Removable crossmember questions...
Thread Starter
Pro
Joined: Jul 2011
Posts: 508
Likes: 36
From: Ia
Removable crossmember questions...
So I think the throw out bearing in my 77 may be going south. When it gets hot (like after repeated use around town) I get a 'buzz' vibration through the pedal, when I let out the clutch. Or maybe the clutch itself is chattering.. I'm not sure.
At any rate It has gotten me thinking about R&R. Since I have had the motor out a couple times now I thought it might be easier to pull the trans instead. However, I have heard the fixed manual cross-member can be a witch to work around. I also know some of you guys have modified yours to be removable... how did the factory do it? how did you do it? what did you use? what problems did you run into? Just weighing out my options.
And speaking of options... Why on earth would the factory use two different frame configs for auto vs. manual? I understand the autos need the extra clearance, but I would think it would make more sense from a manufacturing and supply chain stance to have just one frame with a removable cross-member that could be swapped back and forth. Especially considering in the later year the manuals made up only a small percentage of production
At any rate It has gotten me thinking about R&R. Since I have had the motor out a couple times now I thought it might be easier to pull the trans instead. However, I have heard the fixed manual cross-member can be a witch to work around. I also know some of you guys have modified yours to be removable... how did the factory do it? how did you do it? what did you use? what problems did you run into? Just weighing out my options.
And speaking of options... Why on earth would the factory use two different frame configs for auto vs. manual? I understand the autos need the extra clearance, but I would think it would make more sense from a manufacturing and supply chain stance to have just one frame with a removable cross-member that could be swapped back and forth. Especially considering in the later year the manuals made up only a small percentage of production
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Manual transmission crossmembers were welded until the 1981 model year.
AT frames not only had the removable crossmember, they did not have the clutch bracketry the standard trans frame received.
...Why on earth would the factory use two different frame configs for auto vs. manual?...
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
The factory already had the drive line in the frame and married the body to the frame.
Yes..it can be a balancing act when getting the transmission out. Rotating it and pulling it to the rear while allowing the engine to drop slightly so the bell housing can be removed with the transmission die to literally 1/8" holding you up. It can depends on the car also....but most of the ones I have done may me work for it.
Obviously...if you get it out...make sure you inspect/change out your pilot bushing with a NON metallic designed one if you are doing a complete clutch set-up.
DUB
Yes..it can be a balancing act when getting the transmission out. Rotating it and pulling it to the rear while allowing the engine to drop slightly so the bell housing can be removed with the transmission die to literally 1/8" holding you up. It can depends on the car also....but most of the ones I have done may me work for it.
Obviously...if you get it out...make sure you inspect/change out your pilot bushing with a NON metallic designed one if you are doing a complete clutch set-up.
DUB
Thread Starter
Pro
Joined: Jul 2011
Posts: 508
Likes: 36
From: Ia
Drifting
Joined: Sep 2007
Posts: 1,572
Likes: 51
From: Wichita Kansas
The automatic crossmember is bolted in with 3 bolts on each side. On each side there are bracket/tabs welded to the frame that the crossmember mates with. Horizontal bolts go through the tabs and cross member. The on each side of the crossmember there are tabs (as I can't find a better word) that mate to the under side of the frame rails. 2 bolts each side going up into the frame. The cross member goes in and out very easy for mark up of any modification.
Advanced
Joined: Nov 2014
Posts: 55
Likes: 4
From: Slidell Louisiana
The automatic crossmember is bolted in with 3 bolts on each side. On each side there are bracket/tabs welded to the frame that the crossmember mates with. Horizontal bolts go through the tabs and cross member. The on each side of the crossmember there are tabs (as I can't find a better word) that mate to the under side of the frame rails. 2 bolts each side going up into the frame. The cross member goes in and out very easy for mark up of any modification.
Yep.....pretty good description
Team Owner
Joined: Jul 2004
Posts: 40,412
Likes: 792
From: Redondo Beach, California
Took my 68 Convertible manual car to J&D Corvettes (Bellflower, California) for a TKO600 install. I wanted a removable crossmember and provided the way I wanted them to do it.
Take a Sawzall and cut the factory tranny crossmember about 1 1/2 feet from the center of the crossmember. Next take a piece of stiff paper and make the outline of the crossmember cross section. Use this outline to create four flanges. Weld two flanges on the crossmember stubs still welded to the frame. Weld the other two flanges to the cut out crossmember section. Drill 4 holes in each flange. After positioning the tranny against the bellhousing, install the removable crossmember.
Makes removing the tranny soooo much easier.
Take a Sawzall and cut the factory tranny crossmember about 1 1/2 feet from the center of the crossmember. Next take a piece of stiff paper and make the outline of the crossmember cross section. Use this outline to create four flanges. Weld two flanges on the crossmember stubs still welded to the frame. Weld the other two flanges to the cut out crossmember section. Drill 4 holes in each flange. After positioning the tranny against the bellhousing, install the removable crossmember.
Makes removing the tranny soooo much easier.
Drifting
Joined: Sep 2007
Posts: 1,572
Likes: 51
From: Wichita Kansas
These photos should be a big help!
Side note: If I'm correct to think this photo is the RH side I'm certain that the long bolt needs to go in from the aft or the underbody/floor pan access will not let it come out? I just know on my 78 bolt left and right will only go in from the aft as the floor pan will interfere.
Side note: If I'm correct to think this photo is the RH side I'm certain that the long bolt needs to go in from the aft or the underbody/floor pan access will not let it come out? I just know on my 78 bolt left and right will only go in from the aft as the floor pan will interfere.
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Advanced
Joined: Nov 2014
Posts: 55
Likes: 4
From: Slidell Louisiana
These photos should be a big help!
Side note: If I'm correct to think this photo is the RH side I'm certain that the long bolt needs to go in from the aft or the underbody/floor pan access will not let it come out? I just know on my 78 bolt left and right will only go in from the aft as the floor pan will interfere.
Side note: If I'm correct to think this photo is the RH side I'm certain that the long bolt needs to go in from the aft or the underbody/floor pan access will not let it come out? I just know on my 78 bolt left and right will only go in from the aft as the floor pan will interfere.