Post Reply
User avatar
sh0rtlife
Verde
Verde
Posts: 536
Joined: Fri Jun 02, 2006 7:45 am
Location: portland, oregon, USA

thump thump thump

Post by sh0rtlife »

well i finally found where the thumping comes from on hard acceleration ...seems the rear joint is contacting the body...mind you its only on hard acceleration ONLY.....

when i first worked on the car i installed the new rubber joints for the previous owner....ive read alot of posts about different sized joints and am wondering if its this rear joint that is a different size from stock....what i do know is that the spacer blocks on the transaxle mount are thinner than milano ones if that helps any ...

the gtv6 in question is an 83 "leftover" ballocco if it matters

the question is...what do i do about it?..and how do i correct it?...there were ZERO vibrations or anything abnormal ..smooth as silk EXCEPT on HARD launches...at first i thought it was violent wheel hop

heres a few quick shots a grabbed today
Attachments
1-Picture 1337.jpg
1-Picture 1337.jpg (75.05 KiB) Viewed 6136 times
1-Picture 1338.jpg
1-Picture 1338.jpg (90.14 KiB) Viewed 6136 times
Image
Paul Bird
Gold
Gold
Posts: 125
Joined: Sun Dec 05, 2004 4:26 am
Location: Bournemouth
Contact:

Post by Paul Bird »

Hi Shortlife,

Have you checked your gearbox mounts?
User avatar
sh0rtlife
Verde
Verde
Posts: 536
Joined: Fri Jun 02, 2006 7:45 am
Location: portland, oregon, USA

Post by sh0rtlife »

i didnt do a full inspect of them but they looked to be in good shape..ill get a good look at em tomaro and make sure 1 hasnt failed

the car only has 70,000 miles on it....waiting on a sender for the TS box im putting in
Image
User avatar
MD
Verde
Verde
Posts: 2541
Joined: Mon Nov 22, 2004 2:37 am
Location: Brisbane, Australia
Contact:

Post by MD »

A word of caution to all.
A close look at the transmission tunnel clearly shows where the rear brake lines are located with respect to the drive shaft. On this occasion it's a simple case of bump stop adjustment. End of story.

The other story is not so cute. This is when the donut lets go and thrashes around in the tunnel tearing everything up in sight INCLUDING your rear brake line. Suddenly you are in deep doodoo.

Solution:

Relocate your rear brake line NOW. If you could forecast when your driveline will fail, you would never have to worry about it..
Transaxle Alfas Haul More Arse
Greg Gordon
Verde
Verde
Posts: 1552
Joined: Mon Nov 29, 2004 7:06 pm

Post by Greg Gordon »

Adjust the snubber, problem solved.

Greg Gordon,
www.hiperformancestore.com
User avatar
Giuliettaevo2
Verde
Verde
Posts: 790
Joined: Sun May 08, 2005 11:56 pm
Location: Netherlands

Post by Giuliettaevo2 »

and double check the gearbox mounts... get a tire-iron and try to lift the gearbox from the front beam which holds the de-dion triangle.
Drive it like you stole it...
Greg Gordon
Verde
Verde
Posts: 1552
Joined: Mon Nov 29, 2004 7:06 pm

Post by Greg Gordon »

I agree the gearbox mounts are important, and often overlooked.
User avatar
MD
Verde
Verde
Posts: 2541
Joined: Mon Nov 22, 2004 2:37 am
Location: Brisbane, Australia
Contact:

Post by MD »

Guys,

You are missing my point here. Check it out :

Simply adjusting the snubber and having the best gearbox mounts in the world aren't going to change a thing in relation to this hazzard.

I repeat. Move the brake line.
Attachments
Split drive tunnel backlit.jpg
Split drive tunnel backlit.jpg (71.13 KiB) Viewed 6075 times
Tunnel Split by Driveshaft 1.jpg
Tunnel Split by Driveshaft 1.jpg (31.58 KiB) Viewed 6074 times
Split drive tunnel, note position of hydraulics.jpg
Split drive tunnel, note position of hydraulics.jpg (176.63 KiB) Viewed 6075 times
Transaxle Alfas Haul More Arse
User avatar
sh0rtlife
Verde
Verde
Posts: 536
Joined: Fri Jun 02, 2006 7:45 am
Location: portland, oregon, USA

Post by sh0rtlife »

totaly agree i will plan on re-locating the line later this year....i want it running on the INSIDE of the car anyway as it seems like the smart location for it

so the snubber adjustment is all that was causeing this?
Image
User avatar
Giuliettaevo2
Verde
Verde
Posts: 790
Joined: Sun May 08, 2005 11:56 pm
Location: Netherlands

Post by Giuliettaevo2 »

even if you cut the rear brake line the car will still brake... that is why there are two separate hydraulic systems.

That driveshaftfailure could have been avoided i think, in 99% of the cases the donuts(guibos) die first and that's something you will notice. :( if you choose to carry on driving while hearing a strange rumbling sound underneath your car, accompanied by a strange vibration, you're asking for it. please realize this is just my opinion, although based on my own experience with alot of 75's. 8)

Shortlife, check the gearbox mounts... snubber adjustment may not be the only thing that needs doing to solve this problem.
Drive it like you stole it...
User avatar
sh0rtlife
Verde
Verde
Posts: 536
Joined: Fri Jun 02, 2006 7:45 am
Location: portland, oregon, USA

Post by sh0rtlife »

anyone care to explain the differences in joint sizes so i can get it out of my mind??
Image
Greg Gordon
Verde
Verde
Posts: 1552
Joined: Mon Nov 29, 2004 7:06 pm

Post by Greg Gordon »

MD, I promise I am not missing the point about the brake line. I chose to limit my post to the cause of the "thumping".

Greg
Post Reply