Installation of the Smitty 5-speed Toyota Kit
By Steve Gerow
Pasadena CA
These are notes on the installation of the Smitty 5-speed Toyota kit on my 59 BN6 with 29D engine and 10" coil spring clutch. Some suppliers in the Los Angeles area are included for convenience. These notes are being posted so they'll be in the archive for future use.
I had posted questions and received much useful off-list information regarding this conversion. Thanks to Robert Barback, Dean Caccavo and Jim LeBlanc as well as several others. Vive La Liste!
Robert Barback's notes on his BT7 installation follow mine.
Smitty Kit:
The Smitty kit is a well-made and engineered product for a reasonable price. None of the following comments are intended to disparage this product or Smitty, but rather to get more information out there for future use. Posters in this list have said they'd put one of the kits on in a weekend. Mine was more of a fiddle and Smitty cautions that these cars tend to be different and each install is a process. Smitty 805-495-1488.
Smitty's manual is comprehensive and is said to be available ahead of time if you are interested in purchasing the kit (I haven't verified that). The manual supplies all the needed Toyota part numbers with plenty of drawings.
Retaining Engine Position for easy reinstallation:
With the transmission removed the engine mounts are not too far off from the balance point of the engine. Therefore it is possible to hold the engine in the proper position with a carefully measured block of wood between the valve cover and the firewall. The pressure from the engine tilting is not enough to cause any significant flex in the firewall. Be careful!
I bought the $69 Transmission Jack from Harbor Frieght and used it in combo with my floor jack and an overhead cable hoist ("comealong"). I used the floor jack to move the engine up and down with a 2x4 under the back of the pan (non-concours pan--lotsa dings). I used the comealong hanging from the garage rafters to lift the tail end of the Healey and Toyota transes up via a fan belt looped under the back of each trans. Having the two jacks was more important than the comealong. The transmission jack accurately holds and supports the trans and allows it to roll forward and backward. Many people say this is fairly easy to do with just a floor jack.
Transmission:
The Toyota transmissions come with the shift tower in 3 positions--front, middle and back. Mine is the front tower and I surely wouldn't want the shift lever any further back than that, although Smitty says you can use all 3--he also says front is best. The others require bending the shift lever forward then up. Center-shifters are different.
I got my transmission from Foreign Auto Salvage in North Hollywood CA for $300. Upon disassembly, found chipped gears and at least 2 tablespoons of coarse metal chips in the inside. Foreign Auto instantly replaced it with no hassle. The second trans appears to be from a Toyota Sedan, because it came with a long, chrome shift lever with a fake leather ball on the end. The trucks tend to have black shift levers. I took it apart and it was perfect on the inside. Put a gasket set in it. Smitty's manual doesn't mention this, but the gasket set comes with front & rear seals included, which I'd purchased separately.
In the junkyard you may want to check out the 5th gear ratio by putting a mark on the input shaft and seeing how far the output turns. I didn't do this until I had the trans installed in the car--unfortunately it seems mine has an 18% overdrive--most are supposed to be 22%. Oh well.
Suggest retorquing the main case bolts till they feel snug. Mine felt like they might be starting to strip at 40 lb-ft and the Chilton Toyota Truck manual says to use 53. Likewise the front nose cover said 27 and 19 or 20 feels more like it. Most guys ignore or don't know these figures and just torque till they feel snug.
Toyota uses a splined yoke which slides in and out of the rear of the trans--this instead of the splined 2-piece shaft from the Healey. Smitty says to get the yoke from the junk yard. I did this, but the one I got had a non-removable u-joint in it. Which brings me to the driveshaft fabrication.
Driveshaft:
The going rate for these driveshafts seems to be about $200. Mine was fabricated by Driveshaft Specialist in Irwindale CA (626) 334-2418. He quoted me $135 to fab it cannibalizing the flange off my Healey shaft. He actually built it fresh in 2 days using an aftermarket Toyota sliding yoke for $115 total, leaving my Healey shaft intact. Wow! He told me that since Toyota makes (or made) some of their trucks in the US, US-made yokes are available at large savings over the original part. Smitty's manual describes how to measure for the driveshaft needed.
Clutch:
Likewise, another lister emailed me who had had a custom clutch disc made by a clutch specialist. I did not do this, as I'd already special-ordered a remanufactured disc from Toyota for $73 and could not return it. He said you can have a custom disc made for half this, though I didn't check. I've had a recommendation of Valley Clutch Co also in Irwindale CA at (626)962-8787. This fellow said his Toyota disc was the same thickness as the minimum thickness specified for the Healey clutch. I was not able to find a spec for disc thickness for the Healey either in Haynes or in the Official manual. My Healey disc appeared to be nearly new and the Toyota disc was maybe 20 thousanths thicker. I did not experience any interference or rivet problems with my BN6 clutch, as Robert did with his BT7.
Thicker clutch disc would give more clearance:
It occurs to me that if the assembled clutch cover is too thick from the engine to the T/O plate and the T/0 bearing is riding on the clutch all the time, then you could have a thicker clutch disc fabricated which would move the levers and clutch T/O plate down toward the flywheel, giving clearance in front of the T/O bearing. I would seek guidance from the clutch fabricator on this issue before going ahead with it. It also occurs you could make a telescoping adjustable slave pushrod out of a piece of steel tubing, jam nuts and a 1/4-20 screw.
Rebuilding the clutch slave cylinder:
My clutch slave cylinder needed an overhaul. One lister suggested leaving the cylinder hanging under the car and letting it bleed by gravity into a pan. I used a turkey baster to remove all the old brake fluid from the reservoir and filled it up again with new Castrol LMA. I allowed about 1/2 the reservoir to drain out through the bleed screw and all the bubbles were gone.
Slave Cylinder and clutch pushrod:
Two emailers said they'd had to use a different Toyota T/O bearing because the original was not extending far enough forward to fully depress the clutch. Rather than do this I shimmed the ball stud with approximately 3/16" of washers. Moving the ball stud forward moves the lever rest position near the front of the opening which is most desirable for guaranteeing the clutch will disengage. The slave cylinder can then operate it with maximum travel. Adjusting the length of the pushrod may be necessary in order to proplerly bottom the slave piston. I used a 16d nail as a practice pushrod to experiment with lengths. In my case the Smitty-supplied pushrod worked fine.
