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#1 Impact noise on each bump

Posted: Tue Sep 08, 2020 9:14 am
by Mich7920
Hi,
I need help please !
Coming back from vacations in Brittany which were the 1st long km after a total restoration of the engine and the front part, I noticed a problem of shock on each bump. Metallic shocks that I could feel under my feet from time to time.
I put the car on the lift and I think it's the box that hits.

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All the brakets and bush are brand new as well as the damping system of the gearbox ( spring and bushs ). The 3rd point is tightened flush as indicated in the manual.
What did I do wrong ?
Thanks for help
Mich

#2 Re: Impact noise on each bump

Posted: Tue Sep 08, 2020 9:27 am
by mgcjag
Hi Mich....are you missing the lower rubber mount here is a photo of mine the rubber comes through the plate like a large grommet .....sorry photo is dark try to add brightness....Steve
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#3 Re: Impact noise on each bump

Posted: Tue Sep 08, 2020 9:45 am
by Mich7920
Hi Steve,
Sure I didn't do that !!!
Of course my axle hurt the support without this "grommet"
What Is the page of the manual that I miss ?
And what about the very compress spring ? Is it normal ?
Thanks a lot. :bigrin:
Mich

#4 Re: Impact noise on each bump

Posted: Tue Sep 08, 2020 11:09 am
by mgcjag
Hi Mich..the diagram is from SNGB i think...not sure u missed anything in the service manual as i dont think it shows this mount......spring does look quite compressed...but not sure it thats ok.....have you set the engine stabiliser at rear top of engine to body...Steve

#5 Re: Impact noise on each bump

Posted: Tue Sep 08, 2020 11:25 am
by Mich7920
Thanks Steve,
I set the engine stabiliser yes but I'm going to repair what I did wrong, so I'll be obliged to unscrew it and I'l recheck it after.
Thanks for your help.
Mich

#6 Re: Impact noise on each bump

Posted: Tue Sep 08, 2020 2:30 pm
by 1954Etype
Mich, check your exhaust is clearing the body properly.

#7 Re: Impact noise on each bump

Posted: Tue Sep 08, 2020 2:57 pm
by Mich7920
I wanted this to be the solution so badly...
But I did the job right.

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What I did notice, though:
1 - The engine/gearbox assembly is not in line with the gearbox mount. No more than 5 mm but still.
We can see a trace on the center bush
2- The gearbox case is in contact with the aluminium sheet and wears it out. I can bend it.
3 - The stabiliser's step washer was free ( before disassembling the gearbox support )

The exhaust was my first idea but it's ok. Thanks Angus

#8 Re: Impact noise on each bump

Posted: Tue Sep 08, 2020 3:39 pm
by Moeregaard
The sources of mystery clunks and rattles in E-Types are many and can be really frustrating to track down. I always look for the obvious first, such as perished rubber bits and witness marks on adjacent components, but the one that drove me nuts with my first E-Type many years ago was a surprise.

The 1/2" bolt that ties the two pieces of the lower A-arm together, to form the lower damper mount, lives in a relatively hostile environment. The damper mount bushing will often seize itself to the bolt, while a small amount of play will develop between the A-arm pieces, resulting in a clunk that is most noticeable when driving over rough pavement at slower speeds. The bushing is now available, but back in the bad old days of limited parts availability I had to turn a pair from some unknown grade of stainless steel. A new bolt and a liberal application of copper grease made things right again.

Any clunks emanating from the rear transmission mount should be dealt with immediately, because failure of the rubber bobbin down there can put undue strain on the engine stabilizer on the firewall.

#9 Re: Impact noise on each bump

Posted: Fri Sep 18, 2020 12:07 pm
by positivfoto
stupid answer but true, you have always check your shock absorbers.

#10 Re: Impact noise on each bump

Posted: Fri Sep 18, 2020 1:11 pm
by Mich7920
There's no stupid answer of course !
I checked my exhaust, put in line the engine /gearbox, changed the spring and center bush and adjusted carrefully the stabilisater.
Now I wait to make a try on the road.
I'll check the shock absorber if there is still some fault.
Thanks

#11 Re: Impact noise on each bump

Posted: Sun Oct 25, 2020 5:23 pm
by Mich7920
I solved my parasitic noises.
- I have refocused the engine and gearbox assembly.
- Bend the protective aluminum sheet that touched the box.
- Correctly adjusted the 3rd support point.
- Even if they didn't really touch each other, I put a bigger gap between the 2 exhaust pipes.
- Tighten the bolts at the head of the shock absorbers that I had left too free.
Happy ! :bouncyyellow: