modding manual cross member for automatic
Thread Starter
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
modding manual cross member for automatic
I did look around here not really finding the info I need perhaps I missed it and you can clue me in or direct me,
My 69 is a automatic bolt in cross member my 68 donor chassis is manual, welded in tranny cross member,
I am for now keeping the th400, so I know when budget and desire allows I will add a 700 but for now keeping the 400 tranny what is the best way for my shop man to modify the fixed tranny cross member so that the 400 can be dropped out and 700 or another 400 installed when that time comes....I am guessing some will say "kit" but is there a "work with what I have" way to do it?
Thanks!
My 69 is a automatic bolt in cross member my 68 donor chassis is manual, welded in tranny cross member,
I am for now keeping the th400, so I know when budget and desire allows I will add a 700 but for now keeping the 400 tranny what is the best way for my shop man to modify the fixed tranny cross member so that the 400 can be dropped out and 700 or another 400 installed when that time comes....I am guessing some will say "kit" but is there a "work with what I have" way to do it?
Thanks!
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
Some members have modified the crossmember by sectioning it just inboard of the side rails and welding plates on the four ends, then using bolts to clamp the plates together. A really nice job. Search and you'll find pics.
Thread Starter
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
Team Owner
Joined: Jul 2004
Posts: 40,408
Likes: 792
From: Redondo Beach, California
My 68 Convertible. This was done at J&D Corvettes in Bellflower Ca. Did a beautiful job. The stock Muncie 4 speed was also replaced with a TKO 600 five speed. A removable crossmember makes such a nasty transmission/clutch replacement so much easier.
Last edited by 68/70Vette; Sep 30, 2014 at 10:55 PM.
Burning Brakes
Joined: Dec 2008
Posts: 971
Likes: 45
From: Middlesex NJ
Here is how I made mine removable. Did it on my car and my buddies.
If you do it like mine start on one side by cutting completely through then install your plates on that one side first in the opening you cut into the member and then weld it up.
Then do the other side this way you didn't remove it completely and have to now measure and align things.
I forget who I got the plates from but you can get the idea from my pics. Just remember if you put them in to high they will hit the floor of the body and too low and they will be the lowest part of your frame to ground clearance.
in frame
side
removed
If you do it like mine start on one side by cutting completely through then install your plates on that one side first in the opening you cut into the member and then weld it up.
Then do the other side this way you didn't remove it completely and have to now measure and align things.
I forget who I got the plates from but you can get the idea from my pics. Just remember if you put them in to high they will hit the floor of the body and too low and they will be the lowest part of your frame to ground clearance.
in frame
side
removed
Team Owner
Joined: Jul 2004
Posts: 40,408
Likes: 792
From: Redondo Beach, California
This was done to my 68 Corvette at J&D Corvette in Bellflower when they installed my TKO 600 5 speed tranny.
I have factory 69 side pipes and a removable crossmember on my 68. The 69 side pipes means there's no exhaust pipes in the way, and the removable crossmember means the tranny can be dropped with no struggle. Working on the tranny/clutch is made sooooo much easier. If you're not NCRS and you have to replace the clutch or tranny, you must think seriously about this mod.
I have factory 69 side pipes and a removable crossmember on my 68. The 69 side pipes means there's no exhaust pipes in the way, and the removable crossmember means the tranny can be dropped with no struggle. Working on the tranny/clutch is made sooooo much easier. If you're not NCRS and you have to replace the clutch or tranny, you must think seriously about this mod.
Thread Starter
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
This was done to my 68 Corvette at J&D Corvette in Bellflower when they installed my TKO 600 5 speed tranny.
I have factory 69 side pipes and a removable crossmember on my 68. The 69 side pipes means there's no exhaust pipes in the way, and the removable crossmember means the tranny can be dropped with no struggle. Working on the tranny/clutch is made sooooo much easier. If you're not NCRS and you have to replace the clutch or tranny, you must think seriously about this mod.
I have factory 69 side pipes and a removable crossmember on my 68. The 69 side pipes means there's no exhaust pipes in the way, and the removable crossmember means the tranny can be dropped with no struggle. Working on the tranny/clutch is made sooooo much easier. If you're not NCRS and you have to replace the clutch or tranny, you must think seriously about this mod.
I am keeping the th400 for now, as budget goes I want AC before 700,
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Verdad Gallardo
Team Owner
Joined: Jul 2004
Posts: 40,408
Likes: 792
From: Redondo Beach, California
For people that want to convert their auto to manual, I think you should order the parts in advance...just to make sure when you do it, the parts are still there.
You need to order the clutch and brake assemblies. Actually the clutch pedal lever works with the auto trans brake support rod. If you have an auto C3 to convert to manual, it's just terrible to work with the clutch/brake assembly inside the driver's firewall. If you remove the steering column, it's so much easier.
I replaced the vacuum power brakes on my 70 with the Hydraulic Boost GM power brakes (Hydoboost?) To install this system, I removed the steering column and the install became very easy.
You need to order the clutch and brake assemblies. Actually the clutch pedal lever works with the auto trans brake support rod. If you have an auto C3 to convert to manual, it's just terrible to work with the clutch/brake assembly inside the driver's firewall. If you remove the steering column, it's so much easier.
I replaced the vacuum power brakes on my 70 with the Hydraulic Boost GM power brakes (Hydoboost?) To install this system, I removed the steering column and the install became very easy.