Trans shaking in Reverse... 67 GTV - Alfa Romeo Bulletin Board & Forums
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 16 (permalink) Old 08-17-2015, 02:50 AM Thread Starter
Registered User
 
Join Date: Sep 2014
Location: Niskayuna, NY
Posts: 11
Trans shaking in Reverse... 67 GTV

There's a whole lot of shakin' going on here. My 67 GTV shifts and runs flawlessly when driving forwards. In reverse, however, I get some major gear backlash and the car starts to buck like a bronco - from what seems to be slipping and grabbing in clutch. Reverse gear has a tendency to pop out as well. Any thoughts here? I bought the car in this condition a year or so back but never noticed how bad until I got to slight inclines.

The car came with a lightened clutch plate. Any help would be appreciated.
-Gerald
Geradcaca is offline  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 08-17-2015, 05:02 AM
Richard Jemison
Platinum Subscriber
 
Alfar7's Avatar
 
Join Date: Apr 2005
Location: Pensacola, Fl. U.S.A.
Posts: 6,870
movement

You should change out the transmission mount to the more atiffer/ridgid one designed for the 101/105 series cars, now sold as the
reinforced mount.

As well the large flat rubber "washers" can be doubled or trippled to keep the trans from moving.

It is jumping out of gear because the shifter is contacting the tunnel structure. Another indication of a trashed trans mount.

You should check your motor mounts as well as they are likely contributors to the too soft issue.

Richard Jemison
RJR Racing

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

"When you are dead you don`t know it.
Only those around you are distressed.
Same with stupid"
Alfar7 is offline  
post #3 of 16 (permalink) Old 08-27-2015, 11:06 PM
Registered User
 
RedJewel's Avatar
 
Join Date: Feb 2006
Location: Olympia, WA, USA
Posts: 47
Garage
Shudder, Judder, Thump Thump Thump

Great timing Geradcaca...I to have this issue and have just started working on it ('59 Giulietta with '74 5-speed). Seems that the cause is the mechanical clutch linkage. It changes the amount of clutch engagement as the car moves in reverse. The momentary loading/unloading cycling appears to cause the jumping/bucking. The faster you move, or the more the incline, the greater the shudder. The hydraulic clutch in the later cars allows the driveline to 'float' independently from the vehicle and is not affected by the slight body to driveline movement.

I just purchased this from Centerline: Trans Mount 101/105 Part # TM725
Original style transmission mount for 101 Giulia 5-speed cars, and 105 Giulia cars, including GTV, Duetto, and TI/Super 1965-68.
Can also be installed as a heavy duty upgrade on 115 cars 1969 and later with very little increase in harshness.
For competition use (GTA) round holes on both sides of the mount may be filled with metal dowels for added stiffness.



Here are the dowels mentioned (from Alfa Stop):
Aluminium reinforcing plugs for gearbox rear crossmember support silentbloc


I was guided to the problem soulution(s) by this 2004 post on the AlfaBB:
Duetto: Clutch Shudder in Reverse Gear (be sure to read the linked posts from the Alfa Digest).

An excerpt from one of the Alfa Digest links referenced in the post...
"Betcha somebody put in a later gearbox at some point, with its later transmission mounting bushing, as this is exactly what I experienced with the '67 GT Junior I used to own when I put in a later gearbox. The problem: The '67s have a mechanical clutch release, with a cable that is pulled by a bellcrank when you press on the pedal. Pulled tight, the clutch releases; left slack, the clutch engages. With the original gearbox, the bushing was designed to make this work in both directions.

The problem is that the later gearboxes have a softer bushing with a different shape, because the later 'box uses a hydraulic clutch. Going forwards, this is no problem, because the rear-wheel torque "does the right thing," keeping the cable taut when you're on the pedal. But going backwards, the rear-wheel torque as you start to engage the clutch slackens the cable, which causes a sharp engagement of the clutch -- the first jerk. This causes the cable to go taut again, which makes the car jerk backward, which makes the cable go slack, which makes the car jerk, which -- and it keeps up till you put it in neutral."

This post from the Alfa Digest in 2002 was the very informative. Edited from the Alfa Digest...
Subject: judder in reverse
From: "Watry, Andrew (LNG-MBC)" <[email protected]>
Date: Wed, 13 Feb 2002 14:33:47 -0500
Re Steve's query.

To some extent they just do that, but there are a few things to check, in what has been my experience the order of severity:

1. Motor mounts (on the engine) have good strong rubber and are tightly bolted top and bottom
2. Trans mount (at rear of trans) in good condition and installed right way up
3. Trans mount bolts all tight?
4. Clutch is in good shape as in not roughly engaging or juddering on its own?
5. Throttle linkage works smooth and OK, and car has low smooth idle speed? High idle can contribute to problem.
6. I assume as a 67 it still has the mechanical clutch. Does it have cable or rod actuation on the last link from the bellcrank to the TO actuation arm? (a viciously debated Digest thread) Rod may cause less compliance and therefore more oscillation cycles.
7. There is a relatively simple rubber-bumper hood stop "solution" that can be threaded into the trans mount, effectively arresting the fore-aft motion of the gearbox. Some say it works. It was written up in one or more club newsletters, which I don't have handy.

My current Super had incredible reverse judder when I bought it, because, as it turned out, one motor mount that was not well seated on the cross member and was not bolted in. Even after fixing that, it still has slight judder in reverse, especially uphill, as have other Supers I've owned. For reasons probably relating to the cumulative effect of the above factors, some cars are worse than others.
Andrew Watry
Berlina Register

I hope this helps
Ron

1959 Giulietta Sprint 'Veloce-ized' - owned since April 1975

Last edited by RedJewel; 08-30-2015 at 11:19 AM.
RedJewel is offline  
Sponsored Links
Advertisement
 
post #4 of 16 (permalink) Old 08-30-2015, 10:54 AM
Registered User
 
Join Date: May 2005
Posts: 5,269
I recall a rubber buffer that was added to the early transmission carriers to control this. early TX supports were softer than the later ones. But they are also off-center, and just stuffing a later rubber support in will mis-align the drive shaft.

I have the Alfa notice for the buffer somewhere and will try to find it. Anybody else remember this?

Robert
60sRacer is offline  
post #5 of 16 (permalink) Old 08-31-2015, 06:05 PM Thread Starter
Registered User
 
Join Date: Sep 2014
Location: Niskayuna, NY
Posts: 11
Thank you very much for the extensive added detail. I have received the updated trans mount and pitched in for the heavy duty engine mounts as well as some additional trans mount bushings. As luck would have it my synchro bushing went the other week so I have to pull the entire gearbox and will most likely send it out for a full refurb - not knowing if it was done correctly to begin with complicates the refurb process if I were to do it myself.

I can only assume it will take until late spring for me to verify whether the fix works or not. Love those upstate NY winters...

Gerald
Geradcaca is offline  
post #6 of 16 (permalink) Old 09-02-2015, 09:11 AM
Registered User
Platinum Subscriber
 
Andrew's Avatar
 
Join Date: Mar 2004
Location: Berkeley, CA
Posts: 20,720
There was a service bulletin on this, from 1965. It involves screwing a "hood bumper" or similar rubber stop in the trans mount to keep the trans from moving fore/aft. In my experience the modern mechanical clutch mounts will transmit a lot of vibration. I have gone with a hydraulic mount in my Super, and installed the bumper stop. Attached is a PDF of the factory drawing from the bulletin.

Applies only to mechanical clutches, not hydraulic, which was the real fix.

Andrew
Attached Images
 
Andrew is offline  
post #7 of 16 (permalink) Old 06-22-2019, 03:39 AM
Registered User
 
Tom Frasca's Avatar
 
Join Date: Dec 2016
Location: New York
Posts: 1,663
Garage
Quote:
Originally Posted by Andrew View Post
There was a service bulletin on this, from 1965. It involves screwing a "hood bumper" or similar rubber stop in the trans mount to keep the trans from moving fore/aft. In my experience the modern mechanical clutch mounts will transmit a lot of vibration. I have gone with a hydraulic mount in my Super, and installed the bumper stop. Attached is a PDF of the factory drawing from the bulletin.

Applies only to mechanical clutches, not hydraulic, which was the real fix.

Andrew
Is there a supplier or recommended material rubber, plastic etc. I am going to do this fix, searching ABB for more info,

Thanks

The older I get.. the faster I was....
Tom
Tom Frasca is online now  
post #8 of 16 (permalink) Old 06-22-2019, 05:00 AM
Registered User
 
alfa2go's Avatar
 
Join Date: Feb 2005
Location: Brisbane, Australia
Posts: 2,644
A bonnet/hood stop for a Giulia does the trick. From the usual suspects.

https://classicalfa.com/rb075-bonnet...giulia-saloon/

66' Giulia Super, '67 GT Veloce, '72 Montreal

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
www.montreal.alfa-male.com

Last edited by alfa2go; 06-22-2019 at 06:02 AM.
alfa2go is online now  
post #9 of 16 (permalink) Old 06-22-2019, 07:06 PM
Registered User
 
Join Date: Oct 2004
Posts: 1,504
Quote:
Originally Posted by Tom Frasca View Post
Is there a supplier or recommended material rubber, plastic etc. I am going to do this fix, searching ABB for more info,

Thanks
I have a few of the factory version. PM me if interested.

Chuck
Attached Images
 
6alfas is offline  
post #10 of 16 (permalink) Old 06-22-2019, 07:20 PM
Registered User
 
Tom Frasca's Avatar
 
Join Date: Dec 2016
Location: New York
Posts: 1,663
Garage
PM Sent!

The older I get.. the faster I was....
Tom
Tom Frasca is online now  
post #11 of 16 (permalink) Old 06-23-2019, 09:26 PM
Registered User
 
Join Date: May 2005
Posts: 5,269
It's not just the hydraulic clutch that fixes this problem. The Alfa factory solution was aimed at the early Alfas because they have a much softer rear transmission mount than the later cars. The early cars were powered by 1300 and 1600 engines, much less torque than the 1750 and 2000 engines. I solved my identical problem by using the 2 L rear transmission mount.

Robert
60sRacer is offline  
post #12 of 16 (permalink) Old 06-24-2019, 08:54 PM
Del
Senior Member
Gold Subscriber
 
Join Date: May 2005
Location: seattle
Posts: 15,106
My experience through the decades with Alfa drivetrains and manual transmission says that there is a chance of a sticky/worn clutch disc due to perhaps due to oil contamination if the clutch is jerky when backing up, esp back up a grade (the ratio of the reverse gear is part of the problem).

Had this in several early Alfas, including my Sprint GT, and getting rid of the glazed and sticky disc, and facing the flywheel, solved the problem completely. Same thing also happened with our 91 164S with a wornout sticky clutch disc (190k miles) when backing up out of the driveway (jerky and jumpy). Installing a new clutch, etc, of course cured the problem.

Del

Seattle

1989 Milano, Shankle Sport
1991 164S, stock
1994 164LS (~Q)
1972 Morgan 27

previously owned since 1964:

62 Morris MiniMinor 850, 67 Austin 1275 Cooper S (Downton 3/4 race), 64 Giulia Sprint GT (1st red one made), 72 Fiat 128 Sedan, 75 Alfetta Sedan, 78 Alfetta Sedan, 78 GTV, 81 GTV6, 86 GTV6

Last edited by Del; 06-24-2019 at 08:58 PM.
Del is offline  
post #13 of 16 (permalink) Old 06-25-2019, 05:50 AM
Registered User
 
Tom Frasca's Avatar
 
Join Date: Dec 2016
Location: New York
Posts: 1,663
Garage
My clutch was fine and I used the later mount, this is apparently a design problem with the ealy clutch cars, we will find out soon enough!

The older I get.. the faster I was....
Tom
Tom Frasca is online now  
post #14 of 16 (permalink) Old 06-25-2019, 09:46 AM
Del
Senior Member
Gold Subscriber
 
Join Date: May 2005
Location: seattle
Posts: 15,106
In the case of my cars with this problem, the mounts were fine. It was just the grabby clutch disc, with the gear ratio of the reverse gear accentuating the grabbing/juddering. When it is really bad, it will also show up in 1st gear at lower engine rpms when engaging from a stop.

Del

Seattle

1989 Milano, Shankle Sport
1991 164S, stock
1994 164LS (~Q)
1972 Morgan 27

previously owned since 1964:

62 Morris MiniMinor 850, 67 Austin 1275 Cooper S (Downton 3/4 race), 64 Giulia Sprint GT (1st red one made), 72 Fiat 128 Sedan, 75 Alfetta Sedan, 78 Alfetta Sedan, 78 GTV, 81 GTV6, 86 GTV6

Last edited by Del; 06-26-2019 at 09:02 PM.
Del is offline  
post #15 of 16 (permalink) Old 06-26-2019, 08:30 PM
Registered User
Platinum Subscriber
 
Andrew's Avatar
 
Join Date: Mar 2004
Location: Berkeley, CA
Posts: 20,720
On my 67 Super I did the fix I detail above, it was better. The car has a hydraulic style 1750/2000 rear trans mount. I tried a 1600 mount but the vibration was very high, though the reverse judder was better. I don't know if there are different firmnesses of 1600 style trans mounts available.
My 67 GTV has much less judder in reverse though I have not looked into its mount setup yet. It can vary car to car.
Andrew
Andrew is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome