View Full Version : HVDA conversion

02-12-2008, 01:52 PM
Install complete!! Now there is another Triumph cruising the highways and back roads of central Florida with a Toyota gear box. Thanks Herman, smooth short shifts and a 5th gear!!!



02-12-2008, 01:53 PM
How cool is that !!!!!!

congrats! enjoy!

02-12-2008, 02:17 PM

What year Supra did that tranny come out of? I have yet to see the metal plate in the middle of the tranny on any that I have seen at the recycle yards. I found one last weekend that was out of a 1984 Supra. I could not find the milege of the doner call. Worries me that the thing might not last as long as I would like.

TR3A Still original so far
BN4 with Toyota
BJ8 soon to have Toyota

02-12-2008, 02:50 PM

I just finished my HVDA conversion this past Saturday. I used a 1983 Supra transmission that I took to a transmission shop to have it torn apart and checked. It didn't need anything but I had all new seals put in. There is a guy that has 6 or 7 Supra transmissions in Beloit, WI. He specializes in taking Supras apart and selling parts. I paid $200. for mine.

Frank, I didn't see a pedal stop in your pictures. Just wondering if you did that. I am in the Chicago area where it is snowing again. I am leaving for Florida tomorrow and will be stopping in Lakeland on Friday to see a friend. Small world.


02-12-2008, 04:11 PM
Looks good Frank (just like my 3A). One thing I noticed is that with the 3A, the shifter sits short. Mine too.

The steel plate 5-speeds were used in Toyota 2wd pick-up trucks. The Supras have an aluminum plate.

For my speedo, I had to use a right angle to get the cable away from the exhaust.

02-12-2008, 05:09 PM
Looks great Frank. I also have the steel banded transmission. Did you have the flywheel redrilled for the TR6 pressure plate? Did you install his hydrolic throw out bearing as well?

02-12-2008, 05:43 PM
Nice Frank. I've got the HVDA kit that's going in on the restoration. The engine is just about done, so I'll be bolting up the trans pretty soon now.

I bought a resurfaced TR4A flywheel off of ebay for $40. I could've machined my old flywheel at work to accept the diaphragm pressure plate, but I also wanted the later style, bolt-on ring gear.

02-12-2008, 06:00 PM
According to this link the steel plate was also used on later Supras.
"Toyota lists a change from an alloy sandwich plate to a steel sandwich plate around 1989. The steel sandwich plate has some minor internal differences, and it is believed to be slightly stronger (some wider bearings, some wider gears, slightly different gear selection mechanism etc). In theory the all alloy version of the W58 should be the exact same strength as any other all alloy W-Series transmission. The steel plate version is considered much harder to find and worth approximately three to five times as much as an all alloy version."
I bought a 1989 W58 from a supra that has the steel band. Now I'm building the courage to tell my wife I need to buy the HVDA kit.

02-12-2008, 07:10 PM
To answer the questions.
Yes I did use a pedal stop, I have less than an inch of travel of the master cylinder piston.

The shifter does seem to sit lower, but it sure is smooth.

Had my flywheel drilled and taped for the TR6 pressure plate but had a lot of trouble getting it balanced. The hole in the center of the flywheel is about 7/8". The machine shops need a minimum of 1 1/8 to set it on the arbor used for balancing.

Yes I used the new throw out bearing setup

02-12-2008, 07:55 PM
I have a steel plate W55? from a truck (in my 4A project) as well as a Supra W58 in the 3A (and a spare Supra for that matter).

My steel banded is from a truck, has taller 1-2 and according to the charts has less OD. I don't know how to find out what ratios they actually are but rely on the charts too.

Very smooth and with the short shifter, it's great for speed shifts.

Here's visual comparison bewteen the two. Celica Supra is top one, truck on bottom.

02-12-2008, 09:15 PM
One more.

Frank, notice the curved right angle adapter screwed onto the tranny. I covered the cable with thermo-tec heat shield to protect it from the exhaust pipe.

Also shown is the HVDA supplied cable holder-bracket just behind the starter buldge.

02-13-2008, 05:08 AM
I am not worried about how long my HVDA will last.

Within weeks of spending about 2 grand to rebuild my original transmission, yes another thrust washer disintegrated. Rather than rebuild it again, I decided to go with the Toyota. There are literally thousands of them available for less than $400 apiece.

I love driving down the freeway at 70 MPH turning only 2800 RPM.

02-13-2008, 08:06 AM
My steel banded is from a truck, has taller 1-2 and according to the charts has less OD. I don't know how to find out what ratios they actually are but rely on the charts too.

It's easy enough to figure out the ratios yourself. You may need a helper to count revolutions. Mark both the input shaft and output with a magic marker. I maked on one of the splines. Put the box in neutral and align both marks at 12:00. Put it in the gear you want to check. Turn the input shaft a number of times...10X is convenient. While you're doing that, have you buddy count the number of times plus any fractions that the output shaft turns. Simple math will give you the ratio. It will be as close as you can estimate on the output end. By comparing your figures that you counted in each gear with the chart, it will be very apparent which box you have. That's what I did to verify I actually had a W58 from a Celica.