|Like a lot of folks on the TDIClub, I became
interested in changing my stock .74 fifth gear to
a .68 fifth gear. The swap promised a lot of
benefits, such as reducing the highway cruising
RPM of my TDI, reducing fuel consumption and
raising the top end speed--although I had little
interest in exploring the limits of my speedo.
I am not a mechanic and had no reason to think
I could successfully remove and install the gears
on my own. Yet, I forged on. I inquired about
finding a mechanic in Central Pennsylvania who
may be interested and trusted to complete this
swap on the TDIClub's forums. I received almost
no feedback, except from a fellow TDIer who
uses the handle "JWLionKing." He suggested I
use his regular TDI mechanic who had
completed a swap on his TDI. This seemed like
a sound approach and the only drawback was
the mechanic's location--about 2.5 hours from
my home. I called Chris Fisher in Huntingdon,
Pennsylvania and explained what I wanted to do.
Chris is a likeable, friendly and knowledgeable
guy who knew immediately what was being
proposed, so we made an appointment. I had to
wait to find a time and day when I could wait on
the car because the distance was too great to
conveniently leave the Jetta overnight.
So on the morning of June 10, 2006 I set out on
a very peaceful and enjoyable journey over the
Tuscasrora Mountains, enjoying the wonderful
torque of my RocketChipped TDI, pulling
through the uphill grades and curves having
almost as much fun as a fella on a mid-sized
sport bike. It's a beautiful ride through rural
Pennsylvania in the early summer morning
headed Northwest from Gettysburg to
Huntingdon--and along the way saying "so long"
to my somewhat buzzy stock fifth gear.
I arrived at Chris' shop, named Car Tunes at
about 8:30 a.m. He immediately went to work.
Chris used to swap gears in first generation
GTIs when he was a younger mechanic and
didn't waste anytime getting to the gears. Chris
did run into one problem: what he thought would
be a 12mm torx bolt turned out to be a 14mm
bolt. Something new in the A5 platform
transmissions. Just about the instant Chris was
ready to say, "Hmmmm?" We heard the clatter
of the the Snap-On dealer's truck pull up
outside his shop. The dealer walked in and took
a look and Chris said, "You have something that
will fit on this?" and moments later he was back
in business. The Snap-On dealer arrived as if
on cue and Chris never missed a beat. And like I
have read in so many posts, struggled a bit
getting the stock gears off in pristine condition,
but he did it and two hours later after much VW
and muscle car chat my Jetta's transmission was
getting buttoned up and a drink of a half-liter of
fresh VW's G55 gear oil.
A quick test drive and on my way home. I did
notice the shifting seemed to be "notchier,"
which I attributed to having the new gear. The
swap seemed great for about 2,000 miles, then
one eveing on the last leg of my commute, I
descended a hill, down shifted at the bottom to
climb another and wasn't able to select fifth
gear. It was like it wasn't there. No grinding. No
nothing. I stayed in fourth and figured I could get
home about 11 miles away, but mindful that
some mysterious piece of the gear, its
components or other widget, could be floating
around inside the gearbox. I eventually
attempted to try fifth again and was able to
"wiggle" it in. This told me that the assembly had
not come apart and there must be something
locking me out of fifth.
I called Chris and he was genuinely concerned
and disappointed. He wanted to see the
transmission as much as I wanted to have it
fixed. Because it was not something that was
easily diagnosed I wanted to trailer my Jetta to
Chris' shop. And three-week nightmare began. I
first rented a U-Haul car dolly, but the Jetta
didn't fit. The loop that hold the tire straps stood
upright far too many inches for the front valance
to clear and once I measured the rest of the
assembly concluded this wasn't going to be an
easy solution without removing the front of the
car's body work.
|So I returned the dolly and asked about a car
trailer. The U-Haul representative didn't have
one on his lot and couldn't ensure me my Jetta
would fit on it either. I then checked with a
hauling company and they wanted almost $400
to haul the car (one-way) to Huntingdon.
Ultimately I ended up buying a car hauler for
$1,800 figuring I could use it and sell it and
take less than a $400 deprecation hit. But now
that I have it, and knowing how well the Jetta
loads onto it and rides behind my Nissan Titan,
I think I'm going to keep it a while and look for
a project car.
|Damaged caused by the U-Haul strap loops. I could not see
them and my wife, who was guiding me onto the dolly didn't
anticipate the damage until it was done. The dolly ramp is
quite steep and it's very difficult to maintain speed while
having enough control to safely hit the wheel pockets. I
would not consider a U-Haul car dolly for an A5 unless I was
willing to remove the front bodywork.
|Once I got my car back to Chris, it was a 45
minute fix. He pulled the transmission cover
and instantly discovered the circular spring
was not fully seated and blocking the
transmission selector from the fifth gear. He
buttoned her up and it's been smooth sailing
ever since. I'm passing the 2,000 milestone
this week--the point that the original swap
failed. My only regret is the promises of
increased fuel economy haven't panned out. I
know I'm analyzing a small sample with a few
inconsistent variables, but no matter how I look
at it at this point I'm either getting from 2% to
4% fewer miles per gallon. I used to average
43.5 mpgs and now I'm getting about 41.7
mpgs. UPDATE: I'm currently working on what
may be my best tank yet. I believe the
summer's heat may have had a detrimental
effect on my mileage, despite the .68 swap.
I finished this tank at 676.8 miles taking on
14.5 gallons for 46.69 MPGs. I had 1.2 gallons
remaining and could have hit 732.8 miles on
the tank--making me a somewhat dubious,
albeit virtual member of the 700 mile club!
If you're contemplating a gear swap, be
forewarned it can be an expensive venture and
the potential return on your investment is so
slim that if you have any difficulties, you've
blow any benefit all while voiding any warranty
coverage on your transmission.
|This page is a draft. I will update it with more images, economic info, graphs, etc.
in the near future.