Transmission Cross Member
#1
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iTrader: (3)
Joined: Sep 2003
Posts: 6,859
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From: Cypress, California
Car: 1989 GTA
Engine: 369 TPI
Transmission: 4L60E
Axle/Gears: 3.70 Nine Bolt
Transmission Cross Member
I have shown some pictures of my transmission cross member in another thread on exhaust termination boxes. These are progress pictures as the cross member is nearing completion. So I thought I would start a separate thread instead of adding to the other one.
I built this for 3 reasons. One is to be able to run one exhaust pipe along side of the passenger side of my new 4L60E transmission. With the factory crossmember in place the pipe would have to dip very low and there would not be much ground clearance. My cross member will allow the pipe to run much higher with pretty much the same ground clearance I now have.
The 2nd reason was to remove the factory torque arm off of the transmission tail housing to the cross member. The 3rd reason was to build in a drive shaft loop. All three aims have be accomplished. The final weld will be the drive shaft loop. I have left it off for the time being as I don't want to remove the drive shaft every time I check things out. Here are some pictures.
The center picture would be if you were looking forward from the rear end. The high mount on the right is for the exhaust pipe clearance. The picture on the right is if you were looking to the rear from the engine. The front hole is where the transmission mount goes. The picture on the left would be looking at it from the drivers side.
I built this for 3 reasons. One is to be able to run one exhaust pipe along side of the passenger side of my new 4L60E transmission. With the factory crossmember in place the pipe would have to dip very low and there would not be much ground clearance. My cross member will allow the pipe to run much higher with pretty much the same ground clearance I now have.
The 2nd reason was to remove the factory torque arm off of the transmission tail housing to the cross member. The 3rd reason was to build in a drive shaft loop. All three aims have be accomplished. The final weld will be the drive shaft loop. I have left it off for the time being as I don't want to remove the drive shaft every time I check things out. Here are some pictures.
The center picture would be if you were looking forward from the rear end. The high mount on the right is for the exhaust pipe clearance. The picture on the right is if you were looking to the rear from the engine. The front hole is where the transmission mount goes. The picture on the left would be looking at it from the drivers side.
Last edited by 1989GTATransAm; 01-06-2009 at 07:25 PM.
#2
Thread Starter
Supreme Member
iTrader: (3)
Joined: Sep 2003
Posts: 6,859
Likes: 14
From: Cypress, California
Car: 1989 GTA
Engine: 369 TPI
Transmission: 4L60E
Axle/Gears: 3.70 Nine Bolt
Re: Transmission Cross Member
Here are three more pictures with one showing the torque arm mount in place. The first two pictures show the underside as you would see from the bottom of the car.
#3
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Joined: Jul 1999
Posts: 17,174
Likes: 140
From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Transmission Cross Member
Looks good but I don't think your driveshaft loop is legal.
Driveshafts must have a retaining loop 1/4" minimum thickness and 2" wide steel or 7/8" x .065" wall welded steel tubing.
Aluminum driveshaft loops won't pass a tech inspection.
Driveshafts must have a retaining loop 1/4" minimum thickness and 2" wide steel or 7/8" x .065" wall welded steel tubing.
Aluminum driveshaft loops won't pass a tech inspection.
#4
Thread Starter
Supreme Member
iTrader: (3)
Joined: Sep 2003
Posts: 6,859
Likes: 14
From: Cypress, California
Car: 1989 GTA
Engine: 369 TPI
Transmission: 4L60E
Axle/Gears: 3.70 Nine Bolt
Re: Transmission Cross Member
I have already twisted and broken the stock aluminum drive shaft on the chasis dyno. The driveshaft loop is more for my protection. I have never been called for a driveshaft loop at the track. If asked I can say I have one. It is 1/2 inch thick by 1 inch long but made of aluminum tubing as you stated.
#5
Member
iTrader: (1)
Joined: Jul 2007
Posts: 111
Likes: 0
From: Calgary, AB, CA
Car: 91 Formula
Engine: L98 350 TPI
Transmission: TH700R4
Axle/Gears: 3.23
Re: Transmission Cross Member
Damn nice welding , can you post photos once it is installed? The piece looks great, I am curious to see how your design fits in the car.
#6
Junior Member
iTrader: (1)
Joined: Feb 2008
Posts: 46
Likes: 0
From: Wilmington DE
Car: 91 Bird
Engine: Pontiac 500 + CID
Transmission: 3 speed auto
Re: Transmission Cross Member
I do not think that is strong enuff, and "loop" is too small.(my Alu shaft is much larger than stock, may help you as well) I got my set up from ED QUAY...its all chrome molly light but much stronger 9and did away with the weak stock rubber mount) You did nice looking work... but maybe you should have looked around at what others were using/selling frist. Good luck with your project!
Last edited by PROSTOCK5031; 01-18-2009 at 01:31 PM.
#7
Thread Starter
Supreme Member
iTrader: (3)
Joined: Sep 2003
Posts: 6,859
Likes: 14
From: Cypress, California
Car: 1989 GTA
Engine: 369 TPI
Transmission: 4L60E
Axle/Gears: 3.70 Nine Bolt
Re: Transmission Cross Member
I will continue on the mount in February. I have to mount it in the car one more time. One more gusset needs to be installed. Just need the final dimension. Also will weld the loop in place. Then on to the paint shop. We shall see on the strength.
The loop barely clears the tunnel now.
The loop barely clears the tunnel now.
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