Manual Transmissions

[Paul K.]

I have been thinking on converting my automatic R-1 to a manual transmission with overdrive. I like to keep things original, however, I prefer the manuals. Living in Southern, CA low revs on the freeway is what I am looking for. A couple of questions,

1. What are the RPMs of the stock Stude overdrive at around 70 mph using a more common 3:31 rear axle? Is it much lower than the auto?

2. Are there any modern 5 speed transmissions that fit the Stude 289?

3. Has anyone done this that has advice to offer regarding ease of conversion?

Thanks,

Paul Katson

[Jim78]

I have been thinking on converting my automatic R-1 to a manual transmission with overdrive. I like to keep things original, however, I prefer the manuals. Living in Southern, CA low revs on the freeway is what I am looking for. A couple of questions,

1. What are the RPMs of the stock Stude overdrive at around 70 mph using a more common 3:31 rear axle? Is it much lower than the auto?

2. Are there any modern 5 speed transmissions that fit the Stude 289?

3. Has anyone done this that has advice to offer regarding ease of conversion?

Paul,

Thanks,

Paul Katson

Go to the Studebaker Drivers Club Forum. Use the "Search" function, and you can find much discussion on this topic. The standard Studebaker overdrive transmission may not fit because of the X-member, and there are several other options. There have been a number of folks who have mated modern 5-speed transmissions to the Studebaker motor, and various adapter plates are available to do this. Obviously, going from the automatic to standard would require acquiring the clutch pedal and linkage. Another (probably simpler) option is to swap to a late model GM automatic transmission with overdrive. That's been done, too.

[okc63avanti]

I have been thinking on converting my automatic R-1 to a manual transmission with overdrive. I like to keep things original, however, I prefer the manuals. Living in Southern, CA low revs on the freeway is what I am looking for. A couple of questions,

1. What are the RPMs of the stock Stude overdrive at around 70 mph using a more common 3:31 rear axle? Is it much lower than the auto?

2. Are there any modern 5 speed transmissions that fit the Stude 289?

3. Has anyone done this that has advice to offer regarding ease of conversion?

Thanks,

Paul Katson

My 63 Avanti R1 is being converted from an R1 with PowerShift automatic to an R2+ with a Tremec TKO 5 speed. The work is being done by Mike Myer at Myer Studebaker in Ohio. I've written a Microsoft Excel spreadsheet and you can download from Bob Johnstone's website. The spreadsheet let's you input the diameter of your tires, transmission ratios and the rear end ratio to calculate RPM at 60 and 70 MPH.

To make the conversion here's whats involved. Mike found a early 61~62 289 bell housing with GM bolt pattern for a Borg-Warner T10. These are getting hard to come by. Phil Fairborn at Fairborn Studebaker has a new bell housing with that pattern but I believe it requires the use of a hydraulic throw-out bearing (maybe not a bad idea). There are also some adapter plates if you can't find an early bell housing or what to save a little money.

The Tremec TKO new will run about $2100, I'm not sure what a used one would go for but you would want to make sure it wasn't abused and is in good shape. The older Borg Warner T5 are not rated to handle the torque that a R series engine can put out. The mid~late 90's Camaro & Firebirds used a Tremec 3550 and that may be a good choice if you can find one.

Mike will use a GM clutch plate to match up with the input spline count Tremec uses for GM applications. Once trans is installed and both are in the chassis, the driveshaft will be taken to a driveshaft shop Mike is comfortable with to have it shortened and balanced.

Do check out Bob Johnstone's website its a great source of technical data and there is quite a bit posted on 5 speed transmissions.

My link

[tjl2244]

I have converted my R-1 automatic to a World-Class T-5 from a '93 Mustang. Dan Giblin, whom you can locate on the SDC Forum, sells an excellent adapter kit that fits like a glove on the Stude bellhousing. Note that you will need a new bellhousing for a manual-shift car, a new brake and clutch pedal bracket, and all the linkages. Various vendors can find all of this stuff, but it will take some phone calls to gather it all. The main advantage of a T-5 over a TKO is cost -- TKOs are more than twice as expensive. The down side, such as it is, is that WC T-5s are rated for "only" 300 HP, whereas TKOs can take 450+. The R-1 engine maxes out at 240, however, and even the R-2 can only get to 290. You'd need an R-3 to stress the T-5. Since you've got 3:31 gears, as I do, you're not going to be doing any drag racing, anyway.