Golf MK4 2.0L transmission upgrade

mobilni

Member
Joined
May 1, 2011
Location
Canada
TDI
98 Beetle TDI, Jetta 2001 TDI, Golf 2001 GLS TDI
Hello,
I need suggestion of how to upgrade O2J transmission on Golf with 2.0L engine.
Car has everything stock but gears is way to short. I have spare TDI transmission from Jetta,
and wondering what is better solution for me: Just change 5 gear or change complete transmission?
Gear ratio is:

1st 2nd 3rd 4th 5th R&P

3.778 2.118 1.360 1.029 0.837 4.235 2.0L Beetle,Golf/Jetta IV

3.778 2.118 1.360 0.971 0.756 3.389 TDI Beetle, Golf/Jetta IV

What is right way to go? Thank you.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis (where it's safe)
TDI
There are just too many to list....
You can bolt the 02J from the TDI in there, but it will be somewhat poochy around town. Out on the highway at higher sustained speeds it will be fine though.

If you want to get an idea of how it "feels", the early NCS Jetta S, 2011 through 2015 I think, uses the slightly updated version of that same engine but gets bolted to a higher ratio 5sp box. It is a slightly different transmission (I forget the code), but the gearing is closer to what the ALH cars used.

So if you see one of those 2.slo Jetta S manuals for sale at a lot local to you, go test drive one and you'll get the idea. I think at 80 MPH they are around 3k or so, pretty close to what an ALH is doing. Much better than the 4k+ the trans you have now wants to spin the engine at those speeds.
 

mobilni

Member
Joined
May 1, 2011
Location
Canada
TDI
98 Beetle TDI, Jetta 2001 TDI, Golf 2001 GLS TDI
Hello, thank you very much for replay, I will try to find 2011 to test drive. So you think that bes way is to just replace 5 gear in 2.0 for highway driving?
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis (where it's safe)
TDI
There are just too many to list....
The fifth gear alone is not the big change.... the big change is the final drive ratio. Because math. If you have the whole gearbox, I'd swap the whole thing in.
 

mobilni

Member
Joined
May 1, 2011
Location
Canada
TDI
98 Beetle TDI, Jetta 2001 TDI, Golf 2001 GLS TDI
Hello, I do have spare transmission from ALH so swap is not the problem. Thank you very much.
 

FXF

Member
Joined
May 7, 2021
Location
NY
TDI
2013 JSW 6MT
I've never driven a car with a TDI spec 02J. I remember reading about someone who swapped one into a 1.8t powered New Beetle and supposedly that worked ok.

I swapped an 02M from a Golf 1.8t into my old MKIV Jetta 2.0 and it became a whole different driving experience. The car felt quicker off the line with the taller first and second gears compared to the stock 02J, and the double overdrive 6th got me roughly 5mpg higher fuel economy on the highway. 3rd 4th and 5th were almost identical to the 02J which worked out perfectly fine.

If I had to do it again I'd definitely do another 02M swap.
 

mobilni

Member
Joined
May 1, 2011
Location
Canada
TDI
98 Beetle TDI, Jetta 2001 TDI, Golf 2001 GLS TDI
Thank you for sharing your experience. Will look in to for sure.
 
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