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Installing a new 4 speed hump

Started by hemienvy, October 09, 2022, 03:56:22 PM

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hemienvy

I bought the hump from Brewers, I'm putting it on the floor to draw a line for cutting the floor.
The hump does not seem to want to fit perfectly in any one particular position.
So how critical is the positioning before you weld it ? 1/4-inch in one direction or another ?
Or do you just cut the floor roughly one inch in from wherever the edge is, then put the tranny
and shifter in the car, then center up the shifter in the hole, then weld ?
What is the preferred order/method of doing this ?

Dmod1974

Definitely the preferred method would be to mock up the engine/trans/shifter so you can center it in the opening and make sure you have adequate throw clearance in all directions.  Leaving an inch overlap to start with is a good idea; you can always trim it more later on, but this will give you a good starting point to mock up everything.

Dakota

To add to the last post, I'd suggest putting in your gas pedal (bracket and rubber pedal) before finalizing the hump position. My hump ended up crowding the gas pedal too much.   I had to bash the hump with a dead blow hammer and widen the mounting holes in the firewall for the pedal bracket to create some space for my foot around the pedal.  Also, don't forget (like I did) to account for the thickness of the carpet and any underpayment (like Dynamat) with the pedal spacing.

I still don't like how close my pedal is to the hump I'm probably going to have to bend the pedal bracket a bit.


RUNCHARGER

Towards the back of the hump on the drivers side maybe 2 inches from the back, there is a dip in the flange of the hump that fits into a dip in the floor that places the hump in the correct spot. But yes I would wait until the trans and shifter are mocked up before cutting the opening and glueing in the hump. Autobody Glue is the way to go on this deal, you have to seam seal it anyway. I also cut the opening with a zip wheel and debur the edges of the cut.
Also, when you cut the opening be aware of where the crossmember is and don't cut through it.
Sheldon

larry4406

I used an OEM hump I took out of a car in a salvage yard.  It mated with the floor plan ridges perfectly and self aligned. 

I traced the flange on the floor, offset the flange amount, then cut the floor pan leaving the portion that covers the torsion bar cross member.  I added welds to secure the pan portion over the cross member.

I welded the hump to the pan from below.  Rotisserie sure helped.

71GranCoupe

Quote from: larry4406 on October 10, 2022, 01:38:14 PM
I used an OEM hump I took out of a car in a salvage yard.  It mated with the floor plan ridges perfectly and self aligned. 

I traced the flange on the floor, offset the flange amount, then cut the floor pan leaving the portion that covers the torsion bar cross member.  I added welds to secure the pan portion over the cross member.

I welded the hump to the pan from below.  Rotisserie sure helped.

Excellent info for the question, even better grade 4 speed humps should have the self-aligning ability. Some of the cheaper ones may not. It's best is to have a template for cutting the metal. If you don't have access to one, then cut the opening a little small then adjust to get the proper fit.

anlauto

Quote from: RUNCHARGER on October 10, 2022, 09:56:17 AM
Towards the back of the hump on the drivers side maybe 2 inches from the back, there is a dip in the flange of the hump that fits into a dip in the floor that places the hump in the correct spot. But yes I would wait until the trans and shifter are mocked up before cutting the opening and glueing in the hump. Autobody Glue is the way to go on this deal, you have to seam seal it anyway. I also cut the opening with a zip wheel and debur the edges of the cut.
Also, when you cut the opening be aware of where the crossmember is and don't cut through it.

Any one I've ever installed just basically fell in place.... :dunno:
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