72Cutlass_442

Hello All,
I have a 1972 cutlass S that I am currently converting to a manual from an automatic. I am in the end stages and am trying to figure out how to hook up the reverse light switch. On some websites, I've see the reverse switch connected to the muncie itself but when I try to find the switch for my car specifically, it is on the steering column. Is this correct? How does the car know when I shift as there are no connections between the muncie and the steering column. What am I missing? Does anyone have any photos of this connection?

joe_padavano

What you are missing is that every GM car built since the 1969 model year has had a backdrive linkage that locks the shifter with the ignition key. On manual trans cars with floor shift, this is a linkage that connects the steering column to the shift linkage on the trans and requires you to have the trans in reverse to lock the column and remove the key. Since that linkage was required by federal law and was already there, it was easier and cheaper to just use the backup light switch on the steering column instead of having a separate one on the trans. Unless you plan to find and install this backdrive linkage, your only other option is to use a 1968-prior style backup light switch that mounts directly on the trans. And as always, the diagrams are in the Chassis Service Manual.

72Cutlass_442

I think I understand. So is the linkage the same linkage that the automatic uses to shift? I googled the back drive linkage and am finding what appears to be the automatic linkage which I have. I have also stumbled across this drawing but I though it was for column shift manuals.

joe_padavano

The backdrive linkage is SIMILAR to the parts used for a column shift car. Specific part numbers may differ. And FYI, that PDF says it is for a four speed manual trans. There were no column-shifted four speed manuals from Oldsmobile.

72Cutlass_442

Oh gotcha, I wasn't aware. Upon doing some research, it appears they are identical part #s from the steering column to the shifter linkage. I just need that part that connects the two. Thanks for clearing all that up!

joe_padavano

Looks like the parts you need are reproduced. You need the lever for the reverse fork and the rod between them as well as the lever and pivot stud that go on the 3-4 shift shaft.

https://www.chicagomusclecarparts.com/products/777084

72Cutlass_442

That is exactly what I need. Thank you for looking into that for me. Now all I need to do is modify the automatic steering column to function with this linkage.

My442

The reverse light switch for a 4 speed 70-72 Olds is mounted on the steering column.They are reproduced.

Will the back drive linkage installed and adjusted (The Factory Assembly manual shows how to do it), when you put the car
in reverse, the bowl on the steering column rotates and trips the reverse light switch.

There are no modifications to the automatic column - I did a conversion and it works fine.

Be aware that the steering will be locked when the car is placed into reverse.

joe_padavano

A couple of clarifications. Obviously you need to remove the AT shift arm from the column. The arm locks into the shift gate inside the column. If you want, you can replace the shift bowl with one that does not have the boss for the shifter arm.

Placing the trans into reverse does not lock the steering. I believe what you meant to say is that you MUST shift into reverse in order to turn the key to the LOCK position. That's always a good idea on an MT car anyway.

72Cutlass_442

So no internal modifications needed to the column. Thats good to know, I was planning on getting in there tonight and messing around. And thank you joe_padavano for clearing that up, I was concerned that I wouldn't have steering in reverse. That would be difficult to navigate. I do have another issue. I purchased a flywheel from partsgeek about 2 weeks ago and I finally was at a place to put it on last night but it wouldn't fit. I am returning it but now I'm nervous to purchase another one. I know there are some better sites but I wonder why it didn't fit as it say its for my car. Anyone have any thoughts on that? The brand is Exedy and the part number is FWGM101

joe_padavano

It doesn't fit because it is for a Chevy. Here's a hint. Most parts sites will show Chevy parts as fitting Oldsmobiles, assuming that everyone has already put a Chevy motor in their car. Ignore any on-line catalog, or at least assume it is wrong until proven correct. For example, if you go to RockAuto and search for a flywheel for a 1970 Olds, you'll get two listings. One is a 153 tooth and one is a 168 tooth. BOTH of those are for Chevy motors. The correct Olds flywheel has 166 teeth.

Here's one that DOES fit an Olds.

https://www.summitracing.com/parts/c.../model/cutlass

72Cutlass_442

Well that's irritating. I believe the one I got has 168 teeth. So if it has 166 teeth, it should fit? I've found a few places that say they are for my car and do say the teeth count is 166 and are a bit cheaper than the one from summit, but I don't want to make another mistake.

joe_padavano

All Olds flywheels have 166 teeth. I do not know if all flywheels with 166 teeth fit an Olds, however. If it says 166 tooth AND it says something like "Oldsmobile 260/307/350/403/455" then you're probably good.