3rd & 4th gears backwards!?

[JimT1971RR]

I was taking my 71 bird out for a little test drive to check out a couple of adjustments I made to the brakes, when I discovered something very unusual. When I put the car into 3rd gear it is actually going into 4th and vice versa. The first thing I did was crawl under the car to see if the lever was installed upside down but it wasn't. I thought I would try to switch the direction but because my shifter is in the rearward, console, position, the linkage hits the transmission support cross member.

I am considering trying to slighty bend the linkage to make it clear the cross member but it is very strong.

Does anyone have any suggestions short of removing the box and tearing it apart?

Thanks,
Jim

[71bird]

Which way is the shift lever pointed? Up or down?

[JimT1971RR]

It is pointing upward. That is how it looks in the pictures in my fsm. I thought about turning it downward but that is when the shift rod hits the cross member.

[gcoupe72]

You can't assemble the gears wrong.
The counter-shaft gears are made as an assembly.
I can't wait to hear what you find!

[JimT1971RR]

I was looking at some images of the 833 transmission last night. The OD units have the 3 - 4 shift arm pointing downward instead up upward. Since I bought the car in it's current configuration, I am wondering if it is an OD trans? I am going to do a test in the next day or two. Hopefully I can find out something!

[JimT1971RR]

Update: Looked at pad on side of transmission. Date code number sequence is 5780 which I calculated to be roughly mid 1977. The engine is a 440 out of a van or motor home with a date code of 12/1/76. I think the two are possibly original to each other. Since I am not really planning on racing the car, having an Overdrive transmission is really a positive, except that 3 & 4 are backwards. I think I am going to have to fabricate a new shift rod to so I can flip over the 3-4 shift lever to the downward position and therefore make the pattern correct again.

Any thoughts would be appreciated.
Jim

[71bird]

Yes the shift rod is longer for the OD transmission.I might be wrong, but if that is a OD trans, they only put them behind 318's and/6's. Not meant for high torque.Maybe someone else will jump in on that one.I'm putting a Passon OD in my car, but its made for high power motors.

[JimT1971RR]

Things are starting to make sense now! I was just reading a couple of articles on ALLPAR. One about the OD 833 and one about the B-Series Vans. It appears that when they came up with the OD 833, they didn't change 4th gear but rather changed 3rd from 1.40 to 0.71 to make it the OD gear. Then they just flipped over the shift lever to "fool" you into thinking 4th was the OD. Additionally, starting in 1977 they offered this transmission on the B-series vans mated to 400s and 440s. So like I thought, it is possible that my entire drivetrain came out of the same van. It was just modified to fit into my car.

I am going to see if I can find any serial numbers to confirm.

Thanks to all!

[72bluNblu]

Yes the shift rod is longer for the OD transmission.I might be wrong, but if that is a OD trans, they only put them behind 318's and/6's. Not meant for high torque.Maybe someone else will jump in on that one.I'm putting a Passon OD in my car, but its made for high power motors.

The 833 OD's are not as strong as a regular 833. Because of the way that 3rd and 4th gears are "switched", more stress is put on the input bearing when the car is in the overdrive gear. Which is why the 833 OD's had larger input bearings and input bearing retainers.

The bigger issue is the aluminum cases of the 833 OD's, as after awhile the shafts can get sloppy. That's an easy enough fix as folks have had the shafts bushed in the case to repair the cases, works pretty slick. But not all the OD's were aluminum cases, some were cast iron, so that may not be an issue on this one.

Regardless, while the 833 OD isn't as strong as a regular 833, we all know that the regular 833 is a brute on the street. An 833 OD will hold up behind a 440 on the street. I have actually heard of them doing duty behind 440's that saw frequent strip time too, although I'm not sure I would recommend that. But for a street car the 833 OD is a great transmission, even behind a 440. They have a pretty wide gear spread also, so they're not the greatest for racing to begin with.

I would be curious to see what they did with the bellhousing. The 833 OD's have larger input bearing retainers at 5.125, and use the larger bolt pattern. They do make a bearing retainer that reduces them down to 4.8" with the 4.16" pattern now, but what was frequently done was either turning down the input bearing retainer or opening up the bell housing register.

Here's an awesome article on 833's in general, which also explains the strength "issue" with the 833 OD.

http://www.slantsix.org/articles/4-spee ... speed1.htm

And here's a bunch of info on ID'ing 833's

http://www.brewersperformance.com/orderinfo.htm