CAV GT40 Transaxle Update

I am in the final phase of revising the 016 transaxle in my #40 CAV. Didn't like the high rpm's of the AAZ geared box. I had a new ring and pinion, new 5th gear(.72), a Wavetech LSD, along with a rebuild of the transaxle done by German Transaxles of America. I'll be writing a separate thread on this part after a few miles of test driving.

I wanted to write down a few things that might make this revision easier for anyone considering a similar project. This is a project you can do at home without any special tools or equipment. I do not recommend using air tools. Pre-planning and organizing will make this job much easier.
- Take photos of every nut, bolt, bracket and area you put a hand on.
- Bag and tag every nut/ bolt/ bracket removed.
- You do not have to strip the entire rear suspension to remove the trans.
- Jack the car under the adapter plate to support the rear of the engine.
* Remove the rear cam shell only, not the bracing.
* Remove the muffler, sway bar and mount, cross brace, CV joints,
shift linkage, rear trans mounting brackets and hydraulic clutch line.
* Unbolt the trans and with a friend pull trans back from motor. You
will have to move some stuff out of the way to clear trans.
- The re-installation is simply the reverse of the above. I advise having
2 people to do this. You might find the transaxle difficult to go into the
pilot bushing, but put trans in a gear and wiggle. Shouting and cursing
tends to help a lot.
- I did install a new throw out bearing because the old one looked tired.
- I did not touch the clutch, pressure plate, flywheel or pilot bushing.
These items looked to be in good condition. My car has 12K miles on
the odometer.

I'm planning on test driving the car today or tomorrow and expect to see a lot less rpm at highway speeds. So far it's been an interesting project.
Like Tom, I put a upgraded 016 from GTA in my car and it's been a couple of months and I couldn't be happier with it. It came a little tight, wanting a pause and gentle shifting from first to second but that loosened up after a few hundred miles and it's now really great.
For installation, I found using an engine lift with cargo straps makes the installation easier. Measure the angle of the old box as it sits in your garage before removal and sling it to exactly that angle on the lift. That helps insure your pinion won't bind. Also lightly lube the pinion and use a clutch alignment tool to be sure everything it straight before you wiggle it into place. It's also a good time to check your clutch wear and replace the clutch hydraulic fluid.


Howard Jones

Here's a little trick to re installing transaxle's.

Measure the mounting bolts that are used to hold the GRBX to the adapter plate or in some cases the rear of the engine or bell housing. There are usually at least 4, sometimes 5 or 6 prominent bolts that hold the gearbox on. Pick the 4 that are best spaced around the perimeter. Try to use the ones that are easiest to reach. Usually two at the top and two at the bottom work best.

Now acquire slightly longer versions of the 4 bolts that you will use. About 2 to 3 inches longer is best. In any case they need to be long enough that the GRBX can rest on them but not contact the piolet bearing. Cut off the hex head and round the end with a grinder

Now when it time to re install the gearbox.............

You can thread (finger tight only!) the longer "guild pins" into the adapter plate for example and simply slide the gearbox in place over the guide pins. This will usually line up the piolet bearing and short permanent alinement pins pretty much right on the money without any jiggling and cussing or damage to the throw-out bearing, piolet bearing or your hands.

Now remove the "guide pins" one at a time and replace with the proper bolt. I used this one more times than I can count on both Porsche and Renault GRBX's although I prefer to remove the engine/GRBX from the car as a unit and reinstall as a unit. I tend to prefer longer processes over harder processes. It makes the GRBX mating REALLY easy, but that's just me.

Walla! Your friend who came over to help can watch you perform a cool trick and you both can get to the beer without a busted finger or the wife can remain on the couch and you can get to the beer without.............well you know what I mean.
I agree that making alignment pins would make the job easier. However, I have these crazy #10 by 1.25 threaded bolts retaining the trans to the adapter. Getting longer bolts rather just replacement bolts would be easier than finding a Democrat in the Maricopa County Sheriffs department. It just more expedient to shout and curse.
It's been a bit of time since my last post. Problem: really bad mechanic (me!). I'd fire him but he won't leave.

Finally completed the installation of the 016 modified by German Transaxles of America in Bend, Oregon. I want to acknowledge this company for an excellent job. Had a new ring & pinion (3.22), 5th gear (.072) and a Wavetrac LSD installed along with a complete rebuild. Job was done promptly, excellent communications and quality work. Anyone with the AAZ 016 should consider this modification. To those who say no parts, no reliability about the 016, not true.

Took the GT40 for it's test drive and the "new" 016 did everything I had hoped for. 1st gear is much better and useable. Gear shifting is more definitive and firm. The gear box is quieter and smoother. The rpm/mph ratios are excellent. I can drive easily in town in 3rd gear. 4th gear performs well in the mid-range, 40-55 mph. The real improvement is 65 mph at 1950 rpm's. My "342" easily pulls the car from 65 up without a down shift. The entire driving experience is upgraded now that the engine is not screaming above 3000+ rpm's all the time. Calculated top speed is stupid high! Yeah I know, tires, torque and aero will prohibit ,but it still sounds good.

I don't know how much longer this modification will be available, but your 016 equipped GT40 will be far better with this upgrade.
Dear Tom, i would like to do your same work on my 016. Please can you tell me how much you payed for the parts to GTA?
Thank you