Re: [alfa] Replacing Transmission Mount 74 Spider and Protecting New One

[Caxambu <caxambu@xxxxxxxxxx>]

Here is a reprint of a tranny mount replacement procedure I sent to the 
list a little over 5 years ago. The mount seems to still be in good 
shape. I replaced the engine mounts soon afterward. I think the life of 
the tranny mount is somewhat dependent on the condition of the engine 
mounts. If oil is getting on the rubber, see about fixing the source of 
the leak:

Not necessary to remove the tranny from the car. With a bit of 
imaginative shopping you can fashion an inexpensive "press" from a 
length of allthread rod, some washers, nuts, and a short section of 
pipe, or in this case, a PVC plumbing adapter. The entire process was 
not too painful and made a huge difference in the feel of the car; 
shifting, take off, braking, bumps, backing uphill, etc. are all now 
much smoother and solid. ***Please take sufficient time and care to 
secure the car solidly on strong jackstands before crawling under the 
car.***

What follows is a more detailed description. A big thanks to Bob Brady 
who initially shared his description of the hardware and process.

O found a PVC adapter at a local "More of Everything" hardware store. 
One side was threaded internally, the other was not. The numbers on the 
end of it say "COLONIAL   U.S.A. D-2466  SCH 40  PVC-1  CAV. A   2-1/2" 
 NSF-PW".  It was approx. 5" long X 3-5/16" od x 2-7/8"id (smooth end) 
x 2-5/8"id (threaded end). I believe it was intended for mating iron 
(galvanized?) pipe to a PVC section. I chose it with replacement tranny 
mount bushing in hand-- the i.d. of this adapter was just slightly 
larger than the o.d. of the bushing. I knew the bushing could easily 
pass thru this "receiver" and the receiver had enough meat on the 
non-threaded end to butt up solid against the tranny housing, and enough 
meat on the threaded end to hold the largest washer solid. Didn't need 
to hone out the inside like Bob Brady did, but I did cut off a 1-1/2" 
off of the threaded end (easy to cut PVC w/ a hacksaw!) because it 
didn't actually need to be that long (needs to be only slightly longer 
than the width of the bushing) and I needed the extra manuverability 
because the master cylinder on my car is right down there by the side of 
the tranny mount which makes it a little tight. In fact, unlike Bob, I 
removed the bushing towards the passenger side for this reason.

The other parts were a 1 ft. section of 1/2"allthread rod, 3 nuts (two 
for double-nutting one side, the other for squeeze action), various 
washers, the most important ones being large enough to cover the 
threaded end of the PVC receiver (3"od x 1-3/8"id x 3/16" thick), and 
the other one (2-1/2"od x 1-1/16" id x 3/16" thick)  just slightly 
smaller than the tranny housing (again I used the replacement bushing to 
find a suitable size.) Buy two of each and stack them together to give 
extra strength-- I just noticed mine bent a little. Since these washers 
had large center holes, I bought smaller ones to stack to give the nuts 
a good seating. The large center holes actually helped because you'll 
notice the inner hole of the bushing is offset, and this gave me 
adequate play.

Raised the rear of the car and secured it until I was satisfied with 
jackstands.

I dropped the tranny crossmember by removing the four 13mm bolts (buy 
replacements! Bob warned me about this but I ignored it until closing it 
all back up-- snapped two-- luckily got the remains out easy but it 
meant another unnecesssary triip to the HW store.) and the two 13mm nuts 
for the front driveshaft section bearing. This let the rear of the 
tranny down far enough to work.

Removed the bushing's thru bolt, set aside the tranny x-member, and 
arranged the receiver and assorted washers and allthread rod and started 
wrenching. The washers dished, the nut got difficult to turn; I thought 
something was going to break, but kept at it. Sure enough, the bushing 
moved slightly, not with a snap or a bang, but a subtle release. From 
there it was easier but tedious wrenching until it was out.

I kept the replacement bushing in the freezer overnight but it still 
didn't "just slip in." BTW the large open gap in the bushing goes toward 
the top-- the inner metal tube where the thru bolt goes sits offset more 
toward the bottom. When mounted, the tranny's weight will push down on 
the outer section, making the inner steel tube end up almost in the 
center of the circle.

Tried reversing the operation to press the repl. bushing in but managed 
to lodge it in there crooked. The new one's rubber was in much better 
shape (the offset was still intact) and I couldn't get the allthread rod 
centered enough to get a square push. That's when I had to use the 
propane torch lightly on the aluminum tranny housing, then it was easy 
to hammer it in straight with a block of wood.

Buttoned it back up the reverse of the disassembly steps.

Took about three hours, not counting the shopping, or the busted 
crossmember mounting  bolts extraction.

You would not believe the difference! The car is a thousand times more 
comfortable!

--Caxambu
1969 Spider Veloce
Seattle WA



Jon_Durham@domain.elided wrote:


> Date: 4 Dec 2003 21:16:55 -0000
> From: "Jon_Durham@domain.elided" <Jon_Durham@domain.elided>
> Subject: [alfa] Replacing Transmission Mount 74 Spider and Protecting New One
>
> Can someone instruct me on replacing my transmission mount? Also, how can I 
> protect the rubber on the new one to keep it from deteriorating?
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