I just got my giles pump in and now i am looking to get the RPMS down on the freeway. I have found a .75 5th gear and was planniing too swap this in and replace the .89. Is this a good idea or am i better with a differant trans? just looking for better fuel econmony
Car is a 1991 Jetta NA 1.6 198,000 Aircond, and Power steering
Timing Belt, Head gasket, injectors and glow plugs are all new.
Giles pump timing is set at .95
going with a taller 5th will definitely help rpm's... but going uphill you might need to downshift into 4th... but maybe with the Giles pump you won't need to???
i heard the 5th gear can be installed with the tranny in the car... hmmmmm
If you just switch out the 5th gear, there will be quite a spread between 4th and 5th. I would imagine that it would be better just to swtich out the tranny unless you have experience taking apart trannys. If you just swap out 5th, I would also swap out 4th too with and AOP (1.03 ratio) and that will help close the spread between 4th and 5th.
I'm just in the process of replacing the 5th gear on an AGS
transmission (blown 5th) with a .745 gear ass'y.
It might be possible to do this in situ, but I think it wouuld
be pretty tricky.
It's not just that you'll have to unbolt eveything to lower
the trans. end sufficiently to remove the 5th gear housing,
you also have to remove that hex socket plug, remove
the selector shaft guts and reach into that dark, little tunnel
to lock the trans. in two gears simultaneously.
Then you'll have to have sufficient clearance to unscrew,
re-torque the retaining bolt.
I suppose it might be do-able, but I think you'd find it a bit
of a pain...easier to work with on the bench.
Just my, usually ill-informed, opinion.
I work for a shop So I have a lift I can try in the car worst case i will take the trans out.
There is a lot of info at this site. You may want to give hime a call. He also has a wonderfully done intro on his site.
www.brokevw.com Jim