out) : Again since buying the car, had a stearing wheel shake randomly between 55 and 70 MPH. Wheel balancing hadn't sorted it, but whilst front end was in bits, found the wheel bearing looked like this:

Replaced with a new Timken set (they did provide me an engineering apprenticeship after all and they are the best for a few extra pennies) and now all sorted.

And as for the general ride quality, it's chalk and Cheese. Last year i was watching out for even the smallest pebble on the road and avoiding it. Now even Northampton County Councils largest man trap just gets laughed at.
Very happy

Can't stop fiddling though. The boot back wall trim and spare wheel cover have bugged me since ownership , being very tatty. So I'm doing a bit of boot re-trim, but that's for another post later.
Tony

Now you can enjoy it Tony - excellent work and valuable lessons for all of us.

Cheers,

Richard

Excellent to hear Tony, the main job now is to enjoy driving it!

I've suffered exactly the same issue with the MGB gearlever gaiter pulling it out of gear, I'll try your fix.