The Stovebolt Site Forums The Shop Area Driveline 4 speed or T5?

A good friend has offered me a 4-speed transmission that was in a 63 or 64 Corvette. He says it’s in excellent working order and should fit my ‘59 Apache with the 235. I’ve had the shifter moved to the floor with a Hurst unit and wondering if anybody out there has done something like this and can offer any info and/or advice? I’ve been on this site for a couple years but this is my first post, and have enjoyed looking and learning from it!

I'm editing my original post, as I've come to the conclusion that the T5 is going to be the way to go. Now, I need to know which out of the many different transmissions that were made will work best in the truck, with the least modifications. From what I know (what little it is), I think I should try to find a unit from the '82-'87 or so model years, with the mechanical speedo. What model number transmission should I look for? They all begin with 1352~ with 3 more numbers. I have no idea what the differences are between them, maybe based on which vehicle they were originally installed in? I've just had the engine rebuilt and right now its still revving pretty much at 50mph, so Id like to get this truck more driveable in modern traffic and have less strain on the newly built engine.
Any information is welcome and appreciated, since I know this is a popular swap and these units are 'disappearing' quickly!

Check to see if the new transmission uses the same front driveshaft yoke. The later yokes have 28 splines vs 16 on the 59. Also, the Corvette linkage mounts on the rear of the housing, there may be an issue with the shift lever hitting the seat. All this can be worked around.
Fred

Welcome from Brunswick, glad to have another 59' on the site. I'm working out the same swap your talking about but with a 327. It all comes down to what transmission you are talking about, if it's the Saginaw the swap is much easier. If the transmission is a Muncie it's a little more complicated. There are shifters available to move the linkage forward on a Saginaw, the Muncie has an issue with the reverse shift linkage being in the way. Both transmissions use a rear mount requiring a crossmember. A 4 speed is still only going to give you a 1:1 final ratio.

Probably a Borg Warner four speed. The trans will physically bolt up to the bell housing so no issues there. You will have to look at the input snout. If its a course spline input snout, then your present clutch is fine. However, you have it all apart, now would be as good a time as any to refresh those parts. So, I would install a real oilite pilot bushing in the crank. Remove the pressure plate and clutch and look at the flywheel. If the flywheel is pretty worn or gouged, you might consider taking it to a machine shop and have it machined (make sure they have the ability to surface grind. If all they do is chuck it into a drum lathe, go someplace else.) The stock clutch could be 9 1/2 inches, heavy duty might be 11. If you have a 9 1/2 inch clutch measure the flywheel and you will note that it will take a 10 inch clutch. So if you want to upgrade, use a 10 inch clutch and pressure plate. Stock type flat fingered diaphragm pressure plates take the longer GM style throw out bearing, the more performance oriented cone shaped diaphragm pressure plates use the shorter GM throw out bearing.

Look at the front bearing retainer on the trans. It needs to be smooth, rust free and without gouging. If its not great, get a replacement because that is what the throw out bearing rides on. It needs to be clean and smooth for nice smooth engagement and disengagement.

Out put shaft, as was earlier noted, count the splines. You might have to swap yokes. Finally, you may have to shorten the drive shaft just a bit. You need 3/4 to an inch of clearance between the yoke and trans. Install the driveshaft in the trans until it bottoms out. Then pull it out to seat the rear u-joint. The shaft needs to pull out at least 3/4 of an inch.

I ran a car 4 spd for a few years in my '60 C10 / 235. 1st & reverse were too high for my liking, PITA getting going on hills.

Thanks to all who've replied to my question. I've just had the engine totally rebuilt and my mechanic suggested either a 4 speed or the S-10 5 speed, since the engine revs pretty high at around 50mph. Although I'm not interested in doing any highway driving with it, I'd like it to be a little more "user friendly" around town and everyday traffic. Also, the shifter sometimes pops out of 3rd gear, which someone on this site with the same issue was told its the transmission and not a shifter problem, so I'm looking at transmission work anyway. That said, I think I'd be better off with an all synchro unit and the extra gear the 4 speed would provide, which I hope will cut the revs down a bit. I guess right now I need to find out what kind of Transmission that 4 speed is. Thanks, again, for your input and advice!

Before you spend your hard earned money make sure you know the transmission gear ratios to confirm it's a good match for you engine, rear and tire size. A Saginaw trans could have 4 or 5 different 1st gear ratios...the same is true with the T-5's, so do your homework first.

Mike B

Thanks, I’m seeing that some “detective work” is gonna be necessary. Thanks, much!

The 4 speed top gear is direct, will not cut down the revs at all, only a S-10 5 speed will have OD in top gear.

Ed

Thanks, Ed, T-5 may be the way to go, if I choose to do it at all. I had no idea of all the factors that must be considered. Thanks again to all for your input!